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Diffstat (limited to 'ffmpeg/libavformat/mp3dec.c')
-rw-r--r--ffmpeg/libavformat/mp3dec.c91
1 files changed, 65 insertions, 26 deletions
diff --git a/ffmpeg/libavformat/mp3dec.c b/ffmpeg/libavformat/mp3dec.c
index 57e4ba3..5d484e9 100644
--- a/ffmpeg/libavformat/mp3dec.c
+++ b/ffmpeg/libavformat/mp3dec.c
@@ -19,6 +19,7 @@
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
+#include "libavutil/opt.h"
#include "libavutil/avstring.h"
#include "libavutil/intreadwrite.h"
#include "libavutil/dict.h"
@@ -36,11 +37,15 @@
#define XING_TOC_COUNT 100
typedef struct {
+ AVClass *class;
int64_t filesize;
+ int64_t header_filesize;
int xing_toc;
int start_pad;
int end_pad;
-} MP3Context;
+ int usetoc;
+ int is_cbr;
+} MP3DecContext;
/* mp3 read */
@@ -62,6 +67,8 @@ static int mp3_read_probe(AVProbeData *p)
for(; buf < end; buf= buf2+1) {
buf2 = buf;
+ if(ff_mpa_check_header(AV_RB32(buf2)))
+ continue;
for(frames = 0; buf2 < end; frames++) {
header = AV_RB32(buf2);
@@ -76,11 +83,11 @@ static int mp3_read_probe(AVProbeData *p)
}
// keep this in sync with ac3 probe, both need to avoid
// issues with MPEG-files!
- if (first_frames>=4) return AVPROBE_SCORE_MAX/2+1;
- else if(max_frames>200)return AVPROBE_SCORE_MAX/2;
- else if(max_frames>=4) return AVPROBE_SCORE_MAX/4;
+ if (first_frames>=4) return AVPROBE_SCORE_EXTENSION + 1;
+ else if(max_frames>200)return AVPROBE_SCORE_EXTENSION;
+ else if(max_frames>=4) return AVPROBE_SCORE_EXTENSION / 2;
else if(ff_id3v2_match(buf0, ID3v2_DEFAULT_MAGIC) && 2*ff_id3v2_tag_len(buf0) >= p->buf_size)
- return AVPROBE_SCORE_MAX/8;
+ return p->buf_size < PROBE_BUF_MAX ? AVPROBE_SCORE_EXTENSION / 4 : AVPROBE_SCORE_EXTENSION - 2;
else if(max_frames>=1) return 1;
else return 0;
//mpegps_mp3_unrecognized_format.mpg has max_frames=3
@@ -89,23 +96,25 @@ static int mp3_read_probe(AVProbeData *p)
static void read_xing_toc(AVFormatContext *s, int64_t filesize, int64_t duration)
{
int i;
- MP3Context *mp3 = s->priv_data;
+ MP3DecContext *mp3 = s->priv_data;
+ int fill_index = mp3->usetoc && duration > 0;
if (!filesize &&
!(filesize = avio_size(s->pb))) {
av_log(s, AV_LOG_WARNING, "Cannot determine file size, skipping TOC table.\n");
- return;
+ fill_index = 0;
}
for (i = 0; i < XING_TOC_COUNT; i++) {
uint8_t b = avio_r8(s->pb);
-
- av_add_index_entry(s->streams[0],
+ if (fill_index)
+ 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;
+ if (fill_index)
+ mp3->xing_toc = 1;
}
/**
@@ -113,11 +122,11 @@ static void read_xing_toc(AVFormatContext *s, int64_t filesize, int64_t duration
*/
static int mp3_parse_vbr_tags(AVFormatContext *s, AVStream *st, int64_t base)
{
- MP3Context *mp3 = s->priv_data;
+ MP3DecContext *mp3 = s->priv_data;
uint32_t v, spf;
unsigned frames = 0; /* Total number of frames in file */
unsigned size = 0; /* Total number of bytes in the stream */
- const int64_t xing_offtbl[2][2] = {{32, 17}, {17,9}};
+ static const int64_t xing_offtbl[2][2] = {{32, 17}, {17,9}};
MPADecodeHeader c;
int vbrtag_size = 0;
int is_cbr;
@@ -143,7 +152,7 @@ static int mp3_parse_vbr_tags(AVFormatContext *s, AVStream *st, int64_t base)
frames = avio_rb32(s->pb);
if(v & XING_FLAG_SIZE)
size = avio_rb32(s->pb);
- if (v & XING_FLAG_TOC && frames)
+ if (v & XING_FLAG_TOC)
read_xing_toc(s, size, av_rescale_q(frames, (AVRational){spf, c.sample_rate},
st->time_base));
if(v & 8)
@@ -185,12 +194,15 @@ 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;
}
static int mp3_read_header(AVFormatContext *s)
{
- MP3Context *mp3 = s->priv_data;
+ MP3DecContext *mp3 = s->priv_data;
AVStream *st;
int64_t off;
@@ -226,7 +238,7 @@ static int mp3_read_header(AVFormatContext *s)
static int mp3_read_packet(AVFormatContext *s, AVPacket *pkt)
{
- MP3Context *mp3 = s->priv_data;
+ MP3DecContext *mp3 = s->priv_data;
int ret, size;
int64_t pos;
@@ -273,29 +285,42 @@ static int check(AVFormatContext *s, int64_t pos)
static int mp3_seek(AVFormatContext *s, int stream_index, int64_t timestamp,
int flags)
{
- MP3Context *mp3 = s->priv_data;
- AVIndexEntry *ie;
+ MP3DecContext *mp3 = s->priv_data;
+ AVIndexEntry *ie, ie1;
AVStream *st = s->streams[0];
int64_t ret = av_index_search_timestamp(st, timestamp, flags);
int i, j;
+ int dir = (flags&AVSEEK_FLAG_BACKWARD) ? -1 : 1;
+
+ 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;
- if (!mp3->xing_toc) {
+ 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;
#define MIN_VALID 3
for(i=0; i<4096; i++) {
- int64_t pos = ie->pos + i;
+ int64_t pos = ie->pos + i*dir;
for(j=0; j<MIN_VALID; j++) {
ret = check(s, pos);
if(ret < 0)
@@ -308,7 +333,7 @@ static int mp3_seek(AVFormatContext *s, int stream_index, int64_t timestamp,
if(j!=MIN_VALID)
i=0;
- ret = avio_seek(s->pb, ie->pos + i, SEEK_SET);
+ ret = avio_seek(s->pb, ie->pos + i*dir, SEEK_SET);
if (ret < 0)
return ret;
ff_update_cur_dts(s, st, ie->timestamp);
@@ -316,14 +341,28 @@ static int mp3_seek(AVFormatContext *s, int stream_index, int64_t timestamp,
return 0;
}
+static const AVOption options[] = {
+ { "usetoc", "use table of contents", offsetof(MP3DecContext, usetoc), AV_OPT_TYPE_INT, {.i64 = -1}, -1, 1, AV_OPT_FLAG_DECODING_PARAM},
+ { NULL },
+};
+
+static const AVClass demuxer_class = {
+ .class_name = "mp3",
+ .item_name = av_default_item_name,
+ .option = options,
+ .version = LIBAVUTIL_VERSION_INT,
+ .category = AV_CLASS_CATEGORY_DEMUXER,
+};
+
AVInputFormat ff_mp3_demuxer = {
.name = "mp3",
.long_name = NULL_IF_CONFIG_SMALL("MP2/3 (MPEG audio layer 2/3)"),
- .priv_data_size = sizeof(MP3Context),
.read_probe = mp3_read_probe,
.read_header = mp3_read_header,
.read_packet = mp3_read_packet,
.read_seek = mp3_seek,
+ .priv_data_size = sizeof(MP3DecContext),
.flags = AVFMT_GENERIC_INDEX,
- .extensions = "mp2,mp3,m2a", /* XXX: use probe */
+ .extensions = "mp2,mp3,m2a,mpa", /* XXX: use probe */
+ .priv_class = &demuxer_class,
};
generated by cgit v1.2.3 (git 2.39.1) at 2025-12-06 15:23:00 +0000