[FFmpeg-devel] [PATCH] avcodec/libsvtav1: add support for setting chroma sample location

[James Almer]

On 4/25/2022 6:02 PM, Jan Ekström wrote:
> Support for configuring this was added with version 1.0.0.
> ---
>   libavcodec/libsvtav1.c | 22 ++++++++++++++++++++++
>   1 file changed, 22 insertions(+)
> 
> diff --git a/libavcodec/libsvtav1.c b/libavcodec/libsvtav1.c
> index 2e3d96ce37..a670dab822 100644
> --- a/libavcodec/libsvtav1.c
> +++ b/libavcodec/libsvtav1.c
> @@ -205,6 +205,28 @@ static int config_enc_params(EbSvtAv1EncConfiguration *param,
>       else
>           param->color_range = !!(desc->flags & AV_PIX_FMT_FLAG_RGB);
>   
> +#if SVT_AV1_CHECK_VERSION(1, 0, 0)
> +    if (avctx->chroma_sample_location != AVCHROMA_LOC_UNSPECIFIED) {
> +        switch (avctx->chroma_sample_location) {
> +        case AVCHROMA_LOC_LEFT:
> +            param->chroma_sample_position = EB_CSP_VERTICAL;
> +            break;
> +        case AVCHROMA_LOC_TOPLEFT:
> +            param->chroma_sample_position = EB_CSP_COLOCATED;
> +            break;
> +        default:
> +            av_log(avctx, AV_LOG_INFO,
> +                   "Specified chroma sample location %s (%d) is unsupported "
> +                   "on the AV1 bit stream level. Usage of a container that "
> +                   "allows passing this information - such as Matroska - "
> +                   "is recommended.\n",
> +                   av_chroma_location_name(avctx->chroma_sample_location),

This can return NULL on invalid AVChromaLocation values, so better check 
for that and print a different log message.

> +                   avctx->chroma_sample_location);
> +            break;
> +        }
> +    }
> +#endif
> +
>       if (avctx->profile != FF_PROFILE_UNKNOWN)
>           param->profile = avctx->profile;
>