2 * Copyright (C) 2006 Andre Noll <maan@tuebingen.mpg.de>
4 * Licensed under the GPL v2. For licencing details see COPYING.
7 * based in parts on libfaad, Copyright (C) 2003-2005 M. Bakker,
11 /** \file aac_afh.c para_server's aac audio format handler. */
14 #include <mp4v2/mp4v2.h>
23 static int aac_find_stsz(unsigned char *buf, size_t buflen, off_t *skip)
27 for (i = 0; i + 16 < buflen; i++) {
28 unsigned char *p = buf + i;
29 unsigned sample_count, sample_size;
31 if (p[0] != 's' || p[1] != 't' || p[2] != 's' || p[3] != 'z')
33 PARA_DEBUG_LOG("found stsz@%d\n", i);
35 sample_size = aac_read_int32(buf + i);
36 PARA_DEBUG_LOG("sample size: %d\n", sample_size);
38 sample_count = aac_read_int32(buf + i);
40 PARA_DEBUG_LOG("sample count: %d\n", sample_count);
47 static int atom_cmp(const unsigned char *buf1, const char *buf2)
49 return memcmp(buf1, buf2, 4)? 1 : 0;
52 static int read_atom_header(unsigned char *buf, uint64_t *subsize, unsigned char type[5])
55 uint64_t size = aac_read_int32(buf);
57 memcpy(type, buf + 4, 4);
60 PARA_DEBUG_LOG("size: %llu, type: %s\n", (long long unsigned)size, type);
67 for (i = 0; i < 8; i++)
68 size |= ((uint64_t)buf[i]) << ((7 - i) * 8);
73 static char *get_tag(unsigned char *p, int size)
78 buf = para_malloc(size + 1);
82 PARA_DEBUG_LOG("size: %d: %s\n", size, buf);
86 static void read_tags(unsigned char *buf, size_t buflen, struct afh_info *afhi)
88 unsigned char *p = buf;
90 while (p + 32 < buf + buflen) {
91 unsigned char *q, type1[5], type2[5];
92 uint64_t size1, size2;
95 ret = read_atom_header(p, &size1, type1);
96 ret2 = read_atom_header(p + ret, &size2, type2);
98 if (size2 <= 16 || atom_cmp(type2, "data")) {
103 q = p + ret + ret2 + 8;
104 if (q + size2 > buf + buflen)
106 if (!atom_cmp(type1, "\xa9" "ART"))
107 afhi->tags.artist = get_tag(q, size2);
108 else if (!atom_cmp(type1, "\xa9" "alb"))
109 afhi->tags.album = get_tag(q, size2);
110 else if (!atom_cmp(type1, "\xa9" "nam"))
111 afhi->tags.title = get_tag(q, size2);
112 else if (!atom_cmp(type1, "\xa9" "cmt"))
113 afhi->tags.comment = get_tag(q, size2);
114 else if (!atom_cmp(type1, "\xa9" "day"))
115 afhi->tags.year = get_tag(q, size2);
120 static void read_meta(unsigned char *buf, size_t buflen, struct afh_info *afhi)
122 unsigned char *p = buf;
124 while (p + 4 < buf + buflen) {
126 if (p[0] != 'i' || p[1] != 'l' || p[2] != 's' || p[3] != 't') {
131 return read_tags(p, buflen - (p - buf), afhi);
135 static void aac_get_taginfo(unsigned char *buf, size_t buflen,
136 struct afh_info *afhi)
140 unsigned char type[5];
142 for (i = 0; i + 24 < buflen; i++) {
143 unsigned char *p = buf + i;
144 if (p[0] != 'm' || p[1] != 'e' || p[2] != 't' || p[3] != 'a')
146 PARA_INFO_LOG("found metadata at offset %d\n", i);
149 i += read_atom_header(p, &subsize, type);
151 return read_meta(p, buflen - i, afhi);
153 PARA_INFO_LOG("no meta data\n");
156 static ssize_t aac_compute_chunk_table(struct afh_info *afhi,
157 unsigned char *map, size_t numbytes)
163 ret = aac_find_stsz(map, numbytes, &skip);
166 afhi->chunks_total = ret;
167 PARA_DEBUG_LOG("sz table has %" PRIu32 " entries\n", afhi->chunks_total);
168 afhi->chunk_table = para_malloc((afhi->chunks_total + 1) * sizeof(size_t));
169 for (i = 1; i <= afhi->chunks_total; i++) {
170 if (skip + 4 > numbytes)
172 sum += aac_read_int32(map + skip);
173 afhi->chunk_table[i] = sum;
175 // if (i < 10 || i + 10 > afhi->chunks_total)
176 // PARA_DEBUG_LOG("offset #%d: %zu\n", i, afhi->chunk_table[i]);
181 static int aac_set_chunk_tv(struct afh_info *afhi,
182 mp4AudioSpecificConfig *mp4ASC, uint32_t *seconds)
184 float tmp = mp4ASC->sbr_present_flag == 1? 2047 : 1023;
185 struct timeval total;
188 if (!mp4ASC->samplingFrequency)
190 ms = 1000.0 * afhi->chunks_total * tmp / mp4ASC->samplingFrequency;
192 tv_divide(afhi->chunks_total, &total, &afhi->chunk_tv);
193 PARA_INFO_LOG("%luHz, %lus (%" PRIu32 " x %lums)\n",
194 mp4ASC->samplingFrequency, ms / 1000,
195 afhi->chunks_total, tv2ms(&afhi->chunk_tv));
198 *seconds = ms / 1000;
203 * Init m4a file and write some tech data to given pointers.
205 static int aac_get_file_info(char *map, size_t numbytes, __a_unused int fd,
206 struct afh_info *afhi)
211 unsigned long rate = 0, decoder_len;
212 unsigned char channels = 0;
213 mp4AudioSpecificConfig mp4ASC;
214 NeAACDecHandle handle = NULL;
215 unsigned char *umap = (unsigned char *) map;
217 ret = aac_find_esds(umap, numbytes, &skip, &decoder_len);
220 aac_get_taginfo(umap, numbytes, afhi);
222 ret = -E_AAC_AFH_INIT;
223 if (NeAACDecInit(handle, umap + skip, decoder_len, &rate, &channels))
227 PARA_DEBUG_LOG("rate: %lu, channels: %d\n", rate, channels);
229 if (NeAACDecAudioSpecificConfig(umap + skip, numbytes - skip, &mp4ASC))
231 if (!mp4ASC.samplingFrequency)
233 ret = aac_compute_chunk_table(afhi, umap, numbytes);
237 ret = aac_set_chunk_tv(afhi, &mp4ASC, &afhi->seconds_total);
240 ret = aac_find_entry_point(umap + skip, numbytes - skip, &skip);
243 afhi->chunk_table[0] = ret;
244 for (i = 1; i<= afhi->chunks_total; i++)
245 afhi->chunk_table[i] += ret;
246 afhi->channels = channels;
247 afhi->frequency = rate;
248 ret = (afhi->chunk_table[afhi->chunks_total] - afhi->chunk_table[0]) * 8; /* bits */
249 ret += (channels * afhi->seconds_total * 500); /* avoid rounding error */
250 afhi->bitrate = ret / (channels * afhi->seconds_total * 1000);
254 NeAACDecClose(handle);
258 static int aac_rewrite_tags(const char *map, size_t mapsize,
259 struct taginfo *tags, int fd, const char *filename)
262 const MP4Tags *mdata;
263 int ret = write_all(fd, map, mapsize);
267 lseek(fd, 0, SEEK_SET);
268 h = MP4Modify(filename, 0);
270 PARA_ERROR_LOG("MP4Modify() failed, fd = %d\n", fd);
273 mdata = MP4TagsAlloc();
275 if (!MP4TagsFetch(mdata, h)) {
276 PARA_ERROR_LOG("MP4Tags_Fetch() failed\n");
281 if (!MP4TagsSetAlbum(mdata, tags->album)) {
282 PARA_ERROR_LOG("Could not set album\n");
286 if (!MP4TagsSetArtist(mdata, tags->artist)) {
287 PARA_ERROR_LOG("Could not set album\n");
291 if (!MP4TagsSetComments(mdata, tags->comment)) {
292 PARA_ERROR_LOG("Could not set comment\n");
296 if (!MP4TagsSetName(mdata, tags->title)) {
297 PARA_ERROR_LOG("Could not set title\n");
301 if (!MP4TagsSetReleaseDate(mdata, tags->year)) {
302 PARA_ERROR_LOG("Could not set release date\n");
307 if (!MP4TagsStore(mdata, h)) {
308 PARA_ERROR_LOG("Could not store tags\n");
320 static const char * const aac_suffixes[] = {"m4a", "mp4", NULL};
322 * the init function of the aac audio format handler
324 * \param afh pointer to the struct to initialize
326 void aac_afh_init(struct audio_format_handler *afh)
328 afh->get_file_info = aac_get_file_info,
329 afh->suffixes = aac_suffixes;
330 afh->rewrite_tags = aac_rewrite_tags;