[FFmpeg-devel] [PATCH 2/2] pthread_frame: change the criterium for updating thread contexts

[James Almer]

On 6/9/2020 8:20 AM, Anton Khirnov wrote:
> Currently the next thread's context is updated from the previous one's
> if the codec descriptor is not marked as intra-only. That is not
> entirely correct, since that property does not necessarily imply
> anything about how a specific decoder implementation behaves.
> 
> Instead, use the presence of the update_thread_context() callback to
> decide whether an update should be performed. Fixes races in CFHD,
> should cause no behaviour change in any other decoders.
> ---
>  libavcodec/pthread_frame.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/libavcodec/pthread_frame.c b/libavcodec/pthread_frame.c
> index 601f170447..3255aa9337 100644
> --- a/libavcodec/pthread_frame.c
> +++ b/libavcodec/pthread_frame.c
> @@ -246,7 +246,7 @@ static int update_context_from_thread(AVCodecContext *dst, AVCodecContext *src,
>  {
>      int err = 0;
>  
> -    if (dst != src && (for_user || !(src->codec_descriptor->props & AV_CODEC_PROP_INTRA_ONLY))) {
> +    if (dst != src && (for_user || src->codec->update_thread_context)) {
>          dst->time_base = src->time_base;
>          dst->framerate = src->framerate;
>          dst->width     = src->width;

LGTM.