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>
18 #include "portable_io.h"
24 static int aac_find_stsz(char *buf, size_t buflen, off_t *skip)
28 for (i = 0; i + 16 < buflen; i++) {
30 unsigned sample_count, sample_size;
32 if (p[0] != 's' || p[1] != 't' || p[2] != 's' || p[3] != 'z')
34 PARA_DEBUG_LOG("found stsz@%d\n", i);
36 sample_size = read_u32_be(buf + i);
37 PARA_DEBUG_LOG("sample size: %u\n", sample_size);
39 sample_count = read_u32_be(buf + i);
41 PARA_DEBUG_LOG("sample count: %u\n", sample_count);
48 static int atom_cmp(const char *buf1, const char *buf2)
50 return memcmp(buf1, buf2, 4)? 1 : 0;
53 static int read_atom_header(char *buf, uint64_t *subsize, char type[5])
55 uint64_t size = read_u32_be(buf);
57 memcpy(type, buf + 4, 4);
60 PARA_DEBUG_LOG("size: %llu, type: %s\n", (long long unsigned)size, type);
67 size = read_u64_be(buf);
72 static char *get_tag(char *p, int size)
77 buf = para_malloc(size + 1);
81 PARA_DEBUG_LOG("size: %d: %s\n", size, buf);
85 static void read_tags(char *buf, size_t buflen, struct afh_info *afhi)
89 while (p + 32 < buf + buflen) {
90 char *q, type1[5], type2[5];
91 uint64_t size1, size2;
94 ret = read_atom_header(p, &size1, type1);
95 ret2 = read_atom_header(p + ret, &size2, type2);
97 if (size2 <= 16 || atom_cmp(type2, "data")) {
102 q = p + ret + ret2 + 8;
103 if (q + size2 > buf + buflen)
105 if (!atom_cmp(type1, "\xa9" "ART"))
106 afhi->tags.artist = get_tag(q, size2);
107 else if (!atom_cmp(type1, "\xa9" "alb"))
108 afhi->tags.album = get_tag(q, size2);
109 else if (!atom_cmp(type1, "\xa9" "nam"))
110 afhi->tags.title = get_tag(q, size2);
111 else if (!atom_cmp(type1, "\xa9" "cmt"))
112 afhi->tags.comment = get_tag(q, size2);
113 else if (!atom_cmp(type1, "\xa9" "day"))
114 afhi->tags.year = get_tag(q, size2);
119 static void read_meta(char *buf, size_t buflen, struct afh_info *afhi)
123 while (p + 4 < buf + buflen) {
125 if (p[0] != 'i' || p[1] != 'l' || p[2] != 's' || p[3] != 't') {
130 return read_tags(p, buflen - (p - buf), afhi);
134 static void aac_get_taginfo(char *buf, size_t buflen, struct afh_info *afhi)
140 for (i = 0; i + 24 < buflen; i++) {
142 if (p[0] != 'm' || p[1] != 'e' || p[2] != 't' || p[3] != 'a')
144 PARA_INFO_LOG("found metadata at offset %d\n", i);
147 i += read_atom_header(p, &subsize, type);
149 return read_meta(p, buflen - i, afhi);
151 PARA_INFO_LOG("no meta data\n");
154 static ssize_t aac_compute_chunk_table(struct afh_info *afhi,
155 char *map, size_t numbytes)
161 ret = aac_find_stsz(map, numbytes, &skip);
164 afhi->chunks_total = ret;
165 PARA_DEBUG_LOG("sz table has %" PRIu32 " entries\n", afhi->chunks_total);
166 afhi->chunk_table = para_malloc((afhi->chunks_total + 1) * sizeof(size_t));
167 for (i = 1; i <= afhi->chunks_total; i++) {
168 if (skip + 4 > numbytes)
170 sum += read_u32_be(map + skip);
171 afhi->chunk_table[i] = sum;
173 // if (i < 10 || i + 10 > afhi->chunks_total)
174 // PARA_DEBUG_LOG("offset #%d: %zu\n", i, afhi->chunk_table[i]);
179 static int aac_set_chunk_tv(struct afh_info *afhi,
180 mp4AudioSpecificConfig *mp4ASC, uint32_t *seconds)
182 float tmp = mp4ASC->sbr_present_flag == 1? 2047 : 1023;
183 struct timeval total;
186 ms = 1000.0 * afhi->chunks_total * tmp / mp4ASC->samplingFrequency;
188 tv_divide(afhi->chunks_total, &total, &afhi->chunk_tv);
189 PARA_INFO_LOG("%luHz, %lus (%" PRIu32 " x %lums)\n",
190 mp4ASC->samplingFrequency, ms / 1000,
191 afhi->chunks_total, tv2ms(&afhi->chunk_tv));
194 *seconds = ms / 1000;
199 * Init m4a file and write some tech data to given pointers.
201 static int aac_get_file_info(char *map, size_t numbytes, __a_unused int fd,
202 struct afh_info *afhi)
207 unsigned long rate = 0, decoder_len;
208 unsigned char channels = 0;
209 mp4AudioSpecificConfig mp4ASC;
210 NeAACDecHandle handle = NULL;
212 ret = aac_find_esds(map, numbytes, &skip, &decoder_len);
215 aac_get_taginfo(map, numbytes, afhi);
217 ret = -E_AAC_AFH_INIT;
218 if (NeAACDecInit(handle, (unsigned char *)map + skip, decoder_len,
223 PARA_DEBUG_LOG("rate: %lu, channels: %d\n", rate, channels);
225 if (NeAACDecAudioSpecificConfig((unsigned char *)map + skip,
226 numbytes - skip, &mp4ASC))
228 if (!mp4ASC.samplingFrequency)
230 ret = aac_compute_chunk_table(afhi, map, numbytes);
234 ret = aac_set_chunk_tv(afhi, &mp4ASC, &afhi->seconds_total);
237 ret = aac_find_entry_point(map + skip, numbytes - skip, &skip);
240 afhi->chunk_table[0] = ret;
241 for (i = 1; i<= afhi->chunks_total; i++)
242 afhi->chunk_table[i] += ret;
243 set_max_chunk_size(afhi);
244 afhi->channels = channels;
245 afhi->frequency = rate;
246 ret = (afhi->chunk_table[afhi->chunks_total] - afhi->chunk_table[0]) * 8; /* bits */
247 ret += (channels * afhi->seconds_total * 500); /* avoid rounding error */
248 afhi->bitrate = ret / (channels * afhi->seconds_total * 1000);
252 NeAACDecClose(handle);
256 static int aac_rewrite_tags(const char *map, size_t mapsize,
257 struct taginfo *tags, int fd, const char *filename)
260 const MP4Tags *mdata;
261 int ret = write_all(fd, map, mapsize);
265 lseek(fd, 0, SEEK_SET);
266 h = MP4Modify(filename, 0);
268 PARA_ERROR_LOG("MP4Modify() failed, fd = %d\n", fd);
271 mdata = MP4TagsAlloc();
273 if (!MP4TagsFetch(mdata, h)) {
274 PARA_ERROR_LOG("MP4Tags_Fetch() failed\n");
279 if (!MP4TagsSetAlbum(mdata, tags->album)) {
280 PARA_ERROR_LOG("Could not set album\n");
284 if (!MP4TagsSetArtist(mdata, tags->artist)) {
285 PARA_ERROR_LOG("Could not set album\n");
289 if (!MP4TagsSetComments(mdata, tags->comment)) {
290 PARA_ERROR_LOG("Could not set comment\n");
294 if (!MP4TagsSetName(mdata, tags->title)) {
295 PARA_ERROR_LOG("Could not set title\n");
299 if (!MP4TagsSetReleaseDate(mdata, tags->year)) {
300 PARA_ERROR_LOG("Could not set release date\n");
305 if (!MP4TagsStore(mdata, h)) {
306 PARA_ERROR_LOG("Could not store tags\n");
318 static const char * const aac_suffixes[] = {"m4a", "mp4", NULL};
320 * the init function of the aac audio format handler
322 * \param afh pointer to the struct to initialize
324 void aac_afh_init(struct audio_format_handler *afh)
326 afh->get_file_info = aac_get_file_info,
327 afh->suffixes = aac_suffixes;
328 afh->rewrite_tags = aac_rewrite_tags;