afh: Dynamic chunks.
[paraslash.git] / aac_afh.c
1 /*
2 * Copyright (C) 2006 Andre Noll <maan@tuebingen.mpg.de>
3 *
4 * Licensed under the GPL v2. For licencing details see COPYING.
5 */
6 /*
7 * based in parts on libfaad, Copyright (C) 2003-2005 M. Bakker,
8 * Ahead Software AG
9 */
10
11 /** \file aac_afh.c para_server's aac audio format handler. */
12
13 #include <regex.h>
14 #include <mp4v2/mp4v2.h>
15
16 #include "para.h"
17 #include <mp4ff.h>
18 #include "error.h"
19 #include "portable_io.h"
20 #include "afh.h"
21 #include "string.h"
22 #include "aac.h"
23 #include "fd.h"
24
25 struct aac_afh_context {
26 const void *map;
27 size_t mapsize;
28 size_t fpos;
29 int32_t track;
30 mp4ff_t *mp4ff;
31 mp4AudioSpecificConfig masc;
32 mp4ff_callback_t cb;
33 };
34
35 static uint32_t aac_afh_read_cb(void *user_data, void *dest, uint32_t want)
36 {
37 struct aac_afh_context *c = user_data;
38 uint32_t have, rv;
39
40 if (want == 0 || c->fpos >= c->mapsize) {
41 PARA_INFO_LOG("failed attempt to read %u bytes @%zu\n", want,
42 c->fpos);
43 errno = EAGAIN;
44 return -1;
45 }
46 have = c->mapsize - c->fpos;
47 rv = PARA_MIN(have, want);
48 PARA_DEBUG_LOG("reading %u bytes @%zu\n", rv, c->fpos);
49 memcpy(dest, c->map + c->fpos, rv);
50 c->fpos += rv;
51 return rv;
52 }
53
54 static uint32_t aac_afh_seek_cb(void *user_data, uint64_t pos)
55 {
56 struct aac_afh_context *c = user_data;
57 c->fpos = pos;
58 return 0;
59 }
60
61 static int32_t aac_afh_get_track(mp4ff_t *mp4ff, mp4AudioSpecificConfig *masc)
62 {
63 int32_t i, rc, num_tracks = mp4ff_total_tracks(mp4ff);
64
65 assert(num_tracks >= 0);
66 for (i = 0; i < num_tracks; i++) {
67 unsigned char *buf = NULL;
68 unsigned buf_size = 0;
69
70 mp4ff_get_decoder_config(mp4ff, i, &buf, &buf_size);
71 if (buf) {
72 rc = NeAACDecAudioSpecificConfig(buf, buf_size, masc);
73 free(buf);
74 if (rc < 0)
75 continue;
76 return i;
77 }
78 }
79 return -1; /* no audio track */
80 }
81
82 static int aac_afh_open(const void *map, size_t mapsize, void **afh_context)
83 {
84 int ret;
85 struct aac_afh_context *c = para_malloc(sizeof(*c));
86
87 c->map = map;
88 c->mapsize = mapsize;
89 c->fpos = 0;
90 c->cb.read = aac_afh_read_cb;
91 c->cb.seek = aac_afh_seek_cb;
92 c->cb.user_data = c;
93
94 ret = -E_MP4FF_OPEN;
95 c->mp4ff = mp4ff_open_read(&c->cb);
96 if (!c->mp4ff)
97 goto free_ctx;
98 c->track = aac_afh_get_track(c->mp4ff, &c->masc);
99 ret = -E_MP4FF_TRACK;
100 if (c->track < 0)
101 goto close_mp4ff;
102 *afh_context = c;
103 return 0;
104 close_mp4ff:
105 mp4ff_close(c->mp4ff);
106 free_ctx:
107 free(c);
108 *afh_context = NULL;
109 return ret;
110 }
111
112 static void aac_afh_close(void *afh_context)
113 {
114 struct aac_afh_context *c = afh_context;
115 mp4ff_close(c->mp4ff);
116 free(c);
117 }
118
119 /**
120 * Libmp4ff function to reposition the file to the given sample.
121 *
122 * \param f The opaque handle returned by mp4ff_open_read().
123 * \param track The number of the (audio) track.
124 * \param sample Destination.
125 *
126 * We need this function to obtain the offset of the sample within the audio
127 * file. Unfortunately, it is not exposed in the mp4ff header.
128 *
129 * \return This function always returns 0.
130 */
131 int32_t mp4ff_set_sample_position(mp4ff_t *f, const int32_t track, const int32_t sample);
132
133 static int aac_afh_get_chunk(long unsigned chunk_num, void *afh_context,
134 const char **buf, size_t *len)
135 {
136 struct aac_afh_context *c = afh_context;
137 int32_t ss;
138 size_t offset;
139
140 assert(chunk_num <= INT_MAX);
141 /* this function always returns zero */
142 mp4ff_set_sample_position(c->mp4ff, c->track, chunk_num);
143 offset = c->fpos;
144 ss = mp4ff_read_sample_getsize(c->mp4ff, c->track, chunk_num);
145 if (ss <= 0)
146 return -E_MP4FF_BAD_SAMPLE;
147 assert(ss + offset <= c->mapsize);
148 *buf = c->map + offset;
149 *len = ss;
150 return 1;
151 }
152 static int aac_find_stsz(char *buf, size_t buflen, off_t *skip)
153 {
154 int i;
155
156 for (i = 0; i + 16 < buflen; i++) {
157 char *p = buf + i;
158 unsigned sample_count, sample_size;
159
160 if (p[0] != 's' || p[1] != 't' || p[2] != 's' || p[3] != 'z')
161 continue;
162 PARA_DEBUG_LOG("found stsz@%d\n", i);
163 i += 8;
164 sample_size = read_u32_be(buf + i);
165 PARA_DEBUG_LOG("sample size: %u\n", sample_size);
166 i += 4;
167 sample_count = read_u32_be(buf + i);
168 i += 4;
169 PARA_DEBUG_LOG("sample count: %u\n", sample_count);
170 *skip = i;
171 return sample_count;
172 }
173 return -E_STSZ;
174 }
175
176 static int atom_cmp(const char *buf1, const char *buf2)
177 {
178 return memcmp(buf1, buf2, 4)? 1 : 0;
179 }
180
181 static int read_atom_header(char *buf, uint64_t *subsize, char type[5])
182 {
183 uint64_t size = read_u32_be(buf);
184
185 memcpy(type, buf + 4, 4);
186 type[4] = '\0';
187
188 PARA_DEBUG_LOG("size: %llu, type: %s\n", (long long unsigned)size, type);
189 if (size != 1) {
190 *subsize = size;
191 return 8;
192 }
193 buf += 4;
194 size = 0;
195 size = read_u64_be(buf);
196 *subsize = size;
197 return 16;
198 }
199
200 static char *get_tag(char *p, int size)
201 {
202 char *buf;
203
204 assert(size > 0);
205 buf = para_malloc(size + 1);
206
207 memcpy(buf, p, size);
208 buf[size] = '\0';
209 PARA_DEBUG_LOG("size: %d: %s\n", size, buf);
210 return buf;
211 }
212
213 static void read_tags(char *buf, size_t buflen, struct afh_info *afhi)
214 {
215 char *p = buf;
216
217 while (p + 32 < buf + buflen) {
218 char *q, type1[5], type2[5];
219 uint64_t size1, size2;
220 int ret, ret2;
221
222 ret = read_atom_header(p, &size1, type1);
223 ret2 = read_atom_header(p + ret, &size2, type2);
224
225 if (size2 <= 16 || atom_cmp(type2, "data")) {
226 p += size1;
227 continue;
228 }
229 size2 -= 16;
230 q = p + ret + ret2 + 8;
231 if (q + size2 > buf + buflen)
232 break;
233 if (!atom_cmp(type1, "\xa9" "ART"))
234 afhi->tags.artist = get_tag(q, size2);
235 else if (!atom_cmp(type1, "\xa9" "alb"))
236 afhi->tags.album = get_tag(q, size2);
237 else if (!atom_cmp(type1, "\xa9" "nam"))
238 afhi->tags.title = get_tag(q, size2);
239 else if (!atom_cmp(type1, "\xa9" "cmt"))
240 afhi->tags.comment = get_tag(q, size2);
241 else if (!atom_cmp(type1, "\xa9" "day"))
242 afhi->tags.year = get_tag(q, size2);
243 p += size1;
244 }
245 }
246
247 static void read_meta(char *buf, size_t buflen, struct afh_info *afhi)
248 {
249 char *p = buf;
250
251 while (p + 4 < buf + buflen) {
252
253 if (p[0] != 'i' || p[1] != 'l' || p[2] != 's' || p[3] != 't') {
254 p++;
255 continue;
256 }
257 p += 4;
258 return read_tags(p, buflen - (p - buf), afhi);
259 }
260 }
261
262 static void aac_get_taginfo(char *buf, size_t buflen, struct afh_info *afhi)
263 {
264 int i;
265 uint64_t subsize;
266 char type[5];
267
268 for (i = 0; i + 24 < buflen; i++) {
269 char *p = buf + i;
270 if (p[0] != 'm' || p[1] != 'e' || p[2] != 't' || p[3] != 'a')
271 continue;
272 PARA_INFO_LOG("found metadata at offset %d\n", i);
273 i += 8;
274 p = buf + i;
275 i += read_atom_header(p, &subsize, type);
276 p = buf + i;
277 return read_meta(p, buflen - i, afhi);
278 }
279 PARA_INFO_LOG("no meta data\n");
280 }
281
282 static ssize_t aac_compute_chunk_table(struct afh_info *afhi,
283 char *map, size_t numbytes)
284 {
285 int ret, i;
286 size_t sum = 0;
287 off_t skip;
288
289 ret = aac_find_stsz(map, numbytes, &skip);
290 if (ret < 0)
291 return ret;
292 afhi->chunks_total = ret;
293 PARA_DEBUG_LOG("sz table has %" PRIu32 " entries\n", afhi->chunks_total);
294 afhi->chunk_table = para_malloc((afhi->chunks_total + 1) * sizeof(size_t));
295 for (i = 1; i <= afhi->chunks_total; i++) {
296 if (skip + 4 > numbytes)
297 break;
298 sum += read_u32_be(map + skip);
299 afhi->chunk_table[i] = sum;
300 skip += 4;
301 // if (i < 10 || i + 10 > afhi->chunks_total)
302 // PARA_DEBUG_LOG("offset #%d: %zu\n", i, afhi->chunk_table[i]);
303 }
304 return skip;
305 }
306
307 static int aac_set_chunk_tv(struct afh_info *afhi,
308 mp4AudioSpecificConfig *mp4ASC, uint32_t *seconds)
309 {
310 float tmp = mp4ASC->sbr_present_flag == 1? 2047 : 1023;
311 struct timeval total;
312 long unsigned ms;
313
314 ms = 1000.0 * afhi->chunks_total * tmp / mp4ASC->samplingFrequency;
315 ms2tv(ms, &total);
316 tv_divide(afhi->chunks_total, &total, &afhi->chunk_tv);
317 PARA_INFO_LOG("%luHz, %lus (%" PRIu32 " x %lums)\n",
318 mp4ASC->samplingFrequency, ms / 1000,
319 afhi->chunks_total, tv2ms(&afhi->chunk_tv));
320 if (ms < 1000)
321 return -E_MP4ASC;
322 *seconds = ms / 1000;
323 return 1;
324 }
325
326 /*
327 * Init m4a file and write some tech data to given pointers.
328 */
329 static int aac_get_file_info(char *map, size_t numbytes, __a_unused int fd,
330 struct afh_info *afhi)
331 {
332 int i;
333 size_t skip;
334 ssize_t ret;
335 unsigned long rate = 0, decoder_len;
336 unsigned char channels = 0;
337 mp4AudioSpecificConfig mp4ASC;
338 NeAACDecHandle handle = NULL;
339
340 ret = aac_find_esds(map, numbytes, &skip, &decoder_len);
341 if (ret < 0)
342 goto out;
343 aac_get_taginfo(map, numbytes, afhi);
344 handle = aac_open();
345 ret = -E_AAC_AFH_INIT;
346 if (NeAACDecInit(handle, (unsigned char *)map + skip, decoder_len,
347 &rate, &channels))
348 goto out;
349 if (!channels)
350 goto out;
351 PARA_DEBUG_LOG("rate: %lu, channels: %d\n", rate, channels);
352 ret = -E_MP4ASC;
353 if (NeAACDecAudioSpecificConfig((unsigned char *)map + skip,
354 numbytes - skip, &mp4ASC))
355 goto out;
356 if (!mp4ASC.samplingFrequency)
357 goto out;
358 ret = aac_compute_chunk_table(afhi, map, numbytes);
359 if (ret < 0)
360 goto out;
361 skip = ret;
362 ret = aac_set_chunk_tv(afhi, &mp4ASC, &afhi->seconds_total);
363 if (ret < 0)
364 goto out;
365 ret = aac_find_entry_point(map + skip, numbytes - skip, &skip);
366 if (ret < 0)
367 goto out;
368 afhi->chunk_table[0] = ret;
369 for (i = 1; i<= afhi->chunks_total; i++)
370 afhi->chunk_table[i] += ret;
371 set_max_chunk_size(afhi);
372 afhi->channels = channels;
373 afhi->frequency = rate;
374 ret = (afhi->chunk_table[afhi->chunks_total] - afhi->chunk_table[0]) * 8; /* bits */
375 ret += (channels * afhi->seconds_total * 500); /* avoid rounding error */
376 afhi->bitrate = ret / (channels * afhi->seconds_total * 1000);
377 ret = 1;
378 out:
379 if (handle)
380 NeAACDecClose(handle);
381 return ret;
382 }
383
384 static int aac_rewrite_tags(const char *map, size_t mapsize,
385 struct taginfo *tags, int fd, const char *filename)
386 {
387 MP4FileHandle h;
388 const MP4Tags *mdata;
389 int ret = write_all(fd, map, mapsize);
390
391 if (ret < 0)
392 return ret;
393 lseek(fd, 0, SEEK_SET);
394 h = MP4Modify(filename, 0);
395 if (!h) {
396 PARA_ERROR_LOG("MP4Modify() failed, fd = %d\n", fd);
397 return -E_MP4V2;
398 }
399 mdata = MP4TagsAlloc();
400 assert(mdata);
401 if (!MP4TagsFetch(mdata, h)) {
402 PARA_ERROR_LOG("MP4Tags_Fetch() failed\n");
403 ret = -E_MP4V2;
404 goto close;
405 }
406
407 if (!MP4TagsSetAlbum(mdata, tags->album)) {
408 PARA_ERROR_LOG("Could not set album\n");
409 ret = -E_MP4V2;
410 goto tags_free;
411 }
412 if (!MP4TagsSetArtist(mdata, tags->artist)) {
413 PARA_ERROR_LOG("Could not set album\n");
414 ret = -E_MP4V2;
415 goto tags_free;
416 }
417 if (!MP4TagsSetComments(mdata, tags->comment)) {
418 PARA_ERROR_LOG("Could not set comment\n");
419 ret = -E_MP4V2;
420 goto tags_free;
421 }
422 if (!MP4TagsSetName(mdata, tags->title)) {
423 PARA_ERROR_LOG("Could not set title\n");
424 ret = -E_MP4V2;
425 goto tags_free;
426 }
427 if (!MP4TagsSetReleaseDate(mdata, tags->year)) {
428 PARA_ERROR_LOG("Could not set release date\n");
429 ret = -E_MP4V2;
430 goto tags_free;
431 }
432
433 if (!MP4TagsStore(mdata, h)) {
434 PARA_ERROR_LOG("Could not store tags\n");
435 ret = -E_MP4V2;
436 goto tags_free;
437 }
438 ret = 1;
439 tags_free:
440 MP4TagsFree(mdata);
441 close:
442 MP4Close(h, 0);
443 return ret;
444 }
445
446 static const char * const aac_suffixes[] = {"m4a", "mp4", NULL};
447 /**
448 * the init function of the aac audio format handler
449 *
450 * \param afh pointer to the struct to initialize
451 */
452 void aac_afh_init(struct audio_format_handler *afh)
453 {
454 afh->get_file_info = aac_get_file_info,
455 afh->suffixes = aac_suffixes;
456 afh->rewrite_tags = aac_rewrite_tags;
457 afh->open = aac_afh_open;
458 afh->get_chunk = aac_afh_get_chunk;
459 afh->close = aac_afh_close;
460 }