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mp3enc: move mp3_write_xing() further up in the file.

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It will be need by new functions called from mp3_write_trailer().
This commit is contained in:
Anton Khirnov 2012-02-29 09:11:26 +01:00
parent ba445f5557
commit c68148b1ea
1 changed files with 49 additions and 45 deletions
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94
libavformat/mp3enc.c
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@ -80,6 +80,55 @@ typedef struct MP3Context {
int64_t nb_frames_offset;
} MP3Context;
/* insert a dummy frame containing number of frames */
static void mp3_write_xing(AVFormatContext *s)
{
MP3Context *mp3 = s->priv_data;
AVCodecContext *codec = s->streams[0]->codec;
int bitrate_idx = 1; // 32 kbps
int64_t xing_offset = (codec->channels == 2) ? 32 : 17;
int32_t header;
MPADecodeHeader mpah;
int srate_idx, i, channels;
if (!s->pb->seekable)
return;
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;
}
if (i == FF_ARRAY_ELEMS(avpriv_mpa_freq_tab)) {
av_log(s, AV_LOG_ERROR, "Unsupported sample rate.\n");
return;
}
switch (codec->channels) {
case 1: channels = MPA_MONO; break;
case 2: channels = MPA_STEREO; break;
default: av_log(s, AV_LOG_ERROR, "Unsupported number of channels.\n"); return;
}
/* 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 |= (bitrate_idx << 4 | srate_idx << 2) << 8;
header |= channels << 6;
avio_wb32(s->pb, header);
avpriv_mpegaudio_decode_header(&mpah, header);
ffio_fill(s->pb, 0, xing_offset);
ffio_wfourcc(s->pb, "Xing");
avio_wb32(s->pb, 0x1); // only number of frames
mp3->nb_frames_offset = avio_tell(s->pb);
avio_wb32(s->pb, 0);
mpah.frame_size -= 4 + xing_offset + 4 + 4 + 4;
ffio_fill(s->pb, 0, mpah.frame_size);
}
static int mp3_write_trailer(struct AVFormatContext *s)
{
uint8_t buf[ID3v1_TAG_SIZE];
@ -132,51 +181,6 @@ static const AVClass mp3_muxer_class = {
.version = LIBAVUTIL_VERSION_INT,
};
/* insert a dummy frame containing number of frames */
static void mp3_write_xing(AVFormatContext *s)
{
AVCodecContext *codec = s->streams[0]->codec;
MP3Context *mp3 = s->priv_data;
int bitrate_idx = 1; // 32 kbps
int64_t xing_offset = (codec->channels == 2) ? 32 : 17;
int32_t header;
MPADecodeHeader mpah;
int srate_idx, i, channels;
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;
}
if (i == FF_ARRAY_ELEMS(avpriv_mpa_freq_tab)) {
av_log(s, AV_LOG_ERROR, "Unsupported sample rate.\n");
return;
}
switch (codec->channels) {
case 1: channels = MPA_MONO; break;
case 2: channels = MPA_STEREO; break;
default: av_log(s, AV_LOG_ERROR, "Unsupported number of channels.\n"); return;
}
/* 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 |= (bitrate_idx << 4 | srate_idx << 2) << 8;
header |= channels << 6;
avio_wb32(s->pb, header);
avpriv_mpegaudio_decode_header(&mpah, header);
ffio_fill(s->pb, 0, xing_offset);
ffio_wfourcc(s->pb, "Xing");
avio_wb32(s->pb, 0x1); // only number of frames
mp3->nb_frames_offset = avio_tell(s->pb);
avio_wb32(s->pb, 0);
mpah.frame_size -= 4 + xing_offset + 4 + 4 + 4;
ffio_fill(s->pb, 0, mpah.frame_size);
}
/**
* Write an ID3v2 header at beginning of stream