2 * Copyright (c) Michael Hipp and other authors of the mpglib project.
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2.1 of the License, or (at your option) any later version.
9 * This library 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 GNU
12 * Lesser General Public License for more details.
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with this library; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
24 #include <sys/types.h>
25 #ifdef HAVE_SYS_STAT_H
26 # include <sys/stat.h>
32 const struct parameter param
= { 1 , 1 , 0 , 0 };
34 static const int tabsel_123
[2][3][16] = {
35 { {0,32,64,96,128,160,192,224,256,288,320,352,384,416,448,},
36 {0,32,48,56, 64, 80, 96,112,128,160,192,224,256,320,384,},
37 {0,32,40,48, 56, 64, 80, 96,112,128,160,192,224,256,320,} },
39 { {0,32,48,56,64,80,96,112,128,144,160,176,192,224,256,},
40 {0,8,16,24,32,40,48,56,64,80,96,112,128,144,160,},
41 {0,8,16,24,32,40,48,56,64,80,96,112,128,144,160,} }
44 const long freqs
[9] = { 44100, 48000, 32000,
46 11025 , 12000 , 8000 };
49 unsigned char *wordpointer
;
50 unsigned char *pcm_sample
;
54 #define HDRCMPMASK 0xfffffd00
56 int head_check(unsigned long head
)
58 if( (head
& 0xffe00000) != 0xffe00000)
62 if( ((head
>>12)&0xf) == 0xf)
64 if( ((head
>>10)&0x3) == 0x3 )
71 * the code a header and write the information
72 * into the frame structure
74 int decode_header(struct frame
*fr
,unsigned long newhead
)
76 if(head_check(newhead
) == FALSE
)
79 if( newhead
& (1<<20) ) {
80 fr
->lsf
= (newhead
& (1<<19)) ? 0x0 : 0x1;
88 fr
->lay
= 4-((newhead
>>17)&3);
90 fr
->sampling_frequency
= 6 + ((newhead
>>10)&0x3);
93 fr
->sampling_frequency
= ((newhead
>>10)&0x3) + (fr
->lsf
*3);
94 fr
->error_protection
= ((newhead
>>16)&0x1)^0x1;
96 if(fr
->mpeg25
) /* allow Bitrate change for 2.5 ... */
97 fr
->bitrate_index
= ((newhead
>>12)&0xf);
99 fr
->bitrate_index
= ((newhead
>>12)&0xf);
100 fr
->padding
= ((newhead
>>9)&0x1);
101 fr
->extension
= ((newhead
>>8)&0x1);
102 fr
->mode
= ((newhead
>>6)&0x3);
103 fr
->mode_ext
= ((newhead
>>4)&0x3);
104 fr
->copyright
= ((newhead
>>3)&0x1);
105 fr
->original
= ((newhead
>>2)&0x1);
106 fr
->emphasis
= newhead
& 0x3;
108 fr
->stereo
= (fr
->mode
== MPG_MD_MONO
) ? 1 : 2;
110 if(!fr
->bitrate_index
)
112 fprintf(stderr
,"Free format not supported.\n");
121 fr
->jsbound
= (fr
->mode
== MPG_MD_JOINT_STEREO
) ?
122 (fr
->mode_ext
<<2)+4 : 32;
124 fr
->framesize
= (long) tabsel_123
[fr
->lsf
][0][fr
->bitrate_index
] * 12000;
125 fr
->framesize
/= freqs
[fr
->sampling_frequency
];
126 fr
->framesize
= ((fr
->framesize
+fr
->padding
)<<2)-4;
128 fprintf(stderr
,"Not supported!\n");
134 fr
->jsbound
= (fr
->mode
== MPG_MD_JOINT_STEREO
) ?
135 (fr
->mode_ext
<<2)+4 : fr
->II_sblimit
;
137 fr
->framesize
= (long) tabsel_123
[fr
->lsf
][1][fr
->bitrate_index
] * 144000;
138 fr
->framesize
/= freqs
[fr
->sampling_frequency
];
139 fr
->framesize
+= fr
->padding
- 4;
141 fprintf(stderr
,"Not supported!\n");
146 fr
->do_layer
= do_layer3
;
148 ssize
= (fr
->stereo
== 1) ? 9 : 17;
150 ssize
= (fr
->stereo
== 1) ? 17 : 32;
154 if(fr
->error_protection
)
157 fr
->framesize
= (long) tabsel_123
[fr
->lsf
][2][fr
->bitrate_index
] * 144000;
158 fr
->framesize
/= freqs
[fr
->sampling_frequency
]<<(fr
->lsf
);
159 fr
->framesize
= fr
->framesize
+ fr
->padding
- 4;
162 fprintf(stderr
,"Sorry, unknown layer type.\n");
169 void print_header(struct frame
*fr
)
171 static const char * const modes
[4] = { "Stereo", "Joint-Stereo", "Dual-Channel", "Single-Channel" };
172 static const char * const layers
[4] = { "Unknown" , "I", "II", "III" };
174 fprintf(stderr
,"MPEG %s, Layer: %s, Freq: %ld, mode: %s, modext: %d, BPF : %d\n",
175 fr
->mpeg25
? "2.5" : (fr
->lsf
? "2.0" : "1.0"),
176 layers
[fr
->lay
],freqs
[fr
->sampling_frequency
],
177 modes
[fr
->mode
],fr
->mode_ext
,fr
->framesize
+4);
178 fprintf(stderr
,"Channels: %d, copyright: %s, original: %s, CRC: %s, emphasis: %d.\n",
179 fr
->stereo
,fr
->copyright
?"Yes":"No",
180 fr
->original
?"Yes":"No",fr
->error_protection
?"Yes":"No",
182 fprintf(stderr
,"Bitrate: %d Kbits/s, Extension value: %d\n",
183 tabsel_123
[fr
->lsf
][fr
->lay
-1][fr
->bitrate_index
],fr
->extension
);
186 void print_header_compact(struct frame
*fr
)
188 static const char * const modes
[4] = { "stereo", "joint-stereo", "dual-channel", "mono" };
189 static const char * const layers
[4] = { "Unknown" , "I", "II", "III" };
191 fprintf(stderr
,"MPEG %s layer %s, %d kbit/s, %ld Hz %s\n",
192 fr
->mpeg25
? "2.5" : (fr
->lsf
? "2.0" : "1.0"),
194 tabsel_123
[fr
->lsf
][fr
->lay
-1][fr
->bitrate_index
],
195 freqs
[fr
->sampling_frequency
], modes
[fr
->mode
]);
200 unsigned int getbits(int number_of_bits
)
208 rval
= wordpointer
[0];
210 rval
|= wordpointer
[1];
212 rval
|= wordpointer
[2];
216 bitindex
+= number_of_bits
;
218 rval
>>= (24-number_of_bits
);
220 wordpointer
+= (bitindex
>>3);
226 unsigned int getbits_fast(int number_of_bits
)
231 rval
= wordpointer
[0];
233 rval
|= wordpointer
[1];
236 bitindex
+= number_of_bits
;
238 rval
>>= (16-number_of_bits
);
240 wordpointer
+= (bitindex
>>3);
246 unsigned int get1bit(void)
249 rval
= *wordpointer
<< bitindex
;
252 wordpointer
+= (bitindex
>>3);