FFmpeg coverage

Directory: ../../../ffmpeg/
File: src/libavformat/flacdec.c
Date: 2025-10-30 16:00:47
Exec Total Coverage
Lines: 137 204 67.2%
Functions: 7 7 100.0%
Branches: 69 130 53.1%
Line Branch Exec Source
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 "libavutil/mem.h"
24 #include "libavcodec/avcodec.h"
25 #include "libavcodec/bytestream.h"
26 #include "libavcodec/flac.h"
27 #include "avformat.h"
28 #include "avio_internal.h"
29 #include "demux.h"
30 #include "flac_picture.h"
31 #include "internal.h"
32 #include "rawdec.h"
33 #include "oggdec.h"
34 #include "replaygain.h"
35
36 #define SEEKPOINT_SIZE 18
37
38 typedef struct FLACDecContext {
39 FFRawDemuxerContext rawctx;
40 int found_seektable;
41
42 AVCodecContext *parser_dec;
43 } FLACDecContext;
44
45 32 static void reset_index_position(int64_t metadata_head_size, AVStream *st)
46 {
47 32 FFStream *const sti = ffstream(st);
48 /* the real seek index offset should be the size of metadata blocks with the offset in the frame blocks */
49
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 32 for (int i = 0; i < sti->nb_index_entries; i++)
50 ✗ sti->index_entries[i].pos += metadata_head_size;
51 32 }
52
53 static const uint16_t sr_table[16] = {
54 0, 1764, 3528, 3840, 160, 320, 441, 480, 640, 882, 960, 1920, 0, 0, 0, 0
55 };
56
57 32 static int flac_read_header(AVFormatContext *s)
58 {
59 32 int ret, metadata_last=0, metadata_type, metadata_size, found_streaminfo=0;
60 uint8_t header[4];
61 32 uint8_t *buffer=NULL;
62 uint32_t marker;
63 32 FLACDecContext *flac = s->priv_data;
64 32 AVStream *st = avformat_new_stream(s, NULL);
65
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 32 if (!st)
66 ✗ return AVERROR(ENOMEM);
67 32 st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
68 32 st->codecpar->codec_id = AV_CODEC_ID_FLAC;
69 32 ffstream(st)->need_parsing = AVSTREAM_PARSE_FULL_RAW;
70 /* the parameters will be extracted from the compressed bitstream */
71
72 /* if fLaC marker is not found, assume there is no header */
73 32 marker = avio_rl32(s->pb);
74
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 32 if (marker != MKTAG('f','L','a','C')) {
75 ✗ const int sample_rate = 50 * sr_table[(marker >> 16) & 0xF];
76 ✗ if (sample_rate)
77 ✗ avpriv_set_pts_info(st, 64, 1, sample_rate);
78 ✗ avio_seek(s->pb, -4, SEEK_CUR);
79 ✗ return 0;
80 }
81
82 /* process metadata blocks */
83
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 149 while (!avio_feof(s->pb) && !metadata_last) {
84 117 ret = avio_read(s->pb, header, 4);
85
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 117 if (ret < 0) {
86 ✗ return ret;
87
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 117 } else if (ret != 4) {
88 ✗ return AVERROR_EOF;
89 }
90
91 117 flac_parse_block_header(header, &metadata_last, &metadata_type,
92 &metadata_size);
93
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 117 switch (metadata_type) {
94 /* allocate and read metadata block for supported types */
95 85 case FLAC_METADATA_TYPE_STREAMINFO:
96 case FLAC_METADATA_TYPE_CUESHEET:
97 case FLAC_METADATA_TYPE_PICTURE:
98 case FLAC_METADATA_TYPE_VORBIS_COMMENT:
99 case FLAC_METADATA_TYPE_SEEKTABLE:
100 85 buffer = av_mallocz(metadata_size + AV_INPUT_BUFFER_PADDING_SIZE);
101
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 85 if (!buffer) {
102 ✗ return AVERROR(ENOMEM);
103 }
104 85 ret = ffio_read_size(s->pb, buffer, metadata_size);
105
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 85 if (ret < 0)
106 ✗ goto fail;
107
108 85 break;
109 /* skip metadata block for unsupported types */
110 32 default:
111 32 ret = avio_skip(s->pb, metadata_size);
112
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 32 if (ret < 0)
113 ✗ return ret;
114 }
115
116
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 117 if (metadata_type == FLAC_METADATA_TYPE_STREAMINFO) {
117 uint32_t samplerate;
118 uint64_t samples;
119
120 /* STREAMINFO can only occur once */
121
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 32 if (found_streaminfo) {
122 ✗ RETURN_ERROR(AVERROR_INVALIDDATA);
123 }
124
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 32 if (metadata_size != FLAC_STREAMINFO_SIZE) {
125 ✗ RETURN_ERROR(AVERROR_INVALIDDATA);
126 }
127 32 found_streaminfo = 1;
128 32 st->codecpar->extradata = buffer;
129 32 st->codecpar->extradata_size = metadata_size;
130 32 buffer = NULL;
131
132 /* get sample rate and sample count from STREAMINFO header;
133 * other parameters will be extracted by the parser */
134 32 samplerate = AV_RB24(st->codecpar->extradata + 10) >> 4;
135 32 samples = (AV_RB64(st->codecpar->extradata + 13) >> 24) & ((1ULL << 36) - 1);
136
137 /* set time base and duration */
138
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 32 if (samplerate > 0) {
139 32 avpriv_set_pts_info(st, 64, 1, samplerate);
140
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 32 if (samples > 0)
141 32 st->duration = samples;
142 }
143
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 85 } else if (metadata_type == FLAC_METADATA_TYPE_CUESHEET) {
144 uint8_t isrc[13];
145 uint64_t start;
146 const uint8_t *offset;
147 int i, chapters, track, ti;
148 ✗ if (metadata_size < 431)
149 ✗ RETURN_ERROR(AVERROR_INVALIDDATA);
150 ✗ offset = buffer + 395;
151 ✗ chapters = bytestream_get_byte(&offset) - 1;
152 ✗ if (chapters <= 0)
153 ✗ RETURN_ERROR(AVERROR_INVALIDDATA);
154 ✗ for (i = 0; i < chapters; i++) {
155 ✗ if (offset + 36 - buffer > metadata_size)
156 ✗ RETURN_ERROR(AVERROR_INVALIDDATA);
157 ✗ start = bytestream_get_be64(&offset);
158 ✗ track = bytestream_get_byte(&offset);
159 ✗ bytestream_get_buffer(&offset, isrc, 12);
160 ✗ isrc[12] = 0;
161 ✗ offset += 14;
162 ✗ ti = bytestream_get_byte(&offset);
163 ✗ if (ti <= 0) RETURN_ERROR(AVERROR_INVALIDDATA);
164 ✗ offset += ti * 12;
165 ✗ avpriv_new_chapter(s, track, st->time_base, start, AV_NOPTS_VALUE, isrc);
166 }
167 ✗ av_freep(&buffer);
168
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 85 } else if (metadata_type == FLAC_METADATA_TYPE_PICTURE) {
169 13 ret = ff_flac_parse_picture(s, &buffer, metadata_size, 1);
170 13 av_freep(&buffer);
171
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 13 if (ret < 0) {
172 ✗ av_log(s, AV_LOG_ERROR, "Error parsing attached picture.\n");
173 ✗ return ret;
174 }
175
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 72 } else if (metadata_type == FLAC_METADATA_TYPE_SEEKTABLE) {
176 9 const uint8_t *seekpoint = buffer;
177 9 int i, seek_point_count = metadata_size/SEEKPOINT_SIZE;
178 9 flac->found_seektable = 1;
179
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 9 if ((s->flags&AVFMT_FLAG_FAST_SEEK)) {
180 ✗ for(i=0; i<seek_point_count; i++) {
181 ✗ int64_t timestamp = bytestream_get_be64(&seekpoint);
182 ✗ int64_t pos = bytestream_get_be64(&seekpoint);
183 /* skip number of samples */
184 ✗ bytestream_get_be16(&seekpoint);
185 ✗ av_add_index_entry(st, pos, timestamp, 0, 0, AVINDEX_KEYFRAME);
186 }
187 }
188 9 av_freep(&buffer);
189 }
190 else {
191
192 /* STREAMINFO must be the first block */
193
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 63 if (!found_streaminfo) {
194 ✗ RETURN_ERROR(AVERROR_INVALIDDATA);
195 }
196 /* process supported blocks other than STREAMINFO */
197
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 63 if (metadata_type == FLAC_METADATA_TYPE_VORBIS_COMMENT) {
198 AVDictionaryEntry *chmask;
199
200 31 ret = ff_vorbis_comment(s, &s->metadata, buffer, metadata_size, 1);
201
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 31 if (ret < 0) {
202 ✗ av_log(s, AV_LOG_WARNING, "error parsing VorbisComment metadata\n");
203
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 31 } else if (ret > 0) {
204 19 s->event_flags |= AVFMT_EVENT_FLAG_METADATA_UPDATED;
205 }
206
207 /* parse the channels mask if present */
208 31 chmask = av_dict_get(s->metadata, "WAVEFORMATEXTENSIBLE_CHANNEL_MASK", NULL, 0);
209
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 31 if (chmask) {
210 2 uint64_t mask = strtol(chmask->value, NULL, 0);
211
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 2 if (!mask || mask & ~0x3ffffULL) {
212 ✗ av_log(s, AV_LOG_WARNING,
213 "Invalid value of WAVEFORMATEXTENSIBLE_CHANNEL_MASK\n");
214 } else {
215 2 av_channel_layout_from_mask(&st->codecpar->ch_layout, mask);
216 2 av_dict_set(&s->metadata, "WAVEFORMATEXTENSIBLE_CHANNEL_MASK", NULL, 0);
217 }
218 }
219 }
220 63 av_freep(&buffer);
221 }
222 }
223
224 32 ret = ff_replaygain_export(st, s->metadata);
225
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 32 if (ret < 0)
226 ✗ return ret;
227
228 32 reset_index_position(avio_tell(s->pb), st);
229 32 return 0;
230
231 ✗ fail:
232 ✗ av_free(buffer);
233 ✗ return ret;
234 }
235
236 16 static int raw_flac_probe(const AVProbeData *p)
237 {
238
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 16 if ((p->buf[2] & 0xF0) == 0) // blocksize code invalid
239 ✗ return 0;
240
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 16 if ((p->buf[2] & 0x0F) == 0x0F) // sample rate code invalid
241 ✗ return 0;
242
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 16 if ((p->buf[3] & 0xF0) >= FLAC_MAX_CHANNELS + FLAC_CHMODE_MID_SIDE << 4)
243 // channel mode invalid
244 ✗ return 0;
245
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 16 if ((p->buf[3] & 0x06) == 0x06) // bits per sample code invalid
246 ✗ return 0;
247
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 16 if ((p->buf[3] & 0x01) == 0x01) // reserved bit set
248 ✗ return 0;
249 16 return AVPROBE_SCORE_EXTENSION / 4 + 1;
250 }
251
252 7282 static int flac_probe(const AVProbeData *p)
253 {
254
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 7282 if ((AV_RB16(p->buf) & 0xFFFE) == 0xFFF8)
255 16 return raw_flac_probe(p);
256
257 /* file header + metadata header + checked bytes of streaminfo */
258
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 7266 if (p->buf_size >= 4 + 4 + 13) {
259 7266 int type = p->buf[4] & 0x7f;
260 7266 int size = AV_RB24(p->buf + 5);
261 7266 int min_block_size = AV_RB16(p->buf + 8);
262 7266 int max_block_size = AV_RB16(p->buf + 10);
263 7266 int sample_rate = AV_RB24(p->buf + 18) >> 4;
264
265
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 7266 if (memcmp(p->buf, "fLaC", 4))
266 7236 return 0;
267
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 30 if (type == FLAC_METADATA_TYPE_STREAMINFO &&
268
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 30 size == FLAC_STREAMINFO_SIZE &&
269
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 30 min_block_size >= 16 &&
270
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 30 max_block_size >= min_block_size &&
271
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 30 sample_rate && sample_rate <= 655350)
272 30 return AVPROBE_SCORE_MAX;
273 ✗ return AVPROBE_SCORE_EXTENSION;
274 }
275
276 ✗ return 0;
277 }
278
279 120 av_unused static int64_t flac_read_timestamp(AVFormatContext *s, int stream_index,
280 int64_t *ppos, int64_t pos_limit)
281 {
282 120 FLACDecContext *flac = s->priv_data;
283 120 FFFormatContext *const si = ffformatcontext(s);
284 120 AVPacket *const pkt = si->parse_pkt;
285 120 AVStream *st = s->streams[stream_index];
286 AVCodecParserContext *parser;
287 int ret;
288 120 int64_t pts = AV_NOPTS_VALUE;
289
290
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 120 if (avio_seek(s->pb, *ppos, SEEK_SET) < 0)
291 ✗ return AV_NOPTS_VALUE;
292
293
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 120 if (!flac->parser_dec) {
294 1 flac->parser_dec = avcodec_alloc_context3(NULL);
295
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 1 if (!flac->parser_dec)
296 ✗ return AV_NOPTS_VALUE;
297
298 1 ret = avcodec_parameters_to_context(flac->parser_dec, st->codecpar);
299
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 1 if (ret < 0)
300 ✗ return ret;
301 }
302
303 120 parser = av_parser_init(st->codecpar->codec_id);
304
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 120 if (!parser)
305 ✗ return AV_NOPTS_VALUE;
306 120 parser->flags |= PARSER_FLAG_USE_CODEC_TS;
307
308 1534 for (;;){
309 uint8_t *data;
310 int size;
311
312 1654 ret = ff_raw_read_partial_packet(s, pkt);
313
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 1654 if (ret < 0){
314
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 36 if (ret == AVERROR(EAGAIN))
315 ✗ continue;
316 else {
317 36 av_packet_unref(pkt);
318 av_assert1(!pkt->size);
319 }
320 }
321 1654 av_parser_parse2(parser, flac->parser_dec,
322 1654 &data, &size, pkt->data, pkt->size,
323 pkt->pts, pkt->dts, *ppos);
324
325 1654 av_packet_unref(pkt);
326
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 1654 if (size) {
327
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 229 if (parser->pts != AV_NOPTS_VALUE){
328 // seeking may not have started from beginning of a frame
329 // calculate frame start position from next frame backwards
330 111 *ppos = parser->next_frame_offset - size;
331 111 pts = parser->pts;
332 111 break;
333 }
334
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 1425 } else if (ret < 0)
335 9 break;
336 }
337 120 av_parser_close(parser);
338 120 return pts;
339 }
340
341 32 static int flac_close(AVFormatContext *s)
342 {
343 32 FLACDecContext *flac = s->priv_data;
344
345 32 avcodec_free_context(&flac->parser_dec);
346
347 32 return 0;
348 }
349
350 26 static int flac_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags) {
351 26 AVStream *const st = s->streams[0];
352 26 FFStream *const sti = ffstream(st);
353 int index;
354 int64_t pos;
355 AVIndexEntry e;
356 26 FLACDecContext *flac = s->priv_data;
357
358
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 26 if (!flac->found_seektable || !(s->flags&AVFMT_FLAG_FAST_SEEK)) {
359 26 return -1;
360 }
361
362 ✗ index = av_index_search_timestamp(st, timestamp, flags);
363 ✗ if (index < 0 || index >= sti->nb_index_entries)
364 ✗ return -1;
365
366 ✗ e = sti->index_entries[index];
367 ✗ pos = avio_seek(s->pb, e.pos, SEEK_SET);
368 ✗ if (pos >= 0) {
369 ✗ return 0;
370 }
371 ✗ return -1;
372 }
373
374 const FFInputFormat ff_flac_demuxer = {
375 .p.name = "flac",
376 .p.long_name = NULL_IF_CONFIG_SMALL("raw FLAC"),
377 .p.flags = AVFMT_GENERIC_INDEX,
378 .p.extensions = "flac",
379 .p.priv_class = &ff_raw_demuxer_class,
380 .read_probe = flac_probe,
381 .read_header = flac_read_header,
382 .read_close = flac_close,
383 .read_packet = ff_raw_read_partial_packet,
384 .read_seek = flac_seek,
385 .read_timestamp = flac_read_timestamp,
386 .raw_codec_id = AV_CODEC_ID_FLAC,
387 .priv_data_size = sizeof(FLACDecContext),
388 .flags_internal = FF_INFMT_FLAG_ID3V2_AUTO,
389 };
390