On the RPI, three different /dev/video devices exist (decoder, scaler, encoder).
When probing the devices in order, the originally requested pix fmt
would be mutated causing the wrong one to be chosen when a matching
device was finally found.
Signed-off-by: Aman Gupta <aman@tmm1.net>
ENOMEM indicates an allocation failure, and there are no allocations
happening here. The buffers are pre-allocated and there are simply
none available at this time.
Signed-off-by: Aman Gupta <aman@tmm1.net>
During the initialization stage, the codec attempts to get free
buffers from the driver before any have been queued (this is to keep
the code simple and generic)
When the kernel driver detects this situation, it returns POLLERR in
revents and ffmpeg therefore raises a warning.
This commit disables the warning since no buffers were queued to the
driver yet.
Signed-off-by: Jorge Ramirez-Ortiz <jorge.ramirez-ortiz@linaro.org>
Qualcomm's db410c/db820 Venus driver currently present in mainline
kernel has a bug which mishandles the CMD_STOP requests causing the
decoder to block while draining [1].
This patch removes the workaround that was used to prevent that
situation.
Encoding/Decoding tested on db820c.
[1] on CMD_STOP, the driver is flushing all buffers and never raising
IPIPE which ends up in blocking on poll.
Fixes a warning on recent Linux:
libavcodec/v4l2_context.c: In function 'ff_v4l2_context_set_status':
libavcodec/v4l2_context.c:496:26: warning: comparison is always false due to limited range of data type
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>
Aman Gupta
Jorge Ramirez-Ortiz
Jorge Ramirez-Ortiz
Carl Eugen Hoyos
Michael Niedermayer