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mp3dec: detect CBR and use CBR axiom to seek

This should also work reasonable with truncated and growing mp3s.
Fixes Ticket2590

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
This commit is contained in:
Michael Niedermayer 2013-07-07 13:15:32 +02:00
parent 6150bec3f8
commit e096283ea5

View File

@ -39,10 +39,12 @@
typedef struct {
AVClass *class;
int64_t filesize;
int64_t header_filesize;
int xing_toc;
int start_pad;
int end_pad;
int usetoc;
int is_cbr;
} MP3DecContext;
/* mp3 read */
@ -190,6 +192,9 @@ static int mp3_parse_vbr_tags(AVFormatContext *s, AVStream *st, int64_t base)
if (size && frames && !is_cbr)
st->codec->bit_rate = av_rescale(size, 8 * c.sample_rate, frames * (int64_t)spf);
mp3->is_cbr = is_cbr;
mp3->header_filesize = size;
return 0;
}
@ -279,21 +284,33 @@ static int mp3_seek(AVFormatContext *s, int stream_index, int64_t timestamp,
int flags)
{
MP3DecContext *mp3 = s->priv_data;
AVIndexEntry *ie;
AVIndexEntry *ie, ie1;
AVStream *st = s->streams[0];
int64_t ret = av_index_search_timestamp(st, timestamp, flags);
int i, j;
if (!mp3->xing_toc) {
if (mp3->is_cbr && st->duration > 0 && mp3->header_filesize > s->data_offset) {
int64_t filesize = avio_size(s->pb);
int64_t duration;
if (filesize <= s->data_offset)
filesize = mp3->header_filesize;
filesize -= s->data_offset;
duration = av_rescale(st->duration, filesize, mp3->header_filesize - s->data_offset);
ie = &ie1;
timestamp = av_clip64(timestamp, 0, duration);
ie->timestamp = timestamp;
ie->pos = av_rescale(timestamp, filesize, duration) + s->data_offset;
} else if (mp3->xing_toc) {
if (ret < 0)
return ret;
ie = &st->index_entries[ret];
} else {
st->skip_samples = timestamp <= 0 ? mp3->start_pad + 528 + 1 : 0;
return -1;
}
if (ret < 0)
return ret;
ie = &st->index_entries[ret];
ret = avio_seek(s->pb, ie->pos, SEEK_SET);
if (ret < 0)
return ret;