libavformat/mp3dec.c - FFmpeg coverage

libavformat/mp3dec.c

Line	Branch	Exec	Source
1			/*
2			* MP3 demuxer
3			* Copyright (c) 2003 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 <string.h>
23
24			#include "libavutil/opt.h"
25			#include "libavutil/intreadwrite.h"
26			#include "libavutil/dict.h"
27			#include "libavutil/mathematics.h"
28			#include "libavutil/mem.h"
29			#include "avformat.h"
30			#include "internal.h"
31			#include "avio_internal.h"
32			#include "demux.h"
33			#include "id3v2.h"
34			#include "id3v1.h"
35			#include "replaygain.h"
36
37			#include "libavcodec/codec_id.h"
38			#include "libavcodec/mpegaudio.h"
39			#include "libavcodec/mpegaudiodecheader.h"
40
41			#define XING_FLAG_FRAMES 0x01
42			#define XING_FLAG_SIZE 0x02
43			#define XING_FLAG_TOC 0x04
44			#define XING_FLAC_QSCALE 0x08
45
46			#define XING_TOC_COUNT 100
47
48
49			typedef struct {
50			AVClass *class;
51			int64_t filesize;
52			int xing_toc;
53			int start_pad;
54			int end_pad;
55			int usetoc;
56			unsigned frames; /* Total number of frames in file */
57			unsigned header_filesize; /* Total number of bytes in the stream */
58			unsigned frame_duration; /* Frame duration in st->time_base */
59			int is_cbr;
60			} MP3DecContext;
61
62			enum CheckRet {
63			CHECK_WRONG_HEADER = -1,
64			CHECK_SEEK_FAILED = -2,
65			};
66
67			static int check(AVIOContext pb, int64_t pos, uint32_t header);
68
69			/* mp3 read */
70
71		8456	static int mp3_read_probe(const AVProbeData *p)
72			{
73		8456	int max_frames, first_frames = 0;
74		8456	int whole_used = 0;
75			int frames, ret;
76			int framesizes, max_framesizes;
77			uint32_t header;
78			const uint8_t buf, buf0, buf2, buf3, *end;
79		8456	MPADecodeHeader2 *h = NULL;
80
81		8456	buf0 = p->buf;
82		8456	end = p->buf + p->buf_size - sizeof(uint32_t);
83	3/4 ✓ Branch 4 → 5 taken 120468 times. ✗ Branch 4 → 6 not taken. ✓ Branch 5 → 3 taken 112012 times. ✓ Branch 5 → 6 taken 8456 times.	120468	while (buf0 < end && !*buf0)
84		112012	buf0++;
85
86		8456	max_frames = 0;
87		8456	max_framesizes = 0;
88		8456	buf = buf0;
89
90	2/2 ✓ Branch 24 → 7 taken 488508490 times. ✓ Branch 24 → 25 taken 8456 times.	488516946	for (; buf < end; buf = buf2+1) {
91		488508490	buf2 = buf;
92	2/2 ✓ Branch 19 → 8 taken 488583893 times. ✓ Branch 19 → 20 taken 2 times.	488583895	for (framesizes = frames = 0; buf2 < end; frames++) {
93		488583893	int header_emu = 0;
94			int available;
95
96		488583893	header = AV_RB32(buf2);
97		488583893	ret = avpriv_mpegaudio_decode_header2(&h, header);
98	2/2 ✓ Branch 9 → 10 taken 488506095 times. ✓ Branch 9 → 11 taken 77798 times.	488583893	if (ret != 0)
99		488506095	break;
100
101		77798	available = FFMIN(h->frame_size, end - buf2);
102	2/2 ✓ Branch 13 → 12 taken 30615816 times. ✓ Branch 13 → 14 taken 77798 times.	30693614	for (buf3 = buf2 + 4; buf3 < buf2 + available; buf3++) {
103		30615816	uint32_t next_sync = AV_RB32(buf3);
104		30615816	header_emu += (next_sync & MP3_MASK) == (header & MP3_MASK);
105			}
106	2/2 ✓ Branch 14 → 15 taken 1185 times. ✓ Branch 14 → 16 taken 76613 times.	77798	if (header_emu > 2)
107		1185	break;
108		76613	framesizes += h->frame_size;
109	2/2 ✓ Branch 16 → 17 taken 1208 times. ✓ Branch 16 → 18 taken 75405 times.	76613	if (available < h->frame_size) {
110		1208	frames++;
111		1208	break;
112			}
113		75405	buf2 += h->frame_size;
114			}
115		488508490	max_frames = FFMAX(max_frames, frames);
116		488508490	max_framesizes = FFMAX(max_framesizes, framesizes);
117	2/2 ✓ Branch 20 → 21 taken 8456 times. ✓ Branch 20 → 23 taken 488500034 times.	488508490	if (buf == buf0) {
118		8456	first_frames= frames;
119	1/2 ✗ Branch 21 → 22 not taken. ✓ Branch 21 → 23 taken 8456 times.	8456	if (buf2 == end + sizeof(uint32_t))
120		✗	whole_used = 1;
121			}
122			}
123		8456	av_freep(&h);
124
125			// keep this in sync with ac3 probe, both need to avoid
126			// issues with MPEG-files!
127	2/2 ✓ Branch 26 → 27 taken 75 times. ✓ Branch 26 → 28 taken 8381 times.	8456	if (first_frames>=7) return AVPROBE_SCORE_EXTENSION + 2;
128	3/4 ✓ Branch 28 → 29 taken 1 time. ✓ Branch 28 → 31 taken 8380 times. ✓ Branch 29 → 30 taken 1 time. ✗ Branch 29 → 31 not taken.	8381	else if (max_frames>200 && p->buf_size < 2*max_framesizes)return AVPROBE_SCORE_EXTENSION;
129	4/4 ✓ Branch 31 → 32 taken 42 times. ✓ Branch 31 → 34 taken 8338 times. ✓ Branch 32 → 33 taken 39 times. ✓ Branch 32 → 34 taken 3 times.	8380	else if (max_frames>=4 && p->buf_size < 2*max_framesizes) return AVPROBE_SCORE_EXTENSION / 2;
130	3/4 ✓ Branch 35 → 36 taken 50 times. ✓ Branch 35 → 42 taken 8291 times. ✓ Branch 37 → 38 taken 50 times. ✗ Branch 37 → 42 not taken.	8341	else if (ff_id3v2_match(buf0, ID3v2_DEFAULT_MAGIC) && 2*ff_id3v2_tag_len(buf0) >= p->buf_size)
131	1/2 ✓ Branch 38 → 39 taken 50 times. ✗ Branch 38 → 40 not taken.	50	return p->buf_size < PROBE_BUF_MAX ? AVPROBE_SCORE_EXTENSION / 4 : AVPROBE_SCORE_EXTENSION - 2;
132	3/4 ✓ Branch 42 → 43 taken 31 times. ✓ Branch 42 → 45 taken 8260 times. ✗ Branch 43 → 44 not taken. ✓ Branch 43 → 45 taken 31 times.	8291	else if (first_frames > 1 && whole_used) return 5;
133	4/4 ✓ Branch 45 → 46 taken 4758 times. ✓ Branch 45 → 48 taken 3533 times. ✓ Branch 46 → 47 taken 1466 times. ✓ Branch 46 → 48 taken 3292 times.	8291	else if (max_frames>=1 && p->buf_size < 10*max_framesizes) return 1;
134		6825	else return 0;
135			//mpegps_mp3_unrecognized_format.mpg has max_frames=3
136			}
137
138		39	static void read_xing_toc(AVFormatContext *s, int64_t filesize, int64_t duration)
139			{
140			int i;
141		39	MP3DecContext *mp3 = s->priv_data;
142		39	int fast_seek = s->flags & AVFMT_FLAG_FAST_SEEK;
143	4/6 ✓ Branch 2 → 3 taken 39 times. ✗ Branch 2 → 4 not taken. ✓ Branch 3 → 4 taken 1 time. ✓ Branch 3 → 6 taken 38 times. ✓ Branch 4 → 5 taken 1 time. ✗ Branch 4 → 6 not taken.	39	int fill_index = (mp3->usetoc \|\| fast_seek) && duration > 0;
144
145	1/4 ✗ Branch 7 → 8 not taken. ✓ Branch 7 → 12 taken 39 times. ✗ Branch 9 → 10 not taken. ✗ Branch 9 → 12 not taken.	39	if (!filesize &&
146		✗	(filesize = avio_size(s->pb)) <= 0) {
147		✗	av_log(s, AV_LOG_WARNING, "Cannot determine file size, skipping TOC table.\n");
148		✗	fill_index = 0;
149		✗	filesize = 0;
150			}
151
152	2/2 ✓ Branch 17 → 13 taken 3900 times. ✓ Branch 17 → 18 taken 39 times.	3939	for (i = 0; i < XING_TOC_COUNT; i++) {
153		3900	uint8_t b = avio_r8(s->pb);
154	2/2 ✓ Branch 14 → 15 taken 100 times. ✓ Branch 14 → 16 taken 3800 times.	3900	if (fill_index)
155		100	av_add_index_entry(s->streams[0],
156			av_rescale(b, filesize, 256),
157			av_rescale(i, duration, XING_TOC_COUNT),
158			0, 0, AVINDEX_KEYFRAME);
159			}
160	2/2 ✓ Branch 18 → 19 taken 1 time. ✓ Branch 18 → 20 taken 38 times.	39	if (fill_index)
161		1	mp3->xing_toc = 1;
162		39	}
163
164		86	static void mp3_parse_info_tag(AVFormatContext s, AVStream st,
165			MPADecodeHeader2 *c, uint32_t spf)
166			{
167			#define LAST_BITS(k, n) ((k) & ((1 << (n)) - 1))
168			#define MIDDLE_BITS(k, m, n) LAST_BITS((k) >> (m), ((n) - (m) + 1))
169
170		86	FFStream *const sti = ffstream(st);
171			uint16_t crc;
172			uint32_t v;
173
174			char version[10];
175
176		86	uint32_t peak = 0;
177		86	int32_t r_gain = INT32_MIN, a_gain = INT32_MIN;
178
179		86	MP3DecContext *mp3 = s->priv_data;
180			static const int64_t xing_offtbl[2][2] = {{32, 17}, {17,9}};
181		86	uint64_t fsize = avio_size(s->pb);
182		86	int64_t pos = avio_tell(s->pb);
183	1/2 ✓ Branch 5 → 6 taken 86 times. ✗ Branch 5 → 7 not taken.	86	fsize = fsize >= pos ? fsize - pos : 0;
184
185			/* Check for Xing / Info tag */
186		86	avio_skip(s->pb, xing_offtbl[c->lsf == 1][c->nb_channels == 1]);
187		86	v = avio_rb32(s->pb);
188		86	mp3->is_cbr = v == MKBETAG('I', 'n', 'f', 'o');
189	4/4 ✓ Branch 10 → 11 taken 84 times. ✓ Branch 10 → 13 taken 2 times. ✓ Branch 11 → 12 taken 46 times. ✓ Branch 11 → 13 taken 38 times.	86	if (v != MKBETAG('X', 'i', 'n', 'g') && !mp3->is_cbr)
190		46	return;
191
192		40	v = avio_rb32(s->pb);
193	1/2 ✓ Branch 14 → 15 taken 40 times. ✗ Branch 14 → 17 not taken.	40	if (v & XING_FLAG_FRAMES)
194		40	mp3->frames = avio_rb32(s->pb);
195	2/2 ✓ Branch 17 → 18 taken 39 times. ✓ Branch 17 → 20 taken 1 time.	40	if (v & XING_FLAG_SIZE)
196		39	mp3->header_filesize = avio_rb32(s->pb);
197	3/4 ✓ Branch 20 → 21 taken 40 times. ✗ Branch 20 → 27 not taken. ✓ Branch 21 → 22 taken 39 times. ✓ Branch 21 → 27 taken 1 time.	40	if (fsize && mp3->header_filesize) {
198			uint64_t min, delta;
199		39	min = FFMIN(fsize, mp3->header_filesize);
200		39	delta = FFMAX(fsize, mp3->header_filesize) - min;
201	4/4 ✓ Branch 22 → 23 taken 14 times. ✓ Branch 22 → 25 taken 25 times. ✓ Branch 23 → 24 taken 1 time. ✓ Branch 23 → 25 taken 13 times.	39	if (fsize > mp3->header_filesize && delta > min >> 4) {
202		1	mp3->frames = 0;
203		1	av_log(s, AV_LOG_WARNING,
204			"invalid concatenated file detected - using bitrate for duration\n");
205	2/2 ✓ Branch 25 → 26 taken 1 time. ✓ Branch 25 → 27 taken 37 times.	38	} else if (delta > min >> 4) {
206		1	av_log(s, AV_LOG_WARNING,
207			"filesize and duration do not match (growing file?)\n");
208			}
209			}
210	2/2 ✓ Branch 27 → 28 taken 39 times. ✓ Branch 27 → 30 taken 1 time.	40	if (v & XING_FLAG_TOC)
211		39	read_xing_toc(s, mp3->header_filesize, av_rescale_q(mp3->frames,
212		39	(AVRational){spf, c->sample_rate},
213			st->time_base));
214			/* VBR quality */
215	2/2 ✓ Branch 30 → 31 taken 34 times. ✓ Branch 30 → 32 taken 6 times.	40	if (v & XING_FLAC_QSCALE)
216		34	avio_rb32(s->pb);
217
218			/* Encoder short version string */
219		40	memset(version, 0, sizeof(version));
220		40	avio_read(s->pb, version, 9);
221
222			/* Info Tag revision + VBR method */
223		40	avio_r8(s->pb);
224
225			/* Lowpass filter value */
226		40	avio_r8(s->pb);
227
228			/* ReplayGain peak */
229		40	v = avio_rb32(s->pb);
230		40	peak = av_rescale(v, 100000, 1 << 23);
231
232			/* Radio ReplayGain */
233		40	v = avio_rb16(s->pb);
234
235	2/2 ✓ Branch 37 → 38 taken 1 time. ✓ Branch 37 → 40 taken 39 times.	40	if (MIDDLE_BITS(v, 13, 15) == 1) {
236		1	r_gain = MIDDLE_BITS(v, 0, 8) * 10000;
237
238	1/2 ✓ Branch 38 → 39 taken 1 time. ✗ Branch 38 → 40 not taken.	1	if (v & (1 << 9))
239		1	r_gain *= -1;
240			}
241
242			/* Audiophile ReplayGain */
243		40	v = avio_rb16(s->pb);
244
245	1/2 ✗ Branch 41 → 42 not taken. ✓ Branch 41 → 44 taken 40 times.	40	if (MIDDLE_BITS(v, 13, 15) == 2) {
246		✗	a_gain = MIDDLE_BITS(v, 0, 8) * 10000;
247
248	0/2 ✗ Branch 42 → 43 not taken. ✗ Branch 42 → 44 not taken.	✗	if (v & (1 << 9))
249		✗	a_gain *= -1;
250			}
251
252			/* Encoding flags + ATH Type */
253		40	avio_r8(s->pb);
254
255			/* if ABR {specified bitrate} else {minimal bitrate} */
256		40	avio_r8(s->pb);
257
258			/* Encoder delays */
259		40	v = avio_rb24(s->pb);
260	2/2 ✓ Branch 47 → 48 taken 14 times. ✓ Branch 47 → 50 taken 26 times.	40	if (AV_RB32(version) == MKBETAG('L', 'A', 'M', 'E')
261	2/2 ✓ Branch 48 → 49 taken 2 times. ✓ Branch 48 → 50 taken 12 times.	14	\|\| AV_RB32(version) == MKBETAG('L', 'a', 'v', 'f')
262	2/2 ✓ Branch 49 → 50 taken 1 time. ✓ Branch 49 → 53 taken 1 time.	2	\|\| AV_RB32(version) == MKBETAG('L', 'a', 'v', 'c')
263			) {
264
265		39	mp3->start_pad = v>>12;
266		39	mp3-> end_pad = v&4095;
267		39	sti->start_skip_samples = mp3->start_pad + 528 + 1;
268	2/2 ✓ Branch 50 → 51 taken 38 times. ✓ Branch 50 → 52 taken 1 time.	39	if (mp3->frames) {
269		38	sti->first_discard_sample = -mp3->end_pad + 528 + 1 + mp3->frames * (int64_t)spf;
270		38	sti->last_discard_sample = mp3->frames * (int64_t)spf;
271			}
272		39	av_log(s, AV_LOG_DEBUG, "pad %d %d\n", mp3->start_pad, mp3-> end_pad);
273			}
274
275			/* Misc */
276		40	avio_r8(s->pb);
277
278			/* MP3 gain */
279		40	avio_r8(s->pb);
280
281			/* Preset and surround info */
282		40	avio_rb16(s->pb);
283
284			/* Music length */
285		40	avio_rb32(s->pb);
286
287			/* Music CRC */
288		40	avio_rb16(s->pb);
289
290			/* Info Tag CRC */
291		40	crc = ffio_get_checksum(s->pb);
292		40	v = avio_rb16(s->pb);
293
294	2/2 ✓ Branch 60 → 61 taken 24 times. ✓ Branch 60 → 63 taken 16 times.	40	if (v == crc) {
295		24	ff_replaygain_export_raw(st, r_gain, peak, a_gain, 0);
296		24	av_dict_set(&st->metadata, "encoder", version, 0);
297			}
298			}
299
300		86	static void mp3_parse_vbri_tag(AVFormatContext s, AVStream st, int64_t base)
301			{
302			uint32_t v;
303		86	MP3DecContext *mp3 = s->priv_data;
304
305			/* Check for VBRI tag (always 32 bytes after end of mpegaudio header) */
306		86	avio_seek(s->pb, base + 4 + 32, SEEK_SET);
307		86	v = avio_rb32(s->pb);
308	1/2 ✗ Branch 4 → 5 not taken. ✓ Branch 4 → 11 taken 86 times.	86	if (v == MKBETAG('V', 'B', 'R', 'I')) {
309			/* Check tag version */
310	0/2 ✗ Branch 6 → 7 not taken. ✗ Branch 6 → 11 not taken.	✗	if (avio_rb16(s->pb) == 1) {
311			/* skip delay and quality */
312		✗	avio_skip(s->pb, 4);
313		✗	mp3->header_filesize = avio_rb32(s->pb);
314		✗	mp3->frames = avio_rb32(s->pb);
315			}
316			}
317		86	}
318
319			/**
320			* Look the iTunSMPB tag up under every key it can land on. A COMM frame keeps
321			* its language in the key, and while Apple writes eng, anything that retags
322			* the file is free to write its own, valid or not.
323			*
324			* The bare key is for files remuxed by versions that exposed a COMM descriptor
325			* as a metadata key of its own: those wrote the tag back out as a TXXX frame,
326			* which carries no language and is keyed by its description alone.
327			*/
328		47	static const AVDictionaryEntry find_itunes_smpb(const AVDictionary metadata)
329			{
330			static const char comment[] = "comment-iTunSMPB";
331		47	const AVDictionaryEntry *de = NULL;
332
333	2/2 ✓ Branch 9 → 3 taken 18 times. ✓ Branch 9 → 10 taken 29 times.	47	while ((de = av_dict_get(metadata, comment, de, AV_DICT_IGNORE_SUFFIX))) {
334		18	const char *lang = de->key + sizeof(comment) - 1;
335
336			/* und and xxx come without a suffix, the rest as a three letter one. */
337	3/6 ✓ Branch 3 → 4 taken 18 times. ✗ Branch 3 → 6 not taken. ✓ Branch 4 → 5 taken 18 times. ✗ Branch 4 → 7 not taken. ✓ Branch 5 → 6 taken 18 times. ✗ Branch 5 → 7 not taken.	18	if (!lang \|\| (lang == '-' && strlen(lang + 1) == 3))
338		18	return de;
339			}
340
341		29	return av_dict_get(metadata, "iTunSMPB", NULL, 0);
342			}
343
344			/**
345			* Parse the gapless playback information Apple encoders store in an iTunSMPB
346			* comment instead of in the LAME extension of the Xing tag.
347			*/
348		86	static void mp3_parse_itunes_smpb(AVFormatContext s, AVStream st,
349			const MPADecodeHeader2 *c, uint32_t spf)
350			{
351		86	FFStream *const sti = ffstream(st);
352		86	MP3DecContext *mp3 = s->priv_data;
353			const AVDictionaryEntry *de;
354			int64_t priming, remainder, samples;
355
356			/* A LAME tag, if any, already described the padding. */
357	2/2 ✓ Branch 3 → 4 taken 39 times. ✓ Branch 3 → 5 taken 47 times.	86	if (sti->start_skip_samples)
358		68	return;
359
360	2/2 ✓ Branch 6 → 7 taken 29 times. ✓ Branch 6 → 8 taken 18 times.	47	if (!(de = find_itunes_smpb(s->metadata)))
361		29	return;
362
363	1/2 ✗ Branch 9 → 10 not taken. ✓ Branch 9 → 11 taken 18 times.	18	if (ff_itunes_parse_smpb(de->value, &priming, &remainder, &samples) < 0)
364		✗	return;
365
366	2/4 ✓ Branch 11 → 12 taken 18 times. ✗ Branch 11 → 13 not taken. ✗ Branch 12 → 13 not taken. ✓ Branch 12 → 14 taken 18 times.	18	if (priming > 16384 \|\| !samples)
367		✗	return;
368
369			/* The three counts must add up to what the frames actually decode to. */
370	1/2 ✗ Branch 14 → 15 not taken. ✓ Branch 14 → 17 taken 18 times.	18	if (mp3->frames &&
371	0/2 ✗ Branch 15 → 16 not taken. ✗ Branch 15 → 17 not taken.	✗	priming + samples + remainder != mp3->frames * (int64_t)spf)
372		✗	return;
373
374			/* Contrary to the LAME tag, the priming count covers the decoder delay. */
375		18	sti->start_skip_samples = priming;
376		18	sti->first_discard_sample = priming + samples;
377		18	sti->last_discard_sample = priming + samples + remainder;
378
379		18	st->duration = av_rescale_q(samples, (AVRational){ 1, c->sample_rate },
380			st->time_base);
381			}
382
383			/**
384			* Try to find Xing/Info/VBRI tags and compute duration from info therein
385			*/
386		91	static int mp3_parse_vbr_tags(AVFormatContext s, AVStream st, int64_t base)
387			{
388			uint32_t v, spf;
389		91	MPADecodeHeader2 *c = NULL;
390		91	int vbrtag_size = 0;
391		91	MP3DecContext *mp3 = s->priv_data;
392			int ret;
393
394		91	ffio_init_checksum(s->pb, ff_crcA001_update, 0);
395
396		91	v = avio_rb32(s->pb);
397
398		91	ret = avpriv_mpegaudio_decode_header2(&c, v);
399	2/2 ✓ Branch 5 → 6 taken 2 times. ✓ Branch 5 → 7 taken 89 times.	91	if (ret < 0)
400		2	goto end;
401	1/2 ✓ Branch 7 → 8 taken 89 times. ✗ Branch 7 → 9 not taken.	89	else if (ret == 0)
402		89	vbrtag_size = c->frame_size;
403	2/2 ✓ Branch 9 → 10 taken 3 times. ✓ Branch 9 → 11 taken 86 times.	89	if (c->layer != 3) {
404		3	ret = -1;
405		3	goto end;
406			}
407
408	2/2 ✓ Branch 11 → 12 taken 1 time. ✓ Branch 11 → 13 taken 85 times.	86	spf = c->lsf ? 576 : 1152; /* Samples per frame, layer 3 */
409
410		86	mp3->frames = 0;
411		86	mp3->header_filesize = 0;
412		86	mp3->frame_duration = av_rescale_q(spf, (AVRational){1, c->sample_rate}, st->time_base);
413
414		86	mp3_parse_info_tag(s, st, c, spf);
415		86	mp3_parse_vbri_tag(s, st, base);
416		86	mp3_parse_itunes_smpb(s, st, c, spf);
417
418			/* Packets keep the skipped samples, so shift the timeline instead. */
419	2/2 ✓ Branch 18 → 19 taken 57 times. ✓ Branch 18 → 21 taken 29 times.	86	if (ffstream(st)->start_skip_samples)
420		57	st->start_time = av_rescale_q(ffstream(st)->start_skip_samples,
421		57	(AVRational){1, c->sample_rate},
422			st->time_base);
423
424	4/4 ✓ Branch 21 → 22 taken 47 times. ✓ Branch 21 → 24 taken 39 times. ✓ Branch 22 → 23 taken 46 times. ✓ Branch 22 → 24 taken 1 time.	86	if (!mp3->frames && !mp3->header_filesize) {
425		46	ret = -1;
426		46	goto end;
427			}
428
429			/* Skip the vbr tag frame */
430		40	avio_seek(s->pb, base + vbrtag_size, SEEK_SET);
431
432	2/2 ✓ Branch 25 → 26 taken 39 times. ✓ Branch 25 → 31 taken 1 time.	40	if (mp3->frames) {
433			int64_t full_duration_samples;
434
435		39	full_duration_samples = mp3->frames * (int64_t)spf;
436	1/2 ✓ Branch 26 → 27 taken 39 times. ✗ Branch 26 → 28 not taken.	39	if (st->duration == AV_NOPTS_VALUE)
437		39	st->duration = av_rescale_q(full_duration_samples - mp3->start_pad - mp3->end_pad,
438		39	(AVRational){1, c->sample_rate},
439			st->time_base);
440
441	4/4 ✓ Branch 28 → 29 taken 38 times. ✓ Branch 28 → 31 taken 1 time. ✓ Branch 29 → 30 taken 1 time. ✓ Branch 29 → 31 taken 37 times.	39	if (mp3->header_filesize && !mp3->is_cbr)
442		1	st->codecpar->bit_rate = av_rescale(mp3->header_filesize, 8 * c->sample_rate,
443			full_duration_samples);
444			}
445
446		40	ret = 0;
447
448		91	end:
449		91	av_freep(&c);
450		91	return ret;
451			}
452
453		91	static int mp3_read_header(AVFormatContext *s)
454			{
455		91	FFFormatContext *const si = ffformatcontext(s);
456		91	MP3DecContext *mp3 = s->priv_data;
457			AVStream *st;
458			FFStream *sti;
459			int64_t off;
460			int ret;
461			int i;
462
463		91	s->metadata = si->id3v2_meta;
464		91	si->id3v2_meta = NULL;
465
466		91	st = avformat_new_stream(s, NULL);
467	1/2 ✗ Branch 4 → 5 not taken. ✓ Branch 4 → 6 taken 91 times.	91	if (!st)
468		✗	return AVERROR(ENOMEM);
469		91	sti = ffstream(st);
470
471		91	st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
472		91	st->codecpar->codec_id = AV_CODEC_ID_MP3;
473		91	sti->need_parsing = AVSTREAM_PARSE_FULL_RAW;
474		91	st->start_time = 0;
475
476			// lcm of all mp3 sample rates
477		91	avpriv_set_pts_info(st, 64, 1, 14112000);
478
479		91	ffiocontext(s->pb)->maxsize = -1;
480		91	off = avio_tell(s->pb);
481
482	2/2 ✓ Branch 11 → 12 taken 17 times. ✓ Branch 11 → 13 taken 74 times.	91	if (!av_dict_count(s->metadata))
483		17	ff_id3v1_read(s);
484
485	1/2 ✓ Branch 13 → 14 taken 91 times. ✗ Branch 13 → 16 not taken.	91	if (s->pb->seekable & AVIO_SEEKABLE_NORMAL)
486		91	mp3->filesize = avio_size(s->pb);
487
488	2/2 ✓ Branch 17 → 18 taken 51 times. ✓ Branch 17 → 19 taken 40 times.	91	if (mp3_parse_vbr_tags(s, st, off) < 0)
489		51	avio_seek(s->pb, off, SEEK_SET);
490
491		91	ret = ff_replaygain_export(st, s->metadata);
492	1/2 ✗ Branch 20 → 21 not taken. ✓ Branch 20 → 22 taken 91 times.	91	if (ret < 0)
493		✗	return ret;
494
495		91	ret = ffio_ensure_seekback(s->pb, 64 * 1024 + MPA_MAX_CODED_FRAME_SIZE + 4);
496	1/2 ✗ Branch 23 → 24 not taken. ✓ Branch 23 → 25 taken 91 times.	91	if (ret < 0)
497		✗	return ret;
498
499		91	off = avio_tell(s->pb);
500	1/2 ✓ Branch 38 → 27 taken 717 times. ✗ Branch 38 → 39 not taken.	717	for (i = 0; i < 64 * 1024; i++) {
501			uint32_t header, header2;
502			int frame_size;
503		717	frame_size = check(s->pb, off + i, &header);
504	2/2 ✓ Branch 28 → 29 taken 90 times. ✓ Branch 28 → 33 taken 627 times.	717	if (frame_size > 0) {
505		90	ret = check(s->pb, off + i + frame_size, &header2);
506	2/4 ✓ Branch 30 → 31 taken 90 times. ✗ Branch 30 → 36 not taken. ✓ Branch 31 → 32 taken 90 times. ✗ Branch 31 → 36 not taken.	90	if (ret >= 0 && (header & MP3_MASK) == (header2 & MP3_MASK))
507		90	break;
508	2/2 ✓ Branch 33 → 34 taken 1 time. ✓ Branch 33 → 36 taken 626 times.	627	} else if (frame_size == CHECK_SEEK_FAILED) {
509		1	av_log(s, AV_LOG_ERROR, "Failed to find two consecutive MPEG audio frames.\n");
510		1	return AVERROR_INVALIDDATA;
511			}
512			}
513	1/2 ✗ Branch 39 → 40 not taken. ✓ Branch 39 → 41 taken 90 times.	90	if (i == 64 * 1024) {
514		✗	off = avio_seek(s->pb, off, SEEK_SET);
515			} else {
516	2/2 ✓ Branch 41 → 42 taken 1 time. ✓ Branch 41 → 43 taken 89 times.	90	av_log(s, i > 0 ? AV_LOG_INFO : AV_LOG_VERBOSE, "Skipping %d bytes of junk at %"PRId64".\n", i, off);
517		90	off = avio_seek(s->pb, off + i, SEEK_SET);
518			}
519	1/2 ✗ Branch 46 → 47 not taken. ✓ Branch 46 → 48 taken 90 times.	90	if (off < 0)
520		✗	return off;
521
522			// the seek index is relative to the end of the xing vbr headers
523	2/2 ✓ Branch 50 → 49 taken 100 times. ✓ Branch 50 → 51 taken 90 times.	190	for (int i = 0; i < sti->nb_index_entries; i++)
524		100	sti->index_entries[i].pos += off;
525
526			/* the parameters will be extracted from the compressed bitstream */
527		90	return 0;
528			}
529
530			#define MP3_PACKET_SIZE 1024
531
532		5990	static int mp3_read_packet(AVFormatContext s, AVPacket pkt)
533			{
534		5990	MP3DecContext *mp3 = s->priv_data;
535			int ret, size;
536			int64_t pos;
537
538		5990	size = MP3_PACKET_SIZE;
539		5990	pos = avio_tell(s->pb);
540	3/4 ✓ Branch 3 → 4 taken 5990 times. ✗ Branch 3 → 6 not taken. ✓ Branch 4 → 5 taken 5887 times. ✓ Branch 4 → 6 taken 103 times.	5990	if (mp3->filesize > ID3v1_TAG_SIZE && pos < mp3->filesize)
541		5887	size= FFMIN(size, mp3->filesize - pos);
542
543		5990	ret = av_get_packet(s->pb, pkt, size);
544	2/2 ✓ Branch 7 → 8 taken 103 times. ✓ Branch 7 → 11 taken 5887 times.	5990	if (ret <= 0) {
545	1/2 ✓ Branch 8 → 9 taken 103 times. ✗ Branch 8 → 10 not taken.	103	if(ret<0)
546		103	return ret;
547		✗	return AVERROR_EOF;
548			}
549
550		5887	pkt->flags &= ~AV_PKT_FLAG_CORRUPT;
551		5887	pkt->stream_index = 0;
552
553		5887	return ret;
554			}
555
556			#define SEEK_WINDOW 4096
557
558		17843	static int check(AVIOContext pb, int64_t pos, uint32_t ret_header)
559			{
560		17843	int64_t ret = avio_seek(pb, pos, SEEK_SET);
561			uint8_t header_buf[4];
562			unsigned header;
563		17843	MPADecodeHeader2 *sd = NULL;
564			int frame_size;
565	1/2 ✗ Branch 3 → 4 not taken. ✓ Branch 3 → 5 taken 17843 times.	17843	if (ret < 0)
566		✗	return CHECK_SEEK_FAILED;
567
568		17843	ret = avio_read(pb, &header_buf[0], 4);
569			/* We should always find four bytes for a valid mpa header. */
570	2/2 ✓ Branch 6 → 7 taken 1 time. ✓ Branch 6 → 8 taken 17842 times.	17843	if (ret < 4)
571		1	return CHECK_SEEK_FAILED;
572
573		17842	header = AV_RB32(&header_buf[0]);
574	2/2 ✓ Branch 9 → 10 taken 17490 times. ✓ Branch 9 → 11 taken 352 times.	17842	if (ff_mpa_check_header(header) < 0)
575		17490	return CHECK_WRONG_HEADER;
576	1/2 ✗ Branch 12 → 13 not taken. ✓ Branch 12 → 15 taken 352 times.	352	if (avpriv_mpegaudio_decode_header2(&sd, header)) {
577		✗	av_freep(&sd);
578		✗	return CHECK_WRONG_HEADER;
579			}
580		352	frame_size = sd->frame_size;
581		352	av_freep(&sd);
582
583	2/2 ✓ Branch 16 → 17 taken 180 times. ✓ Branch 16 → 18 taken 172 times.	352	if (ret_header)
584		180	*ret_header = header;
585		352	return frame_size;
586			}
587
588		26	static int64_t mp3_sync(AVFormatContext *s, int64_t target_pos, int flags)
589			{
590	2/2 ✓ Branch 2 → 3 taken 13 times. ✓ Branch 2 → 4 taken 13 times.	26	int dir = (flags&AVSEEK_FLAG_BACKWARD) ? -1 : 1;
591			int64_t best_pos;
592			int best_score, i, j;
593			int64_t ret;
594
595		26	avio_seek(s->pb, FFMAX(target_pos - SEEK_WINDOW, 0), SEEK_SET);
596		26	ret = avio_seek(s->pb, target_pos, SEEK_SET);
597	1/2 ✗ Branch 7 → 8 not taken. ✓ Branch 7 → 9 taken 26 times.	26	if (ret < 0)
598		✗	return ret;
599
600			#define MIN_VALID 3
601		26	best_pos = target_pos;
602		26	best_score = 999;
603	1/2 ✓ Branch 38 → 10 taken 16916 times. ✗ Branch 38 → 39 not taken.	16916	for (i = 0; i < SEEK_WINDOW; i++) {
604	2/2 ✓ Branch 10 → 11 taken 9621 times. ✓ Branch 10 → 12 taken 7295 times.	16916	int64_t pos = target_pos + (dir > 0 ? i - SEEK_WINDOW/4 : -i);
605		16916	int64_t candidate = -1;
606		16916	int score = 999;
607
608	1/2 ✗ Branch 13 → 14 not taken. ✓ Branch 13 → 15 taken 16916 times.	16916	if (pos < 0)
609		✗	continue;
610
611	2/2 ✓ Branch 32 → 16 taken 17036 times. ✓ Branch 32 → 33 taken 52 times.	17088	for (j = 0; j < MIN_VALID; j++) {
612		17036	ret = check(s->pb, pos, NULL);
613	2/2 ✓ Branch 17 → 18 taken 16864 times. ✓ Branch 17 → 23 taken 172 times.	17036	if (ret < 0) {
614	1/2 ✓ Branch 18 → 19 taken 16864 times. ✗ Branch 18 → 20 not taken.	16864	if (ret == CHECK_WRONG_HEADER) {
615		16864	break;
616	0/2 ✗ Branch 20 → 21 not taken. ✗ Branch 20 → 23 not taken.	✗	} else if (ret == CHECK_SEEK_FAILED) {
617		✗	av_log(s, AV_LOG_ERROR, "Could not seek to %"PRId64".\n", pos);
618		✗	return AVERROR(EINVAL);
619			}
620			}
621	6/6 ✓ Branch 23 → 24 taken 81 times. ✓ Branch 23 → 31 taken 91 times. ✓ Branch 24 → 25 taken 59 times. ✓ Branch 24 → 26 taken 22 times. ✓ Branch 27 → 28 taken 68 times. ✓ Branch 27 → 31 taken 13 times.	172	if ((target_pos - pos)*dir <= 0 && FFABS(MIN_VALID/2-j) < score) {
622		68	candidate = pos;
623	2/2 ✓ Branch 28 → 29 taken 59 times. ✓ Branch 28 → 30 taken 9 times.	68	score = FFABS(MIN_VALID/2-j);
624			}
625		172	pos += ret;
626			}
627	4/4 ✓ Branch 33 → 34 taken 49 times. ✓ Branch 33 → 37 taken 16867 times. ✓ Branch 34 → 35 taken 48 times. ✓ Branch 34 → 37 taken 1 time.	16916	if (best_score > score && j == MIN_VALID) {
628		48	best_pos = candidate;
629		48	best_score = score;
630	2/2 ✓ Branch 35 → 36 taken 26 times. ✓ Branch 35 → 37 taken 22 times.	48	if(score == 0)
631		26	break;
632			}
633			}
634
635		26	return avio_seek(s->pb, best_pos, SEEK_SET);
636			}
637
638		146	static int mp3_seek(AVFormatContext *s, int stream_index, int64_t timestamp,
639			int flags)
640			{
641		146	FFFormatContext *const si = ffformatcontext(s);
642		146	MP3DecContext *mp3 = s->priv_data;
643			AVIndexEntry *ie, ie1;
644		146	AVStream *st = s->streams[0];
645		146	FFStream *const sti = ffstream(st);
646			int64_t best_pos;
647		146	int fast_seek = s->flags & AVFMT_FLAG_FAST_SEEK;
648		146	int64_t filesize = mp3->header_filesize;
649
650	2/2 ✓ Branch 4 → 5 taken 60 times. ✓ Branch 4 → 9 taken 86 times.	146	if (filesize <= 0) {
651		60	int64_t size = avio_size(s->pb);
652	2/4 ✓ Branch 6 → 7 taken 60 times. ✗ Branch 6 → 9 not taken. ✓ Branch 7 → 8 taken 60 times. ✗ Branch 7 → 9 not taken.	60	if (size > 0 && size > si->data_offset)
653		60	filesize = size - si->data_offset;
654			}
655
656	5/8 ✓ Branch 9 → 10 taken 26 times. ✓ Branch 9 → 18 taken 120 times. ✓ Branch 10 → 11 taken 26 times. ✗ Branch 10 → 13 not taken. ✓ Branch 11 → 12 taken 26 times. ✗ Branch 11 → 18 not taken. ✗ Branch 12 → 13 not taken. ✓ Branch 12 → 18 taken 26 times.	146	if (mp3->xing_toc && (mp3->usetoc \|\| (fast_seek && !mp3->is_cbr))) {
657		✗	int64_t ret = av_index_search_timestamp(st, timestamp, flags);
658
659			// NOTE: The MP3 TOC is not a precise lookup table. Accuracy is worse
660			// for bigger files.
661		✗	av_log(s, AV_LOG_WARNING, "Using MP3 TOC to seek; may be imprecise.\n");
662
663	0/2 ✗ Branch 15 → 16 not taken. ✗ Branch 15 → 17 not taken.	✗	if (ret < 0)
664		✗	return ret;
665
666		✗	ie = &sti->index_entries[ret];
667	4/6 ✓ Branch 18 → 19 taken 26 times. ✓ Branch 18 → 24 taken 120 times. ✓ Branch 19 → 20 taken 26 times. ✗ Branch 19 → 24 not taken. ✓ Branch 20 → 21 taken 26 times. ✗ Branch 20 → 24 not taken.	146	} else if (fast_seek && st->duration > 0 && filesize > 0) {
668	1/2 ✗ Branch 21 → 22 not taken. ✓ Branch 21 → 23 taken 26 times.	26	if (!mp3->is_cbr)
669		✗	av_log(s, AV_LOG_WARNING, "Using scaling to seek VBR MP3; may be imprecise.\n");
670
671		26	ie = &ie1;
672		26	timestamp = av_clip64(timestamp, 0, st->duration);
673		26	ie->timestamp = timestamp;
674		26	ie->pos = av_rescale(timestamp, filesize, st->duration) + si->data_offset;
675			} else {
676		120	return -1; // generic index code
677			}
678
679		26	best_pos = mp3_sync(s, ie->pos, flags);
680	1/2 ✗ Branch 26 → 27 not taken. ✓ Branch 26 → 28 taken 26 times.	26	if (best_pos < 0)
681		✗	return best_pos;
682
683	4/8 ✓ Branch 28 → 29 taken 26 times. ✗ Branch 28 → 33 not taken. ✓ Branch 29 → 30 taken 26 times. ✗ Branch 29 → 33 not taken. ✓ Branch 30 → 31 taken 26 times. ✗ Branch 30 → 33 not taken. ✓ Branch 31 → 32 taken 26 times. ✗ Branch 31 → 33 not taken.	26	if (mp3->is_cbr && ie == &ie1 && mp3->frames && mp3->header_filesize > 0) {
684		26	ie1.timestamp = mp3->frame_duration * av_rescale(best_pos - si->data_offset, mp3->frames, mp3->header_filesize);
685			}
686
687		26	avpriv_update_cur_dts(s, st, ie->timestamp);
688		26	return 0;
689			}
690
691			static const AVOption options[] = {
692			{ "usetoc", "use table of contents", offsetof(MP3DecContext, usetoc), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, AV_OPT_FLAG_DECODING_PARAM},
693			{ NULL },
694			};
695
696			static const AVClass demuxer_class = {
697			.class_name = "mp3",
698			.item_name = av_default_item_name,
699			.option = options,
700			.version = LIBAVUTIL_VERSION_INT,
701			.category = AV_CLASS_CATEGORY_DEMUXER,
702			};
703
704			const FFInputFormat ff_mp3_demuxer = {
705			.p.name = "mp3",
706			.p.long_name = NULL_IF_CONFIG_SMALL("MP2/3 (MPEG audio layer 2/3)"),
707			.p.flags = AVFMT_GENERIC_INDEX,
708			.p.extensions = "mp2,mp3,m2a,mpa", /* XXX: use probe */
709			.p.priv_class = &demuxer_class,
710			.p.mime_type = "audio/mpeg",
711			.flags_internal = FF_INFMT_FLAG_ID3V2_AUTO,
712			.read_probe = mp3_read_probe,
713			.read_header = mp3_read_header,
714			.read_packet = mp3_read_packet,
715			.read_seek = mp3_seek,
716			.priv_data_size = sizeof(MP3DecContext),
717			};
718