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| author | Limin Wang <lance.lmwang@gmail.com> | 2019-11-11 09:05:02 +0800 |
|---|---|---|
| committer | Michael Niedermayer <michael@niedermayer.cc> | 2019-11-11 20:13:36 +0100 |
| commit | 72915ca8ba66f96717838439ee13cb3f70f9863f (patch) | |
| tree | f1ad58bf8f39ca4ca450e7e5c4172f26c2ae7e5f /libavformat/mp3dec.c | |
| parent | 529145168b005eb4745b606c9d4d8c05c1757df8 (diff) | |
| download | ffmpeg-72915ca8ba66f96717838439ee13cb3f70f9863f.tar.gz | |
avformat/mp3dec: replace SAME_HEADER_MASK with MP3_MASK
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>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Diffstat (limited to 'libavformat/mp3dec.c')
| -rw-r--r-- | libavformat/mp3dec.c | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/libavformat/mp3dec.c b/libavformat/mp3dec.c index dd14174e07..6888c88f83 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; @@ -398,7 +396,7 @@ 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); |