[FFmpeg-devel] [PATCH] avcodec/h264_slice: compute and export film grain seed

[Niklas Haas]

On Wed, 04 Aug 2021 19:00:48 +0200 Niklas Haas <ffmpeg at haasn.xyz> wrote:
> +    if ((sd = av_frame_get_side_data(cur->f, AV_FRAME_DATA_FILM_GRAIN_PARAMS))) {
> +        AVFilmGrainParams *fgp = (AVFilmGrainParams *) sd->data;
> +        fgp->seed = cur->poc + h->poc_offset << 5;
> +    }

The order on this is wrong, it must be be (h->poc_offset << 5).

I'll submit a new patch when I can verify that I actually get the
correct output. I'm not sure if my grain synthesis code is bugged or if
the seed value is just wrong. (The grain I get looks visually similar,
but completely different)