[libcamera-devel] android: Make libyaml dependency optional
diff mbox series

Message ID 20211228095153.611009-1-roman.o.stratiienko@globallogic.com
State New
Headers show
Series
  • [libcamera-devel] android: Make libyaml dependency optional
Related show

Commit Message

Roman Stratiienko Dec. 28, 2021, 9:51 a.m. UTC
Mainline Android has no libyaml in-tree. Moreover camera_hal_config.cpp
uses std::filesystem class that is not permitted for AOSP VNDK vendor
libraries.

External configuration file is no longer mandatory and DTS overlays can
be used to specify camera location and rotation.

Do not require external configuration file for cases where meson.build
can't find libyaml. Assume that cameras without location specified
by V4L2 properties are always external.

Signed-off-by: Roman Stratiienko <roman.o.stratiienko@globallogic.com>
---
 src/android/camera_hal_manager.cpp | 13 +++++++++++++
 src/android/camera_hal_manager.h   |  2 ++
 src/android/meson.build            | 10 ++++++++--
 3 files changed, 23 insertions(+), 2 deletions(-)

Comments

Jacopo Mondi Dec. 28, 2021, 11:05 a.m. UTC | #1
Hi Roman,

cc Hanlin Chen from ChromiumOS as he's planning to extend
configuration file support for the ChromeOS Android HAL.

Before looking into the patch: is there any hope libyaml might become
part of the standard AOSP distribution (or a process in place to request
that).

Thanks
   j

On Tue, Dec 28, 2021 at 11:51:53AM +0200, Roman Stratiienko wrote:
> Mainline Android has no libyaml in-tree. Moreover camera_hal_config.cpp
> uses std::filesystem class that is not permitted for AOSP VNDK vendor
> libraries.
>
> External configuration file is no longer mandatory and DTS overlays can
> be used to specify camera location and rotation.
>
> Do not require external configuration file for cases where meson.build
> can't find libyaml. Assume that cameras without location specified
> by V4L2 properties are always external.
>
> Signed-off-by: Roman Stratiienko <roman.o.stratiienko@globallogic.com>
> ---
>  src/android/camera_hal_manager.cpp | 13 +++++++++++++
>  src/android/camera_hal_manager.h   |  2 ++
>  src/android/meson.build            | 10 ++++++++--
>  3 files changed, 23 insertions(+), 2 deletions(-)
>
> diff --git a/src/android/camera_hal_manager.cpp b/src/android/camera_hal_manager.cpp
> index 5f7bfe265c71b..9e575bfa5204a 100644
> --- a/src/android/camera_hal_manager.cpp
> +++ b/src/android/camera_hal_manager.cpp
> @@ -48,6 +48,7 @@ int CameraHalManager::init()
>  {
>  	cameraManager_ = std::make_unique<CameraManager>();
>
> +#ifdef HAVE_LIBYAML
>  	/*
>  	 * If the configuration file is not available the HAL only supports
>  	 * external cameras. If it exists but it's not valid then error out.
> @@ -56,6 +57,7 @@ int CameraHalManager::init()
>  		LOG(HAL, Error) << "HAL configuration file is not valid";
>  		return -EINVAL;
>  	}
> +#endif
>
>  	/* Support camera hotplug. */
>  	cameraManager_->cameraAdded.connect(this, &CameraHalManager::cameraAdded);
> @@ -133,6 +135,7 @@ void CameraHalManager::cameraAdded(std::shared_ptr<Camera> cam)
>  		}
>  	}
>
> +#ifdef HAVE_LIBYAML
>  	/*
>  	 * The configuration file must be valid, and contain a corresponding
>  	 * entry for internal cameras. External cameras can be initialized
> @@ -145,6 +148,16 @@ void CameraHalManager::cameraAdded(std::shared_ptr<Camera> cam)
>  	}
>
>  	const CameraConfigData *cameraConfigData = halConfig_.cameraConfigData(cam->id());
> +#else
> +	/*
> +	 * Assume that cameras without properties::Location specified are external.
> +	 */
> +	const CameraConfigData *cameraConfigData = nullptr;
> +	if (!isCameraExternal && cameraLocation(cam.get()) < 0) {
> +		isCameraExternal = true;
> +		id = nextExternalCameraId_;
> +	}
> +#endif
>
>  	/*
>  	 * Some cameras whose location is reported by libcamera as external may
> diff --git a/src/android/camera_hal_manager.h b/src/android/camera_hal_manager.h
> index a5f8b933a7902..056abbb0d4e54 100644
> --- a/src/android/camera_hal_manager.h
> +++ b/src/android/camera_hal_manager.h
> @@ -56,7 +56,9 @@ private:
>  	CameraDevice *cameraDeviceFromHalId(unsigned int id) LIBCAMERA_TSA_REQUIRES(mutex_);
>
>  	std::unique_ptr<libcamera::CameraManager> cameraManager_;
> +#ifdef HAVE_LIBYAML
>  	CameraHalConfig halConfig_;
> +#endif
>
>  	const camera_module_callbacks_t *callbacks_;
>  	std::vector<std::unique_ptr<CameraDevice>> cameras_ LIBCAMERA_TSA_GUARDED_BY(mutex_);
> diff --git a/src/android/meson.build b/src/android/meson.build
> index 75b4bf2070851..1e471c291a1e4 100644
> --- a/src/android/meson.build
> +++ b/src/android/meson.build
> @@ -3,7 +3,6 @@
>  android_deps = [
>      dependency('libexif', required : get_option('android')),
>      dependency('libjpeg', required : get_option('android')),
> -    dependency('yaml-0.1', required : get_option('android')),
>      libcamera_private,
>  ]
>
> @@ -41,7 +40,6 @@ android_hal_sources = files([
>      'camera3_hal.cpp',
>      'camera_capabilities.cpp',
>      'camera_device.cpp',
> -    'camera_hal_config.cpp',
>      'camera_hal_manager.cpp',
>      'camera_metadata.cpp',
>      'camera_ops.cpp',
> @@ -56,6 +54,14 @@ android_hal_sources = files([
>
>  android_cpp_args = []
>
> +libyaml_dep = dependency('yaml-0.1', required : false)
> +if libyaml_dep.found()
> +    config_h.set('HAVE_LIBYAML', 1)
> +    android_hal_sources += files([
> +        'camera_hal_config.cpp',
> +    ])
> +endif
> +
>  subdir('cros')
>  subdir('mm')
>
> --
> 2.30.2
>
Roman Stratiienko Dec. 28, 2021, 11:22 a.m. UTC | #2
Hi Jacopo,


вт, 28 дек. 2021 г., 13:04 Jacopo Mondi <jacopo@jmondi.org>:

> Hi Roman,
>
> cc Hanlin Chen from ChromiumOS as he's planning to extend
> configuration file support for the ChromeOS Android HAL.


> Before looking into the patch: is there any hope libyaml might become
> part of the standard AOSP distribution (or a process in place to request
> that)
>

I am not aware of that, and I haven't initiated such a process. It will be
a very slow and bumpy road.

Not sure what is planned for these properties in future, but now it is not
necessary to have it in libcamera to have fully functional hal. Also having
no configuration file available will encourage developers to add
corresponding records to dts, which is also a great thing to align with
linux world.


> Thanks
>    j
>
> On Tue, Dec 28, 2021 at 11:51:53AM +0200, Roman Stratiienko wrote:
> > Mainline Android has no libyaml in-tree. Moreover camera_hal_config.cpp
> > uses std::filesystem class that is not permitted for AOSP VNDK vendor
> > libraries.
> >
> > External configuration file is no longer mandatory and DTS overlays can
> > be used to specify camera location and rotation.
> >
> > Do not require external configuration file for cases where meson.build
> > can't find libyaml. Assume that cameras without location specified
> > by V4L2 properties are always external.
> >
> > Signed-off-by: Roman Stratiienko <roman.o.stratiienko@globallogic.com>
> > ---
> >  src/android/camera_hal_manager.cpp | 13 +++++++++++++
> >  src/android/camera_hal_manager.h   |  2 ++
> >  src/android/meson.build            | 10 ++++++++--
> >  3 files changed, 23 insertions(+), 2 deletions(-)
> >
> > diff --git a/src/android/camera_hal_manager.cpp
> b/src/android/camera_hal_manager.cpp
> > index 5f7bfe265c71b..9e575bfa5204a 100644
> > --- a/src/android/camera_hal_manager.cpp
> > +++ b/src/android/camera_hal_manager.cpp
> > @@ -48,6 +48,7 @@ int CameraHalManager::init()
> >  {
> >       cameraManager_ = std::make_unique<CameraManager>();
> >
> > +#ifdef HAVE_LIBYAML
> >       /*
> >        * If the configuration file is not available the HAL only supports
> >        * external cameras. If it exists but it's not valid then error
> out.
> > @@ -56,6 +57,7 @@ int CameraHalManager::init()
> >               LOG(HAL, Error) << "HAL configuration file is not valid";
> >               return -EINVAL;
> >       }
> > +#endif
> >
> >       /* Support camera hotplug. */
> >       cameraManager_->cameraAdded.connect(this,
> &CameraHalManager::cameraAdded);
> > @@ -133,6 +135,7 @@ void
> CameraHalManager::cameraAdded(std::shared_ptr<Camera> cam)
> >               }
> >       }
> >
> > +#ifdef HAVE_LIBYAML
> >       /*
> >        * The configuration file must be valid, and contain a
> corresponding
> >        * entry for internal cameras. External cameras can be initialized
> > @@ -145,6 +148,16 @@ void
> CameraHalManager::cameraAdded(std::shared_ptr<Camera> cam)
> >       }
> >
> >       const CameraConfigData *cameraConfigData =
> halConfig_.cameraConfigData(cam->id());
> > +#else
> > +     /*
> > +      * Assume that cameras without properties::Location specified are
> external.
> > +      */
> > +     const CameraConfigData *cameraConfigData = nullptr;
> > +     if (!isCameraExternal && cameraLocation(cam.get()) < 0) {
> > +             isCameraExternal = true;
> > +             id = nextExternalCameraId_;
> > +     }
> > +#endif
> >
> >       /*
> >        * Some cameras whose location is reported by libcamera as
> external may
> > diff --git a/src/android/camera_hal_manager.h
> b/src/android/camera_hal_manager.h
> > index a5f8b933a7902..056abbb0d4e54 100644
> > --- a/src/android/camera_hal_manager.h
> > +++ b/src/android/camera_hal_manager.h
> > @@ -56,7 +56,9 @@ private:
> >       CameraDevice *cameraDeviceFromHalId(unsigned int id)
> LIBCAMERA_TSA_REQUIRES(mutex_);
> >
> >       std::unique_ptr<libcamera::CameraManager> cameraManager_;
> > +#ifdef HAVE_LIBYAML
> >       CameraHalConfig halConfig_;
> > +#endif
> >
> >       const camera_module_callbacks_t *callbacks_;
> >       std::vector<std::unique_ptr<CameraDevice>> cameras_
> LIBCAMERA_TSA_GUARDED_BY(mutex_);
> > diff --git a/src/android/meson.build b/src/android/meson.build
> > index 75b4bf2070851..1e471c291a1e4 100644
> > --- a/src/android/meson.build
> > +++ b/src/android/meson.build
> > @@ -3,7 +3,6 @@
> >  android_deps = [
> >      dependency('libexif', required : get_option('android')),
> >      dependency('libjpeg', required : get_option('android')),
> > -    dependency('yaml-0.1', required : get_option('android')),
> >      libcamera_private,
> >  ]
> >
> > @@ -41,7 +40,6 @@ android_hal_sources = files([
> >      'camera3_hal.cpp',
> >      'camera_capabilities.cpp',
> >      'camera_device.cpp',
> > -    'camera_hal_config.cpp',
> >      'camera_hal_manager.cpp',
> >      'camera_metadata.cpp',
> >      'camera_ops.cpp',
> > @@ -56,6 +54,14 @@ android_hal_sources = files([
> >
> >  android_cpp_args = []
> >
> > +libyaml_dep = dependency('yaml-0.1', required : false)
> > +if libyaml_dep.found()
> > +    config_h.set('HAVE_LIBYAML', 1)
> > +    android_hal_sources += files([
> > +        'camera_hal_config.cpp',
> > +    ])
> > +endif
> > +
> >  subdir('cros')
> >  subdir('mm')
> >
> > --
> > 2.30.2
> >
>

Regards,
Roman.
Laurent Pinchart Dec. 28, 2021, 6:27 p.m. UTC | #3
Hi Roman,

On Tue, Dec 28, 2021 at 01:22:34PM +0200, Roman Stratiienko wrote:
> вт, 28 дек. 2021 г., 13:04 Jacopo Mondi:
> > Hi Roman,
> >
> > cc Hanlin Chen from ChromiumOS as he's planning to extend
> > configuration file support for the ChromeOS Android HAL.
> 
> > Before looking into the patch: is there any hope libyaml might become
> > part of the standard AOSP distribution (or a process in place to request
> > that)
> 
> I am not aware of that, and I haven't initiated such a process. It will be
> a very slow and bumpy road.
> 
> Not sure what is planned for these properties in future, but now it is not
> necessary to have it in libcamera to have fully functional hal. Also having
> no configuration file available will encourage developers to add
> corresponding records to dts, which is also a great thing to align with
> linux world.

Our goals align here. This is exactly why we have decided not to set the
camera location in a configuration file for the libcamera core, but to
isolate it in the HAL as a temporary (but in practice likely a long-term
temporary) measure, as we have to support platforms that will take some
time before a firmware (ACPI in this case) update can be deployed.

This being said, we will introduce a configuration file for the
libcamera core in the near future, and we also plan to use libyaml
there. The tuning files for the IPU3 and RkISP1 IPA modules will also
use YAML, and I'd like to move the Raspberry Pi tuning files from JSON
to YAML for consistency.

We could merge this patch in the meantime, but compilation on Android
will likely break again soon. I wonder if we couldn't instead use a
meson wrap to include libyaml as a subproject. This should solve the
issue in the longer term.

By the way, out of curiosity, how do you compile libcamera for Android ?
We have a look at Soong (as the Makefile-based build system is being
phased out), but blueprint files don't support all our needs (and would
be annoying to maintain manually), and there's no way we found to
generate Android.bp files from meson in a way that would integrate with
Soong. This is still an unsolved problem, and I'm increasingly tempted
to do the same as mesa3d and just document that libcamera should be
built outside of AOSP, using the NDK.

> > On Tue, Dec 28, 2021 at 11:51:53AM +0200, Roman Stratiienko wrote:
> > > Mainline Android has no libyaml in-tree. Moreover camera_hal_config.cpp
> > > uses std::filesystem class that is not permitted for AOSP VNDK vendor
> > > libraries.
> > >
> > > External configuration file is no longer mandatory and DTS overlays can
> > > be used to specify camera location and rotation.
> > >
> > > Do not require external configuration file for cases where meson.build
> > > can't find libyaml. Assume that cameras without location specified
> > > by V4L2 properties are always external.
> > >
> > > Signed-off-by: Roman Stratiienko <roman.o.stratiienko@globallogic.com>
> > > ---
> > >  src/android/camera_hal_manager.cpp | 13 +++++++++++++
> > >  src/android/camera_hal_manager.h   |  2 ++
> > >  src/android/meson.build            | 10 ++++++++--
> > >  3 files changed, 23 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/src/android/camera_hal_manager.cpp b/src/android/camera_hal_manager.cpp
> > > index 5f7bfe265c71b..9e575bfa5204a 100644
> > > --- a/src/android/camera_hal_manager.cpp
> > > +++ b/src/android/camera_hal_manager.cpp
> > > @@ -48,6 +48,7 @@ int CameraHalManager::init()
> > >  {
> > >       cameraManager_ = std::make_unique<CameraManager>();
> > >
> > > +#ifdef HAVE_LIBYAML
> > >       /*
> > >        * If the configuration file is not available the HAL only supports
> > >        * external cameras. If it exists but it's not valid then error out.
> > > @@ -56,6 +57,7 @@ int CameraHalManager::init()
> > >               LOG(HAL, Error) << "HAL configuration file is not valid";
> > >               return -EINVAL;
> > >       }
> > > +#endif
> > >
> > >       /* Support camera hotplug. */
> > >       cameraManager_->cameraAdded.connect(this, &CameraHalManager::cameraAdded);
> > > @@ -133,6 +135,7 @@ void CameraHalManager::cameraAdded(std::shared_ptr<Camera> cam)
> > >               }
> > >       }
> > >
> > > +#ifdef HAVE_LIBYAML
> > >       /*
> > >        * The configuration file must be valid, and contain a corresponding
> > >        * entry for internal cameras. External cameras can be initialized
> > > @@ -145,6 +148,16 @@ void CameraHalManager::cameraAdded(std::shared_ptr<Camera> cam)
> > >       }
> > >
> > >       const CameraConfigData *cameraConfigData = halConfig_.cameraConfigData(cam->id());
> > > +#else
> > > +     /*
> > > +      * Assume that cameras without properties::Location specified are external.
> > > +      */
> > > +     const CameraConfigData *cameraConfigData = nullptr;
> > > +     if (!isCameraExternal && cameraLocation(cam.get()) < 0) {
> > > +             isCameraExternal = true;
> > > +             id = nextExternalCameraId_;
> > > +     }
> > > +#endif
> > >
> > >       /*
> > >        * Some cameras whose location is reported by libcamera as external may
> > > diff --git a/src/android/camera_hal_manager.h b/src/android/camera_hal_manager.h
> > > index a5f8b933a7902..056abbb0d4e54 100644
> > > --- a/src/android/camera_hal_manager.h
> > > +++ b/src/android/camera_hal_manager.h
> > > @@ -56,7 +56,9 @@ private:
> > >       CameraDevice *cameraDeviceFromHalId(unsigned int id) LIBCAMERA_TSA_REQUIRES(mutex_);
> > >
> > >       std::unique_ptr<libcamera::CameraManager> cameraManager_;
> > > +#ifdef HAVE_LIBYAML
> > >       CameraHalConfig halConfig_;
> > > +#endif
> > >
> > >       const camera_module_callbacks_t *callbacks_;
> > >       std::vector<std::unique_ptr<CameraDevice>> cameras_ LIBCAMERA_TSA_GUARDED_BY(mutex_);
> > > diff --git a/src/android/meson.build b/src/android/meson.build
> > > index 75b4bf2070851..1e471c291a1e4 100644
> > > --- a/src/android/meson.build
> > > +++ b/src/android/meson.build
> > > @@ -3,7 +3,6 @@
> > >  android_deps = [
> > >      dependency('libexif', required : get_option('android')),
> > >      dependency('libjpeg', required : get_option('android')),
> > > -    dependency('yaml-0.1', required : get_option('android')),
> > >      libcamera_private,
> > >  ]
> > >
> > > @@ -41,7 +40,6 @@ android_hal_sources = files([
> > >      'camera3_hal.cpp',
> > >      'camera_capabilities.cpp',
> > >      'camera_device.cpp',
> > > -    'camera_hal_config.cpp',
> > >      'camera_hal_manager.cpp',
> > >      'camera_metadata.cpp',
> > >      'camera_ops.cpp',
> > > @@ -56,6 +54,14 @@ android_hal_sources = files([
> > >
> > >  android_cpp_args = []
> > >
> > > +libyaml_dep = dependency('yaml-0.1', required : false)
> > > +if libyaml_dep.found()
> > > +    config_h.set('HAVE_LIBYAML', 1)
> > > +    android_hal_sources += files([
> > > +        'camera_hal_config.cpp',
> > > +    ])
> > > +endif
> > > +
> > >  subdir('cros')
> > >  subdir('mm')
> > >
Roman Stratiienko Dec. 29, 2021, 9:45 a.m. UTC | #4
Hi Laurent,

вт, 28 дек. 2021 г. в 20:27, Laurent Pinchart
<laurent.pinchart@ideasonboard.com>:
>
> Hi Roman,
>
> On Tue, Dec 28, 2021 at 01:22:34PM +0200, Roman Stratiienko wrote:
> > вт, 28 дек. 2021 г., 13:04 Jacopo Mondi:
> > > Hi Roman,
> > >
> > > cc Hanlin Chen from ChromiumOS as he's planning to extend
> > > configuration file support for the ChromeOS Android HAL.
> >
> > > Before looking into the patch: is there any hope libyaml might become
> > > part of the standard AOSP distribution (or a process in place to request
> > > that)
> >
> > I am not aware of that, and I haven't initiated such a process. It will be
> > a very slow and bumpy road.
> >
> > Not sure what is planned for these properties in future, but now it is not
> > necessary to have it in libcamera to have fully functional hal. Also having
> > no configuration file available will encourage developers to add
> > corresponding records to dts, which is also a great thing to align with
> > linux world.
>
> Our goals align here. This is exactly why we have decided not to set the
> camera location in a configuration file for the libcamera core, but to
> isolate it in the HAL as a temporary (but in practice likely a long-term
> temporary) measure, as we have to support platforms that will take some
> time before a firmware (ACPI in this case) update can be deployed.
>
> This being said, we will introduce a configuration file for the
> libcamera core in the near future, and we also plan to use libyaml
> there. The tuning files for the IPU3 and RkISP1 IPA modules will also
> use YAML, and I'd like to move the Raspberry Pi tuning files from JSON
> to YAML for consistency.

It's a good idea to have a single file format. Currently we have to
ship boost to run raspberrypi cameras on Android.

> We could merge this patch in the meantime, but compilation on Android
> will likely break again soon. I wonder if we couldn't instead use a
> meson wrap to include libyaml as a subproject. This should solve the
> issue in the longer term.

At this moment we have libyaml with extra Android.bp, which can
satisfy libcamera needs.
But I really like to see it as an optional dependency only to help
fine-tuning things or for ACPI-only platforms.

> By the way, out of curiosity, how do you compile libcamera for Android ?
> We have a look at Soong (as the Makefile-based build system is being
> phased out), but blueprint files don't support all our needs (and would
> be annoying to maintain manually), and there's no way we found to
> generate Android.bp files from meson in a way that would integrate with
> Soong. This is still an unsolved problem, and I'm increasingly tempted
> to do the same as mesa3d and just document that libcamera should be
> built outside of AOSP, using the NDK.

We shipped libcamera in our GloDroid project v0.7.0 release for
raspberry pi about a month ago:
1. https://github.com/GloDroid/glodroid_manifest/releases/tag/v0.7.0
2. https://github.com/GloDroid/glodroid_forks/commits/libcamera-v0.7.0

For building using meson within AOSP we are using some tricks to
extract dependencies from AOSP makesystem and inject them into
meson cross compilation file.

First such kind of approach was integrated into mesa3d and replaced
existing Android.mk files (about 6 month ago).
It doesn't require continuous maintenance as previous Android.mk did
and has proven to be reliable.
It also enables FULL support of mesa3d for Android. Previously only
about 60% of mesa3d drivers were covered with Android.mk files.
Reworking the same approach for libcamera was pretty easy.

And yes, as an official approach for vendors NDK builds would be great
to support.
NDK approach and our meson.build within AOSP approach are 98% aligned.

>
> > > On Tue, Dec 28, 2021 at 11:51:53AM +0200, Roman Stratiienko wrote:
> > > > Mainline Android has no libyaml in-tree. Moreover camera_hal_config.cpp
> > > > uses std::filesystem class that is not permitted for AOSP VNDK vendor
> > > > libraries.
> > > >
> > > > External configuration file is no longer mandatory and DTS overlays can
> > > > be used to specify camera location and rotation.
> > > >
> > > > Do not require external configuration file for cases where meson.build
> > > > can't find libyaml. Assume that cameras without location specified
> > > > by V4L2 properties are always external.
> > > >
> > > > Signed-off-by: Roman Stratiienko <roman.o.stratiienko@globallogic.com>
> > > > ---
> > > >  src/android/camera_hal_manager.cpp | 13 +++++++++++++
> > > >  src/android/camera_hal_manager.h   |  2 ++
> > > >  src/android/meson.build            | 10 ++++++++--
> > > >  3 files changed, 23 insertions(+), 2 deletions(-)
> > > >
> > > > diff --git a/src/android/camera_hal_manager.cpp b/src/android/camera_hal_manager.cpp
> > > > index 5f7bfe265c71b..9e575bfa5204a 100644
> > > > --- a/src/android/camera_hal_manager.cpp
> > > > +++ b/src/android/camera_hal_manager.cpp
> > > > @@ -48,6 +48,7 @@ int CameraHalManager::init()
> > > >  {
> > > >       cameraManager_ = std::make_unique<CameraManager>();
> > > >
> > > > +#ifdef HAVE_LIBYAML
> > > >       /*
> > > >        * If the configuration file is not available the HAL only supports
> > > >        * external cameras. If it exists but it's not valid then error out.
> > > > @@ -56,6 +57,7 @@ int CameraHalManager::init()
> > > >               LOG(HAL, Error) << "HAL configuration file is not valid";
> > > >               return -EINVAL;
> > > >       }
> > > > +#endif
> > > >
> > > >       /* Support camera hotplug. */
> > > >       cameraManager_->cameraAdded.connect(this, &CameraHalManager::cameraAdded);
> > > > @@ -133,6 +135,7 @@ void CameraHalManager::cameraAdded(std::shared_ptr<Camera> cam)
> > > >               }
> > > >       }
> > > >
> > > > +#ifdef HAVE_LIBYAML
> > > >       /*
> > > >        * The configuration file must be valid, and contain a corresponding
> > > >        * entry for internal cameras. External cameras can be initialized
> > > > @@ -145,6 +148,16 @@ void CameraHalManager::cameraAdded(std::shared_ptr<Camera> cam)
> > > >       }
> > > >
> > > >       const CameraConfigData *cameraConfigData = halConfig_.cameraConfigData(cam->id());
> > > > +#else
> > > > +     /*
> > > > +      * Assume that cameras without properties::Location specified are external.
> > > > +      */
> > > > +     const CameraConfigData *cameraConfigData = nullptr;
> > > > +     if (!isCameraExternal && cameraLocation(cam.get()) < 0) {
> > > > +             isCameraExternal = true;
> > > > +             id = nextExternalCameraId_;
> > > > +     }
> > > > +#endif
> > > >
> > > >       /*
> > > >        * Some cameras whose location is reported by libcamera as external may
> > > > diff --git a/src/android/camera_hal_manager.h b/src/android/camera_hal_manager.h
> > > > index a5f8b933a7902..056abbb0d4e54 100644
> > > > --- a/src/android/camera_hal_manager.h
> > > > +++ b/src/android/camera_hal_manager.h
> > > > @@ -56,7 +56,9 @@ private:
> > > >       CameraDevice *cameraDeviceFromHalId(unsigned int id) LIBCAMERA_TSA_REQUIRES(mutex_);
> > > >
> > > >       std::unique_ptr<libcamera::CameraManager> cameraManager_;
> > > > +#ifdef HAVE_LIBYAML
> > > >       CameraHalConfig halConfig_;
> > > > +#endif
> > > >
> > > >       const camera_module_callbacks_t *callbacks_;
> > > >       std::vector<std::unique_ptr<CameraDevice>> cameras_ LIBCAMERA_TSA_GUARDED_BY(mutex_);
> > > > diff --git a/src/android/meson.build b/src/android/meson.build
> > > > index 75b4bf2070851..1e471c291a1e4 100644
> > > > --- a/src/android/meson.build
> > > > +++ b/src/android/meson.build
> > > > @@ -3,7 +3,6 @@
> > > >  android_deps = [
> > > >      dependency('libexif', required : get_option('android')),
> > > >      dependency('libjpeg', required : get_option('android')),
> > > > -    dependency('yaml-0.1', required : get_option('android')),
> > > >      libcamera_private,
> > > >  ]
> > > >
> > > > @@ -41,7 +40,6 @@ android_hal_sources = files([
> > > >      'camera3_hal.cpp',
> > > >      'camera_capabilities.cpp',
> > > >      'camera_device.cpp',
> > > > -    'camera_hal_config.cpp',
> > > >      'camera_hal_manager.cpp',
> > > >      'camera_metadata.cpp',
> > > >      'camera_ops.cpp',
> > > > @@ -56,6 +54,14 @@ android_hal_sources = files([
> > > >
> > > >  android_cpp_args = []
> > > >
> > > > +libyaml_dep = dependency('yaml-0.1', required : false)
> > > > +if libyaml_dep.found()
> > > > +    config_h.set('HAVE_LIBYAML', 1)
> > > > +    android_hal_sources += files([
> > > > +        'camera_hal_config.cpp',
> > > > +    ])
> > > > +endif
> > > > +
> > > >  subdir('cros')
> > > >  subdir('mm')
> > > >
>
> --
> Regards,
>
> Laurent Pinchart

Regards.
Roman
Laurent Pinchart Dec. 29, 2021, 10:14 a.m. UTC | #5
Hi Roman,

On Wed, Dec 29, 2021 at 11:45:17AM +0200, Roman Stratiienko wrote:
> вт, 28 дек. 2021 г. в 20:27, Laurent Pinchart:
> > On Tue, Dec 28, 2021 at 01:22:34PM +0200, Roman Stratiienko wrote:
> > > вт, 28 дек. 2021 г., 13:04 Jacopo Mondi:
> > > > Hi Roman,
> > > >
> > > > cc Hanlin Chen from ChromiumOS as he's planning to extend
> > > > configuration file support for the ChromeOS Android HAL.
> > >
> > > > Before looking into the patch: is there any hope libyaml might become
> > > > part of the standard AOSP distribution (or a process in place to request
> > > > that)
> > >
> > > I am not aware of that, and I haven't initiated such a process. It will be
> > > a very slow and bumpy road.
> > >
> > > Not sure what is planned for these properties in future, but now it is not
> > > necessary to have it in libcamera to have fully functional hal. Also having
> > > no configuration file available will encourage developers to add
> > > corresponding records to dts, which is also a great thing to align with
> > > linux world.
> >
> > Our goals align here. This is exactly why we have decided not to set the
> > camera location in a configuration file for the libcamera core, but to
> > isolate it in the HAL as a temporary (but in practice likely a long-term
> > temporary) measure, as we have to support platforms that will take some
> > time before a firmware (ACPI in this case) update can be deployed.
> >
> > This being said, we will introduce a configuration file for the
> > libcamera core in the near future, and we also plan to use libyaml
> > there. The tuning files for the IPU3 and RkISP1 IPA modules will also
> > use YAML, and I'd like to move the Raspberry Pi tuning files from JSON
> > to YAML for consistency.
> 
> It's a good idea to have a single file format. Currently we have to
> ship boost to run raspberrypi cameras on Android.

I'm happy you agree :-)

> > We could merge this patch in the meantime, but compilation on Android
> > will likely break again soon. I wonder if we couldn't instead use a
> > meson wrap to include libyaml as a subproject. This should solve the
> > issue in the longer term.
> 
> At this moment we have libyaml with extra Android.bp, which can
> satisfy libcamera needs.
> But I really like to see it as an optional dependency only to help
> fine-tuning things or for ACPI-only platforms.

Making it optional may cause difficulties in the future, with
potentially lots of conditional compilation. I'd rather not go that way,
unless we can wrap the yaml parser in a helper class with a dummy
implementation to hide the missing dependency from everything else.

I've quickly tested compiling libyaml as a subproject, and it seems to
work:


commit f1d86859f522c7728d8f854b82296673291750fb
Author: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Date:   Wed Dec 29 12:07:35 2021 +0200

    android: Compile libyaml as a subproject if not available on the system

    AOSP doesn't ship libyaml, making it more difficult to compile libcamera
    for Android. Use a meson wrap to compile libyaml as a subproject if the
    dependency is not found.

    Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

diff --git a/src/android/meson.build b/src/android/meson.build
index 75b4bf207085..1fa67746d058 100644
--- a/src/android/meson.build
+++ b/src/android/meson.build
@@ -3,7 +3,6 @@
 android_deps = [
     dependency('libexif', required : get_option('android')),
     dependency('libjpeg', required : get_option('android')),
-    dependency('yaml-0.1', required : get_option('android')),
     libcamera_private,
 ]

@@ -16,13 +15,35 @@ foreach dep : android_deps
     endif
 endforeach

+cmake = import('cmake')
+
+#
+# libyaml
+#
+# Default to the system version, and fallback to a subproject if not found, as
+# libyaml is not packaged in AOSP.
+#
+libyaml_dep = dependency('yaml-0.1', required : false)
+
+# Fallback to a subproject if libyaml isn't found, as it's not packed in AOSP.
+if not libyaml_dep.found()
+    libyaml_vars = cmake.subproject_options()
+    libyaml_vars.add_cmake_defines({'CMAKE_POSITION_INDEPENDENT_CODE': 'ON'})
+    libyaml = cmake.subproject('libyaml', options : libyaml_vars)
+    libyaml_dep = libyaml.dependency('yaml')
+endif
+
+android_deps += [libyaml_dep]
+
+#
+# libyuv
+#
+# Default to the system version, and fallback to a subproject if not found, as
+# libyuv is typically not provided by distributions.
+#
 libyuv_dep = dependency('libyuv', required : false)

-# Fallback to a subproject if libyuv isn't found, as it's typically not
-# provided by distributions.
 if not libyuv_dep.found()
-    cmake = import('cmake')
-
     libyuv_vars = cmake.subproject_options()
     libyuv_vars.add_cmake_defines({'CMAKE_POSITION_INDEPENDENT_CODE': 'ON'})
     libyuv_vars.set_override_option('cpp_std', 'c++17')
diff --git a/subprojects/.gitignore b/subprojects/.gitignore
index 391fde2ce1e0..f207720b271a 100644
--- a/subprojects/.gitignore
+++ b/subprojects/.gitignore
@@ -1,3 +1,4 @@
 /googletest-release*
+/libyaml
 /libyuv
-/packagecache
\ No newline at end of file
+/packagecache
diff --git a/subprojects/libyaml.wrap b/subprojects/libyaml.wrap
new file mode 100644
index 000000000000..e4426e44774f
--- /dev/null
+++ b/subprojects/libyaml.wrap
@@ -0,0 +1,4 @@
+[wrap-git]
+directory = libyaml
+url = https://github.com/yaml/libyaml
+revision = 2c891fc7a770e8ba2fec34fc6b545c672beb37e6

> > By the way, out of curiosity, how do you compile libcamera for Android ?
> > We have a look at Soong (as the Makefile-based build system is being
> > phased out), but blueprint files don't support all our needs (and would
> > be annoying to maintain manually), and there's no way we found to
> > generate Android.bp files from meson in a way that would integrate with
> > Soong. This is still an unsolved problem, and I'm increasingly tempted
> > to do the same as mesa3d and just document that libcamera should be
> > built outside of AOSP, using the NDK.
> 
> We shipped libcamera in our GloDroid project v0.7.0 release for
> raspberry pi about a month ago:
> 1. https://github.com/GloDroid/glodroid_manifest/releases/tag/v0.7.0
> 2. https://github.com/GloDroid/glodroid_forks/commits/libcamera-v0.7.0
> 
> For building using meson within AOSP we are using some tricks to
> extract dependencies from AOSP makesystem and inject them into
> meson cross compilation file.

Does this mean that you compile libcamera manually, separately from AOSP
? That's probably the best option for now, until Android decides to
integrate support for other build systems (likely never...).

> First such kind of approach was integrated into mesa3d and replaced
> existing Android.mk files (about 6 month ago).
> It doesn't require continuous maintenance as previous Android.mk did
> and has proven to be reliable.
> It also enables FULL support of mesa3d for Android. Previously only
> about 60% of mesa3d drivers were covered with Android.mk files.
> Reworking the same approach for libcamera was pretty easy.
> 
> And yes, as an official approach for vendors NDK builds would be great
> to support.
> NDK approach and our meson.build within AOSP approach are 98% aligned.
> 
> > > > On Tue, Dec 28, 2021 at 11:51:53AM +0200, Roman Stratiienko wrote:
> > > > > Mainline Android has no libyaml in-tree. Moreover camera_hal_config.cpp
> > > > > uses std::filesystem class that is not permitted for AOSP VNDK vendor
> > > > > libraries.
> > > > >
> > > > > External configuration file is no longer mandatory and DTS overlays can
> > > > > be used to specify camera location and rotation.
> > > > >
> > > > > Do not require external configuration file for cases where meson.build
> > > > > can't find libyaml. Assume that cameras without location specified
> > > > > by V4L2 properties are always external.
> > > > >
> > > > > Signed-off-by: Roman Stratiienko <roman.o.stratiienko@globallogic.com>
> > > > > ---
> > > > >  src/android/camera_hal_manager.cpp | 13 +++++++++++++
> > > > >  src/android/camera_hal_manager.h   |  2 ++
> > > > >  src/android/meson.build            | 10 ++++++++--
> > > > >  3 files changed, 23 insertions(+), 2 deletions(-)
> > > > >
> > > > > diff --git a/src/android/camera_hal_manager.cpp b/src/android/camera_hal_manager.cpp
> > > > > index 5f7bfe265c71b..9e575bfa5204a 100644
> > > > > --- a/src/android/camera_hal_manager.cpp
> > > > > +++ b/src/android/camera_hal_manager.cpp
> > > > > @@ -48,6 +48,7 @@ int CameraHalManager::init()
> > > > >  {
> > > > >       cameraManager_ = std::make_unique<CameraManager>();
> > > > >
> > > > > +#ifdef HAVE_LIBYAML
> > > > >       /*
> > > > >        * If the configuration file is not available the HAL only supports
> > > > >        * external cameras. If it exists but it's not valid then error out.
> > > > > @@ -56,6 +57,7 @@ int CameraHalManager::init()
> > > > >               LOG(HAL, Error) << "HAL configuration file is not valid";
> > > > >               return -EINVAL;
> > > > >       }
> > > > > +#endif
> > > > >
> > > > >       /* Support camera hotplug. */
> > > > >       cameraManager_->cameraAdded.connect(this, &CameraHalManager::cameraAdded);
> > > > > @@ -133,6 +135,7 @@ void CameraHalManager::cameraAdded(std::shared_ptr<Camera> cam)
> > > > >               }
> > > > >       }
> > > > >
> > > > > +#ifdef HAVE_LIBYAML
> > > > >       /*
> > > > >        * The configuration file must be valid, and contain a corresponding
> > > > >        * entry for internal cameras. External cameras can be initialized
> > > > > @@ -145,6 +148,16 @@ void CameraHalManager::cameraAdded(std::shared_ptr<Camera> cam)
> > > > >       }
> > > > >
> > > > >       const CameraConfigData *cameraConfigData = halConfig_.cameraConfigData(cam->id());
> > > > > +#else
> > > > > +     /*
> > > > > +      * Assume that cameras without properties::Location specified are external.
> > > > > +      */
> > > > > +     const CameraConfigData *cameraConfigData = nullptr;
> > > > > +     if (!isCameraExternal && cameraLocation(cam.get()) < 0) {
> > > > > +             isCameraExternal = true;
> > > > > +             id = nextExternalCameraId_;
> > > > > +     }
> > > > > +#endif
> > > > >
> > > > >       /*
> > > > >        * Some cameras whose location is reported by libcamera as external may
> > > > > diff --git a/src/android/camera_hal_manager.h b/src/android/camera_hal_manager.h
> > > > > index a5f8b933a7902..056abbb0d4e54 100644
> > > > > --- a/src/android/camera_hal_manager.h
> > > > > +++ b/src/android/camera_hal_manager.h
> > > > > @@ -56,7 +56,9 @@ private:
> > > > >       CameraDevice *cameraDeviceFromHalId(unsigned int id) LIBCAMERA_TSA_REQUIRES(mutex_);
> > > > >
> > > > >       std::unique_ptr<libcamera::CameraManager> cameraManager_;
> > > > > +#ifdef HAVE_LIBYAML
> > > > >       CameraHalConfig halConfig_;
> > > > > +#endif
> > > > >
> > > > >       const camera_module_callbacks_t *callbacks_;
> > > > >       std::vector<std::unique_ptr<CameraDevice>> cameras_ LIBCAMERA_TSA_GUARDED_BY(mutex_);
> > > > > diff --git a/src/android/meson.build b/src/android/meson.build
> > > > > index 75b4bf2070851..1e471c291a1e4 100644
> > > > > --- a/src/android/meson.build
> > > > > +++ b/src/android/meson.build
> > > > > @@ -3,7 +3,6 @@
> > > > >  android_deps = [
> > > > >      dependency('libexif', required : get_option('android')),
> > > > >      dependency('libjpeg', required : get_option('android')),
> > > > > -    dependency('yaml-0.1', required : get_option('android')),
> > > > >      libcamera_private,
> > > > >  ]
> > > > >
> > > > > @@ -41,7 +40,6 @@ android_hal_sources = files([
> > > > >      'camera3_hal.cpp',
> > > > >      'camera_capabilities.cpp',
> > > > >      'camera_device.cpp',
> > > > > -    'camera_hal_config.cpp',
> > > > >      'camera_hal_manager.cpp',
> > > > >      'camera_metadata.cpp',
> > > > >      'camera_ops.cpp',
> > > > > @@ -56,6 +54,14 @@ android_hal_sources = files([
> > > > >
> > > > >  android_cpp_args = []
> > > > >
> > > > > +libyaml_dep = dependency('yaml-0.1', required : false)
> > > > > +if libyaml_dep.found()
> > > > > +    config_h.set('HAVE_LIBYAML', 1)
> > > > > +    android_hal_sources += files([
> > > > > +        'camera_hal_config.cpp',
> > > > > +    ])
> > > > > +endif
> > > > > +
> > > > >  subdir('cros')
> > > > >  subdir('mm')
> > > > >
Roman Stratiienko Dec. 29, 2021, 10:24 a.m. UTC | #6
ср, 29 дек. 2021 г. в 12:14, Laurent Pinchart
<laurent.pinchart@ideasonboard.com>:
>
> Hi Roman,
>
> On Wed, Dec 29, 2021 at 11:45:17AM +0200, Roman Stratiienko wrote:
> > вт, 28 дек. 2021 г. в 20:27, Laurent Pinchart:
> > > On Tue, Dec 28, 2021 at 01:22:34PM +0200, Roman Stratiienko wrote:
> > > > вт, 28 дек. 2021 г., 13:04 Jacopo Mondi:
> > > > > Hi Roman,
> > > > >
> > > > > cc Hanlin Chen from ChromiumOS as he's planning to extend
> > > > > configuration file support for the ChromeOS Android HAL.
> > > >
> > > > > Before looking into the patch: is there any hope libyaml might become
> > > > > part of the standard AOSP distribution (or a process in place to request
> > > > > that)
> > > >
> > > > I am not aware of that, and I haven't initiated such a process. It will be
> > > > a very slow and bumpy road.
> > > >
> > > > Not sure what is planned for these properties in future, but now it is not
> > > > necessary to have it in libcamera to have fully functional hal. Also having
> > > > no configuration file available will encourage developers to add
> > > > corresponding records to dts, which is also a great thing to align with
> > > > linux world.
> > >
> > > Our goals align here. This is exactly why we have decided not to set the
> > > camera location in a configuration file for the libcamera core, but to
> > > isolate it in the HAL as a temporary (but in practice likely a long-term
> > > temporary) measure, as we have to support platforms that will take some
> > > time before a firmware (ACPI in this case) update can be deployed.
> > >
> > > This being said, we will introduce a configuration file for the
> > > libcamera core in the near future, and we also plan to use libyaml
> > > there. The tuning files for the IPU3 and RkISP1 IPA modules will also
> > > use YAML, and I'd like to move the Raspberry Pi tuning files from JSON
> > > to YAML for consistency.
> >
> > It's a good idea to have a single file format. Currently we have to
> > ship boost to run raspberrypi cameras on Android.
>
> I'm happy you agree :-)
>
> > > We could merge this patch in the meantime, but compilation on Android
> > > will likely break again soon. I wonder if we couldn't instead use a
> > > meson wrap to include libyaml as a subproject. This should solve the
> > > issue in the longer term.
> >
> > At this moment we have libyaml with extra Android.bp, which can
> > satisfy libcamera needs.
> > But I really like to see it as an optional dependency only to help
> > fine-tuning things or for ACPI-only platforms.
>
> Making it optional may cause difficulties in the future, with
> potentially lots of conditional compilation. I'd rather not go that way,
> unless we can wrap the yaml parser in a helper class with a dummy
> implementation to hide the missing dependency from everything else.
>
> I've quickly tested compiling libyaml as a subproject, and it seems to
> work:
>

I have some doubts if such an approach supports cross-compilation.
Could meson generate a single ninja.build from all sub-projects?
Implementing the fallback stub sounds not so bad.

>
> commit f1d86859f522c7728d8f854b82296673291750fb
> Author: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> Date:   Wed Dec 29 12:07:35 2021 +0200
>
>     android: Compile libyaml as a subproject if not available on the system
>
>     AOSP doesn't ship libyaml, making it more difficult to compile libcamera
>     for Android. Use a meson wrap to compile libyaml as a subproject if the
>     dependency is not found.
>
>     Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
>
> diff --git a/src/android/meson.build b/src/android/meson.build
> index 75b4bf207085..1fa67746d058 100644
> --- a/src/android/meson.build
> +++ b/src/android/meson.build
> @@ -3,7 +3,6 @@
>  android_deps = [
>      dependency('libexif', required : get_option('android')),
>      dependency('libjpeg', required : get_option('android')),
> -    dependency('yaml-0.1', required : get_option('android')),
>      libcamera_private,
>  ]
>
> @@ -16,13 +15,35 @@ foreach dep : android_deps
>      endif
>  endforeach
>
> +cmake = import('cmake')
> +
> +#
> +# libyaml
> +#
> +# Default to the system version, and fallback to a subproject if not found, as
> +# libyaml is not packaged in AOSP.
> +#
> +libyaml_dep = dependency('yaml-0.1', required : false)
> +
> +# Fallback to a subproject if libyaml isn't found, as it's not packed in AOSP.
> +if not libyaml_dep.found()
> +    libyaml_vars = cmake.subproject_options()
> +    libyaml_vars.add_cmake_defines({'CMAKE_POSITION_INDEPENDENT_CODE': 'ON'})
> +    libyaml = cmake.subproject('libyaml', options : libyaml_vars)
> +    libyaml_dep = libyaml.dependency('yaml')
> +endif
> +
> +android_deps += [libyaml_dep]
> +
> +#
> +# libyuv
> +#
> +# Default to the system version, and fallback to a subproject if not found, as
> +# libyuv is typically not provided by distributions.
> +#
>  libyuv_dep = dependency('libyuv', required : false)
>
> -# Fallback to a subproject if libyuv isn't found, as it's typically not
> -# provided by distributions.
>  if not libyuv_dep.found()
> -    cmake = import('cmake')
> -
>      libyuv_vars = cmake.subproject_options()
>      libyuv_vars.add_cmake_defines({'CMAKE_POSITION_INDEPENDENT_CODE': 'ON'})
>      libyuv_vars.set_override_option('cpp_std', 'c++17')
> diff --git a/subprojects/.gitignore b/subprojects/.gitignore
> index 391fde2ce1e0..f207720b271a 100644
> --- a/subprojects/.gitignore
> +++ b/subprojects/.gitignore
> @@ -1,3 +1,4 @@
>  /googletest-release*
> +/libyaml
>  /libyuv
> -/packagecache
> \ No newline at end of file
> +/packagecache
> diff --git a/subprojects/libyaml.wrap b/subprojects/libyaml.wrap
> new file mode 100644
> index 000000000000..e4426e44774f
> --- /dev/null
> +++ b/subprojects/libyaml.wrap
> @@ -0,0 +1,4 @@
> +[wrap-git]
> +directory = libyaml
> +url = https://github.com/yaml/libyaml
> +revision = 2c891fc7a770e8ba2fec34fc6b545c672beb37e6
>
> > > By the way, out of curiosity, how do you compile libcamera for Android ?
> > > We have a look at Soong (as the Makefile-based build system is being
> > > phased out), but blueprint files don't support all our needs (and would
> > > be annoying to maintain manually), and there's no way we found to
> > > generate Android.bp files from meson in a way that would integrate with
> > > Soong. This is still an unsolved problem, and I'm increasingly tempted
> > > to do the same as mesa3d and just document that libcamera should be
> > > built outside of AOSP, using the NDK.
> >
> > We shipped libcamera in our GloDroid project v0.7.0 release for
> > raspberry pi about a month ago:
> > 1. https://github.com/GloDroid/glodroid_manifest/releases/tag/v0.7.0
> > 2. https://github.com/GloDroid/glodroid_forks/commits/libcamera-v0.7.0
> >
> > For building using meson within AOSP we are using some tricks to
> > extract dependencies from AOSP makesystem and inject them into
> > meson cross compilation file.
>
> Does this mean that you compile libcamera manually, separately from AOSP
> ? That's probably the best option for now, until Android decides to
> integrate support for other build systems (likely never...).

No. Building within AOSP does mean building within AOSP.
Not manually.
It utilizes the Kati (Android.mk) build system.
And Kati is currently tightly bound to Soong, separating both would require some
time for Google if they decide to do so.
And we always have "building using NDK" as a fallback once it happens.

>
> > First such kind of approach was integrated into mesa3d and replaced
> > existing Android.mk files (about 6 month ago).
> > It doesn't require continuous maintenance as previous Android.mk did
> > and has proven to be reliable.
> > It also enables FULL support of mesa3d for Android. Previously only
> > about 60% of mesa3d drivers were covered with Android.mk files.
> > Reworking the same approach for libcamera was pretty easy.
> >
> > And yes, as an official approach for vendors NDK builds would be great
> > to support.
> > NDK approach and our meson.build within AOSP approach are 98% aligned.
> >
> > > > > On Tue, Dec 28, 2021 at 11:51:53AM +0200, Roman Stratiienko wrote:
> > > > > > Mainline Android has no libyaml in-tree. Moreover camera_hal_config.cpp
> > > > > > uses std::filesystem class that is not permitted for AOSP VNDK vendor
> > > > > > libraries.
> > > > > >
> > > > > > External configuration file is no longer mandatory and DTS overlays can
> > > > > > be used to specify camera location and rotation.
> > > > > >
> > > > > > Do not require external configuration file for cases where meson.build
> > > > > > can't find libyaml. Assume that cameras without location specified
> > > > > > by V4L2 properties are always external.
> > > > > >
> > > > > > Signed-off-by: Roman Stratiienko <roman.o.stratiienko@globallogic.com>
> > > > > > ---
> > > > > >  src/android/camera_hal_manager.cpp | 13 +++++++++++++
> > > > > >  src/android/camera_hal_manager.h   |  2 ++
> > > > > >  src/android/meson.build            | 10 ++++++++--
> > > > > >  3 files changed, 23 insertions(+), 2 deletions(-)
> > > > > >
> > > > > > diff --git a/src/android/camera_hal_manager.cpp b/src/android/camera_hal_manager.cpp
> > > > > > index 5f7bfe265c71b..9e575bfa5204a 100644
> > > > > > --- a/src/android/camera_hal_manager.cpp
> > > > > > +++ b/src/android/camera_hal_manager.cpp
> > > > > > @@ -48,6 +48,7 @@ int CameraHalManager::init()
> > > > > >  {
> > > > > >       cameraManager_ = std::make_unique<CameraManager>();
> > > > > >
> > > > > > +#ifdef HAVE_LIBYAML
> > > > > >       /*
> > > > > >        * If the configuration file is not available the HAL only supports
> > > > > >        * external cameras. If it exists but it's not valid then error out.
> > > > > > @@ -56,6 +57,7 @@ int CameraHalManager::init()
> > > > > >               LOG(HAL, Error) << "HAL configuration file is not valid";
> > > > > >               return -EINVAL;
> > > > > >       }
> > > > > > +#endif
> > > > > >
> > > > > >       /* Support camera hotplug. */
> > > > > >       cameraManager_->cameraAdded.connect(this, &CameraHalManager::cameraAdded);
> > > > > > @@ -133,6 +135,7 @@ void CameraHalManager::cameraAdded(std::shared_ptr<Camera> cam)
> > > > > >               }
> > > > > >       }
> > > > > >
> > > > > > +#ifdef HAVE_LIBYAML
> > > > > >       /*
> > > > > >        * The configuration file must be valid, and contain a corresponding
> > > > > >        * entry for internal cameras. External cameras can be initialized
> > > > > > @@ -145,6 +148,16 @@ void CameraHalManager::cameraAdded(std::shared_ptr<Camera> cam)
> > > > > >       }
> > > > > >
> > > > > >       const CameraConfigData *cameraConfigData = halConfig_.cameraConfigData(cam->id());
> > > > > > +#else
> > > > > > +     /*
> > > > > > +      * Assume that cameras without properties::Location specified are external.
> > > > > > +      */
> > > > > > +     const CameraConfigData *cameraConfigData = nullptr;
> > > > > > +     if (!isCameraExternal && cameraLocation(cam.get()) < 0) {
> > > > > > +             isCameraExternal = true;
> > > > > > +             id = nextExternalCameraId_;
> > > > > > +     }
> > > > > > +#endif
> > > > > >
> > > > > >       /*
> > > > > >        * Some cameras whose location is reported by libcamera as external may
> > > > > > diff --git a/src/android/camera_hal_manager.h b/src/android/camera_hal_manager.h
> > > > > > index a5f8b933a7902..056abbb0d4e54 100644
> > > > > > --- a/src/android/camera_hal_manager.h
> > > > > > +++ b/src/android/camera_hal_manager.h
> > > > > > @@ -56,7 +56,9 @@ private:
> > > > > >       CameraDevice *cameraDeviceFromHalId(unsigned int id) LIBCAMERA_TSA_REQUIRES(mutex_);
> > > > > >
> > > > > >       std::unique_ptr<libcamera::CameraManager> cameraManager_;
> > > > > > +#ifdef HAVE_LIBYAML
> > > > > >       CameraHalConfig halConfig_;
> > > > > > +#endif
> > > > > >
> > > > > >       const camera_module_callbacks_t *callbacks_;
> > > > > >       std::vector<std::unique_ptr<CameraDevice>> cameras_ LIBCAMERA_TSA_GUARDED_BY(mutex_);
> > > > > > diff --git a/src/android/meson.build b/src/android/meson.build
> > > > > > index 75b4bf2070851..1e471c291a1e4 100644
> > > > > > --- a/src/android/meson.build
> > > > > > +++ b/src/android/meson.build
> > > > > > @@ -3,7 +3,6 @@
> > > > > >  android_deps = [
> > > > > >      dependency('libexif', required : get_option('android')),
> > > > > >      dependency('libjpeg', required : get_option('android')),
> > > > > > -    dependency('yaml-0.1', required : get_option('android')),
> > > > > >      libcamera_private,
> > > > > >  ]
> > > > > >
> > > > > > @@ -41,7 +40,6 @@ android_hal_sources = files([
> > > > > >      'camera3_hal.cpp',
> > > > > >      'camera_capabilities.cpp',
> > > > > >      'camera_device.cpp',
> > > > > > -    'camera_hal_config.cpp',
> > > > > >      'camera_hal_manager.cpp',
> > > > > >      'camera_metadata.cpp',
> > > > > >      'camera_ops.cpp',
> > > > > > @@ -56,6 +54,14 @@ android_hal_sources = files([
> > > > > >
> > > > > >  android_cpp_args = []
> > > > > >
> > > > > > +libyaml_dep = dependency('yaml-0.1', required : false)
> > > > > > +if libyaml_dep.found()
> > > > > > +    config_h.set('HAVE_LIBYAML', 1)
> > > > > > +    android_hal_sources += files([
> > > > > > +        'camera_hal_config.cpp',
> > > > > > +    ])
> > > > > > +endif
> > > > > > +
> > > > > >  subdir('cros')
> > > > > >  subdir('mm')
> > > > > >
>
> --
> Regards,
>
> Laurent Pinchart
Roman Stratiienko Dec. 29, 2021, 12:17 p.m. UTC | #7
+CC: John Stultz

Laurent,

I would like to make mainline libcamera work on mainline android
without additional patches / extra packages and then give it to John
Stultz for testing with AOSP devboards in this shape.
Unlike mesa3d libcamera doesn't have a lot of generated code,
therefore shipping this code / creating Android.bp is less painful.
In case this tricky plan will succeed and we will have libcamera
inside AOSP, then rationale for adding libyaml into AOSP would be much
easier to formulate.

ср, 29 дек. 2021 г. в 12:24, Roman Stratiienko <r.stratiienko@gmail.com>:
>
> ср, 29 дек. 2021 г. в 12:14, Laurent Pinchart
> <laurent.pinchart@ideasonboard.com>:
> >
> > Hi Roman,
> >
> > On Wed, Dec 29, 2021 at 11:45:17AM +0200, Roman Stratiienko wrote:
> > > вт, 28 дек. 2021 г. в 20:27, Laurent Pinchart:
> > > > On Tue, Dec 28, 2021 at 01:22:34PM +0200, Roman Stratiienko wrote:
> > > > > вт, 28 дек. 2021 г., 13:04 Jacopo Mondi:
> > > > > > Hi Roman,
> > > > > >
> > > > > > cc Hanlin Chen from ChromiumOS as he's planning to extend
> > > > > > configuration file support for the ChromeOS Android HAL.
> > > > >
> > > > > > Before looking into the patch: is there any hope libyaml might become
> > > > > > part of the standard AOSP distribution (or a process in place to request
> > > > > > that)
> > > > >
> > > > > I am not aware of that, and I haven't initiated such a process. It will be
> > > > > a very slow and bumpy road.
> > > > >
> > > > > Not sure what is planned for these properties in future, but now it is not
> > > > > necessary to have it in libcamera to have fully functional hal. Also having
> > > > > no configuration file available will encourage developers to add
> > > > > corresponding records to dts, which is also a great thing to align with
> > > > > linux world.
> > > >
> > > > Our goals align here. This is exactly why we have decided not to set the
> > > > camera location in a configuration file for the libcamera core, but to
> > > > isolate it in the HAL as a temporary (but in practice likely a long-term
> > > > temporary) measure, as we have to support platforms that will take some
> > > > time before a firmware (ACPI in this case) update can be deployed.
> > > >
> > > > This being said, we will introduce a configuration file for the
> > > > libcamera core in the near future, and we also plan to use libyaml
> > > > there. The tuning files for the IPU3 and RkISP1 IPA modules will also
> > > > use YAML, and I'd like to move the Raspberry Pi tuning files from JSON
> > > > to YAML for consistency.
> > >
> > > It's a good idea to have a single file format. Currently we have to
> > > ship boost to run raspberrypi cameras on Android.
> >
> > I'm happy you agree :-)
> >
> > > > We could merge this patch in the meantime, but compilation on Android
> > > > will likely break again soon. I wonder if we couldn't instead use a
> > > > meson wrap to include libyaml as a subproject. This should solve the
> > > > issue in the longer term.
> > >
> > > At this moment we have libyaml with extra Android.bp, which can
> > > satisfy libcamera needs.
> > > But I really like to see it as an optional dependency only to help
> > > fine-tuning things or for ACPI-only platforms.
> >
> > Making it optional may cause difficulties in the future, with
> > potentially lots of conditional compilation. I'd rather not go that way,
> > unless we can wrap the yaml parser in a helper class with a dummy
> > implementation to hide the missing dependency from everything else.
> >
> > I've quickly tested compiling libyaml as a subproject, and it seems to
> > work:
> >
>
> I have some doubts if such an approach supports cross-compilation.
> Could meson generate a single ninja.build from all sub-projects?
> Implementing the fallback stub sounds not so bad.
>
> >
> > commit f1d86859f522c7728d8f854b82296673291750fb
> > Author: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > Date:   Wed Dec 29 12:07:35 2021 +0200
> >
> >     android: Compile libyaml as a subproject if not available on the system
> >
> >     AOSP doesn't ship libyaml, making it more difficult to compile libcamera
> >     for Android. Use a meson wrap to compile libyaml as a subproject if the
> >     dependency is not found.
> >
> >     Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> >
> > diff --git a/src/android/meson.build b/src/android/meson.build
> > index 75b4bf207085..1fa67746d058 100644
> > --- a/src/android/meson.build
> > +++ b/src/android/meson.build
> > @@ -3,7 +3,6 @@
> >  android_deps = [
> >      dependency('libexif', required : get_option('android')),
> >      dependency('libjpeg', required : get_option('android')),
> > -    dependency('yaml-0.1', required : get_option('android')),
> >      libcamera_private,
> >  ]
> >
> > @@ -16,13 +15,35 @@ foreach dep : android_deps
> >      endif
> >  endforeach
> >
> > +cmake = import('cmake')
> > +
> > +#
> > +# libyaml
> > +#
> > +# Default to the system version, and fallback to a subproject if not found, as
> > +# libyaml is not packaged in AOSP.
> > +#
> > +libyaml_dep = dependency('yaml-0.1', required : false)
> > +
> > +# Fallback to a subproject if libyaml isn't found, as it's not packed in AOSP.
> > +if not libyaml_dep.found()
> > +    libyaml_vars = cmake.subproject_options()
> > +    libyaml_vars.add_cmake_defines({'CMAKE_POSITION_INDEPENDENT_CODE': 'ON'})
> > +    libyaml = cmake.subproject('libyaml', options : libyaml_vars)
> > +    libyaml_dep = libyaml.dependency('yaml')
> > +endif
> > +
> > +android_deps += [libyaml_dep]
> > +
> > +#
> > +# libyuv
> > +#
> > +# Default to the system version, and fallback to a subproject if not found, as
> > +# libyuv is typically not provided by distributions.
> > +#
> >  libyuv_dep = dependency('libyuv', required : false)
> >
> > -# Fallback to a subproject if libyuv isn't found, as it's typically not
> > -# provided by distributions.
> >  if not libyuv_dep.found()
> > -    cmake = import('cmake')
> > -
> >      libyuv_vars = cmake.subproject_options()
> >      libyuv_vars.add_cmake_defines({'CMAKE_POSITION_INDEPENDENT_CODE': 'ON'})
> >      libyuv_vars.set_override_option('cpp_std', 'c++17')
> > diff --git a/subprojects/.gitignore b/subprojects/.gitignore
> > index 391fde2ce1e0..f207720b271a 100644
> > --- a/subprojects/.gitignore
> > +++ b/subprojects/.gitignore
> > @@ -1,3 +1,4 @@
> >  /googletest-release*
> > +/libyaml
> >  /libyuv
> > -/packagecache
> > \ No newline at end of file
> > +/packagecache
> > diff --git a/subprojects/libyaml.wrap b/subprojects/libyaml.wrap
> > new file mode 100644
> > index 000000000000..e4426e44774f
> > --- /dev/null
> > +++ b/subprojects/libyaml.wrap
> > @@ -0,0 +1,4 @@
> > +[wrap-git]
> > +directory = libyaml
> > +url = https://github.com/yaml/libyaml
> > +revision = 2c891fc7a770e8ba2fec34fc6b545c672beb37e6
> >
> > > > By the way, out of curiosity, how do you compile libcamera for Android ?
> > > > We have a look at Soong (as the Makefile-based build system is being
> > > > phased out), but blueprint files don't support all our needs (and would
> > > > be annoying to maintain manually), and there's no way we found to
> > > > generate Android.bp files from meson in a way that would integrate with
> > > > Soong. This is still an unsolved problem, and I'm increasingly tempted
> > > > to do the same as mesa3d and just document that libcamera should be
> > > > built outside of AOSP, using the NDK.
> > >
> > > We shipped libcamera in our GloDroid project v0.7.0 release for
> > > raspberry pi about a month ago:
> > > 1. https://github.com/GloDroid/glodroid_manifest/releases/tag/v0.7.0
> > > 2. https://github.com/GloDroid/glodroid_forks/commits/libcamera-v0.7.0
> > >
> > > For building using meson within AOSP we are using some tricks to
> > > extract dependencies from AOSP makesystem and inject them into
> > > meson cross compilation file.
> >
> > Does this mean that you compile libcamera manually, separately from AOSP
> > ? That's probably the best option for now, until Android decides to
> > integrate support for other build systems (likely never...).
>
> No. Building within AOSP does mean building within AOSP.
> Not manually.
> It utilizes the Kati (Android.mk) build system.
> And Kati is currently tightly bound to Soong, separating both would require some
> time for Google if they decide to do so.
> And we always have "building using NDK" as a fallback once it happens.
>
> >
> > > First such kind of approach was integrated into mesa3d and replaced
> > > existing Android.mk files (about 6 month ago).
> > > It doesn't require continuous maintenance as previous Android.mk did
> > > and has proven to be reliable.
> > > It also enables FULL support of mesa3d for Android. Previously only
> > > about 60% of mesa3d drivers were covered with Android.mk files.
> > > Reworking the same approach for libcamera was pretty easy.
> > >
> > > And yes, as an official approach for vendors NDK builds would be great
> > > to support.
> > > NDK approach and our meson.build within AOSP approach are 98% aligned.
> > >
> > > > > > On Tue, Dec 28, 2021 at 11:51:53AM +0200, Roman Stratiienko wrote:
> > > > > > > Mainline Android has no libyaml in-tree. Moreover camera_hal_config.cpp
> > > > > > > uses std::filesystem class that is not permitted for AOSP VNDK vendor
> > > > > > > libraries.
> > > > > > >
> > > > > > > External configuration file is no longer mandatory and DTS overlays can
> > > > > > > be used to specify camera location and rotation.
> > > > > > >
> > > > > > > Do not require external configuration file for cases where meson.build
> > > > > > > can't find libyaml. Assume that cameras without location specified
> > > > > > > by V4L2 properties are always external.
> > > > > > >
> > > > > > > Signed-off-by: Roman Stratiienko <roman.o.stratiienko@globallogic.com>
> > > > > > > ---
> > > > > > >  src/android/camera_hal_manager.cpp | 13 +++++++++++++
> > > > > > >  src/android/camera_hal_manager.h   |  2 ++
> > > > > > >  src/android/meson.build            | 10 ++++++++--
> > > > > > >  3 files changed, 23 insertions(+), 2 deletions(-)
> > > > > > >
> > > > > > > diff --git a/src/android/camera_hal_manager.cpp b/src/android/camera_hal_manager.cpp
> > > > > > > index 5f7bfe265c71b..9e575bfa5204a 100644
> > > > > > > --- a/src/android/camera_hal_manager.cpp
> > > > > > > +++ b/src/android/camera_hal_manager.cpp
> > > > > > > @@ -48,6 +48,7 @@ int CameraHalManager::init()
> > > > > > >  {
> > > > > > >       cameraManager_ = std::make_unique<CameraManager>();
> > > > > > >
> > > > > > > +#ifdef HAVE_LIBYAML
> > > > > > >       /*
> > > > > > >        * If the configuration file is not available the HAL only supports
> > > > > > >        * external cameras. If it exists but it's not valid then error out.
> > > > > > > @@ -56,6 +57,7 @@ int CameraHalManager::init()
> > > > > > >               LOG(HAL, Error) << "HAL configuration file is not valid";
> > > > > > >               return -EINVAL;
> > > > > > >       }
> > > > > > > +#endif
> > > > > > >
> > > > > > >       /* Support camera hotplug. */
> > > > > > >       cameraManager_->cameraAdded.connect(this, &CameraHalManager::cameraAdded);
> > > > > > > @@ -133,6 +135,7 @@ void CameraHalManager::cameraAdded(std::shared_ptr<Camera> cam)
> > > > > > >               }
> > > > > > >       }
> > > > > > >
> > > > > > > +#ifdef HAVE_LIBYAML
> > > > > > >       /*
> > > > > > >        * The configuration file must be valid, and contain a corresponding
> > > > > > >        * entry for internal cameras. External cameras can be initialized
> > > > > > > @@ -145,6 +148,16 @@ void CameraHalManager::cameraAdded(std::shared_ptr<Camera> cam)
> > > > > > >       }
> > > > > > >
> > > > > > >       const CameraConfigData *cameraConfigData = halConfig_.cameraConfigData(cam->id());
> > > > > > > +#else
> > > > > > > +     /*
> > > > > > > +      * Assume that cameras without properties::Location specified are external.
> > > > > > > +      */
> > > > > > > +     const CameraConfigData *cameraConfigData = nullptr;
> > > > > > > +     if (!isCameraExternal && cameraLocation(cam.get()) < 0) {
> > > > > > > +             isCameraExternal = true;
> > > > > > > +             id = nextExternalCameraId_;
> > > > > > > +     }
> > > > > > > +#endif
> > > > > > >
> > > > > > >       /*
> > > > > > >        * Some cameras whose location is reported by libcamera as external may
> > > > > > > diff --git a/src/android/camera_hal_manager.h b/src/android/camera_hal_manager.h
> > > > > > > index a5f8b933a7902..056abbb0d4e54 100644
> > > > > > > --- a/src/android/camera_hal_manager.h
> > > > > > > +++ b/src/android/camera_hal_manager.h
> > > > > > > @@ -56,7 +56,9 @@ private:
> > > > > > >       CameraDevice *cameraDeviceFromHalId(unsigned int id) LIBCAMERA_TSA_REQUIRES(mutex_);
> > > > > > >
> > > > > > >       std::unique_ptr<libcamera::CameraManager> cameraManager_;
> > > > > > > +#ifdef HAVE_LIBYAML
> > > > > > >       CameraHalConfig halConfig_;
> > > > > > > +#endif
> > > > > > >
> > > > > > >       const camera_module_callbacks_t *callbacks_;
> > > > > > >       std::vector<std::unique_ptr<CameraDevice>> cameras_ LIBCAMERA_TSA_GUARDED_BY(mutex_);
> > > > > > > diff --git a/src/android/meson.build b/src/android/meson.build
> > > > > > > index 75b4bf2070851..1e471c291a1e4 100644
> > > > > > > --- a/src/android/meson.build
> > > > > > > +++ b/src/android/meson.build
> > > > > > > @@ -3,7 +3,6 @@
> > > > > > >  android_deps = [
> > > > > > >      dependency('libexif', required : get_option('android')),
> > > > > > >      dependency('libjpeg', required : get_option('android')),
> > > > > > > -    dependency('yaml-0.1', required : get_option('android')),
> > > > > > >      libcamera_private,
> > > > > > >  ]
> > > > > > >
> > > > > > > @@ -41,7 +40,6 @@ android_hal_sources = files([
> > > > > > >      'camera3_hal.cpp',
> > > > > > >      'camera_capabilities.cpp',
> > > > > > >      'camera_device.cpp',
> > > > > > > -    'camera_hal_config.cpp',
> > > > > > >      'camera_hal_manager.cpp',
> > > > > > >      'camera_metadata.cpp',
> > > > > > >      'camera_ops.cpp',
> > > > > > > @@ -56,6 +54,14 @@ android_hal_sources = files([
> > > > > > >
> > > > > > >  android_cpp_args = []
> > > > > > >
> > > > > > > +libyaml_dep = dependency('yaml-0.1', required : false)
> > > > > > > +if libyaml_dep.found()
> > > > > > > +    config_h.set('HAVE_LIBYAML', 1)
> > > > > > > +    android_hal_sources += files([
> > > > > > > +        'camera_hal_config.cpp',
> > > > > > > +    ])
> > > > > > > +endif
> > > > > > > +
> > > > > > >  subdir('cros')
> > > > > > >  subdir('mm')
> > > > > > >
> >
> > --
> > Regards,
> >
> > Laurent Pinchart
Laurent Pinchart Dec. 29, 2021, 2:37 p.m. UTC | #8
Hi Roman,

On Wed, Dec 29, 2021 at 12:24:48PM +0200, Roman Stratiienko wrote:
> ср, 29 дек. 2021 г. в 12:14, Laurent Pinchart:
> > On Wed, Dec 29, 2021 at 11:45:17AM +0200, Roman Stratiienko wrote:
> > > вт, 28 дек. 2021 г. в 20:27, Laurent Pinchart:
> > > > On Tue, Dec 28, 2021 at 01:22:34PM +0200, Roman Stratiienko wrote:
> > > > > вт, 28 дек. 2021 г., 13:04 Jacopo Mondi:
> > > > > > Hi Roman,
> > > > > >
> > > > > > cc Hanlin Chen from ChromiumOS as he's planning to extend
> > > > > > configuration file support for the ChromeOS Android HAL.
> > > > >
> > > > > > Before looking into the patch: is there any hope libyaml might become
> > > > > > part of the standard AOSP distribution (or a process in place to request
> > > > > > that)
> > > > >
> > > > > I am not aware of that, and I haven't initiated such a process. It will be
> > > > > a very slow and bumpy road.
> > > > >
> > > > > Not sure what is planned for these properties in future, but now it is not
> > > > > necessary to have it in libcamera to have fully functional hal. Also having
> > > > > no configuration file available will encourage developers to add
> > > > > corresponding records to dts, which is also a great thing to align with
> > > > > linux world.
> > > >
> > > > Our goals align here. This is exactly why we have decided not to set the
> > > > camera location in a configuration file for the libcamera core, but to
> > > > isolate it in the HAL as a temporary (but in practice likely a long-term
> > > > temporary) measure, as we have to support platforms that will take some
> > > > time before a firmware (ACPI in this case) update can be deployed.
> > > >
> > > > This being said, we will introduce a configuration file for the
> > > > libcamera core in the near future, and we also plan to use libyaml
> > > > there. The tuning files for the IPU3 and RkISP1 IPA modules will also
> > > > use YAML, and I'd like to move the Raspberry Pi tuning files from JSON
> > > > to YAML for consistency.
> > >
> > > It's a good idea to have a single file format. Currently we have to
> > > ship boost to run raspberrypi cameras on Android.
> >
> > I'm happy you agree :-)
> >
> > > > We could merge this patch in the meantime, but compilation on Android
> > > > will likely break again soon. I wonder if we couldn't instead use a
> > > > meson wrap to include libyaml as a subproject. This should solve the
> > > > issue in the longer term.
> > >
> > > At this moment we have libyaml with extra Android.bp, which can
> > > satisfy libcamera needs.
> > > But I really like to see it as an optional dependency only to help
> > > fine-tuning things or for ACPI-only platforms.
> >
> > Making it optional may cause difficulties in the future, with
> > potentially lots of conditional compilation. I'd rather not go that way,
> > unless we can wrap the yaml parser in a helper class with a dummy
> > implementation to hide the missing dependency from everything else.
> >
> > I've quickly tested compiling libyaml as a subproject, and it seems to
> > work:
> 
> I have some doubts if such an approach supports cross-compilation.
> Could meson generate a single ninja.build from all sub-projects?
> Implementing the fallback stub sounds not so bad.

With an additional

	libyaml_vars.append_compile_args('c', '-Wno-unused-value')

it cross-compiles fine for ARM64.

> > commit f1d86859f522c7728d8f854b82296673291750fb
> > Author: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > Date:   Wed Dec 29 12:07:35 2021 +0200
> >
> >     android: Compile libyaml as a subproject if not available on the system
> >
> >     AOSP doesn't ship libyaml, making it more difficult to compile libcamera
> >     for Android. Use a meson wrap to compile libyaml as a subproject if the
> >     dependency is not found.
> >
> >     Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> >
> > diff --git a/src/android/meson.build b/src/android/meson.build
> > index 75b4bf207085..1fa67746d058 100644
> > --- a/src/android/meson.build
> > +++ b/src/android/meson.build
> > @@ -3,7 +3,6 @@
> >  android_deps = [
> >      dependency('libexif', required : get_option('android')),
> >      dependency('libjpeg', required : get_option('android')),
> > -    dependency('yaml-0.1', required : get_option('android')),
> >      libcamera_private,
> >  ]
> >
> > @@ -16,13 +15,35 @@ foreach dep : android_deps
> >      endif
> >  endforeach
> >
> > +cmake = import('cmake')
> > +
> > +#
> > +# libyaml
> > +#
> > +# Default to the system version, and fallback to a subproject if not found, as
> > +# libyaml is not packaged in AOSP.
> > +#
> > +libyaml_dep = dependency('yaml-0.1', required : false)
> > +
> > +# Fallback to a subproject if libyaml isn't found, as it's not packed in AOSP.
> > +if not libyaml_dep.found()
> > +    libyaml_vars = cmake.subproject_options()
> > +    libyaml_vars.add_cmake_defines({'CMAKE_POSITION_INDEPENDENT_CODE': 'ON'})
> > +    libyaml = cmake.subproject('libyaml', options : libyaml_vars)
> > +    libyaml_dep = libyaml.dependency('yaml')
> > +endif
> > +
> > +android_deps += [libyaml_dep]
> > +
> > +#
> > +# libyuv
> > +#
> > +# Default to the system version, and fallback to a subproject if not found, as
> > +# libyuv is typically not provided by distributions.
> > +#
> >  libyuv_dep = dependency('libyuv', required : false)
> >
> > -# Fallback to a subproject if libyuv isn't found, as it's typically not
> > -# provided by distributions.
> >  if not libyuv_dep.found()
> > -    cmake = import('cmake')
> > -
> >      libyuv_vars = cmake.subproject_options()
> >      libyuv_vars.add_cmake_defines({'CMAKE_POSITION_INDEPENDENT_CODE': 'ON'})
> >      libyuv_vars.set_override_option('cpp_std', 'c++17')
> > diff --git a/subprojects/.gitignore b/subprojects/.gitignore
> > index 391fde2ce1e0..f207720b271a 100644
> > --- a/subprojects/.gitignore
> > +++ b/subprojects/.gitignore
> > @@ -1,3 +1,4 @@
> >  /googletest-release*
> > +/libyaml
> >  /libyuv
> > -/packagecache
> > \ No newline at end of file
> > +/packagecache
> > diff --git a/subprojects/libyaml.wrap b/subprojects/libyaml.wrap
> > new file mode 100644
> > index 000000000000..e4426e44774f
> > --- /dev/null
> > +++ b/subprojects/libyaml.wrap
> > @@ -0,0 +1,4 @@
> > +[wrap-git]
> > +directory = libyaml
> > +url = https://github.com/yaml/libyaml
> > +revision = 2c891fc7a770e8ba2fec34fc6b545c672beb37e6
> >
> > > > By the way, out of curiosity, how do you compile libcamera for Android ?
> > > > We have a look at Soong (as the Makefile-based build system is being
> > > > phased out), but blueprint files don't support all our needs (and would
> > > > be annoying to maintain manually), and there's no way we found to
> > > > generate Android.bp files from meson in a way that would integrate with
> > > > Soong. This is still an unsolved problem, and I'm increasingly tempted
> > > > to do the same as mesa3d and just document that libcamera should be
> > > > built outside of AOSP, using the NDK.
> > >
> > > We shipped libcamera in our GloDroid project v0.7.0 release for
> > > raspberry pi about a month ago:
> > > 1. https://github.com/GloDroid/glodroid_manifest/releases/tag/v0.7.0
> > > 2. https://github.com/GloDroid/glodroid_forks/commits/libcamera-v0.7.0
> > >
> > > For building using meson within AOSP we are using some tricks to
> > > extract dependencies from AOSP makesystem and inject them into
> > > meson cross compilation file.
> >
> > Does this mean that you compile libcamera manually, separately from AOSP
> > ? That's probably the best option for now, until Android decides to
> > integrate support for other build systems (likely never...).
> 
> No. Building within AOSP does mean building within AOSP.
> Not manually.
> It utilizes the Kati (Android.mk) build system.
> And Kati is currently tightly bound to Soong, separating both would require some
> time for Google if they decide to do so.
> And we always have "building using NDK" as a fallback once it happens.

I thought they had mostly finished the conversion to Soong, but I could
be wrong. I remember finding a page that listed the timeline and what
types of packages were still allowed to use Android.mk at different
points in the transition, but I can't locate that anymore.

Could you point me to the sources that show how you built libcamera ?

And if it wasn't "fun" enough, they're moving away from Soong to Bazel
(https://android.googlesource.com/platform/build/bazel/+/refs/heads/master/docs/concepts.md).

> > > First such kind of approach was integrated into mesa3d and replaced
> > > existing Android.mk files (about 6 month ago).
> > > It doesn't require continuous maintenance as previous Android.mk did
> > > and has proven to be reliable.
> > > It also enables FULL support of mesa3d for Android. Previously only
> > > about 60% of mesa3d drivers were covered with Android.mk files.
> > > Reworking the same approach for libcamera was pretty easy.
> > >
> > > And yes, as an official approach for vendors NDK builds would be great
> > > to support.
> > > NDK approach and our meson.build within AOSP approach are 98% aligned.
> > >
> > > > > > On Tue, Dec 28, 2021 at 11:51:53AM +0200, Roman Stratiienko wrote:
> > > > > > > Mainline Android has no libyaml in-tree. Moreover camera_hal_config.cpp
> > > > > > > uses std::filesystem class that is not permitted for AOSP VNDK vendor
> > > > > > > libraries.
> > > > > > >
> > > > > > > External configuration file is no longer mandatory and DTS overlays can
> > > > > > > be used to specify camera location and rotation.
> > > > > > >
> > > > > > > Do not require external configuration file for cases where meson.build
> > > > > > > can't find libyaml. Assume that cameras without location specified
> > > > > > > by V4L2 properties are always external.
> > > > > > >
> > > > > > > Signed-off-by: Roman Stratiienko <roman.o.stratiienko@globallogic.com>
> > > > > > > ---
> > > > > > >  src/android/camera_hal_manager.cpp | 13 +++++++++++++
> > > > > > >  src/android/camera_hal_manager.h   |  2 ++
> > > > > > >  src/android/meson.build            | 10 ++++++++--
> > > > > > >  3 files changed, 23 insertions(+), 2 deletions(-)
> > > > > > >
> > > > > > > diff --git a/src/android/camera_hal_manager.cpp b/src/android/camera_hal_manager.cpp
> > > > > > > index 5f7bfe265c71b..9e575bfa5204a 100644
> > > > > > > --- a/src/android/camera_hal_manager.cpp
> > > > > > > +++ b/src/android/camera_hal_manager.cpp
> > > > > > > @@ -48,6 +48,7 @@ int CameraHalManager::init()
> > > > > > >  {
> > > > > > >       cameraManager_ = std::make_unique<CameraManager>();
> > > > > > >
> > > > > > > +#ifdef HAVE_LIBYAML
> > > > > > >       /*
> > > > > > >        * If the configuration file is not available the HAL only supports
> > > > > > >        * external cameras. If it exists but it's not valid then error out.
> > > > > > > @@ -56,6 +57,7 @@ int CameraHalManager::init()
> > > > > > >               LOG(HAL, Error) << "HAL configuration file is not valid";
> > > > > > >               return -EINVAL;
> > > > > > >       }
> > > > > > > +#endif
> > > > > > >
> > > > > > >       /* Support camera hotplug. */
> > > > > > >       cameraManager_->cameraAdded.connect(this, &CameraHalManager::cameraAdded);
> > > > > > > @@ -133,6 +135,7 @@ void CameraHalManager::cameraAdded(std::shared_ptr<Camera> cam)
> > > > > > >               }
> > > > > > >       }
> > > > > > >
> > > > > > > +#ifdef HAVE_LIBYAML
> > > > > > >       /*
> > > > > > >        * The configuration file must be valid, and contain a corresponding
> > > > > > >        * entry for internal cameras. External cameras can be initialized
> > > > > > > @@ -145,6 +148,16 @@ void CameraHalManager::cameraAdded(std::shared_ptr<Camera> cam)
> > > > > > >       }
> > > > > > >
> > > > > > >       const CameraConfigData *cameraConfigData = halConfig_.cameraConfigData(cam->id());
> > > > > > > +#else
> > > > > > > +     /*
> > > > > > > +      * Assume that cameras without properties::Location specified are external.
> > > > > > > +      */
> > > > > > > +     const CameraConfigData *cameraConfigData = nullptr;
> > > > > > > +     if (!isCameraExternal && cameraLocation(cam.get()) < 0) {
> > > > > > > +             isCameraExternal = true;
> > > > > > > +             id = nextExternalCameraId_;
> > > > > > > +     }
> > > > > > > +#endif
> > > > > > >
> > > > > > >       /*
> > > > > > >        * Some cameras whose location is reported by libcamera as external may
> > > > > > > diff --git a/src/android/camera_hal_manager.h b/src/android/camera_hal_manager.h
> > > > > > > index a5f8b933a7902..056abbb0d4e54 100644
> > > > > > > --- a/src/android/camera_hal_manager.h
> > > > > > > +++ b/src/android/camera_hal_manager.h
> > > > > > > @@ -56,7 +56,9 @@ private:
> > > > > > >       CameraDevice *cameraDeviceFromHalId(unsigned int id) LIBCAMERA_TSA_REQUIRES(mutex_);
> > > > > > >
> > > > > > >       std::unique_ptr<libcamera::CameraManager> cameraManager_;
> > > > > > > +#ifdef HAVE_LIBYAML
> > > > > > >       CameraHalConfig halConfig_;
> > > > > > > +#endif
> > > > > > >
> > > > > > >       const camera_module_callbacks_t *callbacks_;
> > > > > > >       std::vector<std::unique_ptr<CameraDevice>> cameras_ LIBCAMERA_TSA_GUARDED_BY(mutex_);
> > > > > > > diff --git a/src/android/meson.build b/src/android/meson.build
> > > > > > > index 75b4bf2070851..1e471c291a1e4 100644
> > > > > > > --- a/src/android/meson.build
> > > > > > > +++ b/src/android/meson.build
> > > > > > > @@ -3,7 +3,6 @@
> > > > > > >  android_deps = [
> > > > > > >      dependency('libexif', required : get_option('android')),
> > > > > > >      dependency('libjpeg', required : get_option('android')),
> > > > > > > -    dependency('yaml-0.1', required : get_option('android')),
> > > > > > >      libcamera_private,
> > > > > > >  ]
> > > > > > >
> > > > > > > @@ -41,7 +40,6 @@ android_hal_sources = files([
> > > > > > >      'camera3_hal.cpp',
> > > > > > >      'camera_capabilities.cpp',
> > > > > > >      'camera_device.cpp',
> > > > > > > -    'camera_hal_config.cpp',
> > > > > > >      'camera_hal_manager.cpp',
> > > > > > >      'camera_metadata.cpp',
> > > > > > >      'camera_ops.cpp',
> > > > > > > @@ -56,6 +54,14 @@ android_hal_sources = files([
> > > > > > >
> > > > > > >  android_cpp_args = []
> > > > > > >
> > > > > > > +libyaml_dep = dependency('yaml-0.1', required : false)
> > > > > > > +if libyaml_dep.found()
> > > > > > > +    config_h.set('HAVE_LIBYAML', 1)
> > > > > > > +    android_hal_sources += files([
> > > > > > > +        'camera_hal_config.cpp',
> > > > > > > +    ])
> > > > > > > +endif
> > > > > > > +
> > > > > > >  subdir('cros')
> > > > > > >  subdir('mm')
> > > > > > >
Laurent Pinchart Dec. 29, 2021, 2:40 p.m. UTC | #9
Hi Roman,

On Wed, Dec 29, 2021 at 02:17:03PM +0200, Roman Stratiienko wrote:
> +CC: John Stultz
> 
> Laurent,
> 
> I would like to make mainline libcamera work on mainline android
> without additional patches / extra packages and then give it to John
> Stultz for testing with AOSP devboards in this shape.
> Unlike mesa3d libcamera doesn't have a lot of generated code,
> therefore shipping this code / creating Android.bp is less painful.

How do you envision this being done ? We don't want to commit generated
sources to the libcamera git repository. Please note that one of the
source files generated during build contains a randomly generated
private key which is thrown away at the end of the build. Committing a
private key to a source tree will not be a very good idea :-)

> In case this tricky plan will succeed and we will have libcamera
> inside AOSP, then rationale for adding libyaml into AOSP would be much
> easier to formulate.
>
> ср, 29 дек. 2021 г. в 12:24, Roman Stratiienko:
> > ср, 29 дек. 2021 г. в 12:14, Laurent Pinchart:
> > > On Wed, Dec 29, 2021 at 11:45:17AM +0200, Roman Stratiienko wrote:
> > > > вт, 28 дек. 2021 г. в 20:27, Laurent Pinchart:
> > > > > On Tue, Dec 28, 2021 at 01:22:34PM +0200, Roman Stratiienko wrote:
> > > > > > вт, 28 дек. 2021 г., 13:04 Jacopo Mondi:
> > > > > > > Hi Roman,
> > > > > > >
> > > > > > > cc Hanlin Chen from ChromiumOS as he's planning to extend
> > > > > > > configuration file support for the ChromeOS Android HAL.
> > > > > >
> > > > > > > Before looking into the patch: is there any hope libyaml might become
> > > > > > > part of the standard AOSP distribution (or a process in place to request
> > > > > > > that)
> > > > > >
> > > > > > I am not aware of that, and I haven't initiated such a process. It will be
> > > > > > a very slow and bumpy road.
> > > > > >
> > > > > > Not sure what is planned for these properties in future, but now it is not
> > > > > > necessary to have it in libcamera to have fully functional hal. Also having
> > > > > > no configuration file available will encourage developers to add
> > > > > > corresponding records to dts, which is also a great thing to align with
> > > > > > linux world.
> > > > >
> > > > > Our goals align here. This is exactly why we have decided not to set the
> > > > > camera location in a configuration file for the libcamera core, but to
> > > > > isolate it in the HAL as a temporary (but in practice likely a long-term
> > > > > temporary) measure, as we have to support platforms that will take some
> > > > > time before a firmware (ACPI in this case) update can be deployed.
> > > > >
> > > > > This being said, we will introduce a configuration file for the
> > > > > libcamera core in the near future, and we also plan to use libyaml
> > > > > there. The tuning files for the IPU3 and RkISP1 IPA modules will also
> > > > > use YAML, and I'd like to move the Raspberry Pi tuning files from JSON
> > > > > to YAML for consistency.
> > > >
> > > > It's a good idea to have a single file format. Currently we have to
> > > > ship boost to run raspberrypi cameras on Android.
> > >
> > > I'm happy you agree :-)
> > >
> > > > > We could merge this patch in the meantime, but compilation on Android
> > > > > will likely break again soon. I wonder if we couldn't instead use a
> > > > > meson wrap to include libyaml as a subproject. This should solve the
> > > > > issue in the longer term.
> > > >
> > > > At this moment we have libyaml with extra Android.bp, which can
> > > > satisfy libcamera needs.
> > > > But I really like to see it as an optional dependency only to help
> > > > fine-tuning things or for ACPI-only platforms.
> > >
> > > Making it optional may cause difficulties in the future, with
> > > potentially lots of conditional compilation. I'd rather not go that way,
> > > unless we can wrap the yaml parser in a helper class with a dummy
> > > implementation to hide the missing dependency from everything else.
> > >
> > > I've quickly tested compiling libyaml as a subproject, and it seems to
> > > work:
> > >
> >
> > I have some doubts if such an approach supports cross-compilation.
> > Could meson generate a single ninja.build from all sub-projects?
> > Implementing the fallback stub sounds not so bad.
> >
> > >
> > > commit f1d86859f522c7728d8f854b82296673291750fb
> > > Author: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > > Date:   Wed Dec 29 12:07:35 2021 +0200
> > >
> > >     android: Compile libyaml as a subproject if not available on the system
> > >
> > >     AOSP doesn't ship libyaml, making it more difficult to compile libcamera
> > >     for Android. Use a meson wrap to compile libyaml as a subproject if the
> > >     dependency is not found.
> > >
> > >     Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > >
> > > diff --git a/src/android/meson.build b/src/android/meson.build
> > > index 75b4bf207085..1fa67746d058 100644
> > > --- a/src/android/meson.build
> > > +++ b/src/android/meson.build
> > > @@ -3,7 +3,6 @@
> > >  android_deps = [
> > >      dependency('libexif', required : get_option('android')),
> > >      dependency('libjpeg', required : get_option('android')),
> > > -    dependency('yaml-0.1', required : get_option('android')),
> > >      libcamera_private,
> > >  ]
> > >
> > > @@ -16,13 +15,35 @@ foreach dep : android_deps
> > >      endif
> > >  endforeach
> > >
> > > +cmake = import('cmake')
> > > +
> > > +#
> > > +# libyaml
> > > +#
> > > +# Default to the system version, and fallback to a subproject if not found, as
> > > +# libyaml is not packaged in AOSP.
> > > +#
> > > +libyaml_dep = dependency('yaml-0.1', required : false)
> > > +
> > > +# Fallback to a subproject if libyaml isn't found, as it's not packed in AOSP.
> > > +if not libyaml_dep.found()
> > > +    libyaml_vars = cmake.subproject_options()
> > > +    libyaml_vars.add_cmake_defines({'CMAKE_POSITION_INDEPENDENT_CODE': 'ON'})
> > > +    libyaml = cmake.subproject('libyaml', options : libyaml_vars)
> > > +    libyaml_dep = libyaml.dependency('yaml')
> > > +endif
> > > +
> > > +android_deps += [libyaml_dep]
> > > +
> > > +#
> > > +# libyuv
> > > +#
> > > +# Default to the system version, and fallback to a subproject if not found, as
> > > +# libyuv is typically not provided by distributions.
> > > +#
> > >  libyuv_dep = dependency('libyuv', required : false)
> > >
> > > -# Fallback to a subproject if libyuv isn't found, as it's typically not
> > > -# provided by distributions.
> > >  if not libyuv_dep.found()
> > > -    cmake = import('cmake')
> > > -
> > >      libyuv_vars = cmake.subproject_options()
> > >      libyuv_vars.add_cmake_defines({'CMAKE_POSITION_INDEPENDENT_CODE': 'ON'})
> > >      libyuv_vars.set_override_option('cpp_std', 'c++17')
> > > diff --git a/subprojects/.gitignore b/subprojects/.gitignore
> > > index 391fde2ce1e0..f207720b271a 100644
> > > --- a/subprojects/.gitignore
> > > +++ b/subprojects/.gitignore
> > > @@ -1,3 +1,4 @@
> > >  /googletest-release*
> > > +/libyaml
> > >  /libyuv
> > > -/packagecache
> > > \ No newline at end of file
> > > +/packagecache
> > > diff --git a/subprojects/libyaml.wrap b/subprojects/libyaml.wrap
> > > new file mode 100644
> > > index 000000000000..e4426e44774f
> > > --- /dev/null
> > > +++ b/subprojects/libyaml.wrap
> > > @@ -0,0 +1,4 @@
> > > +[wrap-git]
> > > +directory = libyaml
> > > +url = https://github.com/yaml/libyaml
> > > +revision = 2c891fc7a770e8ba2fec34fc6b545c672beb37e6
> > >
> > > > > By the way, out of curiosity, how do you compile libcamera for Android ?
> > > > > We have a look at Soong (as the Makefile-based build system is being
> > > > > phased out), but blueprint files don't support all our needs (and would
> > > > > be annoying to maintain manually), and there's no way we found to
> > > > > generate Android.bp files from meson in a way that would integrate with
> > > > > Soong. This is still an unsolved problem, and I'm increasingly tempted
> > > > > to do the same as mesa3d and just document that libcamera should be
> > > > > built outside of AOSP, using the NDK.
> > > >
> > > > We shipped libcamera in our GloDroid project v0.7.0 release for
> > > > raspberry pi about a month ago:
> > > > 1. https://github.com/GloDroid/glodroid_manifest/releases/tag/v0.7.0
> > > > 2. https://github.com/GloDroid/glodroid_forks/commits/libcamera-v0.7.0
> > > >
> > > > For building using meson within AOSP we are using some tricks to
> > > > extract dependencies from AOSP makesystem and inject them into
> > > > meson cross compilation file.
> > >
> > > Does this mean that you compile libcamera manually, separately from AOSP
> > > ? That's probably the best option for now, until Android decides to
> > > integrate support for other build systems (likely never...).
> >
> > No. Building within AOSP does mean building within AOSP.
> > Not manually.
> > It utilizes the Kati (Android.mk) build system.
> > And Kati is currently tightly bound to Soong, separating both would require some
> > time for Google if they decide to do so.
> > And we always have "building using NDK" as a fallback once it happens.
> >
> > >
> > > > First such kind of approach was integrated into mesa3d and replaced
> > > > existing Android.mk files (about 6 month ago).
> > > > It doesn't require continuous maintenance as previous Android.mk did
> > > > and has proven to be reliable.
> > > > It also enables FULL support of mesa3d for Android. Previously only
> > > > about 60% of mesa3d drivers were covered with Android.mk files.
> > > > Reworking the same approach for libcamera was pretty easy.
> > > >
> > > > And yes, as an official approach for vendors NDK builds would be great
> > > > to support.
> > > > NDK approach and our meson.build within AOSP approach are 98% aligned.
> > > >
> > > > > > > On Tue, Dec 28, 2021 at 11:51:53AM +0200, Roman Stratiienko wrote:
> > > > > > > > Mainline Android has no libyaml in-tree. Moreover camera_hal_config.cpp
> > > > > > > > uses std::filesystem class that is not permitted for AOSP VNDK vendor
> > > > > > > > libraries.
> > > > > > > >
> > > > > > > > External configuration file is no longer mandatory and DTS overlays can
> > > > > > > > be used to specify camera location and rotation.
> > > > > > > >
> > > > > > > > Do not require external configuration file for cases where meson.build
> > > > > > > > can't find libyaml. Assume that cameras without location specified
> > > > > > > > by V4L2 properties are always external.
> > > > > > > >
> > > > > > > > Signed-off-by: Roman Stratiienko <roman.o.stratiienko@globallogic.com>
> > > > > > > > ---
> > > > > > > >  src/android/camera_hal_manager.cpp | 13 +++++++++++++
> > > > > > > >  src/android/camera_hal_manager.h   |  2 ++
> > > > > > > >  src/android/meson.build            | 10 ++++++++--
> > > > > > > >  3 files changed, 23 insertions(+), 2 deletions(-)
> > > > > > > >
> > > > > > > > diff --git a/src/android/camera_hal_manager.cpp b/src/android/camera_hal_manager.cpp
> > > > > > > > index 5f7bfe265c71b..9e575bfa5204a 100644
> > > > > > > > --- a/src/android/camera_hal_manager.cpp
> > > > > > > > +++ b/src/android/camera_hal_manager.cpp
> > > > > > > > @@ -48,6 +48,7 @@ int CameraHalManager::init()
> > > > > > > >  {
> > > > > > > >       cameraManager_ = std::make_unique<CameraManager>();
> > > > > > > >
> > > > > > > > +#ifdef HAVE_LIBYAML
> > > > > > > >       /*
> > > > > > > >        * If the configuration file is not available the HAL only supports
> > > > > > > >        * external cameras. If it exists but it's not valid then error out.
> > > > > > > > @@ -56,6 +57,7 @@ int CameraHalManager::init()
> > > > > > > >               LOG(HAL, Error) << "HAL configuration file is not valid";
> > > > > > > >               return -EINVAL;
> > > > > > > >       }
> > > > > > > > +#endif
> > > > > > > >
> > > > > > > >       /* Support camera hotplug. */
> > > > > > > >       cameraManager_->cameraAdded.connect(this, &CameraHalManager::cameraAdded);
> > > > > > > > @@ -133,6 +135,7 @@ void CameraHalManager::cameraAdded(std::shared_ptr<Camera> cam)
> > > > > > > >               }
> > > > > > > >       }
> > > > > > > >
> > > > > > > > +#ifdef HAVE_LIBYAML
> > > > > > > >       /*
> > > > > > > >        * The configuration file must be valid, and contain a corresponding
> > > > > > > >        * entry for internal cameras. External cameras can be initialized
> > > > > > > > @@ -145,6 +148,16 @@ void CameraHalManager::cameraAdded(std::shared_ptr<Camera> cam)
> > > > > > > >       }
> > > > > > > >
> > > > > > > >       const CameraConfigData *cameraConfigData = halConfig_.cameraConfigData(cam->id());
> > > > > > > > +#else
> > > > > > > > +     /*
> > > > > > > > +      * Assume that cameras without properties::Location specified are external.
> > > > > > > > +      */
> > > > > > > > +     const CameraConfigData *cameraConfigData = nullptr;
> > > > > > > > +     if (!isCameraExternal && cameraLocation(cam.get()) < 0) {
> > > > > > > > +             isCameraExternal = true;
> > > > > > > > +             id = nextExternalCameraId_;
> > > > > > > > +     }
> > > > > > > > +#endif
> > > > > > > >
> > > > > > > >       /*
> > > > > > > >        * Some cameras whose location is reported by libcamera as external may
> > > > > > > > diff --git a/src/android/camera_hal_manager.h b/src/android/camera_hal_manager.h
> > > > > > > > index a5f8b933a7902..056abbb0d4e54 100644
> > > > > > > > --- a/src/android/camera_hal_manager.h
> > > > > > > > +++ b/src/android/camera_hal_manager.h
> > > > > > > > @@ -56,7 +56,9 @@ private:
> > > > > > > >       CameraDevice *cameraDeviceFromHalId(unsigned int id) LIBCAMERA_TSA_REQUIRES(mutex_);
> > > > > > > >
> > > > > > > >       std::unique_ptr<libcamera::CameraManager> cameraManager_;
> > > > > > > > +#ifdef HAVE_LIBYAML
> > > > > > > >       CameraHalConfig halConfig_;
> > > > > > > > +#endif
> > > > > > > >
> > > > > > > >       const camera_module_callbacks_t *callbacks_;
> > > > > > > >       std::vector<std::unique_ptr<CameraDevice>> cameras_ LIBCAMERA_TSA_GUARDED_BY(mutex_);
> > > > > > > > diff --git a/src/android/meson.build b/src/android/meson.build
> > > > > > > > index 75b4bf2070851..1e471c291a1e4 100644
> > > > > > > > --- a/src/android/meson.build
> > > > > > > > +++ b/src/android/meson.build
> > > > > > > > @@ -3,7 +3,6 @@
> > > > > > > >  android_deps = [
> > > > > > > >      dependency('libexif', required : get_option('android')),
> > > > > > > >      dependency('libjpeg', required : get_option('android')),
> > > > > > > > -    dependency('yaml-0.1', required : get_option('android')),
> > > > > > > >      libcamera_private,
> > > > > > > >  ]
> > > > > > > >
> > > > > > > > @@ -41,7 +40,6 @@ android_hal_sources = files([
> > > > > > > >      'camera3_hal.cpp',
> > > > > > > >      'camera_capabilities.cpp',
> > > > > > > >      'camera_device.cpp',
> > > > > > > > -    'camera_hal_config.cpp',
> > > > > > > >      'camera_hal_manager.cpp',
> > > > > > > >      'camera_metadata.cpp',
> > > > > > > >      'camera_ops.cpp',
> > > > > > > > @@ -56,6 +54,14 @@ android_hal_sources = files([
> > > > > > > >
> > > > > > > >  android_cpp_args = []
> > > > > > > >
> > > > > > > > +libyaml_dep = dependency('yaml-0.1', required : false)
> > > > > > > > +if libyaml_dep.found()
> > > > > > > > +    config_h.set('HAVE_LIBYAML', 1)
> > > > > > > > +    android_hal_sources += files([
> > > > > > > > +        'camera_hal_config.cpp',
> > > > > > > > +    ])
> > > > > > > > +endif
> > > > > > > > +
> > > > > > > >  subdir('cros')
> > > > > > > >  subdir('mm')
> > > > > > > >
Roman Stratiienko Dec. 29, 2021, 2:56 p.m. UTC | #10
ср, 29 дек. 2021 г. в 16:37, Laurent Pinchart
<laurent.pinchart@ideasonboard.com>:
>
> Hi Roman,
>
> On Wed, Dec 29, 2021 at 12:24:48PM +0200, Roman Stratiienko wrote:
> > ср, 29 дек. 2021 г. в 12:14, Laurent Pinchart:
> > > On Wed, Dec 29, 2021 at 11:45:17AM +0200, Roman Stratiienko wrote:
> > > > вт, 28 дек. 2021 г. в 20:27, Laurent Pinchart:
> > > > > On Tue, Dec 28, 2021 at 01:22:34PM +0200, Roman Stratiienko wrote:
> > > > > > вт, 28 дек. 2021 г., 13:04 Jacopo Mondi:
> > > > > > > Hi Roman,
> > > > > > >
> > > > > > > cc Hanlin Chen from ChromiumOS as he's planning to extend
> > > > > > > configuration file support for the ChromeOS Android HAL.
> > > > > >
> > > > > > > Before looking into the patch: is there any hope libyaml might become
> > > > > > > part of the standard AOSP distribution (or a process in place to request
> > > > > > > that)
> > > > > >
> > > > > > I am not aware of that, and I haven't initiated such a process. It will be
> > > > > > a very slow and bumpy road.
> > > > > >
> > > > > > Not sure what is planned for these properties in future, but now it is not
> > > > > > necessary to have it in libcamera to have fully functional hal. Also having
> > > > > > no configuration file available will encourage developers to add
> > > > > > corresponding records to dts, which is also a great thing to align with
> > > > > > linux world.
> > > > >
> > > > > Our goals align here. This is exactly why we have decided not to set the
> > > > > camera location in a configuration file for the libcamera core, but to
> > > > > isolate it in the HAL as a temporary (but in practice likely a long-term
> > > > > temporary) measure, as we have to support platforms that will take some
> > > > > time before a firmware (ACPI in this case) update can be deployed.
> > > > >
> > > > > This being said, we will introduce a configuration file for the
> > > > > libcamera core in the near future, and we also plan to use libyaml
> > > > > there. The tuning files for the IPU3 and RkISP1 IPA modules will also
> > > > > use YAML, and I'd like to move the Raspberry Pi tuning files from JSON
> > > > > to YAML for consistency.
> > > >
> > > > It's a good idea to have a single file format. Currently we have to
> > > > ship boost to run raspberrypi cameras on Android.
> > >
> > > I'm happy you agree :-)
> > >
> > > > > We could merge this patch in the meantime, but compilation on Android
> > > > > will likely break again soon. I wonder if we couldn't instead use a
> > > > > meson wrap to include libyaml as a subproject. This should solve the
> > > > > issue in the longer term.
> > > >
> > > > At this moment we have libyaml with extra Android.bp, which can
> > > > satisfy libcamera needs.
> > > > But I really like to see it as an optional dependency only to help
> > > > fine-tuning things or for ACPI-only platforms.
> > >
> > > Making it optional may cause difficulties in the future, with
> > > potentially lots of conditional compilation. I'd rather not go that way,
> > > unless we can wrap the yaml parser in a helper class with a dummy
> > > implementation to hide the missing dependency from everything else.
> > >
> > > I've quickly tested compiling libyaml as a subproject, and it seems to
> > > work:
> >
> > I have some doubts if such an approach supports cross-compilation.
> > Could meson generate a single ninja.build from all sub-projects?
> > Implementing the fallback stub sounds not so bad.
>
> With an additional
>
>         libyaml_vars.append_compile_args('c', '-Wno-unused-value')
>
> it cross-compiles fine for ARM64.

Thanks. I'll try that within AOSP.

> > > commit f1d86859f522c7728d8f854b82296673291750fb
> > > Author: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > > Date:   Wed Dec 29 12:07:35 2021 +0200
> > >
> > >     android: Compile libyaml as a subproject if not available on the system
> > >
> > >     AOSP doesn't ship libyaml, making it more difficult to compile libcamera
> > >     for Android. Use a meson wrap to compile libyaml as a subproject if the
> > >     dependency is not found.
> > >
> > >     Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > >
> > > diff --git a/src/android/meson.build b/src/android/meson.build
> > > index 75b4bf207085..1fa67746d058 100644
> > > --- a/src/android/meson.build
> > > +++ b/src/android/meson.build
> > > @@ -3,7 +3,6 @@
> > >  android_deps = [
> > >      dependency('libexif', required : get_option('android')),
> > >      dependency('libjpeg', required : get_option('android')),
> > > -    dependency('yaml-0.1', required : get_option('android')),
> > >      libcamera_private,
> > >  ]
> > >
> > > @@ -16,13 +15,35 @@ foreach dep : android_deps
> > >      endif
> > >  endforeach
> > >
> > > +cmake = import('cmake')
> > > +
> > > +#
> > > +# libyaml
> > > +#
> > > +# Default to the system version, and fallback to a subproject if not found, as
> > > +# libyaml is not packaged in AOSP.
> > > +#
> > > +libyaml_dep = dependency('yaml-0.1', required : false)
> > > +
> > > +# Fallback to a subproject if libyaml isn't found, as it's not packed in AOSP.
> > > +if not libyaml_dep.found()
> > > +    libyaml_vars = cmake.subproject_options()
> > > +    libyaml_vars.add_cmake_defines({'CMAKE_POSITION_INDEPENDENT_CODE': 'ON'})
> > > +    libyaml = cmake.subproject('libyaml', options : libyaml_vars)
> > > +    libyaml_dep = libyaml.dependency('yaml')
> > > +endif
> > > +
> > > +android_deps += [libyaml_dep]
> > > +
> > > +#
> > > +# libyuv
> > > +#
> > > +# Default to the system version, and fallback to a subproject if not found, as
> > > +# libyuv is typically not provided by distributions.
> > > +#
> > >  libyuv_dep = dependency('libyuv', required : false)
> > >
> > > -# Fallback to a subproject if libyuv isn't found, as it's typically not
> > > -# provided by distributions.
> > >  if not libyuv_dep.found()
> > > -    cmake = import('cmake')
> > > -
> > >      libyuv_vars = cmake.subproject_options()
> > >      libyuv_vars.add_cmake_defines({'CMAKE_POSITION_INDEPENDENT_CODE': 'ON'})
> > >      libyuv_vars.set_override_option('cpp_std', 'c++17')
> > > diff --git a/subprojects/.gitignore b/subprojects/.gitignore
> > > index 391fde2ce1e0..f207720b271a 100644
> > > --- a/subprojects/.gitignore
> > > +++ b/subprojects/.gitignore
> > > @@ -1,3 +1,4 @@
> > >  /googletest-release*
> > > +/libyaml
> > >  /libyuv
> > > -/packagecache
> > > \ No newline at end of file
> > > +/packagecache
> > > diff --git a/subprojects/libyaml.wrap b/subprojects/libyaml.wrap
> > > new file mode 100644
> > > index 000000000000..e4426e44774f
> > > --- /dev/null
> > > +++ b/subprojects/libyaml.wrap
> > > @@ -0,0 +1,4 @@
> > > +[wrap-git]
> > > +directory = libyaml
> > > +url = https://github.com/yaml/libyaml
> > > +revision = 2c891fc7a770e8ba2fec34fc6b545c672beb37e6
> > >
> > > > > By the way, out of curiosity, how do you compile libcamera for Android ?
> > > > > We have a look at Soong (as the Makefile-based build system is being
> > > > > phased out), but blueprint files don't support all our needs (and would
> > > > > be annoying to maintain manually), and there's no way we found to
> > > > > generate Android.bp files from meson in a way that would integrate with
> > > > > Soong. This is still an unsolved problem, and I'm increasingly tempted
> > > > > to do the same as mesa3d and just document that libcamera should be
> > > > > built outside of AOSP, using the NDK.
> > > >
> > > > We shipped libcamera in our GloDroid project v0.7.0 release for
> > > > raspberry pi about a month ago:
> > > > 1. https://github.com/GloDroid/glodroid_manifest/releases/tag/v0.7.0
> > > > 2. https://github.com/GloDroid/glodroid_forks/commits/libcamera-v0.7.0
> > > >
> > > > For building using meson within AOSP we are using some tricks to
> > > > extract dependencies from AOSP makesystem and inject them into
> > > > meson cross compilation file.
> > >
> > > Does this mean that you compile libcamera manually, separately from AOSP
> > > ? That's probably the best option for now, until Android decides to
> > > integrate support for other build systems (likely never...).
> >
> > No. Building within AOSP does mean building within AOSP.
> > Not manually.
> > It utilizes the Kati (Android.mk) build system.
> > And Kati is currently tightly bound to Soong, separating both would require some
> > time for Google if they decide to do so.
> > And we always have "building using NDK" as a fallback once it happens.
>
> I thought they had mostly finished the conversion to Soong, but I could
> be wrong. I remember finding a page that listed the timeline and what
> types of packages were still allowed to use Android.mk at different
> points in the transition, but I can't locate that anymore.
>
> Could you point me to the sources that show how you built libcamera ?

1. See link above for libcamera tree with downtree patches.
2. https://github.com/GloDroid/glodroid_device/commit/5c258a304994e69e7257341e889953f1e728126b
3. https://github.com/GloDroid/glodroid_device/commit/be6ba9a457c28a70f1307c69639a7caeecad0b22


> And if it wasn't "fun" enough, they're moving away from Soong to Bazel
> (https://android.googlesource.com/platform/build/bazel/+/refs/heads/master/docs/concepts.md).
>
> > > > First such kind of approach was integrated into mesa3d and replaced
> > > > existing Android.mk files (about 6 month ago).
> > > > It doesn't require continuous maintenance as previous Android.mk did
> > > > and has proven to be reliable.
> > > > It also enables FULL support of mesa3d for Android. Previously only
> > > > about 60% of mesa3d drivers were covered with Android.mk files.
> > > > Reworking the same approach for libcamera was pretty easy.
> > > >
> > > > And yes, as an official approach for vendors NDK builds would be great
> > > > to support.
> > > > NDK approach and our meson.build within AOSP approach are 98% aligned.
> > > >
> > > > > > > On Tue, Dec 28, 2021 at 11:51:53AM +0200, Roman Stratiienko wrote:
> > > > > > > > Mainline Android has no libyaml in-tree. Moreover camera_hal_config.cpp
> > > > > > > > uses std::filesystem class that is not permitted for AOSP VNDK vendor
> > > > > > > > libraries.
> > > > > > > >
> > > > > > > > External configuration file is no longer mandatory and DTS overlays can
> > > > > > > > be used to specify camera location and rotation.
> > > > > > > >
> > > > > > > > Do not require external configuration file for cases where meson.build
> > > > > > > > can't find libyaml. Assume that cameras without location specified
> > > > > > > > by V4L2 properties are always external.
> > > > > > > >
> > > > > > > > Signed-off-by: Roman Stratiienko <roman.o.stratiienko@globallogic.com>
> > > > > > > > ---
> > > > > > > >  src/android/camera_hal_manager.cpp | 13 +++++++++++++
> > > > > > > >  src/android/camera_hal_manager.h   |  2 ++
> > > > > > > >  src/android/meson.build            | 10 ++++++++--
> > > > > > > >  3 files changed, 23 insertions(+), 2 deletions(-)
> > > > > > > >
> > > > > > > > diff --git a/src/android/camera_hal_manager.cpp b/src/android/camera_hal_manager.cpp
> > > > > > > > index 5f7bfe265c71b..9e575bfa5204a 100644
> > > > > > > > --- a/src/android/camera_hal_manager.cpp
> > > > > > > > +++ b/src/android/camera_hal_manager.cpp
> > > > > > > > @@ -48,6 +48,7 @@ int CameraHalManager::init()
> > > > > > > >  {
> > > > > > > >       cameraManager_ = std::make_unique<CameraManager>();
> > > > > > > >
> > > > > > > > +#ifdef HAVE_LIBYAML
> > > > > > > >       /*
> > > > > > > >        * If the configuration file is not available the HAL only supports
> > > > > > > >        * external cameras. If it exists but it's not valid then error out.
> > > > > > > > @@ -56,6 +57,7 @@ int CameraHalManager::init()
> > > > > > > >               LOG(HAL, Error) << "HAL configuration file is not valid";
> > > > > > > >               return -EINVAL;
> > > > > > > >       }
> > > > > > > > +#endif
> > > > > > > >
> > > > > > > >       /* Support camera hotplug. */
> > > > > > > >       cameraManager_->cameraAdded.connect(this, &CameraHalManager::cameraAdded);
> > > > > > > > @@ -133,6 +135,7 @@ void CameraHalManager::cameraAdded(std::shared_ptr<Camera> cam)
> > > > > > > >               }
> > > > > > > >       }
> > > > > > > >
> > > > > > > > +#ifdef HAVE_LIBYAML
> > > > > > > >       /*
> > > > > > > >        * The configuration file must be valid, and contain a corresponding
> > > > > > > >        * entry for internal cameras. External cameras can be initialized
> > > > > > > > @@ -145,6 +148,16 @@ void CameraHalManager::cameraAdded(std::shared_ptr<Camera> cam)
> > > > > > > >       }
> > > > > > > >
> > > > > > > >       const CameraConfigData *cameraConfigData = halConfig_.cameraConfigData(cam->id());
> > > > > > > > +#else
> > > > > > > > +     /*
> > > > > > > > +      * Assume that cameras without properties::Location specified are external.
> > > > > > > > +      */
> > > > > > > > +     const CameraConfigData *cameraConfigData = nullptr;
> > > > > > > > +     if (!isCameraExternal && cameraLocation(cam.get()) < 0) {
> > > > > > > > +             isCameraExternal = true;
> > > > > > > > +             id = nextExternalCameraId_;
> > > > > > > > +     }
> > > > > > > > +#endif
> > > > > > > >
> > > > > > > >       /*
> > > > > > > >        * Some cameras whose location is reported by libcamera as external may
> > > > > > > > diff --git a/src/android/camera_hal_manager.h b/src/android/camera_hal_manager.h
> > > > > > > > index a5f8b933a7902..056abbb0d4e54 100644
> > > > > > > > --- a/src/android/camera_hal_manager.h
> > > > > > > > +++ b/src/android/camera_hal_manager.h
> > > > > > > > @@ -56,7 +56,9 @@ private:
> > > > > > > >       CameraDevice *cameraDeviceFromHalId(unsigned int id) LIBCAMERA_TSA_REQUIRES(mutex_);
> > > > > > > >
> > > > > > > >       std::unique_ptr<libcamera::CameraManager> cameraManager_;
> > > > > > > > +#ifdef HAVE_LIBYAML
> > > > > > > >       CameraHalConfig halConfig_;
> > > > > > > > +#endif
> > > > > > > >
> > > > > > > >       const camera_module_callbacks_t *callbacks_;
> > > > > > > >       std::vector<std::unique_ptr<CameraDevice>> cameras_ LIBCAMERA_TSA_GUARDED_BY(mutex_);
> > > > > > > > diff --git a/src/android/meson.build b/src/android/meson.build
> > > > > > > > index 75b4bf2070851..1e471c291a1e4 100644
> > > > > > > > --- a/src/android/meson.build
> > > > > > > > +++ b/src/android/meson.build
> > > > > > > > @@ -3,7 +3,6 @@
> > > > > > > >  android_deps = [
> > > > > > > >      dependency('libexif', required : get_option('android')),
> > > > > > > >      dependency('libjpeg', required : get_option('android')),
> > > > > > > > -    dependency('yaml-0.1', required : get_option('android')),
> > > > > > > >      libcamera_private,
> > > > > > > >  ]
> > > > > > > >
> > > > > > > > @@ -41,7 +40,6 @@ android_hal_sources = files([
> > > > > > > >      'camera3_hal.cpp',
> > > > > > > >      'camera_capabilities.cpp',
> > > > > > > >      'camera_device.cpp',
> > > > > > > > -    'camera_hal_config.cpp',
> > > > > > > >      'camera_hal_manager.cpp',
> > > > > > > >      'camera_metadata.cpp',
> > > > > > > >      'camera_ops.cpp',
> > > > > > > > @@ -56,6 +54,14 @@ android_hal_sources = files([
> > > > > > > >
> > > > > > > >  android_cpp_args = []
> > > > > > > >
> > > > > > > > +libyaml_dep = dependency('yaml-0.1', required : false)
> > > > > > > > +if libyaml_dep.found()
> > > > > > > > +    config_h.set('HAVE_LIBYAML', 1)
> > > > > > > > +    android_hal_sources += files([
> > > > > > > > +        'camera_hal_config.cpp',
> > > > > > > > +    ])
> > > > > > > > +endif
> > > > > > > > +
> > > > > > > >  subdir('cros')
> > > > > > > >  subdir('mm')
> > > > > > > >
>
> --
> Regards,
>
> Laurent Pinchart
Roman Stratiienko Dec. 29, 2021, 3:43 p.m. UTC | #11
ср, 29 дек. 2021 г. в 16:40, Laurent Pinchart
<laurent.pinchart@ideasonboard.com>:
>
> Hi Roman,
>
> On Wed, Dec 29, 2021 at 02:17:03PM +0200, Roman Stratiienko wrote:
> > +CC: John Stultz
> >
> > Laurent,
> >
> > I would like to make mainline libcamera work on mainline android
> > without additional patches / extra packages and then give it to John
> > Stultz for testing with AOSP devboards in this shape.
> > Unlike mesa3d libcamera doesn't have a lot of generated code,
> > therefore shipping this code / creating Android.bp is less painful.
>
> How do you envision this being done ? We don't want to commit generated
> sources to the libcamera git repository. Please note that one of the
> source files generated during build contains a randomly generated
> private key which is thrown away at the end of the build. Committing a
> private key to a source tree will not be a very good idea :-)

For a couple of years, mesa3d was maintained within AOSP in the following way:

1. Build mesa3d using NDK
2. Copy all auto-generated sources from build/ directory into
./prebuilt directory inside sources
3. Create Android.bp , which includes sources, prebuilt sources,
definitions used to build the sources by NDK.
4. Push that into the AOSP's mesa3d/master branch.
5. Upstream tracking branch lives at mesa3d/upstream-master without
any modifications.

These 5 steps are a little simplified version, but overall it was like that.

Of course that was not easy to maintain and delays between upgrading
the mesa3d version in AOSP were too big (years).

Personally I do not like this scenario, since it wastes a lot of
engineering time. But do not see many other options at this moment for
mainline AOSP.

>
> > In case this tricky plan will succeed and we will have libcamera
> > inside AOSP, then rationale for adding libyaml into AOSP would be much
> > easier to formulate.
> >
> > ср, 29 дек. 2021 г. в 12:24, Roman Stratiienko:
> > > ср, 29 дек. 2021 г. в 12:14, Laurent Pinchart:
> > > > On Wed, Dec 29, 2021 at 11:45:17AM +0200, Roman Stratiienko wrote:
> > > > > вт, 28 дек. 2021 г. в 20:27, Laurent Pinchart:
> > > > > > On Tue, Dec 28, 2021 at 01:22:34PM +0200, Roman Stratiienko wrote:
> > > > > > > вт, 28 дек. 2021 г., 13:04 Jacopo Mondi:
> > > > > > > > Hi Roman,
> > > > > > > >
> > > > > > > > cc Hanlin Chen from ChromiumOS as he's planning to extend
> > > > > > > > configuration file support for the ChromeOS Android HAL.
> > > > > > >
> > > > > > > > Before looking into the patch: is there any hope libyaml might become
> > > > > > > > part of the standard AOSP distribution (or a process in place to request
> > > > > > > > that)
> > > > > > >
> > > > > > > I am not aware of that, and I haven't initiated such a process. It will be
> > > > > > > a very slow and bumpy road.
> > > > > > >
> > > > > > > Not sure what is planned for these properties in future, but now it is not
> > > > > > > necessary to have it in libcamera to have fully functional hal. Also having
> > > > > > > no configuration file available will encourage developers to add
> > > > > > > corresponding records to dts, which is also a great thing to align with
> > > > > > > linux world.
> > > > > >
> > > > > > Our goals align here. This is exactly why we have decided not to set the
> > > > > > camera location in a configuration file for the libcamera core, but to
> > > > > > isolate it in the HAL as a temporary (but in practice likely a long-term
> > > > > > temporary) measure, as we have to support platforms that will take some
> > > > > > time before a firmware (ACPI in this case) update can be deployed.
> > > > > >
> > > > > > This being said, we will introduce a configuration file for the
> > > > > > libcamera core in the near future, and we also plan to use libyaml
> > > > > > there. The tuning files for the IPU3 and RkISP1 IPA modules will also
> > > > > > use YAML, and I'd like to move the Raspberry Pi tuning files from JSON
> > > > > > to YAML for consistency.
> > > > >
> > > > > It's a good idea to have a single file format. Currently we have to
> > > > > ship boost to run raspberrypi cameras on Android.
> > > >
> > > > I'm happy you agree :-)
> > > >
> > > > > > We could merge this patch in the meantime, but compilation on Android
> > > > > > will likely break again soon. I wonder if we couldn't instead use a
> > > > > > meson wrap to include libyaml as a subproject. This should solve the
> > > > > > issue in the longer term.
> > > > >
> > > > > At this moment we have libyaml with extra Android.bp, which can
> > > > > satisfy libcamera needs.
> > > > > But I really like to see it as an optional dependency only to help
> > > > > fine-tuning things or for ACPI-only platforms.
> > > >
> > > > Making it optional may cause difficulties in the future, with
> > > > potentially lots of conditional compilation. I'd rather not go that way,
> > > > unless we can wrap the yaml parser in a helper class with a dummy
> > > > implementation to hide the missing dependency from everything else.
> > > >
> > > > I've quickly tested compiling libyaml as a subproject, and it seems to
> > > > work:
> > > >
> > >
> > > I have some doubts if such an approach supports cross-compilation.
> > > Could meson generate a single ninja.build from all sub-projects?
> > > Implementing the fallback stub sounds not so bad.
> > >
> > > >
> > > > commit f1d86859f522c7728d8f854b82296673291750fb
> > > > Author: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > > > Date:   Wed Dec 29 12:07:35 2021 +0200
> > > >
> > > >     android: Compile libyaml as a subproject if not available on the system
> > > >
> > > >     AOSP doesn't ship libyaml, making it more difficult to compile libcamera
> > > >     for Android. Use a meson wrap to compile libyaml as a subproject if the
> > > >     dependency is not found.
> > > >
> > > >     Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > > >
> > > > diff --git a/src/android/meson.build b/src/android/meson.build
> > > > index 75b4bf207085..1fa67746d058 100644
> > > > --- a/src/android/meson.build
> > > > +++ b/src/android/meson.build
> > > > @@ -3,7 +3,6 @@
> > > >  android_deps = [
> > > >      dependency('libexif', required : get_option('android')),
> > > >      dependency('libjpeg', required : get_option('android')),
> > > > -    dependency('yaml-0.1', required : get_option('android')),
> > > >      libcamera_private,
> > > >  ]
> > > >
> > > > @@ -16,13 +15,35 @@ foreach dep : android_deps
> > > >      endif
> > > >  endforeach
> > > >
> > > > +cmake = import('cmake')
> > > > +
> > > > +#
> > > > +# libyaml
> > > > +#
> > > > +# Default to the system version, and fallback to a subproject if not found, as
> > > > +# libyaml is not packaged in AOSP.
> > > > +#
> > > > +libyaml_dep = dependency('yaml-0.1', required : false)
> > > > +
> > > > +# Fallback to a subproject if libyaml isn't found, as it's not packed in AOSP.
> > > > +if not libyaml_dep.found()
> > > > +    libyaml_vars = cmake.subproject_options()
> > > > +    libyaml_vars.add_cmake_defines({'CMAKE_POSITION_INDEPENDENT_CODE': 'ON'})
> > > > +    libyaml = cmake.subproject('libyaml', options : libyaml_vars)
> > > > +    libyaml_dep = libyaml.dependency('yaml')
> > > > +endif
> > > > +
> > > > +android_deps += [libyaml_dep]
> > > > +
> > > > +#
> > > > +# libyuv
> > > > +#
> > > > +# Default to the system version, and fallback to a subproject if not found, as
> > > > +# libyuv is typically not provided by distributions.
> > > > +#
> > > >  libyuv_dep = dependency('libyuv', required : false)
> > > >
> > > > -# Fallback to a subproject if libyuv isn't found, as it's typically not
> > > > -# provided by distributions.
> > > >  if not libyuv_dep.found()
> > > > -    cmake = import('cmake')
> > > > -
> > > >      libyuv_vars = cmake.subproject_options()
> > > >      libyuv_vars.add_cmake_defines({'CMAKE_POSITION_INDEPENDENT_CODE': 'ON'})
> > > >      libyuv_vars.set_override_option('cpp_std', 'c++17')
> > > > diff --git a/subprojects/.gitignore b/subprojects/.gitignore
> > > > index 391fde2ce1e0..f207720b271a 100644
> > > > --- a/subprojects/.gitignore
> > > > +++ b/subprojects/.gitignore
> > > > @@ -1,3 +1,4 @@
> > > >  /googletest-release*
> > > > +/libyaml
> > > >  /libyuv
> > > > -/packagecache
> > > > \ No newline at end of file
> > > > +/packagecache
> > > > diff --git a/subprojects/libyaml.wrap b/subprojects/libyaml.wrap
> > > > new file mode 100644
> > > > index 000000000000..e4426e44774f
> > > > --- /dev/null
> > > > +++ b/subprojects/libyaml.wrap
> > > > @@ -0,0 +1,4 @@
> > > > +[wrap-git]
> > > > +directory = libyaml
> > > > +url = https://github.com/yaml/libyaml
> > > > +revision = 2c891fc7a770e8ba2fec34fc6b545c672beb37e6
> > > >
> > > > > > By the way, out of curiosity, how do you compile libcamera for Android ?
> > > > > > We have a look at Soong (as the Makefile-based build system is being
> > > > > > phased out), but blueprint files don't support all our needs (and would
> > > > > > be annoying to maintain manually), and there's no way we found to
> > > > > > generate Android.bp files from meson in a way that would integrate with
> > > > > > Soong. This is still an unsolved problem, and I'm increasingly tempted
> > > > > > to do the same as mesa3d and just document that libcamera should be
> > > > > > built outside of AOSP, using the NDK.
> > > > >
> > > > > We shipped libcamera in our GloDroid project v0.7.0 release for
> > > > > raspberry pi about a month ago:
> > > > > 1. https://github.com/GloDroid/glodroid_manifest/releases/tag/v0.7.0
> > > > > 2. https://github.com/GloDroid/glodroid_forks/commits/libcamera-v0.7.0
> > > > >
> > > > > For building using meson within AOSP we are using some tricks to
> > > > > extract dependencies from AOSP makesystem and inject them into
> > > > > meson cross compilation file.
> > > >
> > > > Does this mean that you compile libcamera manually, separately from AOSP
> > > > ? That's probably the best option for now, until Android decides to
> > > > integrate support for other build systems (likely never...).
> > >
> > > No. Building within AOSP does mean building within AOSP.
> > > Not manually.
> > > It utilizes the Kati (Android.mk) build system.
> > > And Kati is currently tightly bound to Soong, separating both would require some
> > > time for Google if they decide to do so.
> > > And we always have "building using NDK" as a fallback once it happens.
> > >
> > > >
> > > > > First such kind of approach was integrated into mesa3d and replaced
> > > > > existing Android.mk files (about 6 month ago).
> > > > > It doesn't require continuous maintenance as previous Android.mk did
> > > > > and has proven to be reliable.
> > > > > It also enables FULL support of mesa3d for Android. Previously only
> > > > > about 60% of mesa3d drivers were covered with Android.mk files.
> > > > > Reworking the same approach for libcamera was pretty easy.
> > > > >
> > > > > And yes, as an official approach for vendors NDK builds would be great
> > > > > to support.
> > > > > NDK approach and our meson.build within AOSP approach are 98% aligned.
> > > > >
> > > > > > > > On Tue, Dec 28, 2021 at 11:51:53AM +0200, Roman Stratiienko wrote:
> > > > > > > > > Mainline Android has no libyaml in-tree. Moreover camera_hal_config.cpp
> > > > > > > > > uses std::filesystem class that is not permitted for AOSP VNDK vendor
> > > > > > > > > libraries.
> > > > > > > > >
> > > > > > > > > External configuration file is no longer mandatory and DTS overlays can
> > > > > > > > > be used to specify camera location and rotation.
> > > > > > > > >
> > > > > > > > > Do not require external configuration file for cases where meson.build
> > > > > > > > > can't find libyaml. Assume that cameras without location specified
> > > > > > > > > by V4L2 properties are always external.
> > > > > > > > >
> > > > > > > > > Signed-off-by: Roman Stratiienko <roman.o.stratiienko@globallogic.com>
> > > > > > > > > ---
> > > > > > > > >  src/android/camera_hal_manager.cpp | 13 +++++++++++++
> > > > > > > > >  src/android/camera_hal_manager.h   |  2 ++
> > > > > > > > >  src/android/meson.build            | 10 ++++++++--
> > > > > > > > >  3 files changed, 23 insertions(+), 2 deletions(-)
> > > > > > > > >
> > > > > > > > > diff --git a/src/android/camera_hal_manager.cpp b/src/android/camera_hal_manager.cpp
> > > > > > > > > index 5f7bfe265c71b..9e575bfa5204a 100644
> > > > > > > > > --- a/src/android/camera_hal_manager.cpp
> > > > > > > > > +++ b/src/android/camera_hal_manager.cpp
> > > > > > > > > @@ -48,6 +48,7 @@ int CameraHalManager::init()
> > > > > > > > >  {
> > > > > > > > >       cameraManager_ = std::make_unique<CameraManager>();
> > > > > > > > >
> > > > > > > > > +#ifdef HAVE_LIBYAML
> > > > > > > > >       /*
> > > > > > > > >        * If the configuration file is not available the HAL only supports
> > > > > > > > >        * external cameras. If it exists but it's not valid then error out.
> > > > > > > > > @@ -56,6 +57,7 @@ int CameraHalManager::init()
> > > > > > > > >               LOG(HAL, Error) << "HAL configuration file is not valid";
> > > > > > > > >               return -EINVAL;
> > > > > > > > >       }
> > > > > > > > > +#endif
> > > > > > > > >
> > > > > > > > >       /* Support camera hotplug. */
> > > > > > > > >       cameraManager_->cameraAdded.connect(this, &CameraHalManager::cameraAdded);
> > > > > > > > > @@ -133,6 +135,7 @@ void CameraHalManager::cameraAdded(std::shared_ptr<Camera> cam)
> > > > > > > > >               }
> > > > > > > > >       }
> > > > > > > > >
> > > > > > > > > +#ifdef HAVE_LIBYAML
> > > > > > > > >       /*
> > > > > > > > >        * The configuration file must be valid, and contain a corresponding
> > > > > > > > >        * entry for internal cameras. External cameras can be initialized
> > > > > > > > > @@ -145,6 +148,16 @@ void CameraHalManager::cameraAdded(std::shared_ptr<Camera> cam)
> > > > > > > > >       }
> > > > > > > > >
> > > > > > > > >       const CameraConfigData *cameraConfigData = halConfig_.cameraConfigData(cam->id());
> > > > > > > > > +#else
> > > > > > > > > +     /*
> > > > > > > > > +      * Assume that cameras without properties::Location specified are external.
> > > > > > > > > +      */
> > > > > > > > > +     const CameraConfigData *cameraConfigData = nullptr;
> > > > > > > > > +     if (!isCameraExternal && cameraLocation(cam.get()) < 0) {
> > > > > > > > > +             isCameraExternal = true;
> > > > > > > > > +             id = nextExternalCameraId_;
> > > > > > > > > +     }
> > > > > > > > > +#endif
> > > > > > > > >
> > > > > > > > >       /*
> > > > > > > > >        * Some cameras whose location is reported by libcamera as external may
> > > > > > > > > diff --git a/src/android/camera_hal_manager.h b/src/android/camera_hal_manager.h
> > > > > > > > > index a5f8b933a7902..056abbb0d4e54 100644
> > > > > > > > > --- a/src/android/camera_hal_manager.h
> > > > > > > > > +++ b/src/android/camera_hal_manager.h
> > > > > > > > > @@ -56,7 +56,9 @@ private:
> > > > > > > > >       CameraDevice *cameraDeviceFromHalId(unsigned int id) LIBCAMERA_TSA_REQUIRES(mutex_);
> > > > > > > > >
> > > > > > > > >       std::unique_ptr<libcamera::CameraManager> cameraManager_;
> > > > > > > > > +#ifdef HAVE_LIBYAML
> > > > > > > > >       CameraHalConfig halConfig_;
> > > > > > > > > +#endif
> > > > > > > > >
> > > > > > > > >       const camera_module_callbacks_t *callbacks_;
> > > > > > > > >       std::vector<std::unique_ptr<CameraDevice>> cameras_ LIBCAMERA_TSA_GUARDED_BY(mutex_);
> > > > > > > > > diff --git a/src/android/meson.build b/src/android/meson.build
> > > > > > > > > index 75b4bf2070851..1e471c291a1e4 100644
> > > > > > > > > --- a/src/android/meson.build
> > > > > > > > > +++ b/src/android/meson.build
> > > > > > > > > @@ -3,7 +3,6 @@
> > > > > > > > >  android_deps = [
> > > > > > > > >      dependency('libexif', required : get_option('android')),
> > > > > > > > >      dependency('libjpeg', required : get_option('android')),
> > > > > > > > > -    dependency('yaml-0.1', required : get_option('android')),
> > > > > > > > >      libcamera_private,
> > > > > > > > >  ]
> > > > > > > > >
> > > > > > > > > @@ -41,7 +40,6 @@ android_hal_sources = files([
> > > > > > > > >      'camera3_hal.cpp',
> > > > > > > > >      'camera_capabilities.cpp',
> > > > > > > > >      'camera_device.cpp',
> > > > > > > > > -    'camera_hal_config.cpp',
> > > > > > > > >      'camera_hal_manager.cpp',
> > > > > > > > >      'camera_metadata.cpp',
> > > > > > > > >      'camera_ops.cpp',
> > > > > > > > > @@ -56,6 +54,14 @@ android_hal_sources = files([
> > > > > > > > >
> > > > > > > > >  android_cpp_args = []
> > > > > > > > >
> > > > > > > > > +libyaml_dep = dependency('yaml-0.1', required : false)
> > > > > > > > > +if libyaml_dep.found()
> > > > > > > > > +    config_h.set('HAVE_LIBYAML', 1)
> > > > > > > > > +    android_hal_sources += files([
> > > > > > > > > +        'camera_hal_config.cpp',
> > > > > > > > > +    ])
> > > > > > > > > +endif
> > > > > > > > > +
> > > > > > > > >  subdir('cros')
> > > > > > > > >  subdir('mm')
> > > > > > > > >
>
> --
> Regards,
>
> Laurent Pinchart

Patch
diff mbox series

diff --git a/src/android/camera_hal_manager.cpp b/src/android/camera_hal_manager.cpp
index 5f7bfe265c71b..9e575bfa5204a 100644
--- a/src/android/camera_hal_manager.cpp
+++ b/src/android/camera_hal_manager.cpp
@@ -48,6 +48,7 @@  int CameraHalManager::init()
 {
 	cameraManager_ = std::make_unique<CameraManager>();
 
+#ifdef HAVE_LIBYAML
 	/*
 	 * If the configuration file is not available the HAL only supports
 	 * external cameras. If it exists but it's not valid then error out.
@@ -56,6 +57,7 @@  int CameraHalManager::init()
 		LOG(HAL, Error) << "HAL configuration file is not valid";
 		return -EINVAL;
 	}
+#endif
 
 	/* Support camera hotplug. */
 	cameraManager_->cameraAdded.connect(this, &CameraHalManager::cameraAdded);
@@ -133,6 +135,7 @@  void CameraHalManager::cameraAdded(std::shared_ptr<Camera> cam)
 		}
 	}
 
+#ifdef HAVE_LIBYAML
 	/*
 	 * The configuration file must be valid, and contain a corresponding
 	 * entry for internal cameras. External cameras can be initialized
@@ -145,6 +148,16 @@  void CameraHalManager::cameraAdded(std::shared_ptr<Camera> cam)
 	}
 
 	const CameraConfigData *cameraConfigData = halConfig_.cameraConfigData(cam->id());
+#else
+	/*
+	 * Assume that cameras without properties::Location specified are external.
+	 */
+	const CameraConfigData *cameraConfigData = nullptr;
+	if (!isCameraExternal && cameraLocation(cam.get()) < 0) {
+		isCameraExternal = true;
+		id = nextExternalCameraId_;
+	}
+#endif
 
 	/*
 	 * Some cameras whose location is reported by libcamera as external may
diff --git a/src/android/camera_hal_manager.h b/src/android/camera_hal_manager.h
index a5f8b933a7902..056abbb0d4e54 100644
--- a/src/android/camera_hal_manager.h
+++ b/src/android/camera_hal_manager.h
@@ -56,7 +56,9 @@  private:
 	CameraDevice *cameraDeviceFromHalId(unsigned int id) LIBCAMERA_TSA_REQUIRES(mutex_);
 
 	std::unique_ptr<libcamera::CameraManager> cameraManager_;
+#ifdef HAVE_LIBYAML
 	CameraHalConfig halConfig_;
+#endif
 
 	const camera_module_callbacks_t *callbacks_;
 	std::vector<std::unique_ptr<CameraDevice>> cameras_ LIBCAMERA_TSA_GUARDED_BY(mutex_);
diff --git a/src/android/meson.build b/src/android/meson.build
index 75b4bf2070851..1e471c291a1e4 100644
--- a/src/android/meson.build
+++ b/src/android/meson.build
@@ -3,7 +3,6 @@ 
 android_deps = [
     dependency('libexif', required : get_option('android')),
     dependency('libjpeg', required : get_option('android')),
-    dependency('yaml-0.1', required : get_option('android')),
     libcamera_private,
 ]
 
@@ -41,7 +40,6 @@  android_hal_sources = files([
     'camera3_hal.cpp',
     'camera_capabilities.cpp',
     'camera_device.cpp',
-    'camera_hal_config.cpp',
     'camera_hal_manager.cpp',
     'camera_metadata.cpp',
     'camera_ops.cpp',
@@ -56,6 +54,14 @@  android_hal_sources = files([
 
 android_cpp_args = []
 
+libyaml_dep = dependency('yaml-0.1', required : false)
+if libyaml_dep.found()
+    config_h.set('HAVE_LIBYAML', 1)
+    android_hal_sources += files([
+        'camera_hal_config.cpp',
+    ])
+endif
+
 subdir('cros')
 subdir('mm')