2 * Copyright (C) 2006-2008 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 */
22 static int aac_find_stsz(unsigned char *buf
, size_t buflen
, off_t
*skip
)
26 for (i
= 0; i
+ 16 < buflen
; i
++) {
27 unsigned char *p
= buf
+ i
;
28 unsigned sample_count
, sample_size
;
30 if (p
[0] != 's' || p
[1] != 't' || p
[2] != 's' || p
[3] != 'z')
32 PARA_DEBUG_LOG("found stsz@%d\n", i
);
34 sample_size
= aac_read_int32(buf
+ i
);
35 PARA_DEBUG_LOG("sample size: %d\n", sample_size
);
37 sample_count
= aac_read_int32(buf
+ i
);
39 PARA_DEBUG_LOG("sample count: %d\n", sample_count
);
46 static int atom_cmp(unsigned char *buf1
, char *buf2
)
48 unsigned char *b2
= (unsigned char *)buf2
;
61 static int read_atom_header(unsigned char *buf
, uint64_t *subsize
, unsigned char type
[5])
64 uint64_t size
= (buf
[0] << 24) + (buf
[1] << 16) + (buf
[2] << 8) + buf
[3];
66 memcpy(type
, buf
+ 4, 4);
69 PARA_DEBUG_LOG("size: %llu, type: %s\n", (long long unsigned)size
, type
);
76 for (i
= 0; i
< 8; i
++)
77 size
|= ((uint64_t)buf
[i
]) << ((7 - i
) * 8);
82 static char *get_tag(unsigned char *p
, int size
)
87 buf
= para_malloc(size
+ 1);
91 PARA_DEBUG_LOG("size: %d: %s\n", size
, buf
);
95 static void read_tags(unsigned char *buf
, size_t buflen
, struct afh_info
*afhi
)
97 unsigned char *p
= buf
;
99 while (p
+ 32 < buf
+ buflen
) {
100 unsigned char *q
, type1
[5], type2
[5];
101 uint64_t size1
, size2
;
104 ret
= read_atom_header(p
, &size1
, type1
);
105 ret2
= read_atom_header(p
+ ret
, &size2
, type2
);
107 if (size2
<= 16 || atom_cmp(type2
, "data")) {
112 q
= p
+ ret
+ ret2
+ 8;
113 if (q
+ size2
> buf
+ buflen
)
115 if (!atom_cmp(type1
, "©ART"))
116 afhi
->tags
.artist
= get_tag(q
, size2
);
117 else if (!atom_cmp(type1
, "©alb"))
118 afhi
->tags
.album
= get_tag(q
, size2
);
119 else if (!atom_cmp(type1
, "©nam"))
120 afhi
->tags
.title
= get_tag(q
, size2
);
121 else if (!atom_cmp(type1
, "©cmt"))
122 afhi
->tags
.comment
= get_tag(q
, size2
);
123 else if (!atom_cmp(type1
, "©day"))
124 afhi
->tags
.year
= get_tag(q
, size2
);
129 static void read_meta(unsigned char *buf
, size_t buflen
, struct afh_info
*afhi
)
131 unsigned char *p
= buf
;
133 while (p
+ 4 < buf
+ buflen
) {
135 if (p
[0] != 'i' || p
[1] != 'l' || p
[2] != 's' || p
[3] != 't') {
140 return read_tags(p
, buflen
- (p
- buf
), afhi
);
144 static void aac_get_taginfo(unsigned char *buf
, size_t buflen
,
145 struct afh_info
*afhi
)
149 unsigned char type
[5];
151 for (i
= 0; i
+ 24 < buflen
; i
++) {
152 unsigned char *p
= buf
+ i
;
153 if (p
[0] != 'm' || p
[1] != 'e' || p
[2] != 't' || p
[3] != 'a')
155 PARA_INFO_LOG("found metadata at offset %d\n", i
);
158 i
+= read_atom_header(p
, &subsize
, type
);
160 return read_meta(p
, buflen
- i
, afhi
);
162 PARA_INFO_LOG("no meta data\n");
165 static ssize_t
aac_compute_chunk_table(struct afh_info
*afhi
,
166 unsigned char *map
, size_t numbytes
)
172 ret
= aac_find_stsz(map
, numbytes
, &skip
);
175 afhi
->chunks_total
= ret
;
176 PARA_DEBUG_LOG("sz table has %lu entries\n", afhi
->chunks_total
);
177 afhi
->chunk_table
= para_malloc((afhi
->chunks_total
+ 1) * sizeof(size_t));
178 for (i
= 1; i
<= afhi
->chunks_total
; i
++) {
179 if (skip
+ 4 > numbytes
)
181 sum
+= aac_read_int32(map
+ skip
);
182 afhi
->chunk_table
[i
] = sum
;
184 // if (i < 10 || i + 10 > afhi->chunks_total)
185 // PARA_DEBUG_LOG("offset #%d: %zu\n", i, afhi->chunk_table[i]);
190 static int aac_set_chunk_tv(struct afh_info
*afhi
,
191 mp4AudioSpecificConfig
*mp4ASC
, long unsigned *seconds
)
193 float tmp
= mp4ASC
->sbr_present_flag
== 1? 2047 : 1023;
194 struct timeval total
;
195 long unsigned ms
= 1000.0 * afhi
->chunks_total
* tmp
196 / mp4ASC
->samplingFrequency
;
198 if (!mp4ASC
->samplingFrequency
)
200 ms
= 1000.0 * afhi
->chunks_total
* tmp
/ mp4ASC
->samplingFrequency
;
202 tv_divide(afhi
->chunks_total
, &total
, &afhi
->chunk_tv
);
203 PARA_INFO_LOG("%luHz, %lus (%lu x %lums)\n",
204 mp4ASC
->samplingFrequency
, ms
/ 1000,
205 afhi
->chunks_total
, tv2ms(&afhi
->chunk_tv
));
208 *seconds
= ms
/ 1000;
213 * Init m4a file and write some tech data to given pointers.
215 static int aac_get_file_info(char *map
, size_t numbytes
, __a_unused
int fd
,
216 struct afh_info
*afhi
)
221 unsigned long rate
= 0, decoder_len
;
222 unsigned char channels
= 0;
223 mp4AudioSpecificConfig mp4ASC
;
224 NeAACDecHandle handle
= NULL
;
225 unsigned char *umap
= (unsigned char *) map
;
227 ret
= aac_find_esds(umap
, numbytes
, &skip
, &decoder_len
);
230 aac_get_taginfo(umap
, numbytes
, afhi
);
232 ret
= -E_AAC_AFH_INIT
;
233 if (NeAACDecInit(handle
, umap
+ skip
, decoder_len
, &rate
, &channels
))
237 PARA_DEBUG_LOG("rate: %lu, channels: %d\n", rate
, channels
);
239 if (NeAACDecAudioSpecificConfig(umap
+ skip
, numbytes
- skip
, &mp4ASC
))
241 if (!mp4ASC
.samplingFrequency
)
243 ret
= aac_compute_chunk_table(afhi
, umap
, numbytes
);
247 ret
= aac_set_chunk_tv(afhi
, &mp4ASC
, &afhi
->seconds_total
);
250 ret
= aac_find_entry_point(umap
+ skip
, numbytes
- skip
, &skip
);
253 afhi
->chunk_table
[0] = ret
;
254 for (i
= 1; i
<= afhi
->chunks_total
; i
++)
255 afhi
->chunk_table
[i
] += ret
;
256 afhi
->channels
= channels
;
257 afhi
->frequency
= rate
;
258 ret
= (afhi
->chunk_table
[afhi
->chunks_total
] - afhi
->chunk_table
[0]) * 8; /* bits */
259 ret
+= (channels
* afhi
->seconds_total
* 500); /* avoid rounding error */
260 afhi
->bitrate
= ret
/ (channels
* afhi
->seconds_total
* 1000);
264 NeAACDecClose(handle
);
268 static const char* aac_suffixes
[] = {"m4a", "mp4", NULL
};
270 * the init function of the aac audio format handler
272 * \param afh pointer to the struct to initialize
274 void aac_afh_init(struct audio_format_handler
*afh
)
276 afh
->get_file_info
= aac_get_file_info
,
277 afh
->suffixes
= aac_suffixes
;