2 * Copyright (C) 2006-2007 Andre Noll <maan@systemlinux.org>
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
19 * based in parts on libfaad, Copyright (C) 2003-2005 M. Bakker,
23 /** \file aac_afh.c para_server's aac audio format handler */
30 static int aac_find_stsz(unsigned char *buf, off_t buflen, off_t *skip)
34 for (i = 0; i + 16 < buflen; i++) {
35 unsigned char *p = buf + i;
36 unsigned sample_count, sample_size;
38 if (p[0] != 's' || p[1] != 't' || p[2] != 's' || p[3] != 'z')
40 PARA_INFO_LOG("found stsz@%d\n", i);
42 sample_size = aac_read_int32(buf + i);
43 PARA_INFO_LOG("sample size: %d\n", sample_size);
45 sample_count = aac_read_int32(buf + i);
47 PARA_INFO_LOG("sample count: %d\n", sample_count);
54 static ssize_t aac_compute_chunk_table(struct audio_format_info *afi,
55 unsigned char *map, off_t numbytes)
61 ret = aac_find_stsz(map, numbytes, &skip);
64 afi->chunks_total = ret;
65 PARA_INFO_LOG("sz table has %lu entries\n", afi->chunks_total);
66 afi->chunk_table = para_malloc((afi->chunks_total + 1) * sizeof(size_t));
67 for (i = 1; i <= afi->chunks_total; i++) {
68 if (skip + 4 > numbytes)
70 sum += aac_read_int32(map + skip);
71 afi->chunk_table[i] = sum;
73 // if (i < 10 || i + 10 > afi->chunks_total)
74 // PARA_DEBUG_LOG("offset #%d: %zu\n", i, afi->chunk_table[i]);
79 static long unsigned aac_set_chunk_tv(struct audio_format_info *afi,
80 mp4AudioSpecificConfig *mp4ASC)
82 float tmp = mp4ASC->sbr_present_flag == 1? 2047 : 1023,
83 ms = 1000.0 * afi->chunks_total * tmp / mp4ASC->samplingFrequency;
87 tv_divide(afi->chunks_total, &total, &afi->chunk_tv);
88 PARA_INFO_LOG("%luHz, %fs (%lu x %lums)\n",
89 mp4ASC->samplingFrequency, ms / 1000,
90 afi->chunks_total, tv2ms(&afi->chunk_tv));
91 return ms < 1000? -E_MP4ASC : ms / 1000;
95 * Init m4a file and write some tech data to given pointers.
97 static int aac_get_file_info(char *map, off_t numbytes,
98 struct audio_format_info *afi)
103 unsigned long rate = 0, decoder_len;
104 unsigned char channels = 0;
105 mp4AudioSpecificConfig mp4ASC;
106 NeAACDecHandle handle;
108 ret = aac_find_esds(map, numbytes, &skip);
113 ret = -E_AACDEC_INIT;
114 if (NeAACDecInit(handle, map + skip, decoder_len, &rate, &channels))
118 PARA_INFO_LOG("rate: %lu, channels: %d\n", rate, channels);
120 if (NeAACDecAudioSpecificConfig(map + skip, numbytes - skip, &mp4ASC))
122 if (!mp4ASC.samplingFrequency)
124 ret = aac_compute_chunk_table(afi, map, numbytes);
128 afi->seconds_total = aac_set_chunk_tv(afi, &mp4ASC);
129 ret = aac_find_entry_point(map + skip, numbytes - skip, &skip);
132 afi->chunk_table[0] = ret;
133 for (i = 1; i<= afi->chunks_total; i++)
134 afi->chunk_table[i] += ret;
135 afi->channels = channels;
136 afi->frequency = rate;
137 ret = (afi->chunk_table[afi->chunks_total] - afi->chunk_table[0]) * 8; /* bits */
138 ret += (channels * afi->seconds_total * 500); /* avoid rounding error */
139 afi->bitrate = ret / (channels * afi->seconds_total * 1000);
140 sprintf(afi->info_string, "audio_file_info1:%lu x %lums, "
141 "%uHz, %d channel%s, %ukb/s\n"
142 "audio_file_info2:\n"
143 "audio_file_info3:\n",
144 afi->chunks_total, tv2ms(&afi->chunk_tv),
145 afi->frequency, channels, channels == 1? "" : "s", afi->bitrate
147 tv_scale(20, &afi->chunk_tv, &afi->eof_tv);
153 static const char* aac_suffixes[] = {"m4a", "mp4", NULL};
155 * the init function of the aac audio format handler
157 * \param afh pointer to the struct to initialize
159 void aac_afh_init(struct audio_format_handler *afh)
161 afh->get_file_info = aac_get_file_info,
162 afh->suffixes = aac_suffixes;