2 * Copyright (C) 2003-2007 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_afh.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>
36 /** \cond some defines and structs which are only used in this file */
39 * MIN_CONSEC_GOOD_FRAMES defines how many consecutive valid MP3 frames we need
40 * to see before we decide we are looking at a real MP3 file
42 #define MIN_CONSEC_GOOD_FRAMES 4
43 #define FRAME_HEADER_SIZE 4
44 #define MIN_FRAME_SIZE 21
55 unsigned int copyright;
56 unsigned int original;
57 unsigned int emphasis;
69 struct mp3header header;
76 static const int frequencies[3][4] = {
77 {22050,24000,16000,50000}, /* MPEG 2.0 */
78 {44100,48000,32000,50000}, /* MPEG 1.0 */
79 {11025,12000,8000,50000} /* MPEG 2.5 */
82 static const int mp3info_bitrate[2][3][14] = {
84 {32,48,56,64,80,96,112,128,144,160,176,192,224,256}, /* layer 1 */
85 {8,16,24,32,40,48,56,64,80,96,112,128,144,160}, /* layer 2 */
86 {8,16,24,32,40,48,56,64,80,96,112,128,144,160} /* layer 3 */
90 {32,64,96,128,160,192,224,256,288,320,352,384,416,448}, /* layer 1 */
91 {32,48,56,64,80,96,112,128,160,192,224,256,320,384}, /* layer 2 */
92 {32,40,48,56,64,80,96,112,128,160,192,224,256,320} /* layer 3 */
96 static const int frame_size_index[] = {24000, 72000, 72000};
97 static const char *mode_text[] = {"stereo", "joint stereo", "dual channel", "mono", "invalid"};
99 static struct mp3info mp3;
101 static int header_frequency(struct mp3header *h)
103 if (h->version > 2 || h->freq > 3)
104 return -E_HEADER_FREQ;
105 return frequencies[h->version][h->freq];
108 static const char *header_mode(struct mp3header *h)
111 h->mode = 4; /* invalid */
112 return mode_text[h->mode];
115 static int header_channels(struct mp3header *h)
124 static int header_bitrate(struct mp3header *h)
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];
131 static int frame_length(struct mp3header *header)
133 int hb, hf = header_frequency(header);
137 hb = header_bitrate(header);
140 if (header->sync != 0xFFE || header->layer > 3)
142 return frame_size_index[3 - header->layer] *
143 ((header->version & 1) + 1) * hb / hf
147 static void write_info_str(struct audio_format_info *afi)
149 int v = mp3.id3_isvalid;
151 snprintf(afi->info_string, MMD_INFO_SIZE,
152 "audio_file_info1:%lu x %lums, %u 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",
156 tv2ms(&afi->chunk_tv),
159 afi->frequency / 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)"
170 * Remove trailing whitespace from the end of a string
172 static char *unpad(char *string)
174 char *pos = string + strlen(string) - 1;
175 while (isspace(pos[0]))
180 static int compare_headers(struct mp3header *h1,struct mp3header *h2)
182 if ((*(uint*)h1) == (*(uint*)h2))
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))
197 * get next MP3 frame header.
199 * On success, the header frame length is returned and the given header
200 * structure that is filled in. A return value of zero means that we did not
201 * retrieve a valid frame header, and a negative return value indicates an
204 static int get_header(unsigned char *map, off_t numbytes, off_t *fpos,
205 struct mp3header *header)
209 if (*fpos + FRAME_HEADER_SIZE > numbytes) {
210 *fpos = numbytes - 1;
214 header->layer = (map[*fpos + 1] >> 1) & 3;
215 header->sync = (((int)map[*fpos]<<4) | ((int)(map[*fpos + 1]&0xE0)>>4));
216 if (map[*fpos + 1] & 0x10)
217 header->version = (map[*fpos + 1] >> 3) & 1;
220 if ((header->sync != 0xFFE) || (header->layer != 1)) {
225 header->crc = map[*fpos + 1] & 1;
226 header->bitrate = (map[*fpos + 2] >> 4) & 0x0F;
227 header->freq = (map[*fpos + 2] >> 2) & 0x3;
228 header->padding = (map[*fpos + 2] >>1) & 0x1;
229 header->mode = (map[*fpos + 3] >> 6) & 0x3;
230 fl = frame_length(header);
231 ret = (fl >= MIN_FRAME_SIZE)? fl : -E_FRAME_LENGTH;
233 *fpos += FRAME_HEADER_SIZE;
238 * find the next mp3 header
240 * Return the length of the next frame header or zero if the end of the file is
243 static int mp3_seek_next_header(unsigned char *map, off_t numbytes, off_t *fpos)
245 int k, l = 0, first_len;
246 struct mp3header h, h2;
247 long valid_start = 0;
249 for (; *fpos < numbytes; (*fpos)++) {
250 if (map[*fpos] != 0xff)
253 first_len = get_header(map, numbytes, fpos, &h);
256 *fpos += first_len - FRAME_HEADER_SIZE;
257 for (k = 1; k < MIN_CONSEC_GOOD_FRAMES; k++) {
258 if ((l = get_header(map, numbytes, fpos, &h2)) <= 0)
260 if (!compare_headers(&h, &h2))
262 *fpos += l - FRAME_HEADER_SIZE;
264 if (k == MIN_CONSEC_GOOD_FRAMES) {
266 memcpy(&(mp3.header), &h2, sizeof(struct mp3header));
273 static void mp3_get_id3(unsigned char *map, off_t numbytes, off_t *fpos)
276 mp3.id3.title[0] = '\0';
277 mp3.id3.artist[0] = '\0';
278 mp3.id3.album[0] = '\0';
279 mp3.id3.comment[0] = '\0';
280 mp3.id3.year[0] = '\0';
283 *fpos = numbytes - 128;
284 if (strncmp("TAG", map + *fpos, 3)) {
285 PARA_INFO_LOG("%s", "no id3 tag\n");
288 *fpos = numbytes - 125;
289 memcpy(mp3.id3.title, map + *fpos, 30);
291 mp3.id3.title[30] = '\0';
292 memcpy(mp3.id3.artist, map + *fpos, 30);
294 mp3.id3.artist[30] = '\0';
295 memcpy(mp3.id3.album, map + *fpos, 30);
297 mp3.id3.album[30] = '\0';
298 memcpy(mp3.id3.year, map + *fpos, 4);
300 mp3.id3.year[4] = '\0';
301 memcpy(mp3.id3.comment, map + *fpos, 30);
302 mp3.id3.comment[30] = '\0';
304 unpad(mp3.id3.title);
305 unpad(mp3.id3.artist);
306 unpad(mp3.id3.album);
308 unpad(mp3.id3.comment);
311 static int find_valid_start(unsigned char *map, off_t numbytes, off_t *fpos)
315 frame_len = get_header(map, numbytes, fpos, &mp3.header);
319 frame_len = mp3_seek_next_header(map, numbytes, fpos);
323 *fpos -= FRAME_HEADER_SIZE;
325 return -E_FRAME_LENGTH;
329 static int mp3_read_info(unsigned char *map, off_t numbytes,
330 struct audio_format_info *afi)
332 long fl_avg = 0, freq_avg = 0, br_avg = 0;
333 int ret, len = 0, old_br = -1;
334 struct timeval total_time = {0, 0};
335 unsigned chunk_table_size = 1000; /* gets increased on demand */
338 afi->chunks_total = 0;
339 afi->chunk_table = para_malloc(chunk_table_size * sizeof(size_t));
340 mp3_get_id3(map, numbytes, &fpos);
345 struct timeval tmp, cct; /* current chunk time */
347 len = find_valid_start(map, numbytes, &fpos);
350 freq = header_frequency(&mp3.header);
351 br = header_bitrate(&mp3.header);
352 fl = frame_length(&mp3.header);
353 if (freq < 0 || br < 0 || fl < 0)
357 tv_divide(br * 125, &tmp, &cct);
358 tv_add(&cct, &total_time, &tmp);
360 //PARA_DEBUG_LOG("%s: br: %d, freq: %d, fl: %d, cct: %lu\n", __func__, br, freq, fl, cct.tv_usec);
361 if (afi->chunks_total >= chunk_table_size) {
362 chunk_table_size *= 2;
363 afi->chunk_table = para_realloc(afi->chunk_table,
364 chunk_table_size * sizeof(size_t));
366 afi->chunk_table[afi->chunks_total] = fpos;
367 // if (afi->chunks_total < 10 || !(afi->chunks_total % 1000))
368 // PARA_INFO_LOG("chunk #%lu: %zd\n", afi->chunks_total,
369 // afi->chunk_table[afi->chunks_total]);
371 if (afi->chunks_total == 1) {
378 freq_avg += (freq - freq_avg) / (afi->chunks_total + 1);
379 fl_avg += (fl - fl_avg) / (afi->chunks_total + 1);
380 br_avg += (br - br_avg) / ((long)afi->chunks_total + 1);
386 if (!afi->chunks_total || !freq_avg || !br_avg)
388 afi->chunk_table[afi->chunks_total] = numbytes - 1;
389 afi->bitrate = br_avg;
390 afi->frequency = freq_avg;
391 afi->channels = header_channels(&mp3.header);
392 afi->seconds_total = (tv2ms(&total_time) + 500) / 1000;
393 tv_divide(afi->chunks_total, &total_time, &afi->chunk_tv);
394 PARA_DEBUG_LOG("%lu chunks, each %lums\n", afi->chunks_total,
395 tv2ms(&afi->chunk_tv));
396 tv_scale(3, &afi->chunk_tv, &afi->eof_tv);
397 PARA_DEBUG_LOG("eof timeout: %lu\n", tv2ms(&afi->eof_tv));
400 PARA_ERROR_LOG("%s\n", PARA_STRERROR(-ret));
401 free(afi->chunk_table);
406 * Read mp3 information from audio file
408 static int mp3_get_file_info(char *map, off_t numbytes,
409 struct audio_format_info *afi)
413 ret = mp3_read_info((unsigned char *)map, numbytes, afi);
417 if (afi->seconds_total < 2 || !afi->chunks_total)
422 static const char* mp3_suffixes[] = {"mp3", NULL};
425 * the init function of the mp3 audio format handler
427 * \param afh pointer to the struct to initialize
429 void mp3_init(struct audio_format_handler *afh)
431 afh->get_file_info = mp3_get_file_info;
432 afh->suffixes = mp3_suffixes;