mp3_afh.c: Kill unused mp3.filename
[paraslash.git] / mp3_afh.c
1 /*
2 * Copyright (C) 2003-2007 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 /** \file mp3_afh.c para_server's mp3 audio format handler */
20
21 /*
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
24 * in part on
25 *
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>
29 */
30
31 #include "server.cmdline.h"
32 #include "server.h"
33 #include "vss.h"
34 #include "afh.h"
35 #include "error.h"
36 #include "fd.h"
37 #include "string.h"
38
39 /** \cond some defines and structs which are only used in this file */
40
41 /*
42 * MIN_CONSEC_GOOD_FRAMES defines how many consecutive valid MP3 frames we need
43 * to see before we decide we are looking at a real MP3 file
44 */
45 #define MIN_CONSEC_GOOD_FRAMES 4
46
47 #define FRAME_HEADER_SIZE 4
48 #define MIN_FRAME_SIZE 21
49
50 struct mp3header {
51 unsigned long sync;
52 unsigned int version;
53 unsigned int layer;
54 unsigned int crc;
55 unsigned int bitrate;
56 unsigned int freq;
57 unsigned int padding;
58 unsigned int mode;
59 unsigned int copyright;
60 unsigned int original;
61 unsigned int emphasis;
62 };
63
64 struct id3tag {
65 char title[31];
66 char artist[31];
67 char album[31];
68 char year[5];
69 char comment[31];
70 };
71
72 struct mp3info {
73 struct mp3header header;
74 int id3_isvalid;
75 struct id3tag id3;
76 int vbr;
77 long unsigned br_average;
78 long unsigned seconds;
79 int freq;
80 };
81
82 /** \endcond */
83 static int frequencies[3][4] = {
84 {22050,24000,16000,50000}, /* MPEG 2.0 */
85 {44100,48000,32000,50000}, /* MPEG 1.0 */
86 {11025,12000,8000,50000} /* MPEG 2.5 */
87 };
88
89 static int mp3info_bitrate[2][3][14] = {
90 { /* MPEG 2.0 */
91 {32,48,56,64,80,96,112,128,144,160,176,192,224,256}, /* layer 1 */
92 {8,16,24,32,40,48,56,64,80,96,112,128,144,160}, /* layer 2 */
93 {8,16,24,32,40,48,56,64,80,96,112,128,144,160} /* layer 3 */
94 },
95
96 { /* MPEG 1.0 */
97 {32,64,96,128,160,192,224,256,288,320,352,384,416,448}, /* layer 1 */
98 {32,48,56,64,80,96,112,128,160,192,224,256,320,384}, /* layer 2 */
99 {32,40,48,56,64,80,96,112,128,160,192,224,256,320} /* layer 3 */
100 }
101 };
102
103 static int frame_size_index[] = {24000, 72000, 72000};
104 static const char *mode_text[] = {"stereo", "joint stereo", "dual channel", "mono", "invalid"};
105
106 static FILE *infile;
107 static struct mp3info mp3;
108 static struct audio_format_handler *af;
109 static ssize_t *chunk_table, num_chunks;
110
111 static int header_frequency(struct mp3header *h)
112 {
113 if (h->version > 2 || h->freq > 3)
114 return -E_HEADER_FREQ;
115 return frequencies[h->version][h->freq];
116 }
117
118 static const char *header_mode(struct mp3header *h)
119 {
120 if (h->mode > 4)
121 h->mode = 4; /* invalid */
122 return mode_text[h->mode];
123 }
124 static int header_bitrate(struct mp3header *h)
125 {
126 if (h->layer > 3 || h->bitrate > 14)
127 return -E_HEADER_BITRATE;
128 return mp3info_bitrate[h->version & 1][3 - h->layer][h->bitrate - 1];
129 }
130
131 static int frame_length(struct mp3header *header)
132 {
133 int hb, hf = header_frequency(header);
134
135 if (hf < 0)
136 return hf;
137 hb = header_bitrate(header);
138 if (hb < 0)
139 return hb;
140 if (header->sync != 0xFFE || header->layer > 3)
141 return -E_FRAME;
142 return frame_size_index[3 - header->layer] *
143 ((header->version & 1) + 1) * hb / hf
144 + header->padding;
145 }
146
147 static void write_info_str(char *info_str)
148 {
149 int v = mp3.id3_isvalid;
150
151 snprintf(info_str, MMD_INFO_SIZE,
152 "audio_file_info1:%d x %lums, %lu kbit/s (%cbr) %i KHz %s\n"
153 "audio_file_info2:%s, by %s\n"
154 "audio_file_info3:A: %s, Y: %s, C: %s\n",
155 num_chunks,
156 tv2ms(&af->chunk_tv),
157 mp3.br_average,
158 mp3.vbr? 'v' : 'c',
159 mp3.freq / 1000,
160 header_mode(&mp3.header),
161 v && *mp3.id3.title? mp3.id3.title : "(title tag not set)",
162 v && *mp3.id3.artist? mp3.id3.artist : "(artist tag not set)",
163 v && *mp3.id3.album? mp3.id3.album : "(album tag not set)",
164 v && *mp3.id3.year? mp3.id3.year : "????",
165 v && *mp3.id3.comment? mp3.id3.comment : "(comment tag not set)"
166 );
167 }
168
169 /*
170 * Remove trailing whitespace from the end of a string
171 */
172 static char *unpad(char *string)
173 {
174 char *pos = string + strlen(string) - 1;
175 while (isspace(pos[0]))
176 (pos--)[0] = 0;
177 return string;
178 }
179
180 static int compare_headers(struct mp3header *h1,struct mp3header *h2)
181 {
182 if ((*(uint*)h1) == (*(uint*)h2))
183 return 1;
184 if ((h1->version == h2->version) &&
185 (h1->layer == h2->layer) &&
186 (h1->crc == h2->crc) &&
187 (h1->freq == h2->freq) &&
188 (h1->mode == h2->mode) &&
189 (h1->copyright == h2->copyright) &&
190 (h1->original == h2->original) &&
191 (h1->emphasis == h2->emphasis))
192 return 1;
193 else
194 return 0;
195 }
196
197 /**
198 * get next MP3 frame header.
199 *
200 * \param stream to read the header from
201 * \param header structure that gets filled in by get_header()
202 *
203 * \return On success, the header frame length is returned. A return value of
204 * zero means that we did not retrieve a valid frame header, and a negative
205 * return value indicates an error.
206 */
207 static int get_header(FILE *file, struct mp3header *header)
208 {
209 unsigned char buffer[FRAME_HEADER_SIZE];
210 int fl, ret;
211
212 if (!file || !header)
213 return -E_MP3_NO_FILE;
214 ret = para_fread(buffer, FRAME_HEADER_SIZE, 1, file);
215 if (ret < FRAME_HEADER_SIZE) {
216 header->sync = 0;
217 return ret < 0? ret : 0;
218 }
219 header->layer = (buffer[1] >> 1) & 3;
220 header->sync = (((int)buffer[0]<<4) | ((int)(buffer[1]&0xE0)>>4));
221 if (buffer[1] & 0x10)
222 header->version = (buffer[1] >> 3) & 1;
223 else
224 header->version = 2;
225 if ((header->sync != 0xFFE) || (header->layer != 1)) {
226 header->sync = 0;
227 // PARA_DEBUG_LOG("%s: header not found\n", __func__);
228 return 0;
229 }
230 header->crc = buffer[1] & 1;
231 header->bitrate = (buffer[2] >> 4) & 0x0F;
232 // PARA_DEBUG_LOG("%s: found header, bitrate: %u\n", __func__,
233 // header->bitrate);
234 header->freq = (buffer[2] >> 2) & 0x3;
235 header->padding = (buffer[2] >>1) & 0x1;
236 header->mode = (buffer[3] >> 6) & 0x3;
237 fl = frame_length(header);
238 return (fl >= MIN_FRAME_SIZE)? fl : -E_FRAME_LENGTH;
239 }
240
241 /**
242 * find the next mp3 header
243 *
244 * \return On success, the length of the next frame header. If the end of the
245 * file was reached, the function returns zero. On errors, a negative value is
246 * returned.
247 *
248 */
249 static int mp3_seek_next_header(void)
250 {
251 int k, l = 0, c, first_len, ret;
252 struct mp3header h, h2;
253 long valid_start = 0;
254
255 while (1) {
256 while ((c = fgetc(infile)) != 255 && (c != EOF))
257 ; /* nothing */
258 if (c != 255)
259 return 0;
260 ungetc(c, infile);
261 valid_start = ftell(infile);
262 first_len = get_header(infile, &h);
263 if (first_len <= 0)
264 continue;
265 ret = para_fseek(infile, first_len - FRAME_HEADER_SIZE, SEEK_CUR);
266 if (ret < 0)
267 return ret;
268 for (k = 1; k < MIN_CONSEC_GOOD_FRAMES; k++) {
269 if ((l = get_header(infile, &h2)) <= 0)
270 break;
271 if (!compare_headers(&h, &h2))
272 break;
273 ret = para_fseek(infile, l - FRAME_HEADER_SIZE, SEEK_CUR);
274 if (ret < 0)
275 return ret;
276 }
277 if (k == MIN_CONSEC_GOOD_FRAMES) {
278 ret = para_fseek(infile, valid_start, SEEK_SET);
279 if (ret < 0)
280 return ret;
281 memcpy(&(mp3.header), &h2, sizeof(struct mp3header));
282 return first_len;
283 }
284 }
285 }
286
287 static int mp3_get_id3(void)
288 {
289 char fbuf[4];
290 int ret;
291
292 mp3.id3_isvalid = 0;
293 mp3.id3.title[0] = '\0';
294 mp3.id3.artist[0] = '\0';
295 mp3.id3.album[0] = '\0';
296 mp3.id3.comment[0] = '\0';
297 mp3.id3.year[0] = '\0';
298 ret = para_fseek(infile, -128, SEEK_END);
299 if (ret < 0 )
300 return ret;
301 if (para_fread(fbuf, 1, 3, infile) < 0)
302 return -E_FREAD;
303 fbuf[3] = '\0';
304 if (strcmp("TAG", fbuf)) {
305 PARA_INFO_LOG("%s", "no id3 tag\n");
306 return 0;
307 }
308 ret = para_fseek(infile, -125, SEEK_END);
309 if (ret < 0)
310 return ret;
311 if (para_fread(mp3.id3.title, 1, 30, infile) != 30)
312 return -E_FREAD;
313 mp3.id3.title[30] = '\0';
314 if (para_fread(mp3.id3.artist, 1, 30, infile) != 30)
315 return -E_FREAD;
316 mp3.id3.artist[30] = '\0';
317 if (para_fread(mp3.id3.album, 1, 30, infile) != 30)
318 return -E_FREAD;
319 mp3.id3.album[30] = '\0';
320 if (para_fread(mp3.id3.year, 1, 4, infile) != 4)
321 return -E_FREAD;
322 mp3.id3.year[4] = '\0';
323 if (para_fread(mp3.id3.comment, 1, 30, infile) != 30)
324 return -E_FREAD;
325 mp3.id3.comment[30] = '\0';
326 mp3.id3_isvalid = 1;
327 unpad(mp3.id3.title);
328 unpad(mp3.id3.artist);
329 unpad(mp3.id3.album);
330 unpad(mp3.id3.year);
331 unpad(mp3.id3.comment);
332 return 1;
333 }
334
335 static int find_valid_start(void)
336 {
337 int ret, frame_len;
338
339 if (!infile)
340 return -E_MP3_NO_FILE;
341 frame_len = get_header(infile, &mp3.header);
342 if (frame_len < 0)
343 return frame_len;
344 if (!frame_len) {
345 frame_len = mp3_seek_next_header();
346 if (frame_len <= 0)
347 return frame_len;
348 } else {
349 ret = para_fseek(infile, -FRAME_HEADER_SIZE, SEEK_CUR);
350 if (ret < 0)
351 return ret;
352 }
353 if (frame_len <= 1)
354 return -E_FRAME_LENGTH;
355 return frame_len;
356 }
357
358 static int mp3_read_info(void)
359 {
360 long fl_avg = 0, freq_avg = 0, br_avg = 0;
361 int ret, len = 0, old_br = -1;
362 struct timeval total_time = {0, 0};
363 unsigned chunk_table_size = 1000; /* gets increased on demand */
364
365 num_chunks = 0;
366 chunk_table = para_malloc(chunk_table_size * sizeof(size_t));
367 ret = mp3_get_id3();
368 if (ret < 0)
369 goto err_out;
370 rewind(infile);
371 mp3.vbr = 0;
372 mp3.freq = 0;
373 while (1) {
374 int freq, br, fl;
375 struct timeval tmp, cct; /* current chunk time */
376 if (len > 0) {
377 ret = para_fseek(infile, len, SEEK_CUR);
378 if (ret < 0)
379 goto err_out;
380 }
381 len = find_valid_start();
382 if (len <= 0)
383 break;
384 freq = header_frequency(&mp3.header);
385 br = header_bitrate(&mp3.header);
386 fl = frame_length(&mp3.header);
387 if (freq < 0 || br < 0 || fl < 0)
388 continue;
389 tmp.tv_sec = fl;
390 tmp.tv_usec = 0;
391 tv_divide(br * 125, &tmp, &cct);
392 tv_add(&cct, &total_time, &tmp);
393 total_time = tmp;
394 //PARA_DEBUG_LOG("%s: br: %d, freq: %d, fl: %d, cct: %lu\n", __func__, br, freq, fl, cct.tv_usec);
395 if (num_chunks >= chunk_table_size) {
396 chunk_table_size *= 2;
397 chunk_table = para_realloc(chunk_table,
398 chunk_table_size * sizeof(size_t));
399 }
400 chunk_table[num_chunks] = ftell(infile);
401 if (num_chunks < 10 || !(num_chunks % 1000))
402 PARA_INFO_LOG("chunk #%d: %zd\n", num_chunks,
403 chunk_table[num_chunks]);
404 num_chunks++;
405 if (num_chunks == 1) {
406 // entry = ftell(infile);
407 // PARA_INFO_LOG("entry: %zd\n", entry);
408 freq_avg = freq;
409 br_avg = br;
410 old_br = br;
411 fl_avg = fl;
412 continue;
413 }
414 freq_avg += (freq - freq_avg) / (num_chunks + 1);
415 fl_avg += (fl - fl_avg) / (num_chunks + 1);
416 br_avg += (br - br_avg) / (num_chunks + 1);
417 if (old_br != br)
418 mp3.vbr = 1;
419 old_br = br;
420 }
421 ret = -E_MP3_INFO;
422 if (!num_chunks || !freq_avg || !br_avg)
423 goto err_out;
424 ret= para_fseek(infile, 0, SEEK_END);
425 if (ret < 0)
426 goto err_out;
427 chunk_table[num_chunks] = ftell(infile);
428 mp3.br_average = br_avg;
429 mp3.freq = freq_avg;
430 mp3.seconds = (tv2ms(&total_time) + 500) / 1000;
431 tv_divide(num_chunks, &total_time, &af->chunk_tv);
432 rewind(infile);
433 PARA_DEBUG_LOG("%zu chunks, each %lums\n", num_chunks, tv2ms(&af->chunk_tv));
434 tv_scale(3, &af->chunk_tv, &af->eof_tv);
435 PARA_DEBUG_LOG("eof timeout: %lu\n", tv2ms(&af->eof_tv));
436 return 1;
437 err_out:
438 PARA_ERROR_LOG("%s\n", PARA_STRERROR(-ret));
439 free(chunk_table);
440 return ret;
441 }
442
443 /*
444 * Read mp3 information from audio file
445 */
446 static int mp3_get_file_info(FILE *audio_file, char *info_str,
447 long unsigned *frames, int *seconds, size_t **vss_chunk_table)
448 {
449 int ret;
450
451 if (!audio_file)
452 return -E_MP3_NO_FILE;
453 infile = audio_file;
454 ret = mp3_read_info();
455 if (ret < 0) {
456 infile = NULL;
457 return ret;
458 }
459 write_info_str(info_str);
460 *frames = num_chunks;
461 *seconds = mp3.seconds;
462 *vss_chunk_table = chunk_table;
463 if (*seconds < 2 || !*frames)
464 return -E_MP3_INFO;
465 return 1;
466 }
467
468 static void mp3_close_audio_file(void)
469 {
470 if (!infile)
471 return;
472 fclose(infile);
473 infile = NULL;
474 free(chunk_table);
475 }
476
477 static const char* mp3_suffixes[] = {"mp3", NULL};
478
479 /**
480 * the init function of the mp3 audio format handler
481 *
482 * \param p pointer to the struct to initialize
483 */
484 void mp3_init(struct audio_format_handler *p)
485 {
486 af = p;
487 af->get_file_info = mp3_get_file_info;
488 af->close_audio_file = mp3_close_audio_file;
489 af->get_header_info = NULL;
490 /* eof_tv gets overwritten in mp3_get_file_info() */
491 af->eof_tv.tv_sec = 0;
492 af->eof_tv.tv_usec = 100 * 1000;
493 af->suffixes = mp3_suffixes;
494 }