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 if (!mp4ASC->samplingFrequency)
188 ms = 1000.0 * afhi->chunks_total * tmp / mp4ASC->samplingFrequency;
190 tv_divide(afhi->chunks_total, &total, &afhi->chunk_tv);
191 PARA_INFO_LOG("%luHz, %lus (%" PRIu32 " x %lums)\n",
192 mp4ASC->samplingFrequency, ms / 1000,
193 afhi->chunks_total, tv2ms(&afhi->chunk_tv));
196 *seconds = ms / 1000;
201 * Init m4a file and write some tech data to given pointers.
203 static int aac_get_file_info(char *map, size_t numbytes, __a_unused int fd,
204 struct afh_info *afhi)
209 unsigned long rate = 0, decoder_len;
210 unsigned char channels = 0;
211 mp4AudioSpecificConfig mp4ASC;
212 NeAACDecHandle handle = NULL;
214 ret = aac_find_esds(map, numbytes, &skip, &decoder_len);
217 aac_get_taginfo(map, numbytes, afhi);
219 ret = -E_AAC_AFH_INIT;
220 if (NeAACDecInit(handle, (unsigned char *)map + skip, decoder_len,
225 PARA_DEBUG_LOG("rate: %lu, channels: %d\n", rate, channels);
227 if (NeAACDecAudioSpecificConfig((unsigned char *)map + skip,
228 numbytes - skip, &mp4ASC))
230 if (!mp4ASC.samplingFrequency)
232 ret = aac_compute_chunk_table(afhi, map, numbytes);
236 ret = aac_set_chunk_tv(afhi, &mp4ASC, &afhi->seconds_total);
239 ret = aac_find_entry_point(map + skip, numbytes - skip, &skip);
242 afhi->chunk_table[0] = ret;
243 for (i = 1; i<= afhi->chunks_total; i++)
244 afhi->chunk_table[i] += ret;
245 afhi->channels = channels;
246 afhi->frequency = rate;
247 ret = (afhi->chunk_table[afhi->chunks_total] - afhi->chunk_table[0]) * 8; /* bits */
248 ret += (channels * afhi->seconds_total * 500); /* avoid rounding error */
249 afhi->bitrate = ret / (channels * afhi->seconds_total * 1000);
253 NeAACDecClose(handle);
257 static int aac_rewrite_tags(const char *map, size_t mapsize,
258 struct taginfo *tags, int fd, const char *filename)
261 const MP4Tags *mdata;
262 int ret = write_all(fd, map, mapsize);
266 lseek(fd, 0, SEEK_SET);
267 h = MP4Modify(filename, 0);
269 PARA_ERROR_LOG("MP4Modify() failed, fd = %d\n", fd);
272 mdata = MP4TagsAlloc();
274 if (!MP4TagsFetch(mdata, h)) {
275 PARA_ERROR_LOG("MP4Tags_Fetch() failed\n");
280 if (!MP4TagsSetAlbum(mdata, tags->album)) {
281 PARA_ERROR_LOG("Could not set album\n");
285 if (!MP4TagsSetArtist(mdata, tags->artist)) {
286 PARA_ERROR_LOG("Could not set album\n");
290 if (!MP4TagsSetComments(mdata, tags->comment)) {
291 PARA_ERROR_LOG("Could not set comment\n");
295 if (!MP4TagsSetName(mdata, tags->title)) {
296 PARA_ERROR_LOG("Could not set title\n");
300 if (!MP4TagsSetReleaseDate(mdata, tags->year)) {
301 PARA_ERROR_LOG("Could not set release date\n");
306 if (!MP4TagsStore(mdata, h)) {
307 PARA_ERROR_LOG("Could not store tags\n");
319 static const char * const aac_suffixes[] = {"m4a", "mp4", NULL};
321 * the init function of the aac audio format handler
323 * \param afh pointer to the struct to initialize
325 void aac_afh_init(struct audio_format_handler *afh)
327 afh->get_file_info = aac_get_file_info,
328 afh->suffixes = aac_suffixes;
329 afh->rewrite_tags = aac_rewrite_tags;