[PATCH v2 0/6] media: cedrus: h264: Support multi-slice frames

Jernej Skrabec
2019-09-29T20:01:00Z

This series adds support for decoding multi-slice H264 frames along with
support for V4L2_DEC_CMD_FLUSH and V4L2_BUF_FLAG_M2M_HOLD_CAPTURE_BUF.

Code was tested by modified ffmpeg, which can be found here:
https://github.com/jernejsk/FFmpeg, branch mainline-test
It has to be configured with at least following options:
--enable-v4l2-request --enable-libudev --enable-libdrm

Samples used for testing:
http://jernej.libreelec.tv/videos/h264/BA1_FT_C.mp4
http://jernej.libreelec.tv/videos/h264/h264.mp4

Command line used for testing:
ffmpeg -hwaccel drm -hwaccel_device /dev/dri/card0 -i h264.mp4 -pix_fmt bgra -f fbdev /dev/fb0

Please note that V4L2_DEC_CMD_FLUSH was not tested because I'm
not sure how. ffmpeg follows exactly which slice is last in frame
and sets hold flag accordingly. Improper usage of hold flag would
corrupt ffmpeg assumptions and it would probably crash. Any ideas
how to test this are welcome!

Thanks to Jonas for adjusting ffmpeg.

Please let me know what you think.

Best regards,
Jernej

Changes from v1:
- added Rb tags
- updated V4L2_DEC_CMD_FLUSH documentation
- updated first slice detection in Cedrus
- hold capture buffer flag is set according to source format
- added v4l m2m stateless_(try_)decoder_cmd ioctl helpers

Hans Verkuil (2):
vb2: add V4L2_BUF_FLAG_M2M_HOLD_CAPTURE_BUF
videodev2.h: add V4L2_DEC_CMD_FLUSH

Jernej Skrabec (4):
media: v4l2-mem2mem: add stateless_(try_)decoder_cmd ioctl helpers
media: cedrus: Detect first slice of a frame
media: cedrus: h264: Support multiple slices per frame
media: cedrus: Add support for holding capture buffer

Documentation/media/uapi/v4l/buffer.rst | 13 ++++++
.../media/uapi/v4l/vidioc-decoder-cmd.rst | 10 +++-
.../media/uapi/v4l/vidioc-reqbufs.rst | 6 +++
.../media/videodev2.h.rst.exceptions | 1 +
.../media/common/videobuf2/videobuf2-v4l2.c | 8 +++-
drivers/media/v4l2-core/v4l2-mem2mem.c | 35 ++++++++++++++
drivers/staging/media/sunxi/cedrus/cedrus.h | 1 +
.../staging/media/sunxi/cedrus/cedrus_dec.c | 11 +++++
.../staging/media/sunxi/cedrus/cedrus_h264.c | 11 ++++-
.../staging/media/sunxi/cedrus/cedrus_hw.c | 8 ++--
.../staging/media/sunxi/cedrus/cedrus_video.c | 14 ++++++
include/media/v4l2-mem2mem.h | 46 +++++++++++++++++++
include/media/videobuf2-core.h | 3 ++
include/media/videobuf2-v4l2.h | 5 ++
include/uapi/linux/videodev2.h | 14 ++++--
15 files changed, 175 insertions(+), 11 deletions(-)

--
2.23.0