[FFmpeg-devel] [PATCH] avformat/id3v2: Support null-separated multi-value properties

[Soft Works]

> -----Original Message-----
> From: softworkz <ffmpegagent at gmail.com>
> Sent: Sonntag, 2. März 2025 00:57
> To: ffmpeg-devel at ffmpeg.org
> Cc: softworkz <softworkz at hotmail.com>; softworkz <softworkz at hotmail.com>
> Subject: [PATCH] avformat/id3v2: Support null-separated multi-value
> properties
> 
> From: softworkz <softworkz at hotmail.com>
> 
> Fixes Trac ticket https://trac.ffmpeg.org/ticket/6949
> 
> Signed-off-by: softworkz <softworkz at hotmail.com>
> ---
>     avformat/id3v2: Support null-separated multi-value properties
> 
>     Fixes Trac ticket https://trac.ffmpeg.org/ticket/6949
> 
> Published-As: https://github.com/ffstaging/FFmpeg/releases/tag/pr-
> ffstaging-54%2Fsoftworkz%2Fsubmit_id3v2-v1
> Fetch-It-Via: git fetch https://github.com/ffstaging/FFmpeg pr-
> ffstaging-54/softworkz/submit_id3v2-v1
> Pull-Request: https://github.com/ffstaging/FFmpeg/pull/54
> 
>  libavformat/id3v2.c | 65 ++++++++++++++++++++++++++++-----------------
>  1 file changed, 41 insertions(+), 24 deletions(-)
> 
> diff --git a/libavformat/id3v2.c b/libavformat/id3v2.c
> index 29ee59e1f4..cebb4acd75 100644
> --- a/libavformat/id3v2.c
> +++ b/libavformat/id3v2.c
> @@ -327,39 +327,55 @@ static void read_ttag(AVFormatContext *s,
> AVIOContext *pb, int taglen,
>                        AVDictionary **metadata, const char *key)
>  {
>      uint8_t *dst;
> -    int encoding, dict_flags = AV_DICT_DONT_OVERWRITE |
> AV_DICT_DONT_STRDUP_VAL;
> +    int encoding, nb_values = 0;
>      unsigned genre;
> +    AVDictionaryEntry *tag = NULL;
> 
>      if (taglen < 1)
>          return;
> 
> +    tag = av_dict_get(*metadata, key, NULL, 0);
> +    if (tag)
> +        return;
> +
>      encoding = avio_r8(pb);
>      taglen--; /* account for encoding type byte */
> 
> -    if (decode_str(s, pb, encoding, &dst, &taglen) < 0) {
> -        av_log(s, AV_LOG_ERROR, "Error reading frame %s, skipped\n",
> key);
> -        return;
> -    }
> +    /* Read all null-terminated values */
> +    while (taglen > 0) {
> +        int n = 0, dict_flags = AV_DICT_APPEND |
> AV_DICT_DONT_STRDUP_VAL;
> 
> -    if (!(strcmp(key, "TCON") && strcmp(key, "TCO"))
> &&
> -        (sscanf(dst, "(%d)", &genre) == 1 || sscanf(dst, "%d", &genre)
> == 1) &&
> -        genre <= ID3v1_GENRE_MAX) {
> -        av_freep(&dst);
> -        dst = av_strdup(ff_id3v1_genre_str[genre]);
> -    } else if (!(strcmp(key, "TXXX") && strcmp(key, "TXX"))) {
> -        /* dst now contains the key, need to get value */
> -        key = dst;
>          if (decode_str(s, pb, encoding, &dst, &taglen) < 0) {
>              av_log(s, AV_LOG_ERROR, "Error reading frame %s,
> skipped\n", key);
> -            av_freep(&key);
>              return;
>          }
> -        dict_flags |= AV_DICT_DONT_STRDUP_KEY;
> -    } else if (!*dst)
> -        av_freep(&dst);
> 
> -    if (dst)
> -        av_dict_set(metadata, key, dst, dict_flags);
> +        if (!(strcmp(key, "TCON") && strcmp(key, "TCO")) &&
> +            (sscanf(dst, "(%d)", &genre) == 1 || (sscanf(dst, "%d%n",
> &genre, &n) == 1 && n == strlen(dst))) &&
> +            genre <= ID3v1_GENRE_MAX) {
> +            av_freep(&dst);
> +            dst = av_strdup(ff_id3v1_genre_str[genre]);
> +        } else if (!(strcmp(key, "TXXX") && strcmp(key, "TXX"))) {
> +            /* dst now contains the key, need to get value */
> +            key = dst;
> +            if (decode_str(s, pb, encoding, &dst, &taglen) < 0) {
> +                av_log(s, AV_LOG_ERROR, "Error reading frame %s,
> skipped\n", key);
> +                av_freep(&key);
> +                return;
> +            }
> +        } else if (!*dst) {
> +            av_freep(&dst);
> +            return;
> +        }
> +
> +        if (dst) {
> +            if (nb_values > 0)
> +                av_dict_set(metadata, key, ";", dict_flags &
> ~AV_DICT_DONT_STRDUP_VAL);
> +
> +            av_dict_set(metadata, key, dst, dict_flags);
> +            nb_values++;
> +        }
> +    }
>  }
> 
>  static void read_uslt(AVFormatContext *s, AVIOContext *pb, int taglen,
> @@ -372,7 +388,7 @@ static void read_uslt(AVFormatContext *s,
> AVIOContext *pb, int taglen,
>      int encoding;
>      int ok = 0;
> 
> -    if (taglen < 4)
> +    if (taglen < 1)
>          goto error;
> 
>      encoding = avio_r8(pb);
> @@ -383,10 +399,10 @@ static void read_uslt(AVFormatContext *s,
> AVIOContext *pb, int taglen,
>      lang[3] = '\0';
>      taglen -= 3;
> 
> -    if (decode_str(s, pb, encoding, &descriptor, &taglen) < 0 || taglen
> < 0)
> +    if (decode_str(s, pb, encoding, &descriptor, &taglen) < 0)
>          goto error;
> 
> -    if (decode_str(s, pb, encoding, &text, &taglen) < 0 || taglen < 0)
> +    if (decode_str(s, pb, encoding, &text, &taglen) < 0)
>          goto error;
> 
>      // FFmpeg does not support hierarchical metadata, so concatenate
> the keys.
> @@ -1003,7 +1019,8 @@ static void id3v2_parse(AVIOContext *pb,
> AVDictionary **metadata,
>                          t++;
>                  }
> 
> -                ffio_init_read_context(&pb_local, buffer, b - buffer);
> +                ffio_init_context(&pb_local, buffer, b - buffer, 0,
> NULL, NULL, NULL,
> +                                  NULL);
>                  tlen = b - buffer;
>                  pbx  = &pb_local.pub; // read from sync buffer
>              }
> @@ -1039,7 +1056,7 @@ static void id3v2_parse(AVIOContext *pb,
> AVDictionary **metadata,
>                          av_log(s, AV_LOG_ERROR, "Failed to uncompress
> tag: %d\n", err);
>                          goto seek;
>                      }
> -                    ffio_init_read_context(&pb_local,
> uncompressed_buffer, dlen);
> +                    ffio_init_context(&pb_local, uncompressed_buffer,
> dlen, 0, NULL, NULL, NULL, NULL);
>                      tlen = dlen;
>                      pbx = &pb_local.pub; // read from sync buffer
>                  }
> 
> base-commit: 0e7c2a6287f977c30e08e2a211385c6a80614fe8
> --
> ffmpeg-codebot


Is there any maintainer for avformat/id3v2 or somebody who would be able to review this?

Thanks
sw