0a352c886164e858001fec0397da3aba7cab7cfb
[paraslash.git] / aac_afh.c
1 /*
2 * Copyright (C) 2006-2007 Andre Noll <maan@systemlinux.org>
3 *
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.
8 *
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.
13 *
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.
17 */
18 /*
19 * based in parts on libfaad, Copyright (C) 2003-2005 M. Bakker,
20 * Ahead Software AG
21 */
22
23 /** \file aac_afh.c para_server's aac audio format handler */
24
25 #include "server.h"
26 #include "error.h"
27 #include "string.h"
28 #include "aac.h"
29
30 static int aac_find_stsz(unsigned char *buf, size_t buflen, off_t *skip)
31 {
32 int i;
33
34 for (i = 0; i + 16 < buflen; i++) {
35 unsigned char *p = buf + i;
36 unsigned sample_count, sample_size;
37
38 if (p[0] != 's' || p[1] != 't' || p[2] != 's' || p[3] != 'z')
39 continue;
40 PARA_INFO_LOG("found stsz@%d\n", i);
41 i += 8;
42 sample_size = aac_read_int32(buf + i);
43 PARA_INFO_LOG("sample size: %d\n", sample_size);
44 i += 4;
45 sample_count = aac_read_int32(buf + i);
46 i += 4;
47 PARA_INFO_LOG("sample count: %d\n", sample_count);
48 *skip = i;
49 return sample_count;
50 }
51 return -E_STSZ;
52 }
53
54 static ssize_t aac_compute_chunk_table(struct audio_format_info *afi,
55 unsigned char *map, size_t numbytes)
56 {
57 int ret, i;
58 size_t sum = 0;
59 off_t skip;
60
61 ret = aac_find_stsz(map, numbytes, &skip);
62 if (ret < 0)
63 return ret;
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)
69 break;
70 sum += aac_read_int32(map + skip);
71 afi->chunk_table[i] = sum;
72 skip += 4;
73 // if (i < 10 || i + 10 > afi->chunks_total)
74 // PARA_DEBUG_LOG("offset #%d: %zu\n", i, afi->chunk_table[i]);
75 }
76 return skip;
77 }
78
79 static int aac_set_chunk_tv(struct audio_format_info *afi,
80 mp4AudioSpecificConfig *mp4ASC, long unsigned *seconds)
81 {
82 float tmp = mp4ASC->sbr_present_flag == 1? 2047 : 1023;
83 struct timeval total;
84 long unsigned ms = 1000.0 * afi->chunks_total * tmp
85 / mp4ASC->samplingFrequency;
86
87 if (!mp4ASC->samplingFrequency)
88 return -E_MP4ASC;
89 ms = 1000.0 * afi->chunks_total * tmp / mp4ASC->samplingFrequency;
90 ms2tv(ms, &total);
91 tv_divide(afi->chunks_total, &total, &afi->chunk_tv);
92 PARA_INFO_LOG("%luHz, %lus (%lu x %lums)\n",
93 mp4ASC->samplingFrequency, ms / 1000,
94 afi->chunks_total, tv2ms(&afi->chunk_tv));
95 if (ms < 1000)
96 return -E_MP4ASC;
97 *seconds = ms / 1000;
98 return 1;
99 }
100
101 /*
102 * Init m4a file and write some tech data to given pointers.
103 */
104 static int aac_get_file_info(char *map, size_t numbytes,
105 struct audio_format_info *afi)
106 {
107 int i;
108 size_t skip;
109 ssize_t ret;
110 unsigned long rate = 0, decoder_len;
111 unsigned char channels = 0;
112 mp4AudioSpecificConfig mp4ASC;
113 NeAACDecHandle handle;
114 unsigned char *umap = (unsigned char *) map;
115
116 ret = aac_find_esds(umap, numbytes, &skip, &decoder_len);
117 if (ret < 0)
118 goto out;
119 handle = aac_open();
120 ret = -E_AAC_AFH_INIT;
121 if (NeAACDecInit(handle, umap + skip, decoder_len, &rate, &channels))
122 goto out;
123 if (!channels)
124 goto out;
125 PARA_INFO_LOG("rate: %lu, channels: %d\n", rate, channels);
126 ret = -E_MP4ASC;
127 if (NeAACDecAudioSpecificConfig(umap + skip, numbytes - skip, &mp4ASC))
128 goto out;
129 if (!mp4ASC.samplingFrequency)
130 goto out;
131 ret = aac_compute_chunk_table(afi, umap, numbytes);
132 if (ret < 0)
133 goto out;
134 skip = ret;
135 ret = aac_set_chunk_tv(afi, &mp4ASC, &afi->seconds_total);
136 if (ret < 0)
137 goto out;
138 ret = aac_find_entry_point(umap + skip, numbytes - skip, &skip);
139 if (ret < 0)
140 goto out;
141 afi->chunk_table[0] = ret;
142 for (i = 1; i<= afi->chunks_total; i++)
143 afi->chunk_table[i] += ret;
144 afi->channels = channels;
145 afi->frequency = rate;
146 ret = (afi->chunk_table[afi->chunks_total] - afi->chunk_table[0]) * 8; /* bits */
147 ret += (channels * afi->seconds_total * 500); /* avoid rounding error */
148 afi->bitrate = ret / (channels * afi->seconds_total * 1000);
149 sprintf(afi->info_string, "audio_file_info1:%lu x %lums, "
150 "%uHz, %d channel%s, %ukb/s\n"
151 "audio_file_info2:\n"
152 "audio_file_info3:\n",
153 afi->chunks_total, tv2ms(&afi->chunk_tv),
154 afi->frequency, channels, channels == 1? "" : "s", afi->bitrate
155 );
156 tv_scale(20, &afi->chunk_tv, &afi->eof_tv);
157 ret = 1;
158 out:
159 return ret;
160 }
161
162 static const char* aac_suffixes[] = {"m4a", "mp4", NULL};
163 /**
164 * the init function of the aac audio format handler
165 *
166 * \param afh pointer to the struct to initialize
167 */
168 void aac_afh_init(struct audio_format_handler *afh)
169 {
170 afh->get_file_info = aac_get_file_info,
171 afh->suffixes = aac_suffixes;
172 }