#include "id3v1.h"
#include "libavcodec/mpegaudiodecheader.h"
+#define XING_FLAG_FRAMES 0x01
+#define XING_FLAG_SIZE 0x02
+#define XING_FLAG_TOC 0x04
+
+#define XING_TOC_COUNT 100
+
typedef struct {
int64_t filesize;
+ int xing_toc;
int start_pad;
int end_pad;
} MP3Context;
//mpegps_mp3_unrecognized_format.mpg has max_frames=3
}
+static void read_xing_toc(AVFormatContext *s, int64_t filesize, int64_t duration)
+{
+ int i;
+ MP3Context *mp3 = s->priv_data;
+
+ if (!filesize &&
+ !(filesize = avio_size(s->pb))) {
+ av_log(s, AV_LOG_WARNING, "Cannot determine file size, skipping TOC table.\n");
+ return;
+ }
+
+ for (i = 0; i < XING_TOC_COUNT; i++) {
+ uint8_t b = avio_r8(s->pb);
+
+ av_add_index_entry(s->streams[0],
+ av_rescale(b, filesize, 256),
+ av_rescale(i, duration, XING_TOC_COUNT),
+ 0, 0, AVINDEX_KEYFRAME);
+ }
+ mp3->xing_toc = 1;
+}
+
/**
* Try to find Xing/Info/VBRI tags and compute duration from info therein
*/
if(c.layer != 3)
return -1;
+ spf = c.lsf ? 576 : 1152; /* Samples per frame, layer 3 */
+
/* Check for Xing / Info tag */
avio_skip(s->pb, xing_offtbl[c.lsf == 1][c.nb_channels == 1]);
v = avio_rb32(s->pb);
if(v == MKBETAG('X', 'i', 'n', 'g') || v == MKBETAG('I', 'n', 'f', 'o')) {
v = avio_rb32(s->pb);
- if(v & 0x1)
+ if(v & XING_FLAG_FRAMES)
frames = avio_rb32(s->pb);
- if(v & 0x2)
+ if(v & XING_FLAG_SIZE)
size = avio_rb32(s->pb);
- if(v & 4)
- avio_skip(s->pb, 100);
+ if (v & XING_FLAG_TOC && frames)
+ read_xing_toc(s, size, av_rescale_q(frames, (AVRational){spf, c.sample_rate},
+ st->time_base));
if(v & 8)
avio_skip(s->pb, 4);
/* Skip the vbr tag frame */
avio_seek(s->pb, base + vbrtag_size, SEEK_SET);
- spf = c.lsf ? 576 : 1152; /* Samples per frame, layer 3 */
if(frames)
st->duration = av_rescale_q(frames, (AVRational){spf, c.sample_rate},
st->time_base);
return ret;
}
-static int read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
+static int mp3_seek(AVFormatContext *s, int stream_index, int64_t timestamp,
+ int flags)
{
MP3Context *mp3 = s->priv_data;
- AVStream *st = s->streams[stream_index];
+ AVIndexEntry *ie;
+ AVStream *st = s->streams[0];
+ int64_t ret = av_index_search_timestamp(st, timestamp, flags);
+ uint32_t header = 0;
+
+ if (!mp3->xing_toc) {
+ st->skip_samples = timestamp <= 0 ? mp3->start_pad + 528 + 1 : 0;
+
+ return -1;
+ }
- st->skip_samples = timestamp <= 0 ? mp3->start_pad + 528 + 1 : 0;
+ if (ret < 0)
+ return ret;
+
+ ie = &st->index_entries[ret];
+ ret = avio_seek(s->pb, ie->pos, SEEK_SET);
+ if (ret < 0)
+ return ret;
+
+ while (!s->pb->eof_reached) {
+ header = (header << 8) + avio_r8(s->pb);
+ if (ff_mpa_check_header(header) >= 0) {
+ ff_update_cur_dts(s, st, ie->timestamp);
+ ret = avio_seek(s->pb, -4, SEEK_CUR);
+
+ st->skip_samples = ie->timestamp <= 0 ? mp3->start_pad + 528 + 1 : 0;
+
+ return (ret >= 0) ? 0 : ret;
+ }
+ }
- return -1;
+ return AVERROR_EOF;
}
AVInputFormat ff_mp3_demuxer = {
.read_probe = mp3_read_probe,
.read_header = mp3_read_header,
.read_packet = mp3_read_packet,
- .read_seek = read_seek,
+ .read_seek = mp3_seek,
.flags = AVFMT_GENERIC_INDEX,
.extensions = "mp2,mp3,m2a", /* XXX: use probe */
};