Quoting Asahi Lina via ffmpeg-devel (2023-09-29 09:52:23) > V4L2 provides a line stride to the client for hardware that has > alignment requirements. rawvideo cannot represent this, so switch to > wrapped_avframe for raw video formats and calculate the plane strides > manually. > > This is slightly messy because the existing helper APIs expect > dimensions and an alignment value, while v4l2 provides the stride of > plane 0 and the subsequent plane strides are implied, so we need to > open-code the logic to calculate the plane strides. > > This makes vertical video work properly on Apple Macs with "1080p" > cameras, which are actually square and can support resolutions like > 1080x1920, which require stride padding to a multiple of 64 bytes. > > In principle, this could be extended to support the V4L2 multiplanar > API, though there seem to be practically no capture (not M2M) drivers > that support this, so it's not terribly useful right now. > > Signed-off-by: Asahi Lina <l...@asahilina.net> > --- > libavdevice/v4l2-common.c | 68 +++++++++++------------ > libavdevice/v4l2.c | 138 > +++++++++++++++++++++++++++++++++++++++------- > 2 files changed, 151 insertions(+), 55 deletions(-)
Wrapped AVFrames is an abominable hack that should be going away, not spread to new places. The correct approach is move v4l2 rawvideo to a lavfi source filter, then none of these hacks are needed. -- Anton Khirnov _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".