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 "libavutil/channel_layout.h"
23 #include "libavcodec/flac.h"
24 #include "avformat.h"
25 #include "demux.h"
26 #include "flac_picture.h"
27 #include "internal.h"
28 #include "rawdec.h"
29 #include "oggdec.h"
30 #include "replaygain.h"
31
32 #define SEEKPOINT_SIZE 18
33
34 typedef struct FLACDecContext {
35 FFRawDemuxerContext rawctx;
36 int found_seektable;
37 } FLACDecContext;
38
reset_index_position(int64_t metadata_head_size,AVStream * st)39 static void reset_index_position(int64_t metadata_head_size, AVStream *st)
40 {
41 FFStream *const sti = ffstream(st);
42 /* the real seek index offset should be the size of metadata blocks with the offset in the frame blocks */
43 for (int i = 0; i < sti->nb_index_entries; i++)
44 sti->index_entries[i].pos += metadata_head_size;
45 }
46
flac_read_header(AVFormatContext * s)47 static int flac_read_header(AVFormatContext *s)
48 {
49 int ret, metadata_last=0, metadata_type, metadata_size, found_streaminfo=0;
50 uint8_t header[4];
51 uint8_t *buffer=NULL;
52 FLACDecContext *flac = s->priv_data;
53 AVStream *st = avformat_new_stream(s, NULL);
54 if (!st)
55 return AVERROR(ENOMEM);
56 st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
57 st->codecpar->codec_id = AV_CODEC_ID_FLAC;
58 ffstream(st)->need_parsing = AVSTREAM_PARSE_FULL_RAW;
59 /* the parameters will be extracted from the compressed bitstream */
60
61 /* if fLaC marker is not found, assume there is no header */
62 if (avio_rl32(s->pb) != MKTAG('f','L','a','C')) {
63 avio_seek(s->pb, -4, SEEK_CUR);
64 return 0;
65 }
66
67 /* process metadata blocks */
68 while (!avio_feof(s->pb) && !metadata_last) {
69 if (avio_read(s->pb, header, 4) != 4)
70 return AVERROR(AVERROR_INVALIDDATA);
71 flac_parse_block_header(header, &metadata_last, &metadata_type,
72 &metadata_size);
73 switch (metadata_type) {
74 /* allocate and read metadata block for supported types */
75 case FLAC_METADATA_TYPE_STREAMINFO:
76 case FLAC_METADATA_TYPE_CUESHEET:
77 case FLAC_METADATA_TYPE_PICTURE:
78 case FLAC_METADATA_TYPE_VORBIS_COMMENT:
79 case FLAC_METADATA_TYPE_SEEKTABLE:
80 buffer = av_mallocz(metadata_size + AV_INPUT_BUFFER_PADDING_SIZE);
81 if (!buffer) {
82 return AVERROR(ENOMEM);
83 }
84 if (avio_read(s->pb, buffer, metadata_size) != metadata_size) {
85 RETURN_ERROR(AVERROR(EIO));
86 }
87 break;
88 /* skip metadata block for unsupported types */
89 default:
90 ret = avio_skip(s->pb, metadata_size);
91 if (ret < 0)
92 return ret;
93 }
94
95 if (metadata_type == FLAC_METADATA_TYPE_STREAMINFO) {
96 uint32_t samplerate;
97 uint64_t samples;
98
99 /* STREAMINFO can only occur once */
100 if (found_streaminfo) {
101 RETURN_ERROR(AVERROR_INVALIDDATA);
102 }
103 if (metadata_size != FLAC_STREAMINFO_SIZE) {
104 RETURN_ERROR(AVERROR_INVALIDDATA);
105 }
106 found_streaminfo = 1;
107 st->codecpar->extradata = buffer;
108 st->codecpar->extradata_size = metadata_size;
109 buffer = NULL;
110
111 /* get sample rate and sample count from STREAMINFO header;
112 * other parameters will be extracted by the parser */
113 samplerate = AV_RB24(st->codecpar->extradata + 10) >> 4;
114 samples = (AV_RB64(st->codecpar->extradata + 13) >> 24) & ((1ULL << 36) - 1);
115
116 /* set time base and duration */
117 if (samplerate > 0) {
118 avpriv_set_pts_info(st, 64, 1, samplerate);
119 if (samples > 0)
120 st->duration = samples;
121 }
122 } else if (metadata_type == FLAC_METADATA_TYPE_CUESHEET) {
123 uint8_t isrc[13];
124 uint64_t start;
125 const uint8_t *offset;
126 int i, chapters, track, ti;
127 if (metadata_size < 431)
128 RETURN_ERROR(AVERROR_INVALIDDATA);
129 offset = buffer + 395;
130 chapters = bytestream_get_byte(&offset) - 1;
131 if (chapters <= 0)
132 RETURN_ERROR(AVERROR_INVALIDDATA);
133 for (i = 0; i < chapters; i++) {
134 if (offset + 36 - buffer > metadata_size)
135 RETURN_ERROR(AVERROR_INVALIDDATA);
136 start = bytestream_get_be64(&offset);
137 track = bytestream_get_byte(&offset);
138 bytestream_get_buffer(&offset, isrc, 12);
139 isrc[12] = 0;
140 offset += 14;
141 ti = bytestream_get_byte(&offset);
142 if (ti <= 0) RETURN_ERROR(AVERROR_INVALIDDATA);
143 offset += ti * 12;
144 avpriv_new_chapter(s, track, st->time_base, start, AV_NOPTS_VALUE, isrc);
145 }
146 av_freep(&buffer);
147 } else if (metadata_type == FLAC_METADATA_TYPE_PICTURE) {
148 ret = ff_flac_parse_picture(s, &buffer, metadata_size, 1);
149 av_freep(&buffer);
150 if (ret < 0) {
151 av_log(s, AV_LOG_ERROR, "Error parsing attached picture.\n");
152 return ret;
153 }
154 } else if (metadata_type == FLAC_METADATA_TYPE_SEEKTABLE) {
155 const uint8_t *seekpoint = buffer;
156 int i, seek_point_count = metadata_size/SEEKPOINT_SIZE;
157 flac->found_seektable = 1;
158 if ((s->flags&AVFMT_FLAG_FAST_SEEK)) {
159 for(i=0; i<seek_point_count; i++) {
160 int64_t timestamp = bytestream_get_be64(&seekpoint);
161 int64_t pos = bytestream_get_be64(&seekpoint);
162 /* skip number of samples */
163 bytestream_get_be16(&seekpoint);
164 av_add_index_entry(st, pos, timestamp, 0, 0, AVINDEX_KEYFRAME);
165 }
166 }
167 av_freep(&buffer);
168 }
169 else {
170
171 /* STREAMINFO must be the first block */
172 if (!found_streaminfo) {
173 RETURN_ERROR(AVERROR_INVALIDDATA);
174 }
175 /* process supported blocks other than STREAMINFO */
176 if (metadata_type == FLAC_METADATA_TYPE_VORBIS_COMMENT) {
177 AVDictionaryEntry *chmask;
178
179 ret = ff_vorbis_comment(s, &s->metadata, buffer, metadata_size, 1);
180 if (ret < 0) {
181 av_log(s, AV_LOG_WARNING, "error parsing VorbisComment metadata\n");
182 } else if (ret > 0) {
183 s->event_flags |= AVFMT_EVENT_FLAG_METADATA_UPDATED;
184 }
185
186 /* parse the channels mask if present */
187 chmask = av_dict_get(s->metadata, "WAVEFORMATEXTENSIBLE_CHANNEL_MASK", NULL, 0);
188 if (chmask) {
189 uint64_t mask = strtol(chmask->value, NULL, 0);
190 if (!mask || mask & ~0x3ffffULL) {
191 av_log(s, AV_LOG_WARNING,
192 "Invalid value of WAVEFORMATEXTENSIBLE_CHANNEL_MASK\n");
193 } else {
194 av_channel_layout_from_mask(&st->codecpar->ch_layout, mask);
195 av_dict_set(&s->metadata, "WAVEFORMATEXTENSIBLE_CHANNEL_MASK", NULL, 0);
196 }
197 }
198 }
199 av_freep(&buffer);
200 }
201 }
202
203 ret = ff_replaygain_export(st, s->metadata);
204 if (ret < 0)
205 return ret;
206
207 reset_index_position(avio_tell(s->pb), st);
208 return 0;
209
210 fail:
211 av_free(buffer);
212 return ret;
213 }
214
raw_flac_probe(const AVProbeData * p)215 static int raw_flac_probe(const AVProbeData *p)
216 {
217 if ((p->buf[2] & 0xF0) == 0) // blocksize code invalid
218 return 0;
219 if ((p->buf[2] & 0x0F) == 0x0F) // sample rate code invalid
220 return 0;
221 if ((p->buf[3] & 0xF0) >= FLAC_MAX_CHANNELS + FLAC_CHMODE_MID_SIDE << 4)
222 // channel mode invalid
223 return 0;
224 if ((p->buf[3] & 0x06) == 0x06) // bits per sample code invalid
225 return 0;
226 if ((p->buf[3] & 0x01) == 0x01) // reserved bit set
227 return 0;
228 return AVPROBE_SCORE_EXTENSION / 4 + 1;
229 }
230
flac_probe(const AVProbeData * p)231 static int flac_probe(const AVProbeData *p)
232 {
233 if ((AV_RB16(p->buf) & 0xFFFE) == 0xFFF8)
234 return raw_flac_probe(p);
235
236 /* file header + metadata header + checked bytes of streaminfo */
237 if (p->buf_size >= 4 + 4 + 13) {
238 int type = p->buf[4] & 0x7f;
239 int size = AV_RB24(p->buf + 5);
240 int min_block_size = AV_RB16(p->buf + 8);
241 int max_block_size = AV_RB16(p->buf + 10);
242 int sample_rate = AV_RB24(p->buf + 18) >> 4;
243
244 if (memcmp(p->buf, "fLaC", 4))
245 return 0;
246 if (type == FLAC_METADATA_TYPE_STREAMINFO &&
247 size == FLAC_STREAMINFO_SIZE &&
248 min_block_size >= 16 &&
249 max_block_size >= min_block_size &&
250 sample_rate && sample_rate <= 655350)
251 return AVPROBE_SCORE_MAX;
252 return AVPROBE_SCORE_EXTENSION;
253 }
254
255 return 0;
256 }
257
flac_read_timestamp(AVFormatContext * s,int stream_index,int64_t * ppos,int64_t pos_limit)258 static av_unused int64_t flac_read_timestamp(AVFormatContext *s, int stream_index,
259 int64_t *ppos, int64_t pos_limit)
260 {
261 FFFormatContext *const si = ffformatcontext(s);
262 AVPacket *const pkt = si->parse_pkt;
263 AVStream *st = s->streams[stream_index];
264 AVCodecParserContext *parser;
265 int ret;
266 int64_t pts = AV_NOPTS_VALUE;
267
268 if (avio_seek(s->pb, *ppos, SEEK_SET) < 0)
269 return AV_NOPTS_VALUE;
270
271 parser = av_parser_init(st->codecpar->codec_id);
272 if (!parser){
273 return AV_NOPTS_VALUE;
274 }
275 parser->flags |= PARSER_FLAG_USE_CODEC_TS;
276
277 for (;;){
278 uint8_t *data;
279 int size;
280
281 ret = ff_raw_read_partial_packet(s, pkt);
282 if (ret < 0){
283 if (ret == AVERROR(EAGAIN))
284 continue;
285 else {
286 av_packet_unref(pkt);
287 av_assert1(!pkt->size);
288 }
289 }
290 av_parser_parse2(parser, ffstream(st)->avctx,
291 &data, &size, pkt->data, pkt->size,
292 pkt->pts, pkt->dts, *ppos);
293
294 av_packet_unref(pkt);
295 if (size) {
296 if (parser->pts != AV_NOPTS_VALUE){
297 // seeking may not have started from beginning of a frame
298 // calculate frame start position from next frame backwards
299 *ppos = parser->next_frame_offset - size;
300 pts = parser->pts;
301 break;
302 }
303 } else if (ret < 0)
304 break;
305 }
306 av_parser_close(parser);
307 return pts;
308 }
309
flac_seek(AVFormatContext * s,int stream_index,int64_t timestamp,int flags)310 static int flac_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags) {
311 AVStream *const st = s->streams[0];
312 FFStream *const sti = ffstream(st);
313 int index;
314 int64_t pos;
315 AVIndexEntry e;
316 FLACDecContext *flac = s->priv_data;
317
318 if (!flac->found_seektable || !(s->flags&AVFMT_FLAG_FAST_SEEK)) {
319 return -1;
320 }
321
322 index = av_index_search_timestamp(st, timestamp, flags);
323 if (index < 0 || index >= sti->nb_index_entries)
324 return -1;
325
326 e = sti->index_entries[index];
327 pos = avio_seek(s->pb, e.pos, SEEK_SET);
328 if (pos >= 0) {
329 return 0;
330 }
331 return -1;
332 }
333
334 const AVInputFormat ff_flac_demuxer = {
335 .name = "flac",
336 .long_name = NULL_IF_CONFIG_SMALL("raw FLAC"),
337 .read_probe = flac_probe,
338 .read_header = flac_read_header,
339 .read_packet = ff_raw_read_partial_packet,
340 .read_seek = flac_seek,
341 .read_timestamp = flac_read_timestamp,
342 .flags = AVFMT_GENERIC_INDEX,
343 .extensions = "flac",
344 .raw_codec_id = AV_CODEC_ID_FLAC,
345 .priv_data_size = sizeof(FLACDecContext),
346 .priv_class = &ff_raw_demuxer_class,
347 };
348