2 * Copyright (C) 2003-2006 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 /** \file mp3.c para_server's mp3 audio format handler */
22 * This file is based in part on mp3tech.c and mp3tech.h, Copyright (C)
23 * 2000-2001 Cedric Tefft <cedric@earthling.net>, which in turn is based
26 * * MP3Info 0.5 by Ricardo Cerqueira <rmc@rccn.net>
27 * * MP3Stat 0.9 by Ed Sweetman <safemode@voicenet.com> and
28 * Johannes Overmann <overmann@iname.com>
31 #include "server.cmdline.h"
37 /** \cond some defines and structs which are only used in this file */
40 * MIN_CONSEC_GOOD_FRAMES defines how many consecutive valid MP3 frames we need
41 * to see before we decide we are looking at a real MP3 file
43 #define MIN_CONSEC_GOOD_FRAMES 3
45 #define FRAME_HEADER_SIZE 4
46 #define MIN_FRAME_SIZE 21
57 unsigned int copyright
;
58 unsigned int original
;
59 unsigned int emphasis
;
73 struct mp3header header
;
77 long unsigned br_average
;
78 long unsigned seconds
;
84 static int frequencies
[3][4] = {
85 {22050,24000,16000,50000}, /* MPEG 2.0 */
86 {44100,48000,32000,50000}, /* MPEG 1.0 */
87 {11025,12000,8000,50000} /* MPEG 2.5 */
90 static int mp3info_bitrate
[2][3][14] = {
92 {32,48,56,64,80,96,112,128,144,160,176,192,224,256}, /* layer 1 */
93 {8,16,24,32,40,48,56,64,80,96,112,128,144,160}, /* layer 2 */
94 {8,16,24,32,40,48,56,64,80,96,112,128,144,160} /* layer 3 */
98 {32,64,96,128,160,192,224,256,288,320,352,384,416,448}, /* layer 1 */
99 {32,48,56,64,80,96,112,128,160,192,224,256,320,384}, /* layer 2 */
100 {32,40,48,56,64,80,96,112,128,160,192,224,256,320} /* layer 3 */
104 static int frame_size_index
[] = {24000, 72000, 72000};
105 static const char *mode_text
[] = {"stereo", "joint stereo", "dual channel", "mono", "invalid"};
107 static struct mp3info mp3
;
108 static char mp3buf
[8192];
109 static int chunk_size
;
110 static struct audio_format_handler
*af
;
112 static int header_frequency(struct mp3header
*h
)
114 if (h
->version
> 2 || h
->freq
> 3)
115 return -E_HEADER_FREQ
;
116 return frequencies
[h
->version
][h
->freq
];
119 static const char *header_mode(struct mp3header
*h
)
122 h
->mode
= 4; /* invalid */
123 return mode_text
[h
->mode
];
125 static int header_bitrate(struct mp3header
*h
)
127 if (h
->layer
> 3 || h
->bitrate
> 14)
128 return -E_HEADER_BITRATE
;
129 return mp3info_bitrate
[h
->version
& 1][3 - h
->layer
][h
->bitrate
- 1];
132 static int frame_length(struct mp3header
*header
)
134 int hb
, hf
= header_frequency(header
);
138 hb
= header_bitrate(header
);
141 if (header
->sync
!= 0xFFE || header
->layer
> 3)
143 return frame_size_index
[3 - header
->layer
] *
144 ((header
->version
& 1) + 1) * hb
/ hf
148 static void write_info_str(char *info_str
)
150 int v
= mp3
.id3_isvalid
;
152 snprintf(info_str
, MMD_INFO_SIZE
,
153 "audio_file_info1:%d x %lums, %lu kbit/s (%cbr) %i KHz %s\n"
154 "audio_file_info2:%s, by %s\n"
155 "audio_file_info3:A: %s, Y: %s, C: %s\n",
157 tv2ms(&af
->chunk_tv
),
161 header_mode(&mp3
.header
),
162 v
&& *mp3
.id3
.title
? mp3
.id3
.title
: "(title tag not set)",
163 v
&& *mp3
.id3
.artist
? mp3
.id3
.artist
: "(artist tag not set)",
164 v
&& *mp3
.id3
.album
? mp3
.id3
.album
: "(album tag not set)",
165 v
&& *mp3
.id3
.year
? mp3
.id3
.year
: "????",
166 v
&& *mp3
.id3
.comment
? mp3
.id3
.comment
: "(comment tag not set)"
171 * Remove trailing whitespace from the end of a string
173 static char *unpad(char *string
)
175 char *pos
= string
+ strlen(string
) - 1;
176 while (isspace(pos
[0]))
181 static int compare_headers(struct mp3header
*h1
,struct mp3header
*h2
)
183 if ((*(uint
*)h1
) == (*(uint
*)h2
))
185 if ((h1
->version
== h2
->version
) &&
186 (h1
->layer
== h2
->layer
) &&
187 (h1
->crc
== h2
->crc
) &&
188 (h1
->freq
== h2
->freq
) &&
189 (h1
->mode
== h2
->mode
) &&
190 (h1
->copyright
== h2
->copyright
) &&
191 (h1
->original
== h2
->original
) &&
192 (h1
->emphasis
== h2
->emphasis
))
199 * get next MP3 frame header.
201 * \param stream to read the header from
202 * \param header structure that gets filled in by get_header()
204 * \return On success, the header frame length is returned. A return value of
205 * zero means that we did not retrieve a valid frame header, and a negative
206 * return value indicates an error.
208 static int get_header(FILE *file
, struct mp3header
*header
)
210 unsigned char buffer
[FRAME_HEADER_SIZE
];
213 if (!file
|| !header
)
214 return -E_MP3_NO_FILE
;
215 ret
= para_fread(buffer
, FRAME_HEADER_SIZE
, 1, file
);
216 if (ret
< FRAME_HEADER_SIZE
) {
218 return ret
< 0? ret
: 0;
220 header
->layer
= (buffer
[1] >> 1) & 3;
221 header
->sync
= (((int)buffer
[0]<<4) | ((int)(buffer
[1]&0xE0)>>4));
222 if (buffer
[1] & 0x10)
223 header
->version
= (buffer
[1] >> 3) & 1;
226 if ((header
->sync
!= 0xFFE) || (header
->layer
!= 1)) {
228 // PARA_DEBUG_LOG("%s: header not found\n", __func__);
231 header
->crc
= buffer
[1] & 1;
232 header
->bitrate
= (buffer
[2] >> 4) & 0x0F;
233 // PARA_DEBUG_LOG("%s: found header, bitrate: %u\n", __func__,
235 header
->freq
= (buffer
[2] >> 2) & 0x3;
236 header
->padding
= (buffer
[2] >>1) & 0x1;
237 header
->mode
= (buffer
[3] >> 6) & 0x3;
238 fl
= frame_length(header
);
239 return (fl
>= MIN_FRAME_SIZE
)? fl
: -E_FRAME_LENGTH
;
243 * find the next mp3 header
245 * \return On success, the length of the next frame header. If the end of the
246 * file was reached, the function returns zero. On errors, a negative value is
250 static int mp3_seek_next_header(void)
252 int k
, l
= 0, c
, first_len
;
253 struct mp3header h
, h2
;
254 long valid_start
= 0;
257 while ((c
= fgetc(mp3
.file
)) != 255 && (c
!= EOF
))
262 valid_start
= ftell(mp3
.file
);
263 first_len
= get_header(mp3
.file
, &h
);
266 if (fseek(mp3
.file
, first_len
- FRAME_HEADER_SIZE
, SEEK_CUR
) < 0)
268 for (k
= 1; k
< MIN_CONSEC_GOOD_FRAMES
; k
++) {
269 if ((l
= get_header(mp3
.file
, &h2
)) <= 0)
271 if (!compare_headers(&h
, &h2
))
273 fseek(mp3
.file
, l
- FRAME_HEADER_SIZE
, SEEK_CUR
);
275 if (k
== MIN_CONSEC_GOOD_FRAMES
) {
276 fseek(mp3
.file
, valid_start
, SEEK_SET
);
277 memcpy(&(mp3
.header
), &h2
, sizeof(struct mp3header
));
283 static int mp3_get_id3(void)
288 mp3
.id3
.title
[0] = '\0';
289 mp3
.id3
.artist
[0] = '\0';
290 mp3
.id3
.album
[0] = '\0';
291 mp3
.id3
.comment
[0] = '\0';
292 mp3
.id3
.year
[0] = '\0';
293 if (fseek(mp3
.file
, -128, SEEK_END
))
295 if (para_fread(fbuf
, 1, 3, mp3
.file
) < 0)
298 if (strcmp("TAG", fbuf
)) {
299 PARA_INFO_LOG("%s", "no id3 tag\n");
302 if (fseek(mp3
.file
, -125, SEEK_END
) < 0)
304 if (para_fread(mp3
.id3
.title
, 1, 30, mp3
.file
) != 30)
306 mp3
.id3
.title
[30] = '\0';
307 if (para_fread(mp3
.id3
.artist
, 1, 30, mp3
.file
) != 30)
309 mp3
.id3
.artist
[30] = '\0';
310 if (para_fread(mp3
.id3
.album
, 1, 30, mp3
.file
) != 30)
312 mp3
.id3
.album
[30] = '\0';
313 if (para_fread(mp3
.id3
.year
, 1, 4, mp3
.file
) != 4)
315 mp3
.id3
.year
[4] = '\0';
316 if (para_fread(mp3
.id3
.comment
, 1, 30, mp3
.file
) != 30)
318 mp3
.id3
.comment
[30] = '\0';
320 unpad(mp3
.id3
.title
);
321 unpad(mp3
.id3
.artist
);
322 unpad(mp3
.id3
.album
);
324 unpad(mp3
.id3
.comment
);
328 static int find_valid_start(void)
333 return -E_MP3_NO_FILE
;
334 frame_len
= get_header(mp3
.file
, &mp3
.header
);
338 frame_len
= mp3_seek_next_header();
342 if (fseek(mp3
.file
, -FRAME_HEADER_SIZE
, SEEK_CUR
) < 0)
344 if (frame_len
<= 1) /* FRAME_HEADER_SIZE? */
345 return -E_FRAME_LENGTH
;
349 static int mp3_read_info(void)
351 long fl_avg
= 0, freq_avg
= 0, br_avg
= 0, fcount
= 0;
352 int ret
, len
= 0, old_br
= -1;
353 struct timeval total_time
= {0, 0};
363 struct timeval tmp
, cct
; /* current chunk time */
365 if (fseek(mp3
.file
, len
, SEEK_CUR
) < 0)
367 len
= find_valid_start();
370 freq
= header_frequency(&mp3
.header
);
371 br
= header_bitrate(&mp3
.header
);
372 fl
= frame_length(&mp3
.header
);
373 if (freq
< 0 || br
< 0 || fl
< 0)
377 tv_divide(br
* 125, &tmp
, &cct
);
378 tv_add(&cct
, &total_time
, &tmp
);
380 // PARA_DEBUG_LOG("%s: br: %d, freq: %d, fl: %d, cct: %lu\n", __func__, br, freq, fl, cct.tv_usec);
389 freq_avg
+= (freq
- freq_avg
) / (fcount
+ 1);
390 fl_avg
+= (fl
- fl_avg
) / (fcount
+ 1);
391 br_avg
+= (br
- br_avg
) / (fcount
+ 1);
396 if (!fcount
|| !freq_avg
|| !br_avg
)
398 mp3
.br_average
= br_avg
;
401 mp3
.seconds
= (tv2ms(&total_time
) + 500) / 1000;
402 tv_divide(fcount
, &total_time
, &af
->chunk_tv
);
404 PARA_DEBUG_LOG("chunk_time: %lums\n", tv2ms(&af
->chunk_tv
));
405 tv_scale(30, &af
->chunk_tv
, &af
->eof_tv
);
406 PARA_DEBUG_LOG("eof timeout: %lu\n", tv2ms(&af
->eof_tv
));
411 * Read mp3 information from audio file
413 static int mp3_get_file_info(FILE *audio_file
, char *info_str
,
414 long unsigned *frames
, int *seconds
)
419 return -E_MP3_NO_FILE
;
420 mp3
.file
= audio_file
;
421 ret
= mp3_read_info();
426 write_info_str(info_str
);
427 *frames
= mp3
.frames
;
428 *seconds
= mp3
.seconds
;
429 if (*seconds
< 2 || !*frames
)
434 static int mp3_reposition_stream(long unsigned new_frame
)
438 PARA_DEBUG_LOG("jmp to frame %lu/%i\n", new_frame
, mp3
.frames
);
440 while (count
< new_frame
&& (len
= find_valid_start()) > 0) {
441 // PARA_DEBUG_LOG("%s: jmp to frame %d\n", __func__, count);
442 if (fseek(mp3
.file
, len
, SEEK_CUR
) < 0)
446 if (count
!= new_frame
) {
453 static int mp3_read_next_chunk(void)
455 int len
= find_valid_start();
459 PARA_ERROR_LOG("invalid frame len (%d)\n", len
);
462 chunk_size
= para_fread(mp3buf
, len
, 1, mp3
.file
);
463 if (len
!= chunk_size
)
464 PARA_DEBUG_LOG("short read (%d/%d)\n", chunk_size
, len
);
468 static char *mp3_read_chunk(__a_unused
long unsigned chunk_num
, ssize_t
*len
)
470 *len
= mp3_read_next_chunk();
476 static void mp3_close_audio_file(void)
484 static const char* mp3_suffixes
[] = {"mp3", NULL
};
485 void mp3_init(struct audio_format_handler
*p
)
488 af
->get_file_info
= mp3_get_file_info
;
489 af
->reposition_stream
= mp3_reposition_stream
;
490 af
->read_chunk
= mp3_read_chunk
;
491 af
->close_audio_file
= mp3_close_audio_file
;
492 af
->get_header_info
= NULL
;
493 /* eof_tv gets overwritten in mp3_get_file_info() */
494 af
->eof_tv
.tv_sec
= 0;
495 af
->eof_tv
.tv_usec
= 100 * 1000;
496 af
->suffixes
= mp3_suffixes
;