* MP3 demuxer
* Copyright (c) 2003 Fabrice Bellard
*
- * This file is part of FFmpeg.
+ * This file is part of Libav.
*
- * FFmpeg is free software; you can redistribute it and/or
+ * Libav is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
- * FFmpeg is distributed in the hope that it will be useful,
+ * Libav is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
- * License along with FFmpeg; if not, write to the Free Software
+ * License along with Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "libavutil/avstring.h"
#include "libavutil/intreadwrite.h"
+#include "libavutil/crc.h"
+#include "libavutil/dict.h"
+#include "libavutil/mathematics.h"
#include "avformat.h"
+#include "internal.h"
+#include "avio_internal.h"
#include "id3v2.h"
#include "id3v1.h"
+#include "replaygain.h"
+
+#include "libavcodec/avcodec.h"
#include "libavcodec/mpegaudiodecheader.h"
+#define XING_FLAG_FRAMES 0x01
+#define XING_FLAG_SIZE 0x02
+#define XING_FLAG_TOC 0x04
+#define XING_FLAC_QSCALE 0x08
+
+#define XING_TOC_COUNT 100
+
+typedef struct MP3DecContext {
+ int xing_toc;
+ unsigned frames; /* Total number of frames in file */
+ unsigned size; /* Total number of bytes in the stream */
+ int is_cbr;
+} MP3DecContext;
+
/* mp3 read */
static int mp3_read_probe(AVProbeData *p)
{
int max_frames, first_frames = 0;
- int fsize, frames, sample_rate;
+ int frames, ret;
uint32_t header;
uint8_t *buf, *buf0, *buf2, *end;
- AVCodecContext avctx;
buf0 = p->buf;
end = p->buf + p->buf_size - sizeof(uint32_t);
buf2 = buf;
for(frames = 0; buf2 < end; frames++) {
+ MPADecodeHeader h;
+
header = AV_RB32(buf2);
- fsize = ff_mpa_decode_header(&avctx, header, &sample_rate, &sample_rate, &sample_rate, &sample_rate);
- if(fsize < 0)
+ ret = avpriv_mpegaudio_decode_header(&h, header);
+ if (ret != 0)
break;
- buf2 += fsize;
+ buf2 += h.frame_size;
}
max_frames = FFMAX(max_frames, frames);
if(buf == buf0)
}
// 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>500)return AVPROBE_SCORE_MAX/2;
- else if(max_frames>=4) return AVPROBE_SCORE_MAX/4;
- else if(max_frames>=1) return 1;
- else return 0;
+ if (first_frames >= 10)
+ return AVPROBE_SCORE_EXTENSION + 5;
+ if (first_frames >= 4)
+ return AVPROBE_SCORE_EXTENSION + 1;
+
+ if (max_frames) {
+ int pes = 0, i;
+ unsigned int code = -1;
+
+#define VIDEO_ID 0x000001e0
+#define AUDIO_ID 0x000001c0
+ /* do a search for mpegps headers to be able to properly bias
+ * towards mpegps if we detect this stream as both. */
+ for (i = 0; i<p->buf_size; i++) {
+ code = (code << 8) + p->buf[i];
+ if ((code & 0xffffff00) == 0x100) {
+ if ((code & 0x1f0) == VIDEO_ID) pes++;
+ else if((code & 0x1e0) == AUDIO_ID) pes++;
+ }
+ }
+
+ if (pes)
+ max_frames = (max_frames + pes - 1) / pes;
+ }
+ if (max_frames > 500) return AVPROBE_SCORE_EXTENSION;
+ else if (max_frames >= 4) return AVPROBE_SCORE_EXTENSION / 2;
+ else if (max_frames >= 1) return 1;
+ else return 0;
//mpegps_mp3_unrecognized_format.mpg has max_frames=3
}
+static void read_xing_toc(AVFormatContext *s, int64_t filesize, int64_t duration)
+{
+ int i;
+ MP3DecContext *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;
+}
+
+static void mp3_parse_info_tag(AVFormatContext *s, AVStream *st,
+ MPADecodeHeader *c, uint32_t spf)
+{
+#define LAST_BITS(k, n) ((k) & ((1 << (n)) - 1))
+#define MIDDLE_BITS(k, m, n) LAST_BITS((k) >> (m), ((n) - (m)))
+
+ uint16_t crc;
+ uint32_t v, delays;
+
+ char version[10];
+
+ uint32_t peak = 0;
+ int32_t r_gain = INT32_MIN, a_gain = INT32_MIN;
+
+ MP3DecContext *mp3 = s->priv_data;
+ static const int64_t xing_offtbl[2][2] = { { 32, 17 }, { 17, 9 } };
+
+ /* Check for Xing / Info tag */
+ avio_skip(s->pb, xing_offtbl[c->lsf == 1][c->nb_channels == 1]);
+ v = avio_rb32(s->pb);
+ mp3->is_cbr = v == MKBETAG('I', 'n', 'f', 'o');
+ if (v != MKBETAG('X', 'i', 'n', 'g') && !mp3->is_cbr)
+ return;
+
+ v = avio_rb32(s->pb);
+ if (v & XING_FLAG_FRAMES)
+ mp3->frames = avio_rb32(s->pb);
+ if (v & XING_FLAG_SIZE)
+ mp3->size = avio_rb32(s->pb);
+ if (v & XING_FLAG_TOC && mp3->frames)
+ read_xing_toc(s, mp3->size, av_rescale_q(mp3->frames,
+ (AVRational){spf, c->sample_rate},
+ st->time_base));
+
+ /* VBR quality */
+ if (v & XING_FLAC_QSCALE)
+ avio_rb32(s->pb);
+
+ /* Encoder short version string */
+ memset(version, 0, sizeof(version));
+ avio_read(s->pb, version, 9);
+
+ /* Info Tag revision + VBR method */
+ avio_r8(s->pb);
+
+ /* Lowpass filter value */
+ avio_r8(s->pb);
+
+ /* ReplayGain peak */
+ v = avio_rb32(s->pb);
+ peak = av_rescale(v, 100000, 1 << 23);
+
+ /* Radio ReplayGain */
+ v = avio_rb16(s->pb);
+
+ if (MIDDLE_BITS(v, 13, 15) == 1) {
+ r_gain = MIDDLE_BITS(v, 0, 8) * 10000;
+
+ if (v & (1 << 9))
+ r_gain *= -1;
+ }
+
+ /* Audiophile ReplayGain */
+ v = avio_rb16(s->pb);
+
+ if (MIDDLE_BITS(v, 13, 15) == 2) {
+ a_gain = MIDDLE_BITS(v, 0, 8) * 10000;
+
+ if (v & (1 << 9))
+ a_gain *= -1;
+ }
+
+ /* Encoding flags + ATH Type */
+ avio_r8(s->pb);
+
+ /* if ABR {specified bitrate} else {minimal bitrate} */
+ avio_r8(s->pb);
+
+ /* Encoder delays */
+ delays = avio_rb24(s->pb);
+ st->codecpar->initial_padding = delays >> 12;
+ st->codecpar->trailing_padding = delays & ((1 << 12) - 1);
+
+ /* Misc */
+ avio_r8(s->pb);
+
+ /* MP3 gain */
+ avio_r8(s->pb);
+
+ /* Preset and surround info */
+ avio_rb16(s->pb);
+
+ /* Music length */
+ avio_rb32(s->pb);
+
+ /* Music CRC */
+ avio_rb16(s->pb);
+
+ /* Info Tag CRC */
+ crc = ffio_get_checksum(s->pb);
+ v = avio_rb16(s->pb);
+
+ if (v == crc) {
+ ff_replaygain_export_raw(st, r_gain, peak, a_gain, 0);
+ av_dict_set(&st->metadata, "encoder", version, 0);
+ }
+}
+
+static void mp3_parse_vbri_tag(AVFormatContext *s, AVStream *st, int64_t base)
+{
+ uint32_t v;
+ MP3DecContext *mp3 = s->priv_data;
+
+ /* Check for VBRI tag (always 32 bytes after end of mpegaudio header) */
+ avio_seek(s->pb, base + 4 + 32, SEEK_SET);
+ v = avio_rb32(s->pb);
+ if (v == MKBETAG('V', 'B', 'R', 'I')) {
+ /* Check tag version */
+ if (avio_rb16(s->pb) == 1) {
+ /* skip delay and quality */
+ avio_skip(s->pb, 4);
+ mp3->size = avio_rb32(s->pb);
+ mp3->frames = avio_rb32(s->pb);
+ }
+ }
+}
+
/**
* Try to find Xing/Info/VBRI tags and compute duration from info therein
*/
static int mp3_parse_vbr_tags(AVFormatContext *s, AVStream *st, int64_t base)
{
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}};
MPADecodeHeader c;
int vbrtag_size = 0;
+ MP3DecContext *mp3 = s->priv_data;
+ int ret;
+
+ ffio_init_checksum(s->pb, ff_crcA001_update, 0);
v = avio_rb32(s->pb);
- if(ff_mpa_check_header(v) < 0)
- return -1;
- if (ff_mpegaudio_decode_header(&c, v) == 0)
+ ret = avpriv_mpegaudio_decode_header(&c, v);
+ if (ret < 0)
+ return ret;
+ else if (ret == 0)
vbrtag_size = c.frame_size;
if(c.layer != 3)
return -1;
- /* Check for Xing / Info tag */
- avio_seek(s->pb, xing_offtbl[c.lsf == 1][c.nb_channels == 1], SEEK_CUR);
- 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)
- frames = avio_rb32(s->pb);
- if(v & 0x2)
- size = avio_rb32(s->pb);
- }
+ spf = c.lsf ? 576 : 1152; /* Samples per frame, layer 3 */
- /* Check for VBRI tag (always 32 bytes after end of mpegaudio header) */
- avio_seek(s->pb, base + 4 + 32, SEEK_SET);
- v = avio_rb32(s->pb);
- if(v == MKBETAG('V', 'B', 'R', 'I')) {
- /* Check tag version */
- if(avio_rb16(s->pb) == 1) {
- /* skip delay and quality */
- avio_seek(s->pb, 4, SEEK_CUR);
- frames = avio_rb32(s->pb);
- size = avio_rb32(s->pb);
- }
- }
+ mp3->frames = 0;
+ mp3->size = 0;
+
+ mp3_parse_info_tag(s, st, &c, spf);
+ mp3_parse_vbri_tag(s, st, base);
- if(!frames && !size)
+ if (!mp3->frames && !mp3->size)
return -1;
/* 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},
+ if (mp3->frames)
+ st->duration = av_rescale_q(mp3->frames, (AVRational){spf, c.sample_rate},
st->time_base);
- if(size && frames)
- st->codec->bit_rate = av_rescale(size, 8 * c.sample_rate, frames * (int64_t)spf);
+ if (mp3->size && mp3->frames && !mp3->is_cbr)
+ st->codecpar->bit_rate = av_rescale(mp3->size, 8 * c.sample_rate, mp3->frames * (int64_t)spf);
return 0;
}
-static int mp3_read_header(AVFormatContext *s,
- AVFormatParameters *ap)
+static int mp3_read_header(AVFormatContext *s)
{
AVStream *st;
int64_t off;
+ int ret;
- st = av_new_stream(s, 0);
+ st = avformat_new_stream(s, NULL);
if (!st)
return AVERROR(ENOMEM);
- st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
- st->codec->codec_id = CODEC_ID_MP3;
+ st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
+ st->codecpar->codec_id = AV_CODEC_ID_MP3;
st->need_parsing = AVSTREAM_PARSE_FULL;
st->start_time = 0;
// lcm of all mp3 sample rates
- av_set_pts_info(st, 64, 1, 14112000);
+ avpriv_set_pts_info(st, 64, 1, 14112000);
- off = url_ftell(s->pb);
+ off = avio_tell(s->pb);
- if (!av_metadata_get(s->metadata, "", NULL, AV_METADATA_IGNORE_SUFFIX))
+ if (!av_dict_get(s->metadata, "", NULL, AV_DICT_IGNORE_SUFFIX))
ff_id3v1_read(s);
if (mp3_parse_vbr_tags(s, st, off) < 0)
avio_seek(s->pb, off, SEEK_SET);
+ ret = ff_replaygain_export(st, s->metadata);
+ if (ret < 0)
+ return ret;
+
/* the parameters will be extracted from the compressed bitstream */
return 0;
}
static int mp3_read_packet(AVFormatContext *s, AVPacket *pkt)
{
- int ret, size;
- // AVStream *st = s->streams[0];
-
- size= MP3_PACKET_SIZE;
+ int ret;
- ret= av_get_packet(s->pb, pkt, size);
+ ret = av_get_packet(s->pb, pkt, MP3_PACKET_SIZE);
+ if (ret < 0)
+ return ret;
pkt->stream_index = 0;
- if (ret <= 0) {
- return AVERROR(EIO);
- }
if (ret > ID3v1_TAG_SIZE &&
memcmp(&pkt->data[ret - ID3v1_TAG_SIZE], "TAG", 3) == 0)
return ret;
}
+#define SEEK_PACKETS 4
+#define SEEK_WINDOW (SEEK_PACKETS * MP3_PACKET_SIZE)
+
+/* The toc entry can position to the wrong byte offset, try to pick
+ * the closest frame by probing the data in a window of 4 packets.
+ */
+
+static int check(AVIOContext *pb, int64_t pos, int64_t *out_pos)
+{
+ MPADecodeHeader mh = { 0 };
+ int i;
+ uint32_t header;
+ int64_t off = 0;
+
+
+ for (i = 0; i < SEEK_PACKETS; i++) {
+ off = avio_seek(pb, pos + mh.frame_size, SEEK_SET);
+ if (off < 0)
+ break;
+
+ header = avio_rb32(pb);
+
+
+ if (avpriv_mpegaudio_decode_header(&mh, header))
+ break;
+ out_pos[i] = off;
+ }
+
+ return i;
+}
+
+static int reposition(AVFormatContext *s, int64_t pos)
+{
+ int ret, best_valid = -1;
+ int64_t p, best_pos = -1;
+
+ for (p = FFMAX(pos - SEEK_WINDOW / 2, 0); p < pos + SEEK_WINDOW / 2; p++) {
+ int64_t out_pos[SEEK_PACKETS];
+ ret = check(s->pb, p, out_pos);
+
+ if (best_valid < ret) {
+ int i;
+ for (i = 0; i < ret; i++) {
+ if (llabs(best_pos - pos) > llabs(out_pos[i] - pos)) {
+ best_pos = out_pos[i];
+ best_valid = ret;
+ }
+ }
+ if (best_pos == pos && best_valid == SEEK_PACKETS)
+ break;
+ }
+ }
+
+ if (best_valid <= 0)
+ return AVERROR(ENOSYS);
+
+ p = avio_seek(s->pb, best_pos, SEEK_SET);
+ if (p < 0)
+ return p;
+
+ return 0;
+}
+
+static int mp3_seek(AVFormatContext *s, int stream_index, int64_t timestamp,
+ int flags)
+{
+ MP3DecContext *mp3 = s->priv_data;
+ AVIndexEntry *ie;
+ AVStream *st = s->streams[0];
+ int64_t ret = av_index_search_timestamp(st, timestamp, flags);
+
+ if (!mp3->xing_toc)
+ return AVERROR(ENOSYS);
+
+ if (ret < 0)
+ return ret;
+
+ ie = &st->index_entries[ret];
+
+ ret = reposition(s, ie->pos);
+ if (ret < 0)
+ return ret;
+
+ ff_update_cur_dts(s, st, ie->timestamp);
+
+ return 0;
+}
+
AVInputFormat ff_mp3_demuxer = {
- "mp3",
- NULL_IF_CONFIG_SMALL("MPEG audio layer 2/3"),
- 0,
- mp3_read_probe,
- mp3_read_header,
- mp3_read_packet,
- .flags= AVFMT_GENERIC_INDEX,
- .extensions = "mp2,mp3,m2a", /* XXX: use probe */
+ .name = "mp3",
+ .long_name = NULL_IF_CONFIG_SMALL("MP2/3 (MPEG audio layer 2/3)"),
+ .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,mpa", /* XXX: use probe */
};
projects / ffmpeg / blobdiff