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lavf/mp3enc: support MPEG-2 and MPEG-2.5 sample rates when writing Xing header.

This commit is contained in:
Clément Bœsch 2012-05-09 22:39:40 +02:00
parent 1f2f031c2f
commit ca297513f0
1 changed files with 11 additions and 7 deletions
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18
libavformat/mp3enc.c
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@ -121,17 +121,21 @@ static int mp3_write_xing(AVFormatContext *s)
int64_t xing_offset;
int32_t header, mask;
MPADecodeHeader c;
int srate_idx, i, channels;
int srate_idx, ver = 0, i, channels;
int needed;
if (!s->pb->seekable)
return 0;
for (i = 0; i < FF_ARRAY_ELEMS(avpriv_mpa_freq_tab); i++)
if (avpriv_mpa_freq_tab[i] == codec->sample_rate) {
srate_idx = i;
break;
}
for (i = 0; i < FF_ARRAY_ELEMS(avpriv_mpa_freq_tab); i++) {
const uint16_t base_freq = avpriv_mpa_freq_tab[i];
if (codec->sample_rate == base_freq) ver = 0x3; // MPEG 1
else if (codec->sample_rate == base_freq / 2) ver = 0x2; // MPEG 2
else if (codec->sample_rate == base_freq / 4) ver = 0x0; // MPEG 2.5
else continue;
srate_idx = i;
break;
}
if (i == FF_ARRAY_ELEMS(avpriv_mpa_freq_tab)) {
av_log(s, AV_LOG_WARNING, "Unsupported sample rate, not writing Xing header.\n");
return -1;
@ -145,7 +149,7 @@ static int mp3_write_xing(AVFormatContext *s)
/* dummy MPEG audio header */
header = 0xff << 24; // sync
header |= (0x7 << 5 | 0x3 << 3 | 0x1 << 1 | 0x1) << 16; // sync/mpeg-1/layer 3/no crc*/
header |= (0x7 << 5 | ver << 3 | 0x1 << 1 | 0x1) << 16; // sync/audio-version/layer 3/no crc*/
header |= (srate_idx << 2) << 8;
header |= channels << 6;