diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/demuxers/demux_flac.c | 42 |
1 files changed, 37 insertions, 5 deletions
diff --git a/src/demuxers/demux_flac.c b/src/demuxers/demux_flac.c index 94c668555..bd5c19350 100644 --- a/src/demuxers/demux_flac.c +++ b/src/demuxers/demux_flac.c @@ -23,7 +23,7 @@ * For more information on the FLAC file format, visit: * http://flac.sourceforge.net/ * - * $Id: demux_flac.c,v 1.11 2006/11/09 15:13:19 dgp85 Exp $ + * $Id: demux_flac.c,v 1.12 2006/11/09 23:51:29 dgp85 Exp $ */ #ifdef HAVE_CONFIG_H @@ -97,11 +97,43 @@ static int open_flac_file(demux_flac_t *flac) { if ((preamble[0] != 'f') || (preamble[1] != 'L') || (preamble[2] != 'a') || - (preamble[3] != 'C')) - return 0; + (preamble[3] != 'C')) { + + uint32_t id3size; - /* file is qualified; skip over the signature bytes in the stream */ - flac->input->seek(flac->input, 4, SEEK_SET); + /* Unfortunately some FLAC files have an ID3 flag prefixed on them + * before the actual FLAC headers... these are barely legal, but + * users use them and want them working, so check and skip the ID3 + * tag if present. + */ + if ( preamble[0] != 'I' || preamble[1] != 'D' || preamble[2] != '3' ) + return 0; + + /* First 3 bytes are the ID3 signature as above, then comes two bytes + * encoding the major and minor version of ID3 used, that we can ignore + * as long as we don't try to read the metadata; after those there's a + * single byte with flags that depends on the ID3 version used; and now + * after all that stuff, there's the size of the rest of the tag, which + * is encoded as four bytes.. but only 7 out of 8 bits of every byte is + * used... don't ask. + */ + flac->input->seek(flac->input, 6, SEEK_SET); + if ( flac->input->read(flac->input, preamble, 4) != 4 ) + return 0; + + id3size = (preamble[0] << 7*3) + (preamble[1] << 7*2) + (preamble[2] << 7) + preamble[3]; + + flac->input->seek(flac->input, id3size, SEEK_CUR); + + if ( flac->input->read(flac->input, preamble, 4) != 4 ) + return 0; + + if ( preamble[0] != 'f' || preamble[1] != 'L' || preamble[2] != 'a' || preamble[3] != 'C' ) + return 0; + + } else + /* file is qualified; skip over the signature bytes in the stream */ + flac->input->seek(flac->input, 4, SEEK_SET); /* loop through the metadata blocks; use a do-while construct since there * will always be 1 metadata block */ |