ffmpeg/libavformat/flacdec.c

   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 "flac_picture.h"
  25 #include "internal.h"
  26 #include "rawdec.h"
  27 #include "oggdec.h"
  28 #include "vorbiscomment.h"
  29 #include "replaygain.h"
  30
  31 static int flac_read_header(AVFormatContext *s)
  32 {
  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 = avformat_new_stream(s, NULL);
  37     if (!st)
  38         return AVERROR(ENOMEM);
  39     st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
  40     st->codec->codec_id = AV_CODEC_ID_FLAC;
  41     st->need_parsing = AVSTREAM_PARSE_FULL_RAW;
  42     /* the parameters will be extracted from the compressed bitstream */
  43
  44     /* if fLaC marker is not found, assume there is no header */
  45     if (avio_rl32(s->pb) != MKTAG('f','L','a','C')) {
  46         avio_seek(s->pb, -4, SEEK_CUR);
  47         return 0;
  48     }
  49
  50     /* process metadata blocks */
  51     while (!avio_feof(s->pb) && !metadata_last) {
  52         avio_read(s->pb, header, 4);
  53         flac_parse_block_header(header, &metadata_last, &metadata_type,
  54                                    &metadata_size);
  55         switch (metadata_type) {
  56         /* allocate and read metadata block for supported types */
  57         case FLAC_METADATA_TYPE_STREAMINFO:
  58         case FLAC_METADATA_TYPE_CUESHEET:
  59         case FLAC_METADATA_TYPE_PICTURE:
  60         case FLAC_METADATA_TYPE_VORBIS_COMMENT:
  61             buffer = av_mallocz(metadata_size + FF_INPUT_BUFFER_PADDING_SIZE);
  62             if (!buffer) {
  63                 return AVERROR(ENOMEM);
  64             }
  65             if (avio_read(s->pb, buffer, metadata_size) != metadata_size) {
  66                 RETURN_ERROR(AVERROR(EIO));
  67             }
  68             break;
  69         /* skip metadata block for unsupported types */
  70         default:
  71             ret = avio_skip(s->pb, metadata_size);
  72             if (ret < 0)
  73                 return ret;
  74         }
  75
  76         if (metadata_type == FLAC_METADATA_TYPE_STREAMINFO) {
  77             uint32_t samplerate;
  78             uint64_t samples;
  79
  80             /* STREAMINFO can only occur once */
  81             if (found_streaminfo) {
  82                 RETURN_ERROR(AVERROR_INVALIDDATA);
  83             }
  84             if (metadata_size != FLAC_STREAMINFO_SIZE) {
  85                 RETURN_ERROR(AVERROR_INVALIDDATA);
  86             }
  87             found_streaminfo = 1;
  88             st->codec->extradata      = buffer;
  89             st->codec->extradata_size = metadata_size;
  90             buffer = NULL;
  91
  92             /* get sample rate and sample count from STREAMINFO header;
  93              * other parameters will be extracted by the parser */
  94             samplerate = AV_RB24(st->codec->extradata + 10) >> 4;
  95             samples    = (AV_RB64(st->codec->extradata + 13) >> 24) & ((1ULL << 36) - 1);
  96
  97             /* set time base and duration */
  98             if (samplerate > 0) {
  99                 avpriv_set_pts_info(st, 64, 1, samplerate);
 100                 if (samples > 0)
 101                     st->duration = samples;
 102             }
 103         } else if (metadata_type == FLAC_METADATA_TYPE_CUESHEET) {
 104             uint8_t isrc[13];
 105             uint64_t start;
 106             const uint8_t *offset;
 107             int i, chapters, track, ti;
 108             if (metadata_size < 431)
 109                 RETURN_ERROR(AVERROR_INVALIDDATA);
 110             offset = buffer + 395;
 111             chapters = bytestream_get_byte(&offset) - 1;
 112             if (chapters <= 0)
 113                 RETURN_ERROR(AVERROR_INVALIDDATA);
 114             for (i = 0; i < chapters; i++) {
 115                 if (offset + 36 - buffer > metadata_size)
 116                     RETURN_ERROR(AVERROR_INVALIDDATA);
 117                 start = bytestream_get_be64(&offset);
 118                 track = bytestream_get_byte(&offset);
 119                 bytestream_get_buffer(&offset, isrc, 12);
 120                 isrc[12] = 0;
 121                 offset += 14;
 122                 ti = bytestream_get_byte(&offset);
 123                 if (ti <= 0) RETURN_ERROR(AVERROR_INVALIDDATA);
 124                 offset += ti * 12;
 125                 avpriv_new_chapter(s, track, st->time_base, start, AV_NOPTS_VALUE, isrc);
 126             }
 127             av_freep(&buffer);
 128         } else if (metadata_type == FLAC_METADATA_TYPE_PICTURE) {
 129             ret = ff_flac_parse_picture(s, buffer, metadata_size);
 130             av_freep(&buffer);
 131             if (ret < 0) {
 132                 av_log(s, AV_LOG_ERROR, "Error parsing attached picture.\n");
 133                 return ret;
 134             }
 135         } else {
 136             /* STREAMINFO must be the first block */
 137             if (!found_streaminfo) {
 138                 RETURN_ERROR(AVERROR_INVALIDDATA);
 139             }
 140             /* process supported blocks other than STREAMINFO */
 141             if (metadata_type == FLAC_METADATA_TYPE_VORBIS_COMMENT) {
 142                 AVDictionaryEntry *chmask;
 143
 144                 ret = ff_vorbis_comment(s, &s->metadata, buffer, metadata_size, 1);
 145                 if (ret < 0) {
 146                     av_log(s, AV_LOG_WARNING, "error parsing VorbisComment metadata\n");
 147                 } else if (ret > 0) {
 148                     s->event_flags |= AVFMT_EVENT_FLAG_METADATA_UPDATED;
 149                 }
 150
 151                 /* parse the channels mask if present */
 152                 chmask = av_dict_get(s->metadata, "WAVEFORMATEXTENSIBLE_CHANNEL_MASK", NULL, 0);
 153                 if (chmask) {
 154                     uint64_t mask = strtol(chmask->value, NULL, 0);
 155                     if (!mask || mask & ~0x3ffffULL) {
 156                         av_log(s, AV_LOG_WARNING,
 157                                "Invalid value of WAVEFORMATEXTENSIBLE_CHANNEL_MASK\n");
 158                     } else {
 159                         st->codec->channel_layout = mask;
 160                         av_dict_set(&s->metadata, "WAVEFORMATEXTENSIBLE_CHANNEL_MASK", NULL, 0);
 161                     }
 162                 }
 163             }
 164             av_freep(&buffer);
 165         }
 166     }
 167
 168     ret = ff_replaygain_export(st, s->metadata);
 169     if (ret < 0)
 170         return ret;
 171
 172     return 0;
 173
 174 fail:
 175     av_free(buffer);
 176     return ret;
 177 }
 178
 179 static int flac_probe(AVProbeData *p)
 180 {
 181     if (p->buf_size < 4 || memcmp(p->buf, "fLaC", 4))
 182         return 0;
 183     return AVPROBE_SCORE_EXTENSION;
 184 }
 185
 186 static av_unused int64_t flac_read_timestamp(AVFormatContext *s, int stream_index,
 187                                              int64_t *ppos, int64_t pos_limit)
 188 {
 189     AVPacket pkt, out_pkt;
 190     AVStream *st = s->streams[stream_index];
 191     AVCodecParserContext *parser;
 192     int ret;
 193     int64_t pts = AV_NOPTS_VALUE;
 194
 195     if (avio_seek(s->pb, *ppos, SEEK_SET) < 0)
 196         return AV_NOPTS_VALUE;
 197
 198     av_init_packet(&pkt);
 199     parser = av_parser_init(st->codec->codec_id);
 200     if (!parser){
 201         return AV_NOPTS_VALUE;
 202     }
 203     parser->flags |= PARSER_FLAG_USE_CODEC_TS;
 204
 205     for (;;){
 206         ret = ff_raw_read_partial_packet(s, &pkt);
 207         if (ret < 0){
 208             if (ret == AVERROR(EAGAIN))
 209                 continue;
 210             else
 211                 break;
 212         }
 213         av_init_packet(&out_pkt);
 214         ret = av_parser_parse2(parser, st->codec,
 215                                &out_pkt.data, &out_pkt.size, pkt.data, pkt.size,
 216                                pkt.pts, pkt.dts, *ppos);
 217
 218         av_free_packet(&pkt);
 219         if (out_pkt.size){
 220             int size = out_pkt.size;
 221             if (parser->pts != AV_NOPTS_VALUE){
 222                 // seeking may not have started from beginning of a frame
 223                 // calculate frame start position from next frame backwards
 224                 *ppos = parser->next_frame_offset - size;
 225                 pts = parser->pts;
 226                 break;
 227             }
 228         }
 229     }
 230     av_parser_close(parser);
 231     return pts;
 232 }
 233
 234 AVInputFormat ff_flac_demuxer = {
 235     .name           = "flac",
 236     .long_name      = NULL_IF_CONFIG_SMALL("raw FLAC"),
 237     .read_probe     = flac_probe,
 238     .read_header    = flac_read_header,
 239     .read_packet    = ff_raw_read_partial_packet,
 240     .read_timestamp = flac_read_timestamp,
 241     .flags          = AVFMT_GENERIC_INDEX,
 242     .extensions     = "flac",
 243     .raw_codec_id   = AV_CODEC_ID_FLAC,
 244 };