2 * Copyright (C) 2006-2007 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 */
20 static int aac_find_stsz(unsigned char *buf, size_t buflen, off_t *skip)
24 for (i = 0; i + 16 < buflen; i++) {
25 unsigned char *p = buf + i;
26 unsigned sample_count, sample_size;
28 if (p[0] != 's' || p[1] != 't' || p[2] != 's' || p[3] != 'z')
30 PARA_DEBUG_LOG("found stsz@%d\n", i);
32 sample_size = aac_read_int32(buf + i);
33 PARA_DEBUG_LOG("sample size: %d\n", sample_size);
35 sample_count = aac_read_int32(buf + i);
37 PARA_DEBUG_LOG("sample count: %d\n", sample_count);
44 static ssize_t aac_compute_chunk_table(struct audio_format_info *afi,
45 unsigned char *map, size_t numbytes)
51 ret = aac_find_stsz(map, numbytes, &skip);
54 afi->chunks_total = ret;
55 PARA_DEBUG_LOG("sz table has %lu entries\n", afi->chunks_total);
56 afi->chunk_table = para_malloc((afi->chunks_total + 1) * sizeof(size_t));
57 for (i = 1; i <= afi->chunks_total; i++) {
58 if (skip + 4 > numbytes)
60 sum += aac_read_int32(map + skip);
61 afi->chunk_table[i] = sum;
63 // if (i < 10 || i + 10 > afi->chunks_total)
64 // PARA_DEBUG_LOG("offset #%d: %zu\n", i, afi->chunk_table[i]);
69 static int aac_set_chunk_tv(struct audio_format_info *afi,
70 mp4AudioSpecificConfig *mp4ASC, long unsigned *seconds)
72 float tmp = mp4ASC->sbr_present_flag == 1? 2047 : 1023;
74 long unsigned ms = 1000.0 * afi->chunks_total * tmp
75 / mp4ASC->samplingFrequency;
77 if (!mp4ASC->samplingFrequency)
79 ms = 1000.0 * afi->chunks_total * tmp / mp4ASC->samplingFrequency;
81 tv_divide(afi->chunks_total, &total, &afi->chunk_tv);
82 PARA_INFO_LOG("%luHz, %lus (%lu x %lums)\n",
83 mp4ASC->samplingFrequency, ms / 1000,
84 afi->chunks_total, tv2ms(&afi->chunk_tv));
92 * Init m4a file and write some tech data to given pointers.
94 static int aac_get_file_info(char *map, size_t numbytes,
95 struct audio_format_info *afi)
100 unsigned long rate = 0, decoder_len;
101 unsigned char channels = 0;
102 mp4AudioSpecificConfig mp4ASC;
103 NeAACDecHandle handle = NULL;
104 unsigned char *umap = (unsigned char *) map;
106 ret = aac_find_esds(umap, numbytes, &skip, &decoder_len);
110 ret = -E_AAC_AFH_INIT;
111 if (NeAACDecInit(handle, umap + skip, decoder_len, &rate, &channels))
115 PARA_DEBUG_LOG("rate: %lu, channels: %d\n", rate, channels);
117 if (NeAACDecAudioSpecificConfig(umap + skip, numbytes - skip, &mp4ASC))
119 if (!mp4ASC.samplingFrequency)
121 ret = aac_compute_chunk_table(afi, umap, numbytes);
125 ret = aac_set_chunk_tv(afi, &mp4ASC, &afi->seconds_total);
128 ret = aac_find_entry_point(umap + skip, numbytes - skip, &skip);
131 afi->chunk_table[0] = ret;
132 for (i = 1; i<= afi->chunks_total; i++)
133 afi->chunk_table[i] += ret;
134 afi->channels = channels;
135 afi->frequency = rate;
136 ret = (afi->chunk_table[afi->chunks_total] - afi->chunk_table[0]) * 8; /* bits */
137 ret += (channels * afi->seconds_total * 500); /* avoid rounding error */
138 afi->bitrate = ret / (channels * afi->seconds_total * 1000);
139 sprintf(afi->info_string, "audio_file_info1:%lu x %lums, "
140 "%uHz, %d channel%s, %ukb/s\n"
141 "audio_file_info2:\n"
142 "audio_file_info3:\n",
143 afi->chunks_total, tv2ms(&afi->chunk_tv),
144 afi->frequency, channels, channels == 1? "" : "s", afi->bitrate
146 tv_scale(20, &afi->chunk_tv, &afi->eof_tv);
150 NeAACDecClose(handle);
154 static const char* aac_suffixes[] = {"m4a", "mp4", NULL};
156 * the init function of the aac audio format handler
158 * \param afh pointer to the struct to initialize
160 void aac_afh_init(struct audio_format_handler *afh)
162 afh->get_file_info = aac_get_file_info,
163 afh->suffixes = aac_suffixes;