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comparison decoders/mpglib/common.c @ 261:9b6e82f7c853

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Initial add.
author Ryan C. Gordon <icculus@icculus.org>
date Thu, 21 Feb 2002 19:46:09 +0000
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children e1429f96aded
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260:44a4730a1e6f 261:9b6e82f7c853
1 #include <ctype.h>
2 #include <stdlib.h>
3 #include <signal.h>
4
5 #include <sys/types.h>
6 #include <sys/stat.h>
7 #include <fcntl.h>
8
9 #include "mpg123_sdlsound.h"
10
11 struct parameter param = { 1 , 1 , 0 , 0 };
12
13 int tabsel_123[2][3][16] = {
14 { {0,32,64,96,128,160,192,224,256,288,320,352,384,416,448,},
15 {0,32,48,56, 64, 80, 96,112,128,160,192,224,256,320,384,},
16 {0,32,40,48, 56, 64, 80, 96,112,128,160,192,224,256,320,} },
17
18 { {0,32,48,56,64,80,96,112,128,144,160,176,192,224,256,},
19 {0,8,16,24,32,40,48,56,64,80,96,112,128,144,160,},
20 {0,8,16,24,32,40,48,56,64,80,96,112,128,144,160,} }
21 };
22
23 long freqs[9] = { 44100, 48000, 32000,
24 22050, 24000, 16000 ,
25 11025 , 12000 , 8000 };
26
27 int bitindex;
28 unsigned char *wordpointer;
29 unsigned char *pcm_sample;
30 int pcm_point = 0;
31
32
33 #define HDRCMPMASK 0xfffffd00
34
35 #if 0
36 int head_check(unsigned long head)
37 {
38 if( (head & 0xffe00000) != 0xffe00000)
39 return FALSE;
40 if(!((head>>17)&3))
41 return FALSE;
42 if( ((head>>12)&0xf) == 0xf)
43 return FALSE;
44 if( ((head>>10)&0x3) == 0x3 )
45 return FALSE;
46 return TRUE;
47 }
48 #endif
49
50
51 /*
52 * the code a header and write the information
53 * into the frame structure
54 */
55 int decode_header(struct frame *fr,unsigned long newhead)
56 {
57 if( newhead & (1<<20) ) {
58 fr->lsf = (newhead & (1<<19)) ? 0x0 : 0x1;
59 fr->mpeg25 = 0;
60 }
61 else {
62 fr->lsf = 1;
63 fr->mpeg25 = 1;
64 }
65
66 fr->lay = 4-((newhead>>17)&3);
67 if( ((newhead>>10)&0x3) == 0x3) {
68 fprintf(stderr,"Stream error\n");
69 exit(1);
70 }
71 if(fr->mpeg25) {
72 fr->sampling_frequency = 6 + ((newhead>>10)&0x3);
73 }
74 else
75 fr->sampling_frequency = ((newhead>>10)&0x3) + (fr->lsf*3);
76 fr->error_protection = ((newhead>>16)&0x1)^0x1;
77
78 if(fr->mpeg25) /* allow Bitrate change for 2.5 ... */
79 fr->bitrate_index = ((newhead>>12)&0xf);
80
81 fr->bitrate_index = ((newhead>>12)&0xf);
82 fr->padding = ((newhead>>9)&0x1);
83 fr->extension = ((newhead>>8)&0x1);
84 fr->mode = ((newhead>>6)&0x3);
85 fr->mode_ext = ((newhead>>4)&0x3);
86 fr->copyright = ((newhead>>3)&0x1);
87 fr->original = ((newhead>>2)&0x1);
88 fr->emphasis = newhead & 0x3;
89
90 fr->stereo = (fr->mode == MPG_MD_MONO) ? 1 : 2;
91
92 if(!fr->bitrate_index)
93 {
94 fprintf(stderr,"Free format not supported.\n");
95 return (0);
96 }
97
98 switch(fr->lay)
99 {
100 case 1:
101 #ifdef LAYER1
102 #if 0
103 fr->jsbound = (fr->mode == MPG_MD_JOINT_STEREO) ?
104 (fr->mode_ext<<2)+4 : 32;
105 #endif
106 fr->framesize = (long) tabsel_123[fr->lsf][0][fr->bitrate_index] * 12000;
107 fr->framesize /= freqs[fr->sampling_frequency];
108 fr->framesize = ((fr->framesize+fr->padding)<<2)-4;
109 #else
110 fprintf(stderr,"Not supported!\n");
111 #endif
112 break;
113 case 2:
114 #ifdef LAYER2
115 #if 0
116 fr->jsbound = (fr->mode == MPG_MD_JOINT_STEREO) ?
117 (fr->mode_ext<<2)+4 : fr->II_sblimit;
118 #endif
119 fr->framesize = (long) tabsel_123[fr->lsf][1][fr->bitrate_index] * 144000;
120 fr->framesize /= freqs[fr->sampling_frequency];
121 fr->framesize += fr->padding - 4;
122 #else
123 fprintf(stderr,"Not supported!\n");
124 #endif
125 break;
126 case 3:
127 #if 0
128 fr->do_layer = do_layer3;
129 if(fr->lsf)
130 ssize = (fr->stereo == 1) ? 9 : 17;
131 else
132 ssize = (fr->stereo == 1) ? 17 : 32;
133 #endif
134
135 #if 0
136 if(fr->error_protection)
137 ssize += 2;
138 #endif
139 fr->framesize = (long) tabsel_123[fr->lsf][2][fr->bitrate_index] * 144000;
140 fr->framesize /= freqs[fr->sampling_frequency]<<(fr->lsf);
141 fr->framesize = fr->framesize + fr->padding - 4;
142 break;
143 default:
144 fprintf(stderr,"Sorry, unknown layer type.\n");
145 return (0);
146 }
147 return 1;
148 }
149
150 #if 0
151 void print_header(struct frame *fr)
152 {
153 static char *modes[4] = { "Stereo", "Joint-Stereo", "Dual-Channel", "Single-Channel" };
154 static char *layers[4] = { "Unknown" , "I", "II", "III" };
155
156 fprintf(stderr,"MPEG %s, Layer: %s, Freq: %ld, mode: %s, modext: %d, BPF : %d\n",
157 fr->mpeg25 ? "2.5" : (fr->lsf ? "2.0" : "1.0"),
158 layers[fr->lay],freqs[fr->sampling_frequency],
159 modes[fr->mode],fr->mode_ext,fr->framesize+4);
160 fprintf(stderr,"Channels: %d, copyright: %s, original: %s, CRC: %s, emphasis: %d.\n",
161 fr->stereo,fr->copyright?"Yes":"No",
162 fr->original?"Yes":"No",fr->error_protection?"Yes":"No",
163 fr->emphasis);
164 fprintf(stderr,"Bitrate: %d Kbits/s, Extension value: %d\n",
165 tabsel_123[fr->lsf][fr->lay-1][fr->bitrate_index],fr->extension);
166 }
167
168 void print_header_compact(struct frame *fr)
169 {
170 static char *modes[4] = { "stereo", "joint-stereo", "dual-channel", "mono" };
171 static char *layers[4] = { "Unknown" , "I", "II", "III" };
172
173 fprintf(stderr,"MPEG %s layer %s, %d kbit/s, %ld Hz %s\n",
174 fr->mpeg25 ? "2.5" : (fr->lsf ? "2.0" : "1.0"),
175 layers[fr->lay],
176 tabsel_123[fr->lsf][fr->lay-1][fr->bitrate_index],
177 freqs[fr->sampling_frequency], modes[fr->mode]);
178 }
179
180 #endif
181
182 unsigned int getbits(int number_of_bits)
183 {
184 unsigned long rval;
185
186 if(!number_of_bits)
187 return 0;
188
189 {
190 rval = wordpointer[0];
191 rval <<= 8;
192 rval |= wordpointer[1];
193 rval <<= 8;
194 rval |= wordpointer[2];
195 rval <<= bitindex;
196 rval &= 0xffffff;
197
198 bitindex += number_of_bits;
199
200 rval >>= (24-number_of_bits);
201
202 wordpointer += (bitindex>>3);
203 bitindex &= 7;
204 }
205 return rval;
206 }
207
208 unsigned int getbits_fast(int number_of_bits)
209 {
210 unsigned long rval;
211
212 {
213 rval = wordpointer[0];
214 rval <<= 8;
215 rval |= wordpointer[1];
216 rval <<= bitindex;
217 rval &= 0xffff;
218 bitindex += number_of_bits;
219
220 rval >>= (16-number_of_bits);
221
222 wordpointer += (bitindex>>3);
223 bitindex &= 7;
224 }
225 return rval;
226 }
227
228 unsigned int get1bit(void)
229 {
230 unsigned char rval;
231 rval = *wordpointer << bitindex;
232
233 bitindex++;
234 wordpointer += (bitindex>>3);
235 bitindex &= 7;
236
237 return rval>>7;
238 }
239
240
241