X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=libavformat%2Fmp3dec.c;h=e282218b8b7df5d7e68820226e224579dd7f6b5b;hb=90bc423212396e96a02edc1118982ab7f7766a63;hp=f90348c1145b4b4ea8781c1423f55dabf46fd8a4;hpb=6b4aa5dac8f41aa452d0ce9a1bede9e59a303060;p=ffmpeg

diff --git a/libavformat/mp3dec.c b/libavformat/mp3dec.c
index f90348c1145..e282218b8b7 100644
--- a/libavformat/mp3dec.c
+++ b/libavformat/mp3dec.c
@@ -2,39 +2,60 @@
  * 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);
@@ -48,11 +69,13 @@ static int mp3_read_probe(AVProbeData *p)
         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)
@@ -60,101 +83,262 @@ 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>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;
 }
@@ -163,17 +347,13 @@ static int mp3_read_header(AVFormatContext *s,
 
 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)
@@ -185,13 +365,102 @@ static int mp3_read_packet(AVFormatContext *s, AVPacket *pkt)
     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 */
 };