[FFmpeg-devel] [PATCH 22/39] lavc/hevc/cabac: do not infer WPP use based on HEVCContext.threads_number

[Christophe Gisquet]

Le ven. 7 juin 2024, 15:07, Anton Khirnov <anton at khirnov.net> a écrit :

>          if (pps->tiles_enabled_flag &&
>              pps->tile_id[ctb_addr_ts] != pps->tile_id[ctb_addr_ts - 1]) {
>              int ret;
> -            if (s->threads_number == 1)
> +            if (!is_wpp)
>                  ret = cabac_reinit(lc);
>              else {
>                  ret = ff_init_cabac_decoder(&lc->cc, data, size);
>

I have 2 things to say about this. First is that IIRC, tiles and WPP are
mutually exclusive, so I would have expected your change to introduce dead
code. It might have been changed for a later profile, but I think ffmpeg's
decoder doesn't support this or these profiles. Anyway, I wonder what the
intent of that code was.

Which leads me to the second. FFmpeg decoder does not support tile
threading (the one it's based off does/did) so maybe this code never
mattered for FFmpeg.

Hesitant LGTM, as I find this fishy and wondering if I'm missing something

>