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flacdec.c
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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 #include "libavcodec/bytestream.h"
31 
33 {
34  int ret, metadata_last=0, metadata_type, metadata_size, found_streaminfo=0;
35  uint8_t header[4];
36  uint8_t *buffer=NULL;
37  AVStream *st = avformat_new_stream(s, NULL);
38  if (!st)
39  return AVERROR(ENOMEM);
43  /* the parameters will be extracted from the compressed bitstream */
44 
45  /* if fLaC marker is not found, assume there is no header */
46  if (avio_rl32(s->pb) != MKTAG('f','L','a','C')) {
47  avio_seek(s->pb, -4, SEEK_CUR);
48  return 0;
49  }
50 
51  /* process metadata blocks */
52  while (!url_feof(s->pb) && !metadata_last) {
53  avio_read(s->pb, header, 4);
54  flac_parse_block_header(header, &metadata_last, &metadata_type,
55  &metadata_size);
56  switch (metadata_type) {
57  /* allocate and read metadata block for supported types */
62  buffer = av_mallocz(metadata_size + FF_INPUT_BUFFER_PADDING_SIZE);
63  if (!buffer) {
64  return AVERROR(ENOMEM);
65  }
66  if (avio_read(s->pb, buffer, metadata_size) != metadata_size) {
67  RETURN_ERROR(AVERROR(EIO));
68  }
69  break;
70  /* skip metadata block for unsupported types */
71  default:
72  ret = avio_skip(s->pb, metadata_size);
73  if (ret < 0)
74  return ret;
75  }
76 
77  if (metadata_type == FLAC_METADATA_TYPE_STREAMINFO) {
78  FLACStreaminfo si;
79  /* STREAMINFO can only occur once */
80  if (found_streaminfo) {
82  }
83  if (metadata_size != FLAC_STREAMINFO_SIZE) {
85  }
86  found_streaminfo = 1;
87  st->codec->extradata = buffer;
88  st->codec->extradata_size = metadata_size;
89  buffer = NULL;
90 
91  /* get codec params from STREAMINFO header */
93 
94  /* set time base and duration */
95  if (si.samplerate > 0) {
96  avpriv_set_pts_info(st, 64, 1, si.samplerate);
97  if (si.samples > 0)
98  st->duration = si.samples;
99  }
100  } else if (metadata_type == FLAC_METADATA_TYPE_CUESHEET) {
101  uint8_t isrc[13];
102  uint64_t start;
103  const uint8_t *offset;
104  int i, chapters, track, ti;
105  if (metadata_size < 431)
107  offset = buffer + 395;
108  chapters = bytestream_get_byte(&offset) - 1;
109  if (chapters <= 0)
111  for (i = 0; i < chapters; i++) {
112  if (offset + 36 - buffer > metadata_size)
114  start = bytestream_get_be64(&offset);
115  track = bytestream_get_byte(&offset);
116  bytestream_get_buffer(&offset, isrc, 12);
117  isrc[12] = 0;
118  offset += 14;
119  ti = bytestream_get_byte(&offset);
120  if (ti <= 0) RETURN_ERROR(AVERROR_INVALIDDATA);
121  offset += ti * 12;
122  avpriv_new_chapter(s, track, st->time_base, start, AV_NOPTS_VALUE, isrc);
123  }
124  av_freep(&buffer);
125  } else if (metadata_type == FLAC_METADATA_TYPE_PICTURE) {
126  ret = ff_flac_parse_picture(s, buffer, metadata_size);
127  av_freep(&buffer);
128  if (ret < 0) {
129  av_log(s, AV_LOG_ERROR, "Error parsing attached picture.\n");
130  return ret;
131  }
132  } else {
133  /* STREAMINFO must be the first block */
134  if (!found_streaminfo) {
136  }
137  /* process supported blocks other than STREAMINFO */
138  if (metadata_type == FLAC_METADATA_TYPE_VORBIS_COMMENT) {
139  AVDictionaryEntry *chmask;
140 
141  if (ff_vorbis_comment(s, &s->metadata, buffer, metadata_size, 1)) {
142  av_log(s, AV_LOG_WARNING, "error parsing VorbisComment metadata\n");
143  }
144 
145  /* parse the channels mask if present */
146  chmask = av_dict_get(s->metadata, "WAVEFORMATEXTENSIBLE_CHANNEL_MASK", NULL, 0);
147  if (chmask) {
148  uint64_t mask = strtol(chmask->value, NULL, 0);
149  if (!mask || mask & ~0x3ffffULL) {
151  "Invalid value of WAVEFORMATEXTENSIBLE_CHANNEL_MASK\n");
152  } else {
153  st->codec->channel_layout = mask;
154  av_dict_set(&s->metadata, "WAVEFORMATEXTENSIBLE_CHANNEL_MASK", NULL, 0);
155  }
156  }
157  }
158  av_freep(&buffer);
159  }
160  }
161 
162  ret = ff_replaygain_export(st, s->metadata);
163  if (ret < 0)
164  return ret;
165 
166  return 0;
167 
168 fail:
169  av_free(buffer);
170  return ret;
171 }
172 
173 static int flac_probe(AVProbeData *p)
174 {
175  if (p->buf_size < 4 || memcmp(p->buf, "fLaC", 4))
176  return 0;
178 }
179 
180 static av_unused int64_t flac_read_timestamp(AVFormatContext *s, int stream_index,
181  int64_t *ppos, int64_t pos_limit)
182 {
183  AVPacket pkt, out_pkt;
184  AVStream *st = s->streams[stream_index];
185  AVCodecParserContext *parser;
186  int ret;
187  int64_t pts = AV_NOPTS_VALUE;
188 
189  if (avio_seek(s->pb, *ppos, SEEK_SET) < 0)
190  return AV_NOPTS_VALUE;
191 
192  av_init_packet(&pkt);
193  parser = av_parser_init(st->codec->codec_id);
194  if (!parser){
195  return AV_NOPTS_VALUE;
196  }
197  parser->flags |= PARSER_FLAG_USE_CODEC_TS;
198 
199  for (;;){
200  ret = ff_raw_read_partial_packet(s, &pkt);
201  if (ret < 0){
202  if (ret == AVERROR(EAGAIN))
203  continue;
204  else
205  break;
206  }
207  av_init_packet(&out_pkt);
208  ret = av_parser_parse2(parser, st->codec,
209  &out_pkt.data, &out_pkt.size, pkt.data, pkt.size,
210  pkt.pts, pkt.dts, *ppos);
211 
212  av_free_packet(&pkt);
213  if (out_pkt.size){
214  int size = out_pkt.size;
215  if (parser->pts != AV_NOPTS_VALUE){
216  // seeking may not have started from beginning of a frame
217  // calculate frame start position from next frame backwards
218  *ppos = parser->next_frame_offset - size;
219  pts = parser->pts;
220  break;
221  }
222  }
223  }
224  av_parser_close(parser);
225  return pts;
226 }
227 
229  .name = "flac",
230  .long_name = NULL_IF_CONFIG_SMALL("raw FLAC"),
231  .read_probe = flac_probe,
232  .read_header = flac_read_header,
233  .read_packet = ff_raw_read_partial_packet,
234  .read_timestamp = flac_read_timestamp,
235  .flags = AVFMT_GENERIC_INDEX,
236  .extensions = "flac",
237  .raw_codec_id = AV_CODEC_ID_FLAC,
238 };