[vlc-devel] [VLC 3.x 1/2] codec: dav1d: limit automatic frame thread count

[Marvin Scholz]

Does anyone has an objection against these patches
for 3.x? If not, it would be good to merge them for
the upcoming 3.0.13 release, I think.

On 6 Apr 2021, at 14:01, Marvin Scholz wrote:

> Without this limit, on a processor with many cores it would use
> so many frame threads that it would fail picture pool allocation.
>
> Fix #25190
> ---
>  modules/codec/dav1d.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/modules/codec/dav1d.c b/modules/codec/dav1d.c
> index 3e44d524ed..0498492a73 100644
> --- a/modules/codec/dav1d.c
> +++ b/modules/codec/dav1d.c
> @@ -273,6 +273,7 @@ static int Decode(decoder_t *dec, block_t *block)
>  static int OpenDecoder(vlc_object_t *p_this)
>  {
>      decoder_t *dec = (decoder_t *)p_this;
> +    unsigned i_core_count = vlc_GetCPUCount();
>
>      if (dec->fmt_in.i_codec != VLC_CODEC_AV1)
>          return VLC_EGENERIC;
> @@ -287,7 +288,7 @@ static int OpenDecoder(vlc_object_t *p_this)
>          p_sys->s.n_tile_threads = VLC_CLIP(vlc_GetCPUCount(), 1, 4);
>      p_sys->s.n_frame_threads = var_InheritInteger(p_this, 
> "dav1d-thread-frames");
>      if (p_sys->s.n_frame_threads == 0)
> -        p_sys->s.n_frame_threads = __MAX(1, vlc_GetCPUCount());
> +        p_sys->s.n_frame_threads = (i_core_count < 16) ? i_core_count 
> : 16;
>      p_sys->s.allocator.cookie = dec;
>      p_sys->s.allocator.alloc_picture_callback = NewPicture;
>      p_sys->s.allocator.release_picture_callback = FreePicture;
> -- 
> 2.30.1