Message ID | 20191111010502.1894-2-lance.lmwang@gmail.com |
---|---|
State | Accepted |
Commit | 72915ca8ba66f96717838439ee13cb3f70f9863f |
Headers | show |
On Mon, Nov 11, 2019 at 09:05:02AM +0800, lance.lmwang@gmail.com wrote: > From: Limin Wang <lance.lmwang@gmail.com> > > mp3 header bitstream syntax: > header() > { > syncword 12bits bslsf > id 1bit bslsf > layer 2bit bslsf > protection_bit 1bit bslsf > bitrate_index 4bits bslsf > sampling_frequency 2bits bslsf > padding_bit 1bit bslsf > private_bit 1bit bslsf > mode 2bits bslsf > mode_extension 2bits bslsf > copyright 1bit bslsf > original/home 1bit bslsf > emphasis 2bits bslsf > } > > if the header is masking with MP3_MASK(0xFFFE0CCF), below fields will be cleared: > protection_bit, bitrate_index, sampling_freqency, mode > > with SAME_HEADER_MASK(0xFFFE0C00), extra below fields will be cleared which didn't make > sense: > mode_extension, copyright, original/home, emphasis > > As the MP3_MASK is good for same mp3 header masking and is defined in the > header, so it's preferable to remove SAME_HEADER_MASK to keep the masking same. > > Signed-off-by: Limin Wang <lance.lmwang@gmail.com> > --- > libavformat/mp3dec.c | 4 +--- > 1 file changed, 1 insertion(+), 3 deletions(-) will apply this and the previous patch thx [...]
diff --git a/libavformat/mp3dec.c b/libavformat/mp3dec.c index a047878..71a4ed7 100644 --- a/libavformat/mp3dec.c +++ b/libavformat/mp3dec.c @@ -42,8 +42,6 @@ #define XING_TOC_COUNT 100 -#define SAME_HEADER_MASK \ - (0xffe00000 | (3 << 17) | (3 << 10) | (3 << 19)) typedef struct { AVClass *class; @@ -406,7 +404,7 @@ static int mp3_read_header(AVFormatContext *s) ffio_ensure_seekback(s->pb, i + 1024 + frame_size + 4); ret = check(s->pb, off + i + frame_size, &header2); if (ret >= 0 && - (header & SAME_HEADER_MASK) == (header2 & SAME_HEADER_MASK)) + (header & MP3_MASK) == (header2 & MP3_MASK)) { av_log(s, i > 0 ? AV_LOG_INFO : AV_LOG_VERBOSE, "Skipping %d bytes of junk at %"PRId64".\n", i, off); ret = avio_seek(s->pb, off + i, SEEK_SET);