PHP获取音频文件的相关信息

时间:2022-12-10 14:43:16

项目需求:现在有一个音频文件上传的功能,在上传后PHP需要获取这个音频文件的相关信息,例如:时长等,由于这个文件是放在买的空间上的,没有像ffmpeg这样的扩展来处理,那么PHP能不能获取到这些信息?

下面是之前在项目中用到的一个用PHP进行音频文件头部信息的读取与写入操作的实现,主要针对 WMA 和 MP3 两种格式,供参考。

?
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
<?php
// AudioExif.class.php
// 用PHP进行音频文件头部信息的读取与写入
// 目前只支持 WMA 和 MP3 两种格式, 只支持常用的几个头部信息
//
// 写入信息支持: Title(名称), Artist(艺术家), Copyright(版权), Description (描述)
// Year(年代), Genre (流派), AlbumTitle (专辑标题)
// 其中 mp3 和 wma 略有不同, 具体返回的信息还可能更多, 但只有以上信息可以被写入
// mp3 还支持 Track (曲目编号写入)
// 对于 MP3 文件支持 ID3v1也支持ID3v2, 读取时优先 v2, 写入时总是会写入v1, 必要时写入v2
//
// 用法说明: (由于 wma 使用 Unicode 存取, 故还需要 mb_convert_encoding() 扩展
// 返回数据及写入数据均为 ANSI 编码, 即存什么就显示什么 (中文_GB2312)
//
// require ('AudioExif.class.php');
// $AE = new AudioExif;
// $file = '/path/to/test.mp3';
//
// 1. 检查文件是否完整 (only for wma, mp3始终返回 true)
//
// $AE->CheckSize($file);
//
// 2. 读取信息, 返回值由信息组成的数组, 键名解释参见上方
//
// print_r($AE->GetInfo($file));
//
// 3. 写入信息, 第二参数是一个哈希数组, 键->值, 支持的参见上方的, mp3也支持 Track
// 要求第一参数的文件路径可由本程序写入
// $pa = array('Title' => '新标题', 'AlbumTitle' => '新的专辑名称');
// $AE->SetInfo($file, $pa);
//
// 其它: 该插件花了不少时间搜集查找 wma及mp3 的文件格式说明文档与网页, 希望对大家有用.
// 其实网上已经有不少类似的程序, 但对 wma 实在太少了, 只能在 win 平台下通过 M$ 的
// API 来操作, 而 MP3 也很少有可以在 unix/linux 命令行操作的, 所以特意写了这个模块
//
// 如果发现 bug 或提交 patch, 或加以改进使它更加健壮, 请告诉我.
// (关于 ID3和Wma的文件格式及结构 在网上应该都可以找到参考资料)
//
if (!extension_loaded('mbstring')){
trigger_error('PHP Extension module `mbstring` is required for AudioExif', E_USER_WARNING);
return true;
}
// the Main Class
class AudioExif{
// public vars
var $_wma = false;
var $_mp3 = false;
// Construct
function AudioExif() {
// nothing to do
}
// check the filesize
function CheckSize($file) {
$handler = &$this->_get_handler($file);
if (!$handler) return false;
return $handler->check_size($file);
}
// get the infomations
function GetInfo($file) {
$handler = &$this->_get_handler($file);
if (!$handler) return false;
return $handler->get_info($file);
}
// write the infomations
function SetInfo($file, $pa) {
if (!is_writable($file)) {
trigger_error('AudioExif: file `' . $file . '` can not been overwritten', E_USER_WARNING);
return false;
}
$handler = &$this->_get_handler($file);
if (!$handler) return false;
return $handler->set_info($file, $pa);
}
// private methods
function &_get_handler($file) {
$ext = strtolower(strrchr($file, '.'));
$ret = false;
if ($ext == '.mp3') {
// MP3
$ret = &$this->_mp3;
if (!$ret) $ret = new _Mp3Exif();
 
}
else if ($ext == '.wma')
{ // wma
$ret = &$this->_wma;
if (!$ret) $ret = new _WmaExif();
}
else
{ // unknown
trigger_error('AudioExif not supported `' . $ext . '` file.', E_USER_WARNING);
}
return $ret;
}
}
 
// DBCS => gb2312
function dbcs_gbk($str)
{
// strip the last "\0\0"
$str = substr($str, 0, -2);
return mb_convert_encoding($str, 'GBK', 'UCS-2LE');
}
 
// gb2312 => DBCS
function gbk_dbcs($str)
{
$str = mb_convert_encoding($str, 'UCS-2LE', 'GBK');
$str .= "\0\0";
return $str;
}
 
// file exif
class _AudioExif
{
var $fd;
var $head;
var $head_off;
var $head_buf;
 
// init the file handler
function _file_init($fpath, $write = false)
{
$mode = ($write ? 'rb+' : 'rb');
$this->fd = @fopen($fpath, $mode);
if (!$this->fd)
{
trigger_error('AudioExif: `' . $fpath . '` can not be opened with mode `' . $mode . '`', E_USER_WARNING);
return false;
}
$this->head = false;
$this->head_off = 0;
$this->head_buf = '';
return true;
}
 
// read buffer from the head_buf & move the off pointer
function _read_head_buf($len)
{
if ($len <= 0) return NULL;
$buf = substr($this->head_buf, $this->head_off, $len);
$this->head_off += strlen($buf);
return $buf;
}
 
// read one short value
function _read_head_short()
{
$ord1 = ord(substr($this->head_buf, $this->head_off, 1));
$ord2 = ord(substr($this->head_buf, $this->head_off+1, 1));
$this->head_off += 2;
return ($ord1 + ($ord2<<8));
}
 
// save the file head
function _file_save($head, $olen, $nlen = 0)
{
if ($nlen == 0) $nlen = strlen($head);
if ($nlen == $olen)
{
// shorter
flock($this->fd, LOCK_EX);
fseek($this->fd, 0, SEEK_SET);
fwrite($this->fd, $head, $nlen);
flock($this->fd, LOCK_UN);
}
else
{
// longer, buffer required
$stat = fstat($this->fd);
$fsize = $stat['size'];
 
// buf required (4096?) 应该不会 nlen - olen > 4096 吧
$woff = 0;
$roff = $olen;
 
// read first buffer
flock($this->fd, LOCK_EX);
fseek($this->fd, $roff, SEEK_SET);
$buf = fread($this->fd, 4096);
 
// seek to start
fseek($this->fd, $woff, SEEK_SET);
fwrite($this->fd, $head, $nlen);
$woff += $nlen;
 
// seek to woff & write the data
do
{
$buf2 = $buf;
$roff += 4096;
if ($roff < $fsize)
{
fseek($this->fd, $roff, SEEK_SET);
$buf = fread($this->fd, 4096);
}
 
// save last buffer
$len2 = strlen($buf2);
fseek($this->fd, $woff, SEEK_SET);
fwrite($this->fd, $buf2, $len2);
$woff += $len2;
}
while ($roff < $fsize);
ftruncate($this->fd, $woff);
flock($this->fd, LOCK_UN);
}
}
 
// close the file
function _file_deinit()
{
if ($this->fd)
{
fclose($this->fd);
$this->fd = false;
}
}
}
 
// wma class
class _WmaExif extends _AudioExif
{
var $items1 = array('Title', 'Artist', 'Copyright', 'Description', 'Reserved');
var $items2 = array('Year', 'Genre', 'AlbumTitle');
 
// check file size (length) maybe invalid file
function check_size($file)
{
$ret = false;
if (!$this->_file_init($file)) return true;
if ($this->_init_header())
{
$buf = fread($this->fd, 24);
$tmp = unpack('H32id/Vlen/H8unused', $buf);
if ($tmp['id'] == '3626b2758e66cf11a6d900aa0062ce6c')
{
$stat = fstat($this->fd);
$ret = ($stat['size'] == ($this->head['len'] + $tmp['len']));
}
}
$this->_file_deinit();
return $ret;
}
 
// set info (save the infos)
function set_info($file, $pa)
{
// check the pa
settype($pa, 'array');
if (!$this->_file_init($file, true)) return false;
if (!$this->_init_header())
{
$this->_file_deinit();
return false;
}
 
// parse the old header & generate the new header
$head_body = '';
$st_found = $ex_found = false;
$head_num = $this->head['num'];
while (($tmp = $this->_get_head_frame()) && ($head_num > 0))
{
$head_num--;
if ($tmp['id'] == '3326b2758e66cf11a6d900aa0062ce6c')
{ // Standard Info
// 1-4
$st_found = true;
$st_body1 = $st_body2 = '';
$lenx = unpack('v5', $this->_read_head_buf(10));
$tmp['len'] -= 34; // 10 + 24
for ($i = 0; $i < count($this->items1); $i++)
{
$l = $lenx[$i+1];
$k = $this->items1[$i];
$tmp['len'] -= $l;
 
$data = $this->_read_head_buf($l);
if (isset($pa[$k])) $data = gbk_dbcs($pa[$k]);
 
$st_body2 .= $data;
$st_body1 .= pack('v', strlen($data));
}
// left length
if ($tmp['len'] > 0) $st_body2 .= $this->_read_head_buf($tmp['len']);
 
// save to head_body
$head_body .= pack('H32VH8', $tmp['id'], strlen($st_body1 . $st_body2)+24, $tmp['unused']);
$head_body .= $st_body1 . $st_body2;
 
$st_body2 .= $data;
}
 
// save to head_body
$head_body .= pack('H32Va4', '3326b2758e66cf11a6d900aa0062ce6c', strlen($st_body1 . $st_body2)+24, '');
$head_body .= $st_body1 . $st_body2;
$this->head['num']++;
}
// ex not found?
if (!$ex_found)
{
$inum = 0;
$et_body = '';
foreach ($this->items2 as $k)
{
$nbuf = gbk_dbcs('WM/' . $k);
$vbuf = (isset($pa[$k]) ? gbk_dbcs($pa[$k]) : "");
$et_body .= pack('v', strlen($nbuf)) . $nbuf . pack('vv', 0, strlen($vbuf)) . $vbuf;
$inum++;
}
$head_body .= pack('H32Va4v', '40a4d0d207e3d21197f000a0c95ea850', strlen($et_body)+26, '', $inum);
$head_body .= $et_body;
$this->head['num']++;
}
 
// after save
$new_len = strlen($head_body) + 30;
$old_len = $this->head['len'];
if ($new_len < $old_len)
{
$head_body .= str_repeat("\0", $old_len - $new_len);
$new_len = $old_len;
}
$tmp = $this->head;
$head_buf = pack('H32VVVH4', $tmp['id'], $new_len, $tmp['len2'], $tmp['num'], $tmp['unused']);
$head_buf .= $head_body;
$this->_file_save($head_buf, $old_len, $new_len);
 
// close the file & return
$this->_file_deinit();
return true;
}
 
// get info
function get_info($file)
{
$ret = array();
if (!$this->_file_init($file)) return false;
if (!$this->_init_header())
{
$this->_file_deinit();
return false;
}
 
// get the data from head_buf
$head_num = $this->head['num']; // num of head_frame
while (($tmp = $this->_get_head_frame()) && $head_num > 0)
{
$head_num--;
if ($tmp['id'] == '3326b2758e66cf11a6d900aa0062ce6c')
{ // Standard Info
$lenx = unpack('v*', $this->_read_head_buf(10));
for ($i = 1; $i <= count($this->items1); $i++)
{
$k = $this->items1[$i-1];
$ret[$k] = dbcs_gbk($this->_read_head_buf($lenx[$i]));
}
}
else if ($tmp['id'] == '40a4d0d207e3d21197f000a0c95ea850')
{ // Extended Info
$inum = $this->_read_head_short();
$tmp['len'] -= 26;
while ($inum > 0 && $tmp['len'] > 0)
{
// attribute name
$nlen = $this->_read_head_short();
$nbuf = $this->_read_head_buf($nlen);
 
// the flag & value length
$flag = $this->_read_head_short();
$vlen = $this->_read_head_short();
$vbuf = $this->_read_head_buf($vlen);
 
// update the XX
 
$tmp['len'] -= (6 + $nlen + $vlen);
$inum--;
 
$name = dbcs_gbk($nbuf);
$k = substr($name, 3);
if (in_array($k, $this->items2))
{ // all is string value (refer to falg for other tags)
$ret[$k] = dbcs_gbk($vbuf);
}
}
}
 
else
{ // skip only
if ($tmp['len'] > 24) $this->head_off += ($tmp['len'] - 24);
}
}
$this->_file_deinit();
return $ret;
}
 
// get the header?
function _init_header()
{
fseek($this->fd, 0, SEEK_SET);
$buf = fread($this->fd, 30);
if (strlen($buf) != 30) return false;
$tmp = unpack('H32id/Vlen/Vlen2/Vnum/H4unused', $buf);
if ($tmp['id'] != '3026b2758e66cf11a6d900aa0062ce6c')
return false;
 
$this->head_buf = fread($this->fd, $tmp['len'] - 30);
$this->head = $tmp;
return true;
}
 
// _get_head_frame()
function _get_head_frame()
{
$buf = $this->_read_head_buf(24);
if (strlen($buf) != 24) return false;
$tmp = unpack('H32id/Vlen/H8unused', $buf);
return $tmp;
}
}
 
// mp3 class (if not IDv2 then select IDv1)
class _Mp3Exif extends _AudioExif
{
var $head1;
var $genres = array('Blues','Classic Rock','Country','Dance','Disco','Funk','Grunge','Hip-Hop','Jazz','Metal','New Age','Oldies','Other','Pop','R&B','Rap','Reggae','Rock','Techno','Industrial','Alternative','Ska','Death Metal','Pranks','Soundtrack','Euro-Techno','Ambient','Trip-Hop','Vocal','Jazz+Funk','Fusion','Trance','Classical','Instrumental','Acid','House','Game','Sound Clip','Gospel','Noise','AlternRock','Bass','Soul','Punk','Space','Meditative','Instrumental Pop','Instrumental Rock','Ethnic','Gothic','Darkwave','Techno-Industrial','Electronic','Pop-Folk','Eurodance','Dream','Southern Rock','Comedy','Cult','Gangsta','Top 40','Christian Rap','Pop/Funk','Jungle','Native American','Cabaret','New Wave','Psychadelic','Rave','Showtunes','Trailer','Lo-Fi','Tribal','Acid Punk','Acid Jazz','Polka','Retro','Musical','Rock & Roll','Hard Rock','Unknown');
 
// MP3 always return true
function check_size($file)
{
return true;
}
 
// get info
function get_info($file)
{
if (!$this->_file_init($file)) return false;
$ret = false;
if ($this->_init_header())
{
$ret = ($this->head ? $this->_get_v2_info() : $this->_get_v1_info());
$ret['meta'] = $this->_get_meta_info();
}
$this->_file_deinit();
return $ret;
}
 
// set info
function set_info($file, $pa)
{
if (!$this->_file_init($file, true)) return false;
if ($this->_init_header())
{
// always save v1 info
$this->_set_v1_info($pa);
// set v2 first if need
$this->_set_v2_info($pa);
}
$this->_file_deinit();
return true;
}
 
// get the header information[v1+v2], call after file_init
function _init_header()
{
$this->head1 = false;
$this->head = false;
 
// try to get ID3v1 first
fseek($this->fd, -128, SEEK_END);
$buf = fread($this->fd, 128);
 
if (strlen($buf) == 128 && substr($buf, 0, 3) == 'TAG')
{
$tmp = unpack('a3id/a30Title/a30Artist/a30AlbumTitle/a4Year/a28Description/CReserved/CTrack/CGenre', $buf);
$this->head1 = $tmp;
}
 
// try to get ID3v2
fseek($this->fd, 0, SEEK_SET);
$buf = fread($this->fd, 10);
if (strlen($buf) == 10 && substr($buf, 0, 3) == 'ID3')
{
$tmp = unpack('a3id/Cver/Crev/Cflag/C4size', $buf);
$tmp['size'] = ($tmp['size1']<<21)|($tmp['size2']<<14)|($tmp['size3']<<7)|$tmp['size4'];
unset($tmp['size1'], $tmp['size2'], $tmp['size3'], $tmp['size4']);
 
$this->head = $tmp;
$this->head_buf = fread($this->fd, $tmp['size']);
}
return ($this->head1 || $this->head);
}
 
// get v1 info
function _get_v1_info()
{
$ret = array();
$tmpa = array('Title', 'Artist', 'Copyright', 'Description', 'Year', 'AlbumTitle');
foreach ($tmpa as $tmp)
{
$ret[$tmp] = $this->head1[$tmp];
if ($pos = strpos($ret[$tmp], "\0"))
$ret[$tmp] = substr($ret[$tmp], 0, $pos);
}
 
// count the Genre, [Track]
if ($this->head1['Reserved'] == 0) $ret['Track'] = $this->head1['Track'];
else $ret['Description'] .= chr($ret['Reserved']) . chr($ret['Track']);
 
// Genre_idx
$g = $this->head1['Genre'];
if (!isset($this->genres[$g])) $ret['Genre'] = 'Unknown';
else $ret['Genre'] = $this->genres[$g];
 
// return the value
$ret['ID3v1'] = 'yes';
return $ret;
}
 
// get v2 info
function _get_v2_info()
{
$ret = array();
$items = array( 'TCOP'=>'Copyright', 'TPE1'=>'Artist', 'TIT2'=>'Title', 'TRCK'=> 'Track',
'TCON'=>'Genre', 'COMM'=>'Description', 'TYER'=>'Year', 'TALB'=>'AlbumTitle');
while (true)
{
$buf = $this->_read_head_buf(10);
if (strlen($buf) != 10) break;
$tmp = unpack('a4fid/Nsize/nflag', $buf);
if ($tmp['size'] == 0) break;
$tmp['dat'] = $this->_read_head_buf($tmp['size']);
 
// 0x6000 (11000000 00000000)
if ($tmp['flag'] & 0x6000) continue;
 
// mapping the data
if ($k = $items[$tmp['fid']])
{ // If first char is "\0", just skip
if (substr($tmp['dat'], 0, 1) == "\0") $tmp['dat'] = substr($tmp['dat'], 1);
$ret[$k] = $tmp['dat'];
}
}
 
// reset the genre
if ($g = $ret['Genre'])
{
if (substr($g,0,1) == '(' && substr($g,-1,1) == ')') $g = substr($g, 1, -1);
if (is_numeric($g))
{
$g = intval($g);
$ret['Genre'] = (isset($this->genres[$g]) ? $this->genres[$g] : 'Unknown');
}
}
 
$ret['ID3v1'] = 'no';
return $ret;
}
// get meta info of MP3
function _get_meta_info()
{
// seek to the lead buf: 0xff
$off = 0;
if ($this->head) $off = $this->head['size'] + 10;
fseek($this->fd, $off, SEEK_SET);
while (!feof($this->fd))
{
$skip = ord(fread($this->fd, 1));
if ($skip == 0xff) break;
}
if ($skip != 0xff) return false;
$buf = fread($this->fd, 3);
if (strlen($buf) != 3) return false;
$tmp = unpack('C3', $buf);
if (($tmp[1] & 0xf0) != 0xf0) return false;
// get the meta info
$meta = array();
// get mpeg version
$meta['mpeg'] = ($tmp[1] & 0x08 ? 1 : 2);
$meta['layer'] = ($tmp[1] & 0x04) ? (($tmp[1] & 0x02) ? 1 : 2) : (($tmp[1] & 0x02) ? 3 : 0);
$meta['epro'] = ($tmp[1] & 0x01) ? 'no' : 'yes';
// bit rates
$bit_rates = array(
1 => array(
1 => array(0,32,64,96,128,160,192,224,256,288,320,352,384,416,448,0),
2 => array(0,32,48,56,64,80,96,112,128,160,192,224,256,320,384,0),
3 => array(0,32,40,48,56,64,80,96,112,128,160,192,224,256,320,0)
),
2 => array(
1 => array(0,32,48,56,64,80,96,112,128,144,160,176,192,224,256,0),
2 => array(0,8,16,24,32,40,48,56,64,80,96,112,128,144,160,0),
3 => array(0,8,16,24,32,40,48,56,64,80,96,112,128,144,160,0)
)
);
$i = $meta['mpeg'];
$j = $meta['layer'];
$k = ($tmp[2]>>4);
$meta['bitrate'] = $bit_rates[$i][$j][$k];
// sample rates <采样率>
$sam_rates = array(1=>array(44100,48000,32000,0), 2=>array(22050,24000,16000,0));
$meta['samrate'] = $sam_rates[$i][$k];
$meta["padding"] = ($tmp[2] & 0x02) ? 'on' : 'off';
$meta["private"] = ($tmp[2] & 0x01) ? 'on' : 'off';
// mode & mode_ext
$k = ($tmp[3]>>6);
$channel_modes = array('stereo', 'joint stereo', 'dual channel', 'single channel');
$meta['mode'] = $channel_modes[$k];
$k = (($tmp[3]>>4) & 0x03);
$extend_modes = array('MPG_MD_LR_LR', 'MPG_MD_LR_I', 'MPG_MD_MS_LR', 'MPG_MD_MS_I');
$meta['ext_mode'] = $extend_modes[$k];
$meta['copyright'] = ($tmp[3] & 0x08) ? 'yes' : 'no';
$meta['original'] = ($tmp[3] & 0x04) ? 'yes' : 'no';
$emphasis = array('none', '50/15 microsecs', 'rreserved', 'CCITT J 17');
$k = ($tmp[3] & 0x03);
$meta['emphasis'] = $emphasis[$k];
return $meta;
}
// set v1 info
function _set_v1_info($pa)
{
// ID3v1 (simpled)
$off = -128;
if (!($tmp = $this->head1))
{
$off = 0;
$tmp['id'] = 'TAG';
$tmp['Title'] = $tmp['Artist'] = $tmp['AlbumTitle'] = $tmp['Year'] = $tmp['Description'] = '';
$tmp['Reserved'] = $tmp['Track'] = $tmp['Genre'] = 0;
}
 
// basic items
$items = array('Title', 'Artist', 'Copyright', 'Description', 'Year', 'AlbumTitle');
foreach ($items as $k)
{
if (isset($pa[$k])) $tmp[$k] = $pa[$k];
}
// genre index
if (isset($pa['Genre']))
{
$g = 0;
foreach ($this->genres as $gtmp)
{
if (!strcasecmp($gtmp, $pa['Genre']))
break;
$g++;
}
$tmp['Genre'] = $g;
}
if (isset($pa['Track'])) $tmp['Track'] = intval($pa['Track']);
// pack the data
$buf = pack('a3a30a30a30a4a28CCC', $tmp['id'], $tmp['Title'], $tmp['Artist'], $tmp['AlbumTitle'],
$tmp['Year'], $tmp['Description'], 0, $tmp['Track'], $tmp['Genre']);
flock($this->fd, LOCK_EX);
fseek($this->fd, $off, SEEK_END);
fwrite($this->fd, $buf, 128);
flock($this->fd, LOCK_UN);
}
// set v2 info
function _set_v2_info($pa)
{
if (!$this->head)
{ // insert ID3
return; // 没有就算了
/**
$tmp = array('id'=>'ID3','ver'=>3,'rev'=>0,'flag'=>0);
$tmp['size'] = -10; // +10 => 0
$this->head = $tmp;
$this->head_buf = '';
$this->head_off = 0;
**/
}
$items = array( 'TCOP'=>'Copyright', 'TPE1'=>'Artist', 'TIT2'=>'Title', 'TRAC'=>'Track',
'TCON'=>'Genre', 'COMM'=>'Description', 'TYER'=>'Year', 'TALB'=>'AlbumTitle');
$head_body = '';
while (true)
{
$buf = $this->_read_head_buf(10);
if (strlen($buf) != 10) break;
$tmp = unpack('a4fid/Nsize/nflag', $buf);
if ($tmp['size'] == 0) break;
$data = $this->_read_head_buf($tmp['size']);
if (($k = $items[$tmp['fid']]) && isset($pa[$k]))
{
// the data should prefix by "\0" [replace]
$data = "\0" . $pa[$k];
unset($pa[$k]);
}
$head_body .= pack('a4Nn', $tmp['fid'], strlen($data), $tmp['flag']) . $data;
}
// reverse the items & set the new tags
$items = array_flip($items);
foreach ($pa as $k => $v)
{
if ($fid = $items[$k])
{
$head_body .= pack('a4Nn', $fid, strlen($v) + 1, 0) . "\0" . $v;
}
}
// new length
$new_len = strlen($head_body) + 10;
$old_len = $this->head['size'] + 10;
if ($new_len < $old_len)
{
$head_body .= str_repeat("\0", $old_len - $new_len);
$new_len = $old_len;
}
// count the size1,2,3,4, no include the header
// 较为变态的算法... :p (28bytes integer)
$size = array();
$nlen = $new_len - 10;
for ($i = 4; $i > 0; $i--)
{
$size[$i] = ($nlen & 0x7f);
$nlen >>= 7;
}
$tmp = $this->head;
//echo "old_len : $old_len new_len: $new_len\n";
$head_buf = pack('a3CCCCCCC', $tmp['id'], $tmp['ver'], $tmp['rev'], $tmp['flag'],
$size[1], $size[2], $size[3], $size[4]);
$head_buf .= $head_body;
$this->_file_save($head_buf, $old_len, $new_len);
}

以上所述就是本文的全部内容了,希望大家能够喜欢。