[FFmpeg-devel] [PATCH] lavc/libaomenc: Add a maximum constraint of 64 encoder threads.

[James Almer]

On 11/27/2018 6:18 AM, Jun Zhao wrote:
> fixed the error in Intel(R) Xeon(R) Gold 6152 CPU like:
> [libaom-av1 @ 0x469f340] Failed to initialize encoder: Invalid parameter
> [libaom-av1 @ 0x469f340]   Additional information: g_threads out of range [..MAX_NUM_THREADS]
> 
> Signed-off-by: Jun Zhao <mypopydev at gmail.com>
> ---
>  libavcodec/libaomenc.c |    3 ++-
>  1 files changed, 2 insertions(+), 1 deletions(-)
> 
> diff --git a/libavcodec/libaomenc.c b/libavcodec/libaomenc.c
> index cb31c55..ccb0cf9 100644
> --- a/libavcodec/libaomenc.c
> +++ b/libavcodec/libaomenc.c
> @@ -504,7 +504,8 @@ static av_cold int aom_init(AVCodecContext *avctx,
>      enccfg.g_h            = avctx->height;
>      enccfg.g_timebase.num = avctx->time_base.num;
>      enccfg.g_timebase.den = avctx->time_base.den;
> -    enccfg.g_threads      = avctx->thread_count ? avctx->thread_count : av_cpu_count();
> +    enccfg.g_threads      =
> +	FFMIN(avctx->thread_count ? avctx->thread_count : av_cpu_count(), 64);
>  
>      if (ctx->lag_in_frames >= 0)
>          enccfg.g_lag_in_frames = ctx->lag_in_frames;
> 

Applied. Better to clip the value than to let initialization using
default values fail in the user's face because they have a computer with
a lot logical cores.

libaom should nonetheless either do this clipping internally, or make
this limit clear in the API and/or the documentation.