This series adds the encoder spec and updates the VIDIOC_G/S_PARM
documentation.
This is a follow-up of the original "Stateful Encoding: final bits"
series (1).
The patches in that series that add support for V4L2_CID_MPEG_VIDEO_ENC_FRAME_RATE
and V4L2_BUF_FLAG_TOO_SMALL have been dropped (the first is not necessary
and the second can be skipped for now, see the irc discussion with
Nicolas [3]).
The encoder spec has been updated since [2] with the following
changes:
- Document the optional VIDIOC_ENUM_FRAMEINTERVALS ioctl.
- Document how to use VIDIOC_S_PARM:
1) calling S_PARM for the OUTPUT queue sets both the raw frame interval
(this is a hint only) and the coded frame interval.
2) calling S_PARM for the CAPTURE queue sets the coded frame interval
only. This is optional and can be used for off-line encoding. In
that case the OUTPUT frame interval can be used by the driver to
schedule multiple encoders.
Ideally S_PARM for the OUTPUT queue would just provide a hint, but
existing encoder drivers all use S_PARM for the OUTPUT queue to
define the coded frame interval, and that can't be changed.
- Added a note that if a capture buffer is too small it will be
returned with V4L2_BUF_FLAG_ERROR and that more work has to be
done to properly support this corner case.
- Clarify in the 'Encoding' section that there are more reasons
why 'a buffer queued to OUTPUT may result in more than one buffer
produced on CAPTURE'.
I think that with these changes this stateful encoder spec is ready
to be merged.
Regards,
Hans
[1] https://lore.kernel.org/linux-media/20191119113457.57833-6-hverkuil-cisco@xxxxxxxxx/T/
[2] https://www.mail-archive.com/linux-media@xxxxxxxxxxxxxxx/msg149211.html
[3] https://linuxtv.org/irc/irclogger_log/v4l?date=2020-05-19,Tue
Hans Verkuil (1):
vidioc-g-parm.rst: update the VIDIOC_G/S_PARM documentation
Tomasz Figa (1):
media: docs-rst: Document memory-to-memory video encoder interface
.../userspace-api/media/v4l/dev-encoder.rst | 727 ++++++++++++++++++
.../userspace-api/media/v4l/dev-mem2mem.rst | 1 +
.../userspace-api/media/v4l/pixfmt-v4l2.rst | 5 +
.../userspace-api/media/v4l/v4l2.rst | 2 +
.../media/v4l/vidioc-encoder-cmd.rst | 51 +-
.../userspace-api/media/v4l/vidioc-g-parm.rst | 51 +-
6 files changed, 798 insertions(+), 39 deletions(-)
create mode 100644 Documentation/userspace-api/media/v4l/dev-encoder.rst
--
2.25.1
