2 * Copyright (C) 2003-2008 Andre Noll <maan@systemlinux.org>
4 * Licensed under the GPL v2. For licencing details see COPYING.
7 /** \file mp3_afh.c para_server's mp3 audio format handler */
10 * This file is based in part on mp3tech.c and mp3tech.h, Copyright (C)
11 * 2000-2001 Cedric Tefft <cedric@earthling.net>, which in turn is based
14 * * MP3Info 0.5 by Ricardo Cerqueira <rmc@rccn.net>
15 * * MP3Stat 0.9 by Ed Sweetman <safemode@voicenet.com> and
16 * Johannes Overmann <overmann@iname.com>
26 /** \cond some defines and structs which are only used in this file */
29 * MIN_CONSEC_GOOD_FRAMES defines how many consecutive valid MP3 frames we need
30 * to see before we decide we are looking at a real MP3 file
32 #define MIN_CONSEC_GOOD_FRAMES 4
33 #define FRAME_HEADER_SIZE 4
34 #define MIN_FRAME_SIZE 21
45 unsigned int copyright
;
46 unsigned int original
;
47 unsigned int emphasis
;
51 static const int frequencies
[3][4] = {
52 {22050,24000,16000,50000}, /* MPEG 2.0 */
53 {44100,48000,32000,50000}, /* MPEG 1.0 */
54 {11025,12000,8000,50000} /* MPEG 2.5 */
57 static const int mp3info_bitrate
[2][3][14] = {
59 {32,48,56,64,80,96,112,128,144,160,176,192,224,256}, /* layer 1 */
60 {8,16,24,32,40,48,56,64,80,96,112,128,144,160}, /* layer 2 */
61 {8,16,24,32,40,48,56,64,80,96,112,128,144,160} /* layer 3 */
65 {32,64,96,128,160,192,224,256,288,320,352,384,416,448}, /* layer 1 */
66 {32,48,56,64,80,96,112,128,160,192,224,256,320,384}, /* layer 2 */
67 {32,40,48,56,64,80,96,112,128,160,192,224,256,320} /* layer 3 */
71 static const int frame_size_index
[] = {24000, 72000, 72000};
72 static const char *mode_text
[] = {"stereo", "joint stereo", "dual channel", "mono", "invalid"};
75 * Remove trailing whitespace from the end of a string
77 static char *unpad(char *string
)
79 char *pos
= string
+ strlen(string
) - 1;
80 while (para_isspace(pos
[0]))
85 static char *mp3_get_id3(unsigned char *map
, size_t numbytes
)
87 char title
[31], artist
[31], album
[31], year
[5], comment
[31];
90 if (numbytes
< 128 || strncmp("TAG", (char *)map
+ numbytes
- 128, 3)) {
91 PARA_DEBUG_LOG("no id3 v1 tag\n");
92 return make_message("%s: (no id3 v1 tag)\n%s:\n",
93 status_item_list
[SI_TAGINFO1
],
94 status_item_list
[SI_TAGINFO2
]);
96 fpos
= numbytes
- 125;
97 memcpy(title
, map
+ fpos
, 30);
100 memcpy(artist
, map
+ fpos
, 30);
103 memcpy(album
, map
+ fpos
, 30);
106 memcpy(year
, map
+ fpos
, 4);
109 memcpy(comment
, map
+ fpos
, 30);
116 return make_message("%s: %s, by %s\n" /* taginfo1 */
117 "%s: A: %s, Y: %s, C: %s\n", /* taginfo 2*/
118 status_item_list
[SI_TAGINFO1
],
119 *title
? title
: "(title tag not set)",
120 *artist
? artist
: "(artist tag not set)",
121 status_item_list
[SI_TAGINFO2
],
122 *album
? album
: "(album tag not set)",
123 *year
? year
: "????",
124 *comment
? comment
: "(comment tag not set)"
128 static int header_frequency(struct mp3header
*h
)
130 if (h
->version
> 2 || h
->freq
> 3)
131 return -E_HEADER_FREQ
;
132 return frequencies
[h
->version
][h
->freq
];
135 static const char *header_mode(struct mp3header
*h
)
138 h
->mode
= 4; /* invalid */
139 return mode_text
[h
->mode
];
142 static int header_channels(struct mp3header
*h
)
151 static int header_bitrate(struct mp3header
*h
)
153 if (!h
->layer
|| h
->layer
> 3 || h
->bitrate
> 14 || !h
->bitrate
)
154 return -E_HEADER_BITRATE
;
155 return mp3info_bitrate
[h
->version
& 1][3 - h
->layer
][h
->bitrate
- 1];
158 static int frame_length(struct mp3header
*header
)
160 int hb
, hf
= header_frequency(header
);
164 hb
= header_bitrate(header
);
167 if (header
->sync
!= 0xFFE || header
->layer
> 3)
169 return frame_size_index
[3 - header
->layer
] *
170 ((header
->version
& 1) + 1) * hb
/ hf
174 static int compare_headers(struct mp3header
*h1
,struct mp3header
*h2
)
176 if ((*(uint
*)h1
) == (*(uint
*)h2
))
178 if ((h1
->version
== h2
->version
) &&
179 (h1
->layer
== h2
->layer
) &&
180 (h1
->crc
== h2
->crc
) &&
181 (h1
->freq
== h2
->freq
) &&
182 (h1
->mode
== h2
->mode
) &&
183 (h1
->copyright
== h2
->copyright
) &&
184 (h1
->original
== h2
->original
) &&
185 (h1
->emphasis
== h2
->emphasis
))
191 * get next MP3 frame header.
193 * On success, the header frame length is returned and the given header
194 * structure that is filled in. A return value of zero means that we did not
195 * retrieve a valid frame header, and a negative return value indicates an
198 static int get_header(unsigned char *map
, size_t numbytes
, off_t
*fpos
,
199 struct mp3header
*header
)
203 if (*fpos
+ FRAME_HEADER_SIZE
> numbytes
) {
204 *fpos
= numbytes
- 1;
208 header
->layer
= (map
[*fpos
+ 1] >> 1) & 3;
209 header
->sync
= (((int)map
[*fpos
]<<4) | ((int)(map
[*fpos
+ 1]&0xE0)>>4));
210 if (map
[*fpos
+ 1] & 0x10)
211 header
->version
= (map
[*fpos
+ 1] >> 3) & 1;
214 if ((header
->sync
!= 0xFFE) || (header
->layer
!= 1)) {
219 header
->crc
= map
[*fpos
+ 1] & 1;
220 header
->bitrate
= (map
[*fpos
+ 2] >> 4) & 0x0F;
221 header
->freq
= (map
[*fpos
+ 2] >> 2) & 0x3;
222 header
->padding
= (map
[*fpos
+ 2] >>1) & 0x1;
223 header
->mode
= (map
[*fpos
+ 3] >> 6) & 0x3;
224 fl
= frame_length(header
);
225 ret
= (fl
>= MIN_FRAME_SIZE
)? fl
: -E_FRAME_LENGTH
;
227 *fpos
+= FRAME_HEADER_SIZE
;
232 * find the next mp3 header
234 * Return the length of the next frame header or zero if the end of the file is
237 static int mp3_seek_next_header(unsigned char *map
, size_t numbytes
, off_t
*fpos
,
238 struct mp3header
*result
)
240 int k
, l
= 0, first_len
;
241 struct mp3header h
, h2
;
242 long valid_start
= 0;
244 for (; *fpos
< numbytes
; (*fpos
)++) {
245 if (map
[*fpos
] != 0xff)
248 first_len
= get_header(map
, numbytes
, fpos
, &h
);
251 *fpos
+= first_len
- FRAME_HEADER_SIZE
;
252 for (k
= 1; k
< MIN_CONSEC_GOOD_FRAMES
; k
++) {
253 if ((l
= get_header(map
, numbytes
, fpos
, &h2
)) <= 0)
255 if (!compare_headers(&h
, &h2
))
257 *fpos
+= l
- FRAME_HEADER_SIZE
;
259 if (k
== MIN_CONSEC_GOOD_FRAMES
) {
268 static int find_valid_start(unsigned char *map
, size_t numbytes
, off_t
*fpos
,
269 struct mp3header
*header
)
273 frame_len
= get_header(map
, numbytes
, fpos
, header
);
277 frame_len
= mp3_seek_next_header(map
, numbytes
, fpos
, header
);
281 *fpos
-= FRAME_HEADER_SIZE
;
283 return -E_FRAME_LENGTH
;
287 static int mp3_read_info(unsigned char *map
, size_t numbytes
,
288 struct afh_info
*afhi
)
290 long freq_avg
= 0, br_avg
= 0;
291 int ret
, len
= 0, old_br
= -1, vbr
= 0;
292 struct timeval total_time
= {0, 0};
293 unsigned chunk_table_size
= 1000; /* gets increased on demand */
295 struct mp3header header
;
298 afhi
->chunks_total
= 0;
299 afhi
->chunk_table
= para_malloc(chunk_table_size
* sizeof(size_t));
300 taginfo
= mp3_get_id3(map
, numbytes
);
302 unsigned long freq
, br
, fl
;
303 struct timeval tmp
, cct
; /* current chunk time */
305 len
= find_valid_start(map
, numbytes
, &fpos
, &header
);
308 ret
= header_frequency(&header
);
312 ret
= header_bitrate(&header
);
316 ret
= frame_length(&header
);
322 tv_divide(br
* 125, &tmp
, &cct
);
323 tv_add(&cct
, &total_time
, &tmp
);
325 //PARA_DEBUG_LOG("%s: br: %d, freq: %d, fl: %d, cct: %lu\n", __func__, br, freq, fl, cct.tv_usec);
326 if (afhi
->chunks_total
>= chunk_table_size
) {
327 chunk_table_size
*= 2;
328 afhi
->chunk_table
= para_realloc(afhi
->chunk_table
,
329 chunk_table_size
* sizeof(size_t));
331 afhi
->chunk_table
[afhi
->chunks_total
] = fpos
;
332 // if (afhi->chunks_total < 10 || !(afhi->chunks_total % 1000))
333 // PARA_INFO_LOG("chunk #%lu: %zd\n", afhi->chunks_total,
334 // afhi->chunk_table[afhi->chunks_total]);
335 afhi
->chunks_total
++;
336 if (afhi
->chunks_total
== 1) {
342 freq_avg
+= ((long)freq
- freq_avg
) / ((long)afhi
->chunks_total
+ 1);
343 br_avg
+= ((long)br
- br_avg
) / ((long)afhi
->chunks_total
+ 1);
349 if (!afhi
->chunks_total
|| !freq_avg
|| !br_avg
)
351 afhi
->chunk_table
[afhi
->chunks_total
] = numbytes
- 1;
352 afhi
->bitrate
= br_avg
;
353 afhi
->frequency
= freq_avg
;
354 afhi
->channels
= header_channels(&header
);
355 afhi
->seconds_total
= (tv2ms(&total_time
) + 500) / 1000;
356 tv_divide(afhi
->chunks_total
, &total_time
, &afhi
->chunk_tv
);
357 PARA_DEBUG_LOG("%lu chunks, each %lums\n", afhi
->chunks_total
,
358 tv2ms(&afhi
->chunk_tv
));
359 tv_scale(3, &afhi
->chunk_tv
, &afhi
->eof_tv
);
360 PARA_DEBUG_LOG("eof timeout: %lu\n", tv2ms(&afhi
->eof_tv
));
361 afhi
->info_string
= make_message("%s: %cbr, %s\n%s",
362 status_item_list
[SI_AUDIO_FILE_INFO
], vbr
? 'v' : 'c',
363 header_mode(&header
), taginfo
);
368 PARA_ERROR_LOG("%s\n", para_strerror(-ret
));
369 free(afhi
->chunk_table
);
374 * Read mp3 information from audio file
376 int mp3_get_file_info(char *map
, size_t numbytes
,
377 struct afh_info
*afhi
)
381 ret
= mp3_read_info((unsigned char *)map
, numbytes
, afhi
);
384 if (afhi
->seconds_total
< 2 || !afhi
->chunks_total
)
389 static const char* mp3_suffixes
[] = {"mp3", NULL
};
392 * the init function of the mp3 audio format handler
394 * \param afh pointer to the struct to initialize
396 void mp3_init(struct audio_format_handler
*afh
)
398 afh
->get_file_info
= mp3_get_file_info
;
399 afh
->suffixes
= mp3_suffixes
;