| Message ID | 20190127002208.18913-2-niklas.soderlund@ragnatech.se |
|---|---|
| State | Superseded |
| Headers | show |
| Series |
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| Related | show |
Hi Niklas, Thank you for the patch. On Sun, Jan 27, 2019 at 01:22:03AM +0100, Niklas Söderlund wrote: > Add an initial Stream implementation. The idea is that once capability > support is added to the library each stream will describe its > capabilities using this class. An application will then select one or > more streams based on these capabilities and use them to configure the > camera and capture. > > At this stage all the Stream class provides is a way for a Camera object > to communicate which streams it provides. > > Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se> > --- > include/libcamera/libcamera.h | 1 + > include/libcamera/meson.build | 1 + > include/libcamera/stream.h | 25 +++++++++++++ > src/libcamera/meson.build | 1 + > src/libcamera/stream.cpp | 67 +++++++++++++++++++++++++++++++++++ > 5 files changed, 95 insertions(+) > create mode 100644 include/libcamera/stream.h > create mode 100644 src/libcamera/stream.cpp > > diff --git a/include/libcamera/libcamera.h b/include/libcamera/libcamera.h > index c0511cf6d662b63f..272dfd5e4a67d5de 100644 > --- a/include/libcamera/libcamera.h > +++ b/include/libcamera/libcamera.h > @@ -12,6 +12,7 @@ > #include <libcamera/event_dispatcher.h> > #include <libcamera/event_notifier.h> > #include <libcamera/signal.h> > +#include <libcamera/stream.h> > #include <libcamera/timer.h> > > #endif /* __LIBCAMERA_LIBCAMERA_H__ */ > diff --git a/include/libcamera/meson.build b/include/libcamera/meson.build > index d7cb55ba4a49e1e8..54a680787e5c17aa 100644 > --- a/include/libcamera/meson.build > +++ b/include/libcamera/meson.build > @@ -5,6 +5,7 @@ libcamera_api = files([ > 'event_notifier.h', > 'libcamera.h', > 'signal.h', > + 'stream.h', > 'timer.h', > ]) > > diff --git a/include/libcamera/stream.h b/include/libcamera/stream.h > new file mode 100644 > index 0000000000000000..580f2cc8d3a3ad59 > --- /dev/null > +++ b/include/libcamera/stream.h > @@ -0,0 +1,25 @@ > +/* SPDX-License-Identifier: LGPL-2.1-or-later */ > +/* > + * Copyright (C) 2019, Google Inc. > + * > + * stream.h - Video stream for a Camera > + */ > +#ifndef __LIBCAMERA_STREAM_H__ > +#define __LIBCAMERA_STREAM_H__ > + > +namespace libcamera { > + > +class Stream final > +{ > +public: > + Stream(unsigned int id); > + > + unsigned int id() const { return id_; }; > + > +private: > + unsigned int id_; > +}; > + > +} /* namespace libcamera */ > + > +#endif /* __LIBCAMERA_STREAM_H__ */ > diff --git a/src/libcamera/meson.build b/src/libcamera/meson.build > index f9f25c0ecf1564cc..9f6ff99eebe2f5bc 100644 > --- a/src/libcamera/meson.build > +++ b/src/libcamera/meson.build > @@ -10,6 +10,7 @@ libcamera_sources = files([ > 'media_object.cpp', > 'pipeline_handler.cpp', > 'signal.cpp', > + 'stream.cpp', > 'timer.cpp', > 'v4l2_device.cpp', > ]) > diff --git a/src/libcamera/stream.cpp b/src/libcamera/stream.cpp > new file mode 100644 > index 0000000000000000..307de3710d0ac6b1 > --- /dev/null > +++ b/src/libcamera/stream.cpp > @@ -0,0 +1,67 @@ > +/* SPDX-License-Identifier: LGPL-2.1-or-later */ > +/* > + * Copyright (C) 2019, Google Inc. > + * > + * stream.cpp - Video stream for a Camera > + */ > + > +#include <libcamera/stream.h> > + > +/** > + * \file stream.h > + * \brief Video stream for a Camera > + * > + * A camera device can provide frames in different resolutions and formats > + * concurrently from a single image source. The Stream class represents > + * one of the multiple concurrent streams. > + * > + * All streams exposed by a camera device share the same image source and are > + * thus not fully independent. Parameters related to the image source, such as > + * the exposure time or flash control, are common to all streams. Other > + * parameters, such as format or resolution, may be specified per-stream, > + * depending on the capabilities of the camera device. > + * > + * Camera devices expose at least one stream, and may expose additional streams > + * based on the device capabilities. This can be used, for instance, to > + * implement concurrent viewfinder and video capture, or concurrent viewfinder, > + * video capture and still image capture. > + */ > + > +namespace libcamera { > + > +/** > + * \class Stream > + * \brief Video stream for a camera > + * > + * The Stream class models of all static information which are associated s/of all/all/ ? > + * with a single video stream. Stream are exposed by the Camera object they > + * belong to. > + * > + * Some cameras are capable of supplying more then one stream from the same > + * video source. In such cases an application can inspect all available streams > + * and select the ones that best fit its use case. > + * > + * \todo Add capabilities to the stream API. Without this the Stream class only > + * serves to reveal how many streams of unknown capabilities a camera supports. > + * This in itself is productive as it allows applications to configure and > + * capture from one or more streams even if they won't be able to select the > + * optimal stream for the task. > + */ > + > +/** > + * \brief Create a new stream with a ID s/a ID/an ID/ > + * \param[in] id Numerical ID which should be unique for the camera device the > + * stream belongs to I think we should document the constraints on stream IDs (for instance contiguous IDs starting at 0, but that might not be the best option). This can be done in a subsequent patch as the Stream API will still evolve a lot. Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> > + */ > +Stream::Stream(unsigned int id) > + : id_(id) > +{ > +} > + > +/** > + * \fn Stream::id() > + * \brief Retrieve the streams ID > + * \return The stream ID > + */ > + > +} /* namespace libcamera */
Hi Laurent, Thanks for your feedback. On 2019-01-28 00:19:40 +0200, Laurent Pinchart wrote: > Hi Niklas, > > Thank you for the patch. > > On Sun, Jan 27, 2019 at 01:22:03AM +0100, Niklas Söderlund wrote: > > Add an initial Stream implementation. The idea is that once capability > > support is added to the library each stream will describe its > > capabilities using this class. An application will then select one or > > more streams based on these capabilities and use them to configure the > > camera and capture. > > > > At this stage all the Stream class provides is a way for a Camera object > > to communicate which streams it provides. > > > > Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se> > > --- > > include/libcamera/libcamera.h | 1 + > > include/libcamera/meson.build | 1 + > > include/libcamera/stream.h | 25 +++++++++++++ > > src/libcamera/meson.build | 1 + > > src/libcamera/stream.cpp | 67 +++++++++++++++++++++++++++++++++++ > > 5 files changed, 95 insertions(+) > > create mode 100644 include/libcamera/stream.h > > create mode 100644 src/libcamera/stream.cpp > > > > diff --git a/include/libcamera/libcamera.h b/include/libcamera/libcamera.h > > index c0511cf6d662b63f..272dfd5e4a67d5de 100644 > > --- a/include/libcamera/libcamera.h > > +++ b/include/libcamera/libcamera.h > > @@ -12,6 +12,7 @@ > > #include <libcamera/event_dispatcher.h> > > #include <libcamera/event_notifier.h> > > #include <libcamera/signal.h> > > +#include <libcamera/stream.h> > > #include <libcamera/timer.h> > > > > #endif /* __LIBCAMERA_LIBCAMERA_H__ */ > > diff --git a/include/libcamera/meson.build b/include/libcamera/meson.build > > index d7cb55ba4a49e1e8..54a680787e5c17aa 100644 > > --- a/include/libcamera/meson.build > > +++ b/include/libcamera/meson.build > > @@ -5,6 +5,7 @@ libcamera_api = files([ > > 'event_notifier.h', > > 'libcamera.h', > > 'signal.h', > > + 'stream.h', > > 'timer.h', > > ]) > > > > diff --git a/include/libcamera/stream.h b/include/libcamera/stream.h > > new file mode 100644 > > index 0000000000000000..580f2cc8d3a3ad59 > > --- /dev/null > > +++ b/include/libcamera/stream.h > > @@ -0,0 +1,25 @@ > > +/* SPDX-License-Identifier: LGPL-2.1-or-later */ > > +/* > > + * Copyright (C) 2019, Google Inc. > > + * > > + * stream.h - Video stream for a Camera > > + */ > > +#ifndef __LIBCAMERA_STREAM_H__ > > +#define __LIBCAMERA_STREAM_H__ > > + > > +namespace libcamera { > > + > > +class Stream final > > +{ > > +public: > > + Stream(unsigned int id); > > + > > + unsigned int id() const { return id_; }; > > + > > +private: > > + unsigned int id_; > > +}; > > + > > +} /* namespace libcamera */ > > + > > +#endif /* __LIBCAMERA_STREAM_H__ */ > > diff --git a/src/libcamera/meson.build b/src/libcamera/meson.build > > index f9f25c0ecf1564cc..9f6ff99eebe2f5bc 100644 > > --- a/src/libcamera/meson.build > > +++ b/src/libcamera/meson.build > > @@ -10,6 +10,7 @@ libcamera_sources = files([ > > 'media_object.cpp', > > 'pipeline_handler.cpp', > > 'signal.cpp', > > + 'stream.cpp', > > 'timer.cpp', > > 'v4l2_device.cpp', > > ]) > > diff --git a/src/libcamera/stream.cpp b/src/libcamera/stream.cpp > > new file mode 100644 > > index 0000000000000000..307de3710d0ac6b1 > > --- /dev/null > > +++ b/src/libcamera/stream.cpp > > @@ -0,0 +1,67 @@ > > +/* SPDX-License-Identifier: LGPL-2.1-or-later */ > > +/* > > + * Copyright (C) 2019, Google Inc. > > + * > > + * stream.cpp - Video stream for a Camera > > + */ > > + > > +#include <libcamera/stream.h> > > + > > +/** > > + * \file stream.h > > + * \brief Video stream for a Camera > > + * > > + * A camera device can provide frames in different resolutions and formats > > + * concurrently from a single image source. The Stream class represents > > + * one of the multiple concurrent streams. > > + * > > + * All streams exposed by a camera device share the same image source and are > > + * thus not fully independent. Parameters related to the image source, such as > > + * the exposure time or flash control, are common to all streams. Other > > + * parameters, such as format or resolution, may be specified per-stream, > > + * depending on the capabilities of the camera device. > > + * > > + * Camera devices expose at least one stream, and may expose additional streams > > + * based on the device capabilities. This can be used, for instance, to > > + * implement concurrent viewfinder and video capture, or concurrent viewfinder, > > + * video capture and still image capture. > > + */ > > + > > +namespace libcamera { > > + > > +/** > > + * \class Stream > > + * \brief Video stream for a camera > > + * > > + * The Stream class models of all static information which are associated > > s/of all/all/ ? Yes, thanks. > > > + * with a single video stream. Stream are exposed by the Camera object they > > + * belong to. > > + * > > + * Some cameras are capable of supplying more then one stream from the same > > + * video source. In such cases an application can inspect all available streams > > + * and select the ones that best fit its use case. > > + * > > + * \todo Add capabilities to the stream API. Without this the Stream class only > > + * serves to reveal how many streams of unknown capabilities a camera supports. > > + * This in itself is productive as it allows applications to configure and > > + * capture from one or more streams even if they won't be able to select the > > + * optimal stream for the task. > > + */ > > + > > +/** > > + * \brief Create a new stream with a ID > > s/a ID/an ID/ I thought I found all of them after your good grammar lesson in v2 :-) > > > + * \param[in] id Numerical ID which should be unique for the camera device the > > + * stream belongs to > > I think we should document the constraints on stream IDs (for instance > contiguous IDs starting at 0, but that might not be the best option). > This can be done in a subsequent patch as the Stream API will still > evolve a lot. So far the only constraint is that they need to be unique within a camera. I agree it might be a good idea that they should be contiguous starting from 0, but any integer works with the current implementation. Lets discuss this as the stream API evolves. > > Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> > > > + */ > > +Stream::Stream(unsigned int id) > > + : id_(id) > > +{ > > +} > > + > > +/** > > + * \fn Stream::id() > > + * \brief Retrieve the streams ID > > + * \return The stream ID > > + */ > > + > > +} /* namespace libcamera */ > > -- > Regards, > > Laurent Pinchart
diff --git a/include/libcamera/libcamera.h b/include/libcamera/libcamera.h index c0511cf6d662b63f..272dfd5e4a67d5de 100644 --- a/include/libcamera/libcamera.h +++ b/include/libcamera/libcamera.h @@ -12,6 +12,7 @@ #include <libcamera/event_dispatcher.h> #include <libcamera/event_notifier.h> #include <libcamera/signal.h> +#include <libcamera/stream.h> #include <libcamera/timer.h> #endif /* __LIBCAMERA_LIBCAMERA_H__ */ diff --git a/include/libcamera/meson.build b/include/libcamera/meson.build index d7cb55ba4a49e1e8..54a680787e5c17aa 100644 --- a/include/libcamera/meson.build +++ b/include/libcamera/meson.build @@ -5,6 +5,7 @@ libcamera_api = files([ 'event_notifier.h', 'libcamera.h', 'signal.h', + 'stream.h', 'timer.h', ]) diff --git a/include/libcamera/stream.h b/include/libcamera/stream.h new file mode 100644 index 0000000000000000..580f2cc8d3a3ad59 --- /dev/null +++ b/include/libcamera/stream.h @@ -0,0 +1,25 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ +/* + * Copyright (C) 2019, Google Inc. + * + * stream.h - Video stream for a Camera + */ +#ifndef __LIBCAMERA_STREAM_H__ +#define __LIBCAMERA_STREAM_H__ + +namespace libcamera { + +class Stream final +{ +public: + Stream(unsigned int id); + + unsigned int id() const { return id_; }; + +private: + unsigned int id_; +}; + +} /* namespace libcamera */ + +#endif /* __LIBCAMERA_STREAM_H__ */ diff --git a/src/libcamera/meson.build b/src/libcamera/meson.build index f9f25c0ecf1564cc..9f6ff99eebe2f5bc 100644 --- a/src/libcamera/meson.build +++ b/src/libcamera/meson.build @@ -10,6 +10,7 @@ libcamera_sources = files([ 'media_object.cpp', 'pipeline_handler.cpp', 'signal.cpp', + 'stream.cpp', 'timer.cpp', 'v4l2_device.cpp', ]) diff --git a/src/libcamera/stream.cpp b/src/libcamera/stream.cpp new file mode 100644 index 0000000000000000..307de3710d0ac6b1 --- /dev/null +++ b/src/libcamera/stream.cpp @@ -0,0 +1,67 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ +/* + * Copyright (C) 2019, Google Inc. + * + * stream.cpp - Video stream for a Camera + */ + +#include <libcamera/stream.h> + +/** + * \file stream.h + * \brief Video stream for a Camera + * + * A camera device can provide frames in different resolutions and formats + * concurrently from a single image source. The Stream class represents + * one of the multiple concurrent streams. + * + * All streams exposed by a camera device share the same image source and are + * thus not fully independent. Parameters related to the image source, such as + * the exposure time or flash control, are common to all streams. Other + * parameters, such as format or resolution, may be specified per-stream, + * depending on the capabilities of the camera device. + * + * Camera devices expose at least one stream, and may expose additional streams + * based on the device capabilities. This can be used, for instance, to + * implement concurrent viewfinder and video capture, or concurrent viewfinder, + * video capture and still image capture. + */ + +namespace libcamera { + +/** + * \class Stream + * \brief Video stream for a camera + * + * The Stream class models of all static information which are associated + * with a single video stream. Stream are exposed by the Camera object they + * belong to. + * + * Some cameras are capable of supplying more then one stream from the same + * video source. In such cases an application can inspect all available streams + * and select the ones that best fit its use case. + * + * \todo Add capabilities to the stream API. Without this the Stream class only + * serves to reveal how many streams of unknown capabilities a camera supports. + * This in itself is productive as it allows applications to configure and + * capture from one or more streams even if they won't be able to select the + * optimal stream for the task. + */ + +/** + * \brief Create a new stream with a ID + * \param[in] id Numerical ID which should be unique for the camera device the + * stream belongs to + */ +Stream::Stream(unsigned int id) + : id_(id) +{ +} + +/** + * \fn Stream::id() + * \brief Retrieve the streams ID + * \return The stream ID + */ + +} /* namespace libcamera */
Add an initial Stream implementation. The idea is that once capability support is added to the library each stream will describe its capabilities using this class. An application will then select one or more streams based on these capabilities and use them to configure the camera and capture. At this stage all the Stream class provides is a way for a Camera object to communicate which streams it provides. Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se> --- include/libcamera/libcamera.h | 1 + include/libcamera/meson.build | 1 + include/libcamera/stream.h | 25 +++++++++++++ src/libcamera/meson.build | 1 + src/libcamera/stream.cpp | 67 +++++++++++++++++++++++++++++++++++ 5 files changed, 95 insertions(+) create mode 100644 include/libcamera/stream.h create mode 100644 src/libcamera/stream.cpp