[FFmpeg-devel] [PATCH] libsvtav1: Add workaround for gop_size == 1

[Vignesh Venkat]

On Mon, Jun 26, 2023 at 3:17 PM Ronald S. Bultje <rsbultje at gmail.com> wrote:
>
> Hi,
>
> On Mon, Jun 26, 2023 at 1:47 PM Vignesh Venkatasubramanian <vigneshv-at-google.com at ffmpeg.org> wrote:
>>
>> In some versions of libsvtav1, setting intra_period_length to 0
>> does not produce the intended result (i.e.) all frames produced
>> are not keyframes.
>>
>> Instead handle the gop_size == 1 as a special case by setting
>> the pic_type to EB_AV1_KEY_PICTURE when encoding each frame so
>> that all the output frames are keyframes.
>>
>> SVT-AV1 Bug: https://gitlab.com/AOMediaCodec/SVT-AV1/-/issues/2076
>>
>> Example command: ffmpeg -f lavfi -i testsrc=duration=1:size=64x64:rate=30 -c:v libsvtav1 -g 1 -y test.webm
>>
>> Before: Only first frame is keyframe.
>> After: All frames are keyframes.
>>
>> Signed-off-by: Vignesh Venkatasubramanian <vigneshv at google.com>
>> ---
>>  libavcodec/libsvtav1.c | 16 +++++++++++++++-
>>  1 file changed, 15 insertions(+), 1 deletion(-)
>
>
> It feels a bit dirty to add workarounds in ffmpeg library wrappers for bugs in these libraries. Not 100% against it, but it's not particularly great.
>

Yeah I agree that it's not ideal. But minor changes like this that are
commented/documented is okay i believe.

> Ronald



-- 
Vignesh