| Message ID | 20220723095330.43542-6-jacopo@jmondi.org |
|---|---|
| State | Accepted |
| Headers | show |
| Series |
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| Related | show |
Hi Jacopo, Thank you for the patch. On Sat, Jul 23, 2022 at 11:53:27AM +0200, Jacopo Mondi via libcamera-devel wrote: > Now that V4L2PixelFormat::fromPixelFormat() returns a list of formats > to chose from by checking which ones are actually supported by the video > device. > > The first format found to match one of the device supported ones is > returned. > > As V4L2VideoDevice::toV4L2PixelFormat() is a const function which uses > other functions of the class, those functions has to be made const as > well. > > In particular: > > - enumPixelformats() and enumSizes() do not modify the class state and > can safely be made const. > - formats() uses the above functions and does not itself modify the > class state and can be made const > - add a const version of V4L2Device::ioctl() to be used by the now const > functions Can we avoid that by enumerating all V4L2 pixel formats when the V4L2VideoDevice is opened and caching them internally ? The call to enumPixelformats() with a non-zero code needs to go to the device, but the call in V4L2VideoDevice::toV4L2PixelFormat() can use cached data. > Signed-off-by: Jacopo Mondi <jacopo@jmondi.org> > --- > include/libcamera/internal/v4l2_device.h | 1 + > include/libcamera/internal/v4l2_videodevice.h | 6 ++-- > src/libcamera/v4l2_device.cpp | 15 +++++++++ > src/libcamera/v4l2_videodevice.cpp | 31 ++++++++++++++----- > 4 files changed, 43 insertions(+), 10 deletions(-) > > diff --git a/include/libcamera/internal/v4l2_device.h b/include/libcamera/internal/v4l2_device.h > index a52a5f2c99f9..f7ec3c7004a6 100644 > --- a/include/libcamera/internal/v4l2_device.h > +++ b/include/libcamera/internal/v4l2_device.h > @@ -55,6 +55,7 @@ protected: > int setFd(UniqueFD fd); > > int ioctl(unsigned long request, void *argp); > + int ioctl(unsigned long request, void *argp) const; > > int fd() const { return fd_.get(); } > > diff --git a/include/libcamera/internal/v4l2_videodevice.h b/include/libcamera/internal/v4l2_videodevice.h > index 29fa0bbaf670..6d8850c99afd 100644 > --- a/include/libcamera/internal/v4l2_videodevice.h > +++ b/include/libcamera/internal/v4l2_videodevice.h > @@ -205,7 +205,7 @@ public: > int getFormat(V4L2DeviceFormat *format); > int tryFormat(V4L2DeviceFormat *format); > int setFormat(V4L2DeviceFormat *format); > - Formats formats(uint32_t code = 0); > + Formats formats(uint32_t code = 0) const; > > int setSelection(unsigned int target, Rectangle *rect); > > @@ -251,8 +251,8 @@ private: > int getFormatSingleplane(V4L2DeviceFormat *format); > int trySetFormatSingleplane(V4L2DeviceFormat *format, bool set); > > - std::vector<V4L2PixelFormat> enumPixelformats(uint32_t code); > - std::vector<SizeRange> enumSizes(V4L2PixelFormat pixelFormat); > + std::vector<V4L2PixelFormat> enumPixelformats(uint32_t code) const; > + std::vector<SizeRange> enumSizes(V4L2PixelFormat pixelFormat) const; > > int requestBuffers(unsigned int count, enum v4l2_memory memoryType); > int createBuffers(unsigned int count, > diff --git a/src/libcamera/v4l2_device.cpp b/src/libcamera/v4l2_device.cpp > index 3fc8438f6579..59f92403db80 100644 > --- a/src/libcamera/v4l2_device.cpp > +++ b/src/libcamera/v4l2_device.cpp > @@ -459,6 +459,21 @@ int V4L2Device::ioctl(unsigned long request, void *argp) > return 0; > } > > +/** > + * \copydoc ioctl() > + */ > +int V4L2Device::ioctl(unsigned long request, void *argp) const > +{ > + /* > + * Printing out an error message is usually better performed > + * in the caller, which can provide more context. > + */ > + if (::ioctl(fd_.get(), request, argp) < 0) > + return -errno; > + > + return 0; > +} > + > /** > * \fn V4L2Device::deviceNode() > * \brief Retrieve the device node path > diff --git a/src/libcamera/v4l2_videodevice.cpp b/src/libcamera/v4l2_videodevice.cpp > index 43c3d0f69266..a3242ba755c0 100644 > --- a/src/libcamera/v4l2_videodevice.cpp > +++ b/src/libcamera/v4l2_videodevice.cpp > @@ -1045,7 +1045,7 @@ int V4L2VideoDevice::trySetFormatSingleplane(V4L2DeviceFormat *format, bool set) > * > * \return A list of the supported video device formats > */ > -V4L2VideoDevice::Formats V4L2VideoDevice::formats(uint32_t code) > +V4L2VideoDevice::Formats V4L2VideoDevice::formats(uint32_t code) const > { > Formats formats; > > @@ -1067,7 +1067,7 @@ V4L2VideoDevice::Formats V4L2VideoDevice::formats(uint32_t code) > return formats; > } > > -std::vector<V4L2PixelFormat> V4L2VideoDevice::enumPixelformats(uint32_t code) > +std::vector<V4L2PixelFormat> V4L2VideoDevice::enumPixelformats(uint32_t code) const > { > std::vector<V4L2PixelFormat> formats; > int ret; > @@ -1101,7 +1101,7 @@ std::vector<V4L2PixelFormat> V4L2VideoDevice::enumPixelformats(uint32_t code) > return formats; > } > > -std::vector<SizeRange> V4L2VideoDevice::enumSizes(V4L2PixelFormat pixelFormat) > +std::vector<SizeRange> V4L2VideoDevice::enumSizes(V4L2PixelFormat pixelFormat) const > { > std::vector<SizeRange> sizes; > int ret; > @@ -1990,20 +1990,37 @@ V4L2VideoDevice::fromEntityName(const MediaDevice *media, > } > > /** > - * \brief Convert \a PixelFormat to its corresponding V4L2 FourCC > + * \brief Convert \a PixelFormat to one of the device supported V4L2 FourCC > * \param[in] pixelFormat The PixelFormat to convert > * > + * Convert a\ pixelformat to a V4L2 FourCC that is known to be supported by > + * the video device. You should also document what happens if the device supports multiple V4L2 pixel formats that match the given PixelFormat. > + * > * For multiplanar formats, the V4L2 format variant (contiguous or > * non-contiguous planes) is selected automatically based on the capabilities > * of the video device. If the video device supports the V4L2 multiplanar API, > * non-contiguous formats are preferred. > * > - * \return The V4L2_PIX_FMT_* pixel format code corresponding to \a pixelFormat > + * \return The V4L2PixelFormat corresponding to \a pixelFormat or an invalid > + * PixelFormat if \a pixelFormat is not supported by the video device > */ > V4L2PixelFormat V4L2VideoDevice::toV4L2PixelFormat(const PixelFormat &pixelFormat) const > { > - return V4L2PixelFormat::fromPixelFormat(pixelFormat, > - caps_.isMultiplanar())[0]; > + std::vector<V4L2PixelFormat> deviceFormats = enumPixelformats(0); > + std::vector<V4L2PixelFormat> v4l2PixelFormats = > + V4L2PixelFormat::fromPixelFormat(pixelFormat, caps_.isMultiplanar()); I think we should avoid reintroducing the automatic multiplanar selection, which is the reason why the V4L2VideoDevice::toV4L2PixelFormat() function got dropped in the first place. Merging the single and multi vectors as recommended in the review of an earlier patch in this series will help. I'd also use const references here. It won't make a difference as the two functions return objects by value, but when calling functions that return a reference, it avoids copies. It's thus a good practice to use const references everywhere possible, as there's no drawback using them when the function returns by value (a const reference extends the lifetime of the value returned by the function). > + > + for (const V4L2PixelFormat &v4l2Format : v4l2PixelFormats) { > + auto it = std::find_if(deviceFormats.begin(), deviceFormats.end(), > + [&v4l2Format](const V4L2PixelFormat &deviceFormat) { > + return v4l2Format == deviceFormat; > + }); > + > + if (it != deviceFormats.end()) > + return v4l2Format; > + } > + > + return {}; > } > > /**
diff --git a/include/libcamera/internal/v4l2_device.h b/include/libcamera/internal/v4l2_device.h index a52a5f2c99f9..f7ec3c7004a6 100644 --- a/include/libcamera/internal/v4l2_device.h +++ b/include/libcamera/internal/v4l2_device.h @@ -55,6 +55,7 @@ protected: int setFd(UniqueFD fd); int ioctl(unsigned long request, void *argp); + int ioctl(unsigned long request, void *argp) const; int fd() const { return fd_.get(); } diff --git a/include/libcamera/internal/v4l2_videodevice.h b/include/libcamera/internal/v4l2_videodevice.h index 29fa0bbaf670..6d8850c99afd 100644 --- a/include/libcamera/internal/v4l2_videodevice.h +++ b/include/libcamera/internal/v4l2_videodevice.h @@ -205,7 +205,7 @@ public: int getFormat(V4L2DeviceFormat *format); int tryFormat(V4L2DeviceFormat *format); int setFormat(V4L2DeviceFormat *format); - Formats formats(uint32_t code = 0); + Formats formats(uint32_t code = 0) const; int setSelection(unsigned int target, Rectangle *rect); @@ -251,8 +251,8 @@ private: int getFormatSingleplane(V4L2DeviceFormat *format); int trySetFormatSingleplane(V4L2DeviceFormat *format, bool set); - std::vector<V4L2PixelFormat> enumPixelformats(uint32_t code); - std::vector<SizeRange> enumSizes(V4L2PixelFormat pixelFormat); + std::vector<V4L2PixelFormat> enumPixelformats(uint32_t code) const; + std::vector<SizeRange> enumSizes(V4L2PixelFormat pixelFormat) const; int requestBuffers(unsigned int count, enum v4l2_memory memoryType); int createBuffers(unsigned int count, diff --git a/src/libcamera/v4l2_device.cpp b/src/libcamera/v4l2_device.cpp index 3fc8438f6579..59f92403db80 100644 --- a/src/libcamera/v4l2_device.cpp +++ b/src/libcamera/v4l2_device.cpp @@ -459,6 +459,21 @@ int V4L2Device::ioctl(unsigned long request, void *argp) return 0; } +/** + * \copydoc ioctl() + */ +int V4L2Device::ioctl(unsigned long request, void *argp) const +{ + /* + * Printing out an error message is usually better performed + * in the caller, which can provide more context. + */ + if (::ioctl(fd_.get(), request, argp) < 0) + return -errno; + + return 0; +} + /** * \fn V4L2Device::deviceNode() * \brief Retrieve the device node path diff --git a/src/libcamera/v4l2_videodevice.cpp b/src/libcamera/v4l2_videodevice.cpp index 43c3d0f69266..a3242ba755c0 100644 --- a/src/libcamera/v4l2_videodevice.cpp +++ b/src/libcamera/v4l2_videodevice.cpp @@ -1045,7 +1045,7 @@ int V4L2VideoDevice::trySetFormatSingleplane(V4L2DeviceFormat *format, bool set) * * \return A list of the supported video device formats */ -V4L2VideoDevice::Formats V4L2VideoDevice::formats(uint32_t code) +V4L2VideoDevice::Formats V4L2VideoDevice::formats(uint32_t code) const { Formats formats; @@ -1067,7 +1067,7 @@ V4L2VideoDevice::Formats V4L2VideoDevice::formats(uint32_t code) return formats; } -std::vector<V4L2PixelFormat> V4L2VideoDevice::enumPixelformats(uint32_t code) +std::vector<V4L2PixelFormat> V4L2VideoDevice::enumPixelformats(uint32_t code) const { std::vector<V4L2PixelFormat> formats; int ret; @@ -1101,7 +1101,7 @@ std::vector<V4L2PixelFormat> V4L2VideoDevice::enumPixelformats(uint32_t code) return formats; } -std::vector<SizeRange> V4L2VideoDevice::enumSizes(V4L2PixelFormat pixelFormat) +std::vector<SizeRange> V4L2VideoDevice::enumSizes(V4L2PixelFormat pixelFormat) const { std::vector<SizeRange> sizes; int ret; @@ -1990,20 +1990,37 @@ V4L2VideoDevice::fromEntityName(const MediaDevice *media, } /** - * \brief Convert \a PixelFormat to its corresponding V4L2 FourCC + * \brief Convert \a PixelFormat to one of the device supported V4L2 FourCC * \param[in] pixelFormat The PixelFormat to convert * + * Convert a\ pixelformat to a V4L2 FourCC that is known to be supported by + * the video device. + * * For multiplanar formats, the V4L2 format variant (contiguous or * non-contiguous planes) is selected automatically based on the capabilities * of the video device. If the video device supports the V4L2 multiplanar API, * non-contiguous formats are preferred. * - * \return The V4L2_PIX_FMT_* pixel format code corresponding to \a pixelFormat + * \return The V4L2PixelFormat corresponding to \a pixelFormat or an invalid + * PixelFormat if \a pixelFormat is not supported by the video device */ V4L2PixelFormat V4L2VideoDevice::toV4L2PixelFormat(const PixelFormat &pixelFormat) const { - return V4L2PixelFormat::fromPixelFormat(pixelFormat, - caps_.isMultiplanar())[0]; + std::vector<V4L2PixelFormat> deviceFormats = enumPixelformats(0); + std::vector<V4L2PixelFormat> v4l2PixelFormats = + V4L2PixelFormat::fromPixelFormat(pixelFormat, caps_.isMultiplanar()); + + for (const V4L2PixelFormat &v4l2Format : v4l2PixelFormats) { + auto it = std::find_if(deviceFormats.begin(), deviceFormats.end(), + [&v4l2Format](const V4L2PixelFormat &deviceFormat) { + return v4l2Format == deviceFormat; + }); + + if (it != deviceFormats.end()) + return v4l2Format; + } + + return {}; } /**
Now that V4L2PixelFormat::fromPixelFormat() returns a list of formats to chose from by checking which ones are actually supported by the video device. The first format found to match one of the device supported ones is returned. As V4L2VideoDevice::toV4L2PixelFormat() is a const function which uses other functions of the class, those functions has to be made const as well. In particular: - enumPixelformats() and enumSizes() do not modify the class state and can safely be made const. - formats() uses the above functions and does not itself modify the class state and can be made const - add a const version of V4L2Device::ioctl() to be used by the now const functions Signed-off-by: Jacopo Mondi <jacopo@jmondi.org> --- include/libcamera/internal/v4l2_device.h | 1 + include/libcamera/internal/v4l2_videodevice.h | 6 ++-- src/libcamera/v4l2_device.cpp | 15 +++++++++ src/libcamera/v4l2_videodevice.cpp | 31 ++++++++++++++----- 4 files changed, 43 insertions(+), 10 deletions(-)