1/* 2 * Raw FLAC demuxer 3 * Copyright (c) 2001 Fabrice Bellard 4 * 5 * This file is part of FFmpeg. 6 * 7 * FFmpeg is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU Lesser General Public 9 * License as published by the Free Software Foundation; either 10 * version 2.1 of the License, or (at your option) any later version. 11 * 12 * FFmpeg is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15 * Lesser General Public License for more details. 16 * 17 * You should have received a copy of the GNU Lesser General Public 18 * License along with FFmpeg; if not, write to the Free Software 19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 20 */ 21 22#include "libavcodec/flac.h" 23#include "avformat.h" 24#include "raw.h" 25#include "id3v2.h" 26#include "oggdec.h" 27#include "vorbiscomment.h" 28 29static int flac_read_header(AVFormatContext *s, 30 AVFormatParameters *ap) 31{ 32 uint8_t buf[ID3v2_HEADER_SIZE]; 33 int ret, metadata_last=0, metadata_type, metadata_size, found_streaminfo=0; 34 uint8_t header[4]; 35 uint8_t *buffer=NULL; 36 AVStream *st = av_new_stream(s, 0); 37 if (!st) 38 return AVERROR(ENOMEM); 39 st->codec->codec_type = AVMEDIA_TYPE_AUDIO; 40 st->codec->codec_id = CODEC_ID_FLAC; 41 st->need_parsing = AVSTREAM_PARSE_FULL; 42 /* the parameters will be extracted from the compressed bitstream */ 43 44 /* skip ID3v2 header if found */ 45 ret = get_buffer(s->pb, buf, ID3v2_HEADER_SIZE); 46 if (ret == ID3v2_HEADER_SIZE && ff_id3v2_match(buf)) { 47 int len = ff_id3v2_tag_len(buf); 48 url_fseek(s->pb, len - ID3v2_HEADER_SIZE, SEEK_CUR); 49 } else { 50 url_fseek(s->pb, 0, SEEK_SET); 51 } 52 53 /* if fLaC marker is not found, assume there is no header */ 54 if (get_le32(s->pb) != MKTAG('f','L','a','C')) { 55 url_fseek(s->pb, -4, SEEK_CUR); 56 return 0; 57 } 58 59 /* process metadata blocks */ 60 while (!url_feof(s->pb) && !metadata_last) { 61 get_buffer(s->pb, header, 4); 62 ff_flac_parse_block_header(header, &metadata_last, &metadata_type, 63 &metadata_size); 64 switch (metadata_type) { 65 /* allocate and read metadata block for supported types */ 66 case FLAC_METADATA_TYPE_STREAMINFO: 67 case FLAC_METADATA_TYPE_VORBIS_COMMENT: 68 buffer = av_mallocz(metadata_size + FF_INPUT_BUFFER_PADDING_SIZE); 69 if (!buffer) { 70 return AVERROR(ENOMEM); 71 } 72 if (get_buffer(s->pb, buffer, metadata_size) != metadata_size) { 73 av_freep(&buffer); 74 return AVERROR(EIO); 75 } 76 break; 77 /* skip metadata block for unsupported types */ 78 default: 79 ret = url_fseek(s->pb, metadata_size, SEEK_CUR); 80 if (ret < 0) 81 return ret; 82 } 83 84 if (metadata_type == FLAC_METADATA_TYPE_STREAMINFO) { 85 FLACStreaminfo si; 86 /* STREAMINFO can only occur once */ 87 if (found_streaminfo) { 88 av_freep(&buffer); 89 return AVERROR_INVALIDDATA; 90 } 91 if (metadata_size != FLAC_STREAMINFO_SIZE) { 92 av_freep(&buffer); 93 return AVERROR_INVALIDDATA; 94 } 95 found_streaminfo = 1; 96 st->codec->extradata = buffer; 97 st->codec->extradata_size = metadata_size; 98 buffer = NULL; 99 100 /* get codec params from STREAMINFO header */ 101 ff_flac_parse_streaminfo(st->codec, &si, st->codec->extradata); 102 103 /* set time base and duration */ 104 if (si.samplerate > 0) { 105 av_set_pts_info(st, 64, 1, si.samplerate); 106 if (si.samples > 0) 107 st->duration = si.samples; 108 } 109 } else { 110 /* STREAMINFO must be the first block */ 111 if (!found_streaminfo) { 112 av_freep(&buffer); 113 return AVERROR_INVALIDDATA; 114 } 115 /* process supported blocks other than STREAMINFO */ 116 if (metadata_type == FLAC_METADATA_TYPE_VORBIS_COMMENT) { 117 if (ff_vorbis_comment(s, &s->metadata, buffer, metadata_size)) { 118 av_log(s, AV_LOG_WARNING, "error parsing VorbisComment metadata\n"); 119 } 120 } 121 av_freep(&buffer); 122 } 123 } 124 125 return 0; 126} 127 128static int flac_probe(AVProbeData *p) 129{ 130 uint8_t *bufptr = p->buf; 131 uint8_t *end = p->buf + p->buf_size; 132 133 if(ff_id3v2_match(bufptr)) 134 bufptr += ff_id3v2_tag_len(bufptr); 135 136 if(bufptr > end-4 || memcmp(bufptr, "fLaC", 4)) return 0; 137 else return AVPROBE_SCORE_MAX/2; 138} 139 140AVInputFormat flac_demuxer = { 141 "flac", 142 NULL_IF_CONFIG_SMALL("raw FLAC"), 143 0, 144 flac_probe, 145 flac_read_header, 146 ff_raw_read_partial_packet, 147 .flags= AVFMT_GENERIC_INDEX, 148 .extensions = "flac", 149 .value = CODEC_ID_FLAC, 150 .metadata_conv = ff_vorbiscomment_metadata_conv, 151}; 152