1 /*
2 * common.c: some common bitstream operations
3 *
4 * Copyright (C) 1999-2010 The L.A.M.E. project
5 *
6 * Initially written by Michael Hipp, see also AUTHORS and README.
7 *
8 * This library is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Library General Public
10 * License as published by the Free Software Foundation; either
11 * version 2 of the License, or (at your option) any later version.
12 *
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Library General Public License for more details.
17 *
18 * You should have received a copy of the GNU Library General Public
19 * License along with this library; if not, write to the
20 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
21 * Boston, MA 02111-1307, USA.
22 */
23
24 /* $Id: common.c,v 1.42 2017/08/19 14:20:27 robert Exp $ */
25
26 #ifdef HAVE_CONFIG_H
27 #include <config.h>
28 #endif
29
30 #include <ctype.h>
31 #include <stdlib.h>
32 #include <signal.h>
33
34 #ifdef HAVE_FCNTL_H
35 #include <fcntl.h>
36 #endif
37
38 #ifdef macintosh
39 #include <types.h>
40 #include <stat.h>
41 #else
42 #include <sys/types.h>
43 #include <sys/stat.h>
44 #endif
45
46 #include <assert.h>
47
48 #include "common.h"
49
50 #ifdef WITH_DMALLOC
51 #include <dmalloc.h>
52 #endif
53
54 /* In C++ the array first must be prototyped, why ? */
55
56
57 /* *INDENT-OFF* */
58 const int tabsel_123 [2] [3] [16] = {
59 { {0,32,64,96,128,160,192,224,256,288,320,352,384,416,448,},
60 {0,32,48,56, 64, 80, 96,112,128,160,192,224,256,320,384,},
61 {0,32,40,48, 56, 64, 80, 96,112,128,160,192,224,256,320,} },
62
63 { {0,32,48,56,64,80,96,112,128,144,160,176,192,224,256,},
64 {0,8,16,24,32,40,48,56,64,80,96,112,128,144,160,},
65 {0,8,16,24,32,40,48,56,64,80,96,112,128,144,160,} }
66 };
67
68 const long freqs[9] = { 44100, 48000, 32000,
69 22050, 24000, 16000,
70 11025, 12000, 8000 };
71
72 /* *INDENT-ON* */
73
74
75 real muls[27][64];
76
77 #if 0
78 static void
79 get_II_stuff(struct frame *fr)
80 {
81 /* *INDENT-OFF* */
82 static const int translate [3] [2] [16] = /* char ? */
83 { { { 0,2,2,2,2,2,2,0,0,0,1,1,1,1,1,0 } ,
84 { 0,2,2,0,0,0,1,1,1,1,1,1,1,1,1,0 } } ,
85 { { 0,2,2,2,2,2,2,0,0,0,0,0,0,0,0,0 } ,
86 { 0,2,2,0,0,0,0,0,0,0,0,0,0,0,0,0 } } ,
87 { { 0,3,3,3,3,3,3,0,0,0,1,1,1,1,1,0 } ,
88 { 0,3,3,0,0,0,1,1,1,1,1,1,1,1,1,0 } } };
89 /* *INDENT-ON* */
90
91 int table, sblim;
92 static const struct al_table2 *tables[5] = { alloc_0, alloc_1, alloc_2, alloc_3, alloc_4 };
93 static int sblims[5] = { 27, 30, 8, 12, 30 };
94
95 if (fr->lsf)
96 table = 4;
97 else
98 table = translate[fr->sampling_frequency][2 - fr->stereo][fr->bitrate_index];
99 sblim = sblims[table];
100
101 fr->alloc = tables[table];
102 fr->II_sblimit = sblim;
103 }
104 #endif
105
106 #define HDRCMPMASK 0xfffffd00
107
108 #define MAX_INPUT_FRAMESIZE 4096
109
110 int
head_check(unsigned long head,int check_layer)111 head_check(unsigned long head, int check_layer)
112 {
113 /*
114 look for a valid header.
115 if check_layer > 0, then require that
116 nLayer = check_layer.
117 */
118
119 /* bits 13-14 = layer 3 */
120 int nLayer = 4 - ((head >> 17) & 3);
121
122 if ((head & 0xffe00000) != 0xffe00000) {
123 /* syncword */
124 return FALSE;
125 }
126
127 if (nLayer == 4)
128 return FALSE;
129
130 if (check_layer > 0 && nLayer != check_layer)
131 return FALSE;
132
133 if (((head >> 12) & 0xf) == 0xf) {
134 /* bits 16,17,18,19 = 1111 invalid bitrate */
135 return FALSE;
136 }
137 if (((head >> 10) & 0x3) == 0x3) {
138 /* bits 20,21 = 11 invalid sampling freq */
139 return FALSE;
140 }
141 if ((head & 0x3) == 0x2)
142 /* invalid emphasis */
143 return FALSE;
144 return TRUE;
145 }
146
147
148 #if 0
149 static void
150 print_header(PMPSTR mp, struct frame *fr)
151 {
152 static const char *modes[4] = { "Stereo", "Joint-Stereo", "Dual-Channel", "Single-Channel" };
153 static const char *layers[4] = { "Unknown", "I", "II", "III" };
154
155 lame_report_fnc(mp->report_msg, "MPEG %s, Layer: %s, Freq: %ld, mode: %s, modext: %d, BPF : %d\n",
156 fr->mpeg25 ? "2.5" : (fr->lsf ? "2.0" : "1.0"),
157 layers[fr->lay], freqs[fr->sampling_frequency],
158 modes[fr->mode], fr->mode_ext, fr->framesize + 4);
159 lame_report_fnc(mp->report_msg, "Channels: %d, copyright: %s, original: %s, CRC: %s, emphasis: %d.\n",
160 fr->stereo, fr->copyright ? "Yes" : "No",
161 fr->original ? "Yes" : "No", fr->error_protection ? "Yes" : "No", fr->emphasis);
162 lame_report_fnc(mp->report_msg, "Bitrate: %d Kbits/s, Extension value: %d\n",
163 tabsel_123[fr->lsf][fr->lay - 1][fr->bitrate_index], fr->extension);
164 }
165
166 static void
167 print_header_compact(PMPSTR mp, struct frame *fr)
168 {
169 static const char *modes[4] = { "stereo", "joint-stereo", "dual-channel", "mono" };
170 static const char *layers[4] = { "Unknown", "I", "II", "III" };
171
172 lame_report_fnc(mp->report_err, "MPEG %s layer %s, %d kbit/s, %ld Hz %s\n",
173 fr->mpeg25 ? "2.5" : (fr->lsf ? "2.0" : "1.0"),
174 layers[fr->lay],
175 tabsel_123[fr->lsf][fr->lay - 1][fr->bitrate_index],
176 freqs[fr->sampling_frequency], modes[fr->mode]);
177 }
178
179 #endif
180
181 /*
182 * decode a header and write the information
183 * into the frame structure
184 */
185 int
decode_header(PMPSTR mp,struct frame * fr,unsigned long newhead)186 decode_header(PMPSTR mp, struct frame *fr, unsigned long newhead)
187 {
188
189
190 if (newhead & (1 << 20)) {
191 fr->lsf = (newhead & (1 << 19)) ? 0x0 : 0x1;
192 fr->mpeg25 = 0;
193 }
194 else {
195 fr->lsf = 1;
196 fr->mpeg25 = 1;
197 }
198
199
200 fr->lay = 4 - ((newhead >> 17) & 3);
201
202 if (fr->lay != 3 && fr->mpeg25) {
203 lame_report_fnc(mp->report_err, "MPEG-2.5 is supported by Layer3 only\n");
204 return 0;
205 }
206 if (((newhead >> 10) & 0x3) == 0x3) {
207 lame_report_fnc(mp->report_err, "Stream error\n");
208 return 0;
209 }
210 if (fr->mpeg25) {
211 fr->sampling_frequency = 6 + ((newhead >> 10) & 0x3);
212 }
213 else
214 fr->sampling_frequency = ((newhead >> 10) & 0x3) + (fr->lsf * 3);
215
216 fr->error_protection = ((newhead >> 16) & 0x1) ^ 0x1;
217
218 if (fr->mpeg25) /* allow Bitrate change for 2.5 ... */
219 fr->bitrate_index = ((newhead >> 12) & 0xf);
220
221 fr->bitrate_index = ((newhead >> 12) & 0xf);
222 fr->padding = ((newhead >> 9) & 0x1);
223 fr->extension = ((newhead >> 8) & 0x1);
224 fr->mode = ((newhead >> 6) & 0x3);
225 fr->mode_ext = ((newhead >> 4) & 0x3);
226 fr->copyright = ((newhead >> 3) & 0x1);
227 fr->original = ((newhead >> 2) & 0x1);
228 fr->emphasis = newhead & 0x3;
229
230 fr->stereo = (fr->mode == MPG_MD_MONO) ? 1 : 2;
231
232 switch (fr->lay) {
233 case 1:
234 fr->framesize = (long) tabsel_123[fr->lsf][0][fr->bitrate_index] * 12000;
235 fr->framesize /= freqs[fr->sampling_frequency];
236 fr->framesize = ((fr->framesize + fr->padding) << 2) - 4;
237 fr->down_sample = 0;
238 fr->down_sample_sblimit = SBLIMIT >> (fr->down_sample);
239 break;
240
241 case 2:
242 fr->framesize = (long) tabsel_123[fr->lsf][1][fr->bitrate_index] * 144000;
243 fr->framesize /= freqs[fr->sampling_frequency];
244 fr->framesize += fr->padding - 4;
245 fr->down_sample = 0;
246 fr->down_sample_sblimit = SBLIMIT >> (fr->down_sample);
247 break;
248
249 case 3:
250 #if 0
251 fr->do_layer = do_layer3;
252 if (fr->lsf)
253 ssize = (fr->stereo == 1) ? 9 : 17;
254 else
255 ssize = (fr->stereo == 1) ? 17 : 32;
256 #endif
257
258 #if 0
259 if (fr->error_protection)
260 ssize += 2;
261 #endif
262 if (fr->framesize > MAX_INPUT_FRAMESIZE) {
263 lame_report_fnc(mp->report_err, "Frame size too big.\n");
264 fr->framesize = MAX_INPUT_FRAMESIZE;
265 return (0);
266 }
267
268
269 if (fr->bitrate_index == 0)
270 fr->framesize = 0;
271 else {
272 fr->framesize = (long) tabsel_123[fr->lsf][2][fr->bitrate_index] * 144000;
273 fr->framesize /= freqs[fr->sampling_frequency] << (fr->lsf);
274 fr->framesize = fr->framesize + fr->padding - 4;
275 }
276 break;
277 default:
278 lame_report_fnc(mp->report_err, "Sorry, layer %d not supported\n", fr->lay);
279 return (0);
280 }
281 /* print_header(mp, fr); */
282
283 return 1;
284 }
285
286
287 unsigned int
getbits(PMPSTR mp,int number_of_bits)288 getbits(PMPSTR mp, int number_of_bits)
289 {
290 unsigned long rval;
291
292 if (number_of_bits <= 0 || !mp->wordpointer)
293 return 0;
294
295 {
296 rval = mp->wordpointer[0];
297 rval <<= 8;
298 rval |= mp->wordpointer[1];
299 rval <<= 8;
300 rval |= mp->wordpointer[2];
301 rval <<= mp->bitindex;
302 rval &= 0xffffff;
303
304 mp->bitindex += number_of_bits;
305
306 rval >>= (24 - number_of_bits);
307
308 mp->wordpointer += (mp->bitindex >> 3);
309 mp->bitindex &= 7;
310 }
311 return rval;
312 }
313
314 unsigned int
getbits_fast(PMPSTR mp,int number_of_bits)315 getbits_fast(PMPSTR mp, int number_of_bits)
316 {
317 unsigned long rval;
318
319 {
320 rval = mp->wordpointer[0];
321 rval <<= 8;
322 rval |= mp->wordpointer[1];
323 rval <<= mp->bitindex;
324 rval &= 0xffff;
325 mp->bitindex += number_of_bits;
326
327 rval >>= (16 - number_of_bits);
328
329 mp->wordpointer += (mp->bitindex >> 3);
330 mp->bitindex &= 7;
331 }
332 return rval;
333 }
334
335 unsigned char
get_leq_8_bits(PMPSTR mp,unsigned int number_of_bits)336 get_leq_8_bits(PMPSTR mp, unsigned int number_of_bits)
337 {
338 assert(number_of_bits <= 8);
339 return (unsigned char) getbits_fast(mp, number_of_bits);
340 }
341
342 unsigned short
get_leq_16_bits(PMPSTR mp,unsigned int number_of_bits)343 get_leq_16_bits(PMPSTR mp, unsigned int number_of_bits)
344 {
345 assert(number_of_bits <= 16);
346 return (unsigned short) getbits_fast(mp, number_of_bits);
347 }
348
349 int
set_pointer(PMPSTR mp,long backstep)350 set_pointer(PMPSTR mp, long backstep)
351 {
352 unsigned char *bsbufold;
353
354 if (mp->fsizeold < 0 && backstep > 0) {
355 lame_report_fnc(mp->report_err, "hip: Can't step back %ld bytes!\n", backstep);
356 return MP3_ERR;
357 }
358 bsbufold = mp->bsspace[1 - mp->bsnum] + 512;
359 mp->wordpointer -= backstep;
360 if (backstep)
361 memcpy(mp->wordpointer, bsbufold + mp->fsizeold - backstep, (size_t) backstep);
362 mp->bitindex = 0;
363 return MP3_OK;
364 }
365