[FFmpeg-devel] [FFmpeg-cvslog] avcodec/mpegaudio_parser: Skip APE tags when parsing mp3 packets.

[Alexander Strasser]

On 2018-01-30 04:29 +0000, Dale Curtis wrote:
> ffmpeg | branch: master | Dale Curtis <dalecurtis at chromium.org> | Mon Jan 29 15:10:26 2018 -0800| [42323c3e3a600288e4bf1cefe952486ffc29d280] | committer: Michael Niedermayer
> 
> avcodec/mpegaudio_parser: Skip APE tags when parsing mp3 packets.
> 
> Otherwise the decoder will throw "Missing header" errors when the
> packets are sent for decoding.
> 
> This is similar to 89a420b71b5.
> 
> Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
> 
> > http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=42323c3e3a600288e4bf1cefe952486ffc29d280
> ---
> 
>  libavcodec/mpegaudio_parser.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/libavcodec/mpegaudio_parser.c b/libavcodec/mpegaudio_parser.c
> index 8c39825792..244281b56f 100644
> --- a/libavcodec/mpegaudio_parser.c
> +++ b/libavcodec/mpegaudio_parser.c
> @@ -23,6 +23,7 @@
>  #include "parser.h"
>  #include "mpegaudiodecheader.h"
>  #include "libavutil/common.h"
> +#include "libavformat/apetag.h" // for APE tag.
>  #include "libavformat/id3v1.h" // for ID3v1_TAG_SIZE
>  
>  typedef struct MpegAudioParseContext {
> @@ -120,6 +121,12 @@ static int mpegaudio_parse(AVCodecParserContext *s1,
>          return next;
>      }
>  

> +    if (flush && buf_size >= APE_TAG_FOOTER_BYTES && memcmp(buf, APE_TAG_PREAMBLE, 8) == 0) {

I wonder if it would have been better to write out the preamble as
literal ("APETAGEX"). It just feels a bit wrong to have the data
described in one place (apetag.h) and the length in another.

For this instance it isn't important at all and I would think
APE_TAG_PREAMBLE is very unlikely to ever change.


  Alexander

> +        *poutbuf = NULL;
> +        *poutbuf_size = 0;
> +        return next;
> +    }
> +
>      *poutbuf = buf;
>      *poutbuf_size = buf_size;
>      return next;