Re: [PATCHv3 0/5] Stateful Encoding: final bits

[Tomasz Figa <tfiga@chromium.org>]

On Tue, May 26, 2020 at 12:09 PM Hans Verkuil <hverkuil-cisco@xs4all.nl> wrote:
>
> 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'.
>
> Added in v3:
>
> - Fix some minor typos.
>
> - Make it more explicit that setting S_PARM(OUTPUT) also sets the
>   CAPTURE frame interval.
>
> - Added a new V4L2_FMT_FLAG_ENC_CAP_FRAME_INTERVAL flag to indicate
>   that S_PARM(CAPTURE) can be set separately.
>
> I think that with these changes this stateful encoder spec is ready
> to be merged.

Acked-by: Tomasz Figa <tfiga@chromium.org>

Thanks Hans and everyone for the help with moving this forward.

Best regards,
Tomasz