/* * MP3 muxer and demuxer * Copyright (c) 2003 Fabrice Bellard * * This file is part of FFmpeg. * * FFmpeg 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, * 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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #include <strings.h> #include "libavutil/avstring.h" #include "libavutil/intreadwrite.h" #include "avformat.h" #include "id3v2.h" #include "id3v1.h" #if CONFIG_MP3_DEMUXER #include "libavcodec/mpegaudio.h" #include "libavcodec/mpegaudiodecheader.h" /* mp3 read */ static int mp3_read_probe(AVProbeData *p) { int max_frames, first_frames = 0; int fsize, frames, sample_rate; uint32_t header; uint8_t *buf, *buf0, *buf2, *end; AVCodecContext avctx; buf0 = p->buf; if(ff_id3v2_match(buf0)) { buf0 += ff_id3v2_tag_len(buf0); } max_frames = 0; buf = buf0; end = p->buf + p->buf_size - sizeof(uint32_t); for(; buf < end; buf= buf2+1) { buf2 = buf; for(frames = 0; buf2 < end; frames++) { header = AV_RB32(buf2); fsize = ff_mpa_decode_header(&avctx, header, &sample_rate, &sample_rate, &sample_rate, &sample_rate); if(fsize < 0) break; buf2 += fsize; } max_frames = FFMAX(max_frames, frames); if(buf == buf0) first_frames= frames; } // 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(buf0!=p->buf) return AVPROBE_SCORE_MAX/4-1; else if(max_frames>=1) return 1; else return 0; //mpegps_mp3_unrecognized_format.mpg has max_frames=3 } /** * 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; int frames = -1; /* Total number of frames in file */ const int64_t xing_offtbl[2][2] = {{32, 17}, {17,9}}; MPADecodeHeader c; int vbrtag_size = 0; v = get_be32(s->pb); if(ff_mpa_check_header(v) < 0) return -1; if (ff_mpegaudio_decode_header(&c, v) == 0) vbrtag_size = c.frame_size; if(c.layer != 3) return -1; /* Check for Xing / Info tag */ url_fseek(s->pb, xing_offtbl[c.lsf == 1][c.nb_channels == 1], SEEK_CUR); v = get_be32(s->pb); if(v == MKBETAG('X', 'i', 'n', 'g') || v == MKBETAG('I', 'n', 'f', 'o')) { v = get_be32(s->pb); if(v & 0x1) frames = get_be32(s->pb); } /* Check for VBRI tag (always 32 bytes after end of mpegaudio header) */ url_fseek(s->pb, base + 4 + 32, SEEK_SET); v = get_be32(s->pb); if(v == MKBETAG('V', 'B', 'R', 'I')) { /* Check tag version */ if(get_be16(s->pb) == 1) { /* skip delay, quality and total bytes */ url_fseek(s->pb, 8, SEEK_CUR); frames = get_be32(s->pb); } } if(frames < 0) return -1; /* Skip the vbr tag frame */ url_fseek(s->pb, base + vbrtag_size, SEEK_SET); spf = c.lsf ? 576 : 1152; /* Samples per frame, layer 3 */ st->duration = av_rescale_q(frames, (AVRational){spf, c.sample_rate}, st->time_base); return 0; } static int mp3_read_header(AVFormatContext *s, AVFormatParameters *ap) { AVStream *st; int64_t off; st = av_new_stream(s, 0); if (!st) return AVERROR(ENOMEM); st->codec->codec_type = CODEC_TYPE_AUDIO; st->codec->codec_id = 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); ff_id3v2_read(s); if (!av_metadata_get(s->metadata, "", NULL, AV_METADATA_IGNORE_SUFFIX)) ff_id3v1_read(s); off = url_ftell(s->pb); if (mp3_parse_vbr_tags(s, st, off) < 0) url_fseek(s->pb, off, SEEK_SET); /* the parameters will be extracted from the compressed bitstream */ return 0; } #define MP3_PACKET_SIZE 1024 static int mp3_read_packet(AVFormatContext *s, AVPacket *pkt) { int ret, size; // AVStream *st = s->streams[0]; size= MP3_PACKET_SIZE; ret= av_get_packet(s->pb, pkt, size); pkt->stream_index = 0; if (ret <= 0) { return AVERROR(EIO); } /* note: we need to modify the packet size here to handle the last packet */ pkt->size = ret; return ret; } AVInputFormat 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 */ .metadata_conv = ff_id3v2_metadata_conv, }; #endif #if CONFIG_MP2_MUXER || CONFIG_MP3_MUXER static int id3v1_set_string(AVFormatContext *s, const char *key, uint8_t *buf, int buf_size) { AVMetadataTag *tag; if ((tag = av_metadata_get(s->metadata, key, NULL, 0))) strncpy(buf, tag->value, buf_size); return !!tag; } static int id3v1_create_tag(AVFormatContext *s, uint8_t *buf) { AVMetadataTag *tag; int i, count = 0; memset(buf, 0, ID3v1_TAG_SIZE); /* fail safe */ buf[0] = 'T'; buf[1] = 'A'; buf[2] = 'G'; count += id3v1_set_string(s, "title", buf + 3, 30); count += id3v1_set_string(s, "author", buf + 33, 30); count += id3v1_set_string(s, "album", buf + 63, 30); count += id3v1_set_string(s, "year", buf + 93, 4); count += id3v1_set_string(s, "comment", buf + 97, 30); if ((tag = av_metadata_get(s->metadata, "track", NULL, 0))) { buf[125] = 0; buf[126] = atoi(tag->value); count++; } buf[127] = 0xFF; /* default to unknown genre */ if ((tag = av_metadata_get(s->metadata, "genre", NULL, 0))) { for(i = 0; i <= ID3v1_GENRE_MAX; i++) { if (!strcasecmp(tag->value, ff_id3v1_genre_str[i])) { buf[127] = i; count++; break; } } } return count; } /* simple formats */ static void id3v2_put_size(AVFormatContext *s, int size) { put_byte(s->pb, size >> 21 & 0x7f); put_byte(s->pb, size >> 14 & 0x7f); put_byte(s->pb, size >> 7 & 0x7f); put_byte(s->pb, size & 0x7f); } static void id3v2_put_ttag(AVFormatContext *s, const char *buf, int len, uint32_t tag) { put_be32(s->pb, tag); id3v2_put_size(s, len + 1); put_be16(s->pb, 0); put_byte(s->pb, 3); /* UTF-8 */ put_buffer(s->pb, buf, len); } static int mp3_write_packet(struct AVFormatContext *s, AVPacket *pkt) { put_buffer(s->pb, pkt->data, pkt->size); put_flush_packet(s->pb); return 0; } static int mp3_write_trailer(struct AVFormatContext *s) { uint8_t buf[ID3v1_TAG_SIZE]; /* write the id3v1 tag */ if (id3v1_create_tag(s, buf) > 0) { put_buffer(s->pb, buf, ID3v1_TAG_SIZE); put_flush_packet(s->pb); } return 0; } #endif /* CONFIG_MP2_MUXER || CONFIG_MP3_MUXER */ #if CONFIG_MP2_MUXER AVOutputFormat mp2_muxer = { "mp2", NULL_IF_CONFIG_SMALL("MPEG audio layer 2"), "audio/x-mpeg", "mp2,m2a", 0, CODEC_ID_MP2, CODEC_ID_NONE, NULL, mp3_write_packet, mp3_write_trailer, }; #endif #if CONFIG_MP3_MUXER /** * Write an ID3v2.4 header at beginning of stream */ static int mp3_write_header(struct AVFormatContext *s) { AVMetadataTag *t = NULL; int totlen = 0; int64_t size_pos, cur_pos; put_be32(s->pb, MKBETAG('I', 'D', '3', 0x04)); /* ID3v2.4 */ put_byte(s->pb, 0); put_byte(s->pb, 0); /* flags */ /* reserve space for size */ size_pos = url_ftell(s->pb); put_be32(s->pb, 0); while ((t = av_metadata_get(s->metadata, "", t, AV_METADATA_IGNORE_SUFFIX))) { uint32_t tag = 0; if (t->key[0] == 'T' && strcmp(t->key, "TSSE")) { int i; for (i = 0; *ff_id3v2_tags[i]; i++) if (AV_RB32(t->key) == AV_RB32(ff_id3v2_tags[i])) { int len = strlen(t->value); tag = AV_RB32(t->key); totlen += len + ID3v2_HEADER_SIZE + 2; id3v2_put_ttag(s, t->value, len + 1, tag); break; } } if (!tag) { /* unknown tag, write as TXXX frame */ int len = strlen(t->key), len1 = strlen(t->value); char *buf = av_malloc(len + len1 + 2); if (!buf) return AVERROR(ENOMEM); tag = MKBETAG('T', 'X', 'X', 'X'); strcpy(buf, t->key); strcpy(buf + len + 1, t->value); id3v2_put_ttag(s, buf, len + len1 + 2, tag); totlen += len + len1 + ID3v2_HEADER_SIZE + 3; av_free(buf); } } if(!(s->streams[0]->codec->flags & CODEC_FLAG_BITEXACT)) { totlen += strlen(LIBAVFORMAT_IDENT) + ID3v2_HEADER_SIZE + 2; id3v2_put_ttag(s, LIBAVFORMAT_IDENT, strlen(LIBAVFORMAT_IDENT) + 1, MKBETAG('T', 'S', 'S', 'E')); } cur_pos = url_ftell(s->pb); url_fseek(s->pb, size_pos, SEEK_SET); id3v2_put_size(s, totlen); url_fseek(s->pb, cur_pos, SEEK_SET); return 0; } AVOutputFormat mp3_muxer = { "mp3", NULL_IF_CONFIG_SMALL("MPEG audio layer 3"), "audio/x-mpeg", "mp3", 0, CODEC_ID_MP3, CODEC_ID_NONE, mp3_write_header, mp3_write_packet, mp3_write_trailer, .metadata_conv = ff_id3v2_metadata_conv, }; #endif