Some V4L2 drivers fail to allocate buffers when sizeimage is not set
to a max value. This is indeed the case for s5p-mfc [1]
Most drivers should be able to calculate this value from the frame
dimensions and format - or at least have their own default.
However since this work around should not impact those drivers doing
the "right thing" this commit just provides such a default.
The calculations were extracted from the v4l2 driver used to develop
the ffmpeg v4l2_m2m support [2]. See venc.c and vdec.c
[1] linux.git/drivers/media/platform/s5p-mfc
[2] linux.git/drivers/media/platform/qcom/venus/
This patchset enhances Alexis Ballier's original patch and validates
it using Qualcomm's Venus hardware (driver recently landed upstream
[1]).
This has been tested on Qualcomm's DragonBoard 410c and 820c
Configure/make scripts have been validated on Ubuntu 10.04 and
16.04.
Tested decoders:
- h264
- h263
- mpeg4
- vp8
- vp9
- hevc
Tested encoders:
- h264
- h263
- mpeg4
Tested transcoding (concurrent encoding/decoding)
Some of the changes introduced:
- v4l2: code cleanup and abstractions added
- v4l2: follow the new encode/decode api.
- v4l2: fix display size for NV12 output pool.
- v4l2: handle EOS (EPIPE and draining)
- v4l2: vp8 and mpeg4 decoding and encoding.
- v4l2: hevc and vp9 support.
- v4l2: generate EOF on dequeue errors.
- v4l2: h264_mp4toannexb filtering.
- v4l2: fixed make install and fate issues.
- v4l2: codecs enabled/disabled depending on pixfmt defined
- v4l2: pass timebase/framerate to the context
- v4l2: runtime decoder reconfiguration.
- v4l2: add more frame information
- v4l2: free hardware resources on last reference being released
- v4l2: encoding: disable b-frames for upstreaming (patch required)
[1] https://lwn.net/Articles/697956/
System Level view:
v42l_m2m_enc/dec --> v4l2_m2m --> v4l2_context --> v4l2_buffers
Reviewed-by: Jorge Ramirez <jorge.ramirez-ortiz@linaro.org>
Reviewed-by: Alexis Ballier <aballier@gentoo.org>
Tested-by: Jorge Ramirez <jorge.ramirez-ortiz@linaro.org>
Signed-off-by: wm4 <nfxjfg@googlemail.com>
