[FFmpeg-devel] [PATCH] avformat/mov: don't abort on duplicate Mastering Display Metadata boxes

[Andreas Rheinhardt]

James Almer:
> The VP9 spec defines a SmDm box for this information, and the ISOBMFF spec defines a
> mdvc one. If both are present, just ignore one of them.
> This is in line with clli and CoLL boxes.
> 
> Fixes ticket #10711.
> 
> Signed-off-by: James Almer <jamrial at gmail.com>
> ---
>  libavformat/mov.c | 13 ++++++++++---
>  1 file changed, 10 insertions(+), 3 deletions(-)
> 
> diff --git a/libavformat/mov.c b/libavformat/mov.c
> index e7aa8d1833..5463f36770 100644
> --- a/libavformat/mov.c
> +++ b/libavformat/mov.c
> @@ -6140,8 +6140,10 @@ static int mov_read_smdm(MOVContext *c, AVIOContext *pb, MOVAtom atom)
>          av_log(c->fc, AV_LOG_WARNING, "Unsupported Mastering Display Metadata box version %d\n", version);
>          return 0;
>      }
> -    if (sc->mastering)
> -        return AVERROR_INVALIDDATA;
> +    if (sc->mastering) {
> +        av_log(c->fc, AV_LOG_WARNING, "Ignoring duplicate Mastering Display Metadata\n");

If this is expected (and maybe even encouraged/required by some spec),
then why is this a warning?

> +        return 0;
> +    }
>  
>      avio_skip(pb, 3); /* flags */
>  
> @@ -6178,11 +6180,16 @@ static int mov_read_mdcv(MOVContext *c, AVIOContext *pb, MOVAtom atom)
>  
>      sc = c->fc->streams[c->fc->nb_streams - 1]->priv_data;
>  
> -    if (atom.size < 24 || sc->mastering) {
> +    if (atom.size < 24) {
>          av_log(c->fc, AV_LOG_ERROR, "Invalid Mastering Display Color Volume box\n");
>          return AVERROR_INVALIDDATA;
>      }
>  
> +    if (sc->mastering) {
> +        av_log(c->fc, AV_LOG_WARNING, "Ignoring duplicate Mastering Display Color Volume\n");
> +        return 0;
> +    }
> +
>      sc->mastering = av_mastering_display_metadata_alloc();
>      if (!sc->mastering)
>          return AVERROR(ENOMEM);