2 * Copyright (C) 2006-2008 Andre Noll <maan@systemlinux.org>
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 */
22 static int aac_find_stsz(unsigned char *buf, size_t buflen, off_t *skip)
26 for (i = 0; i + 16 < buflen; i++) {
27 unsigned char *p = buf + i;
28 unsigned sample_count, sample_size;
30 if (p[0] != 's' || p[1] != 't' || p[2] != 's' || p[3] != 'z')
32 PARA_DEBUG_LOG("found stsz@%d\n", i);
34 sample_size = aac_read_int32(buf + i);
35 PARA_DEBUG_LOG("sample size: %d\n", sample_size);
37 sample_count = aac_read_int32(buf + i);
39 PARA_DEBUG_LOG("sample count: %d\n", sample_count);
46 static int atom_cmp(unsigned char *buf1, char *buf2)
48 unsigned char *b2 = (unsigned char *)buf2;
61 static int read_atom_header(unsigned char *buf, uint64_t *subsize, unsigned char type[5])
64 uint64_t size = (buf[0] << 24) + (buf[1] << 16) + (buf[2] << 8) + buf[3];
66 memcpy(type, buf + 4, 4);
69 PARA_DEBUG_LOG("size: %llu, type: %s\n", (long long unsigned)size, type);
76 for (i = 0; i < 8; i++)
77 size |= ((uint64_t)buf[i]) << ((7 - i) * 8);
82 static char *get_tag(unsigned char *p, int size)
87 buf = para_malloc(size + 1);
91 PARA_DEBUG_LOG("size: %d: %s\n", size, buf);
95 static char *read_tags(unsigned char *buf, size_t buflen)
97 unsigned char *p = buf;
98 char *title = NULL, *artist = NULL, *album = NULL, *year = NULL,
99 *comment = NULL, *result;
101 while (p + 32 < buf + buflen) {
102 unsigned char *q, type1[5], type2[5];
103 uint64_t size1, size2;
106 ret = read_atom_header(p, &size1, type1);
107 ret2 = read_atom_header(p + ret, &size2, type2);
109 if (size2 <= 16 || atom_cmp(type2, "data")) {
114 q = p + ret + ret2 + 8;
115 if (q + size2 > buf + buflen)
117 if (!atom_cmp(type1, "©ART"))
118 artist = get_tag(q, size2);
119 else if (!atom_cmp(type1, "©alb"))
120 album = get_tag(q, size2);
121 else if (!atom_cmp(type1, "©nam"))
122 title = get_tag(q, size2);
123 else if (!atom_cmp(type1, "©cmt"))
124 comment = get_tag(q, size2);
125 else if (!atom_cmp(type1, "©day"))
126 year = get_tag(q, size2);
129 result = make_taginfo(title, artist, album, year, comment);
138 static char *read_meta(unsigned char *buf, size_t buflen)
140 unsigned char *p = buf;
142 while (p + 4 < buf + buflen) {
144 if (p[0] != 'i' || p[1] != 'l' || p[2] != 's' || p[3] != 't') {
149 return read_tags(p, buflen - (p - buf));
151 return make_taginfo(NULL, NULL, NULL, NULL, NULL);
154 static char *aac_get_taginfo(unsigned char *buf, size_t buflen)
158 unsigned char type[5];
160 for (i = 0; i + 24 < buflen; i++) {
161 unsigned char *p = buf + i;
162 if (p[0] != 'm' || p[1] != 'e' || p[2] != 't' || p[3] != 'a')
164 PARA_INFO_LOG("found metadata at offset %d\n", i);
167 i += read_atom_header(p, &subsize, type);
169 return read_meta(p, buflen - i);
171 PARA_INFO_LOG("no meta data\n");
172 return make_taginfo(NULL, NULL, NULL, NULL, NULL);
175 static ssize_t aac_compute_chunk_table(struct afh_info *afhi,
176 unsigned char *map, size_t numbytes)
182 ret = aac_find_stsz(map, numbytes, &skip);
185 afhi->chunks_total = ret;
186 PARA_DEBUG_LOG("sz table has %lu entries\n", afhi->chunks_total);
187 afhi->chunk_table = para_malloc((afhi->chunks_total + 1) * sizeof(size_t));
188 for (i = 1; i <= afhi->chunks_total; i++) {
189 if (skip + 4 > numbytes)
191 sum += aac_read_int32(map + skip);
192 afhi->chunk_table[i] = sum;
194 // if (i < 10 || i + 10 > afhi->chunks_total)
195 // PARA_DEBUG_LOG("offset #%d: %zu\n", i, afhi->chunk_table[i]);
200 static int aac_set_chunk_tv(struct afh_info *afhi,
201 mp4AudioSpecificConfig *mp4ASC, long unsigned *seconds)
203 float tmp = mp4ASC->sbr_present_flag == 1? 2047 : 1023;
204 struct timeval total;
205 long unsigned ms = 1000.0 * afhi->chunks_total * tmp
206 / mp4ASC->samplingFrequency;
208 if (!mp4ASC->samplingFrequency)
210 ms = 1000.0 * afhi->chunks_total * tmp / mp4ASC->samplingFrequency;
212 tv_divide(afhi->chunks_total, &total, &afhi->chunk_tv);
213 PARA_INFO_LOG("%luHz, %lus (%lu x %lums)\n",
214 mp4ASC->samplingFrequency, ms / 1000,
215 afhi->chunks_total, tv2ms(&afhi->chunk_tv));
218 *seconds = ms / 1000;
223 * Init m4a file and write some tech data to given pointers.
225 static int aac_get_file_info(char *map, size_t numbytes, __a_unused int fd,
226 struct afh_info *afhi)
231 unsigned long rate = 0, decoder_len;
232 unsigned char channels = 0;
233 mp4AudioSpecificConfig mp4ASC;
234 NeAACDecHandle handle = NULL;
235 unsigned char *umap = (unsigned char *) map;
238 ret = aac_find_esds(umap, numbytes, &skip, &decoder_len);
241 taginfo = aac_get_taginfo(umap, numbytes);
243 ret = -E_AAC_AFH_INIT;
244 if (NeAACDecInit(handle, umap + skip, decoder_len, &rate, &channels))
248 PARA_DEBUG_LOG("rate: %lu, channels: %d\n", rate, channels);
250 if (NeAACDecAudioSpecificConfig(umap + skip, numbytes - skip, &mp4ASC))
252 if (!mp4ASC.samplingFrequency)
254 ret = aac_compute_chunk_table(afhi, umap, numbytes);
258 ret = aac_set_chunk_tv(afhi, &mp4ASC, &afhi->seconds_total);
261 ret = aac_find_entry_point(umap + skip, numbytes - skip, &skip);
264 afhi->chunk_table[0] = ret;
265 for (i = 1; i<= afhi->chunks_total; i++)
266 afhi->chunk_table[i] += ret;
267 afhi->channels = channels;
268 afhi->frequency = rate;
269 ret = (afhi->chunk_table[afhi->chunks_total] - afhi->chunk_table[0]) * 8; /* bits */
270 ret += (channels * afhi->seconds_total * 500); /* avoid rounding error */
271 afhi->bitrate = ret / (channels * afhi->seconds_total * 1000);
272 afhi->info_string = make_message("%s:\n%s",
273 status_item_list[SI_AUDIO_FILE_INFO],
276 tv_scale(20, &afhi->chunk_tv, &afhi->eof_tv);
280 NeAACDecClose(handle);
284 static const char* aac_suffixes[] = {"m4a", "mp4", NULL};
286 * the init function of the aac audio format handler
288 * \param afh pointer to the struct to initialize
290 void aac_afh_init(struct audio_format_handler *afh)
292 afh->get_file_info = aac_get_file_info,
293 afh->suffixes = aac_suffixes;