[FFmpeg-devel] [PATCHv4] flac: ignore duplicated ID3 tags if vorbis tags exist

[wm4]

On Thu,  5 Feb 2015 22:57:07 -0500
Ben Boeckel <mathstuf at gmail.com> wrote:

> FLAC doesn't really support ID3 tags, so warn if they are found at all.
> If vorbis tags are found, toss out duplicate ID3 tags.
> 
> Fixes #3799.
> 
> Signed-off-by: Ben Boeckel <mathstuf at gmail.com>
> ---
>  libavformat/flacdec.c | 27 +++++++++++++++++++++++++++
>  1 file changed, 27 insertions(+)
> 
> diff --git a/libavformat/flacdec.c b/libavformat/flacdec.c
> index 1a8dc19..fdb8e46 100644
> --- a/libavformat/flacdec.c
> +++ b/libavformat/flacdec.c
> @@ -33,6 +33,7 @@ static int flac_read_header(AVFormatContext *s)
>      int ret, metadata_last=0, metadata_type, metadata_size, found_streaminfo=0;
>      uint8_t header[4];
>      uint8_t *buffer=NULL;
> +    int has_idv3 = 0;
>      AVStream *st = avformat_new_stream(s, NULL);
>      if (!st)
>          return AVERROR(ENOMEM);
> @@ -47,6 +48,19 @@ static int flac_read_header(AVFormatContext *s)
>          return 0;
>      }
>  
> +    if (av_dict_count(s->metadata)) {
> +        /* XXX: Is there a better way to parse this out? ID3 parsing is done
> +         * all the way out in avformat_open_input. */
> +        has_idv3 = 1;

Not that I know of... the way libavformat does this is a travesty
though.

> +    }
> +
> +    if (has_idv3) {
> +        int level = AV_LOG_WARNING;
> +        if (s->error_recognition & AV_EF_COMPLIANT)
> +            level = AV_LOG_ERROR;
> +        av_log(s, level, "Spec-compliant FLAC do not support ID3 tags.\n");
> +    }
> +
>      /* process metadata blocks */
>      while (!avio_feof(s->pb) && !metadata_last) {
>          avio_read(s->pb, header, 4);
> @@ -139,8 +153,16 @@ static int flac_read_header(AVFormatContext *s)
>              }
>              /* process supported blocks other than STREAMINFO */
>              if (metadata_type == FLAC_METADATA_TYPE_VORBIS_COMMENT) {
> +                AVDictionary *other_meta = NULL;
>                  AVDictionaryEntry *chmask;
>  
> +                if (has_idv3) {
> +                    av_log(s, AV_LOG_VERBOSE, "FLAC found with ID3 and vorbis tags; ignoring ID3 tags also provided by vorbis.\n");
> +
> +                    av_dict_copy(&other_meta, s->metadata, 0);
> +                    av_dict_free(&s->metadata);

Just swap these pointers?

> +                }
> +
>                  ret = ff_vorbis_comment(s, &s->metadata, buffer, metadata_size, 1);
>                  if (ret < 0) {
>                      av_log(s, AV_LOG_WARNING, "error parsing VorbisComment metadata\n");
> @@ -148,6 +170,11 @@ static int flac_read_header(AVFormatContext *s)
>                      s->event_flags |= AVFMT_EVENT_FLAG_METADATA_UPDATED;
>                  }
>  
> +                if (other_meta) {
> +                    av_dict_copy(&s->metadata, other_meta, AV_DICT_DONT_OVERWRITE);
> +                    av_dict_free(&other_meta);
> +                }
> +
>                  /* parse the channels mask if present */
>                  chmask = av_dict_get(s->metadata, "WAVEFORMATEXTENSIBLE_CHANNEL_MASK", NULL, 0);
>                  if (chmask) {