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source: vbox/trunk/src/libs/ffmpeg-20060710/libavcodec/pcm.c@ 10516

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1/*
2 * PCM codecs
3 * Copyright (c) 2001 Fabrice Bellard.
4 *
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
9 *
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
14 *
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with this library; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
18 */
19
20/**
21 * @file pcm.c
22 * PCM codecs
23 */
24
25#include "avcodec.h"
26#include "bitstream.h" // for ff_reverse
27
28/* from g711.c by SUN microsystems (unrestricted use) */
29
30#define SIGN_BIT (0x80) /* Sign bit for a A-law byte. */
31#define QUANT_MASK (0xf) /* Quantization field mask. */
32#define NSEGS (8) /* Number of A-law segments. */
33#define SEG_SHIFT (4) /* Left shift for segment number. */
34#define SEG_MASK (0x70) /* Segment field mask. */
35
36#define BIAS (0x84) /* Bias for linear code. */
37
38/*
39 * alaw2linear() - Convert an A-law value to 16-bit linear PCM
40 *
41 */
42static int alaw2linear(unsigned char a_val)
43{
44 int t;
45 int seg;
46
47 a_val ^= 0x55;
48
49 t = a_val & QUANT_MASK;
50 seg = ((unsigned)a_val & SEG_MASK) >> SEG_SHIFT;
51 if(seg) t= (t + t + 1 + 32) << (seg + 2);
52 else t= (t + t + 1 ) << 3;
53
54 return ((a_val & SIGN_BIT) ? t : -t);
55}
56
57static int ulaw2linear(unsigned char u_val)
58{
59 int t;
60
61 /* Complement to obtain normal u-law value. */
62 u_val = ~u_val;
63
64 /*
65 * Extract and bias the quantization bits. Then
66 * shift up by the segment number and subtract out the bias.
67 */
68 t = ((u_val & QUANT_MASK) << 3) + BIAS;
69 t <<= ((unsigned)u_val & SEG_MASK) >> SEG_SHIFT;
70
71 return ((u_val & SIGN_BIT) ? (BIAS - t) : (t - BIAS));
72}
73
74/* 16384 entries per table */
75static uint8_t *linear_to_alaw = NULL;
76static int linear_to_alaw_ref = 0;
77
78static uint8_t *linear_to_ulaw = NULL;
79static int linear_to_ulaw_ref = 0;
80
81static void build_xlaw_table(uint8_t *linear_to_xlaw,
82 int (*xlaw2linear)(unsigned char),
83 int mask)
84{
85 int i, j, v, v1, v2;
86
87 j = 0;
88 for(i=0;i<128;i++) {
89 if (i != 127) {
90 v1 = xlaw2linear(i ^ mask);
91 v2 = xlaw2linear((i + 1) ^ mask);
92 v = (v1 + v2 + 4) >> 3;
93 } else {
94 v = 8192;
95 }
96 for(;j<v;j++) {
97 linear_to_xlaw[8192 + j] = (i ^ mask);
98 if (j > 0)
99 linear_to_xlaw[8192 - j] = (i ^ (mask ^ 0x80));
100 }
101 }
102 linear_to_xlaw[0] = linear_to_xlaw[1];
103}
104
105static int pcm_encode_init(AVCodecContext *avctx)
106{
107 avctx->frame_size = 1;
108 switch(avctx->codec->id) {
109 case CODEC_ID_PCM_ALAW:
110 if (linear_to_alaw_ref == 0) {
111 linear_to_alaw = av_malloc(16384);
112 if (!linear_to_alaw)
113 return -1;
114 build_xlaw_table(linear_to_alaw, alaw2linear, 0xd5);
115 }
116 linear_to_alaw_ref++;
117 break;
118 case CODEC_ID_PCM_MULAW:
119 if (linear_to_ulaw_ref == 0) {
120 linear_to_ulaw = av_malloc(16384);
121 if (!linear_to_ulaw)
122 return -1;
123 build_xlaw_table(linear_to_ulaw, ulaw2linear, 0xff);
124 }
125 linear_to_ulaw_ref++;
126 break;
127 default:
128 break;
129 }
130
131 switch(avctx->codec->id) {
132 case CODEC_ID_PCM_S32LE:
133 case CODEC_ID_PCM_S32BE:
134 case CODEC_ID_PCM_U32LE:
135 case CODEC_ID_PCM_U32BE:
136 avctx->block_align = 4 * avctx->channels;
137 break;
138 case CODEC_ID_PCM_S24LE:
139 case CODEC_ID_PCM_S24BE:
140 case CODEC_ID_PCM_U24LE:
141 case CODEC_ID_PCM_U24BE:
142 case CODEC_ID_PCM_S24DAUD:
143 avctx->block_align = 3 * avctx->channels;
144 break;
145 case CODEC_ID_PCM_S16LE:
146 case CODEC_ID_PCM_S16BE:
147 case CODEC_ID_PCM_U16LE:
148 case CODEC_ID_PCM_U16BE:
149 avctx->block_align = 2 * avctx->channels;
150 break;
151 case CODEC_ID_PCM_S8:
152 case CODEC_ID_PCM_U8:
153 case CODEC_ID_PCM_MULAW:
154 case CODEC_ID_PCM_ALAW:
155 avctx->block_align = avctx->channels;
156 break;
157 default:
158 break;
159 }
160
161 avctx->coded_frame= avcodec_alloc_frame();
162 avctx->coded_frame->key_frame= 1;
163
164 return 0;
165}
166
167static int pcm_encode_close(AVCodecContext *avctx)
168{
169 av_freep(&avctx->coded_frame);
170
171 switch(avctx->codec->id) {
172 case CODEC_ID_PCM_ALAW:
173 if (--linear_to_alaw_ref == 0)
174 av_free(linear_to_alaw);
175 break;
176 case CODEC_ID_PCM_MULAW:
177 if (--linear_to_ulaw_ref == 0)
178 av_free(linear_to_ulaw);
179 break;
180 default:
181 /* nothing to free */
182 break;
183 }
184 return 0;
185}
186
187/**
188 * \brief convert samples from 16 bit
189 * \param bps byte per sample for the destination format, must be >= 2
190 * \param le 0 for big-, 1 for little-endian
191 * \param us 0 for signed, 1 for unsigned output
192 * \param samples input samples
193 * \param dst output samples
194 * \param n number of samples in samples buffer.
195 */
196static inline void encode_from16(int bps, int le, int us,
197 short **samples, uint8_t **dst, int n) {
198 if (bps > 2)
199 memset(*dst, 0, n * bps);
200 if (le) *dst += bps - 2;
201 for(;n>0;n--) {
202 register int v = *(*samples)++;
203 if (us) v += 0x8000;
204 (*dst)[le] = v >> 8;
205 (*dst)[1 - le] = v;
206 *dst += bps;
207 }
208 if (le) *dst -= bps - 2;
209}
210
211static int pcm_encode_frame(AVCodecContext *avctx,
212 unsigned char *frame, int buf_size, void *data)
213{
214 int n, sample_size, v;
215 short *samples;
216 unsigned char *dst;
217
218 switch(avctx->codec->id) {
219 case CODEC_ID_PCM_S32LE:
220 case CODEC_ID_PCM_S32BE:
221 case CODEC_ID_PCM_U32LE:
222 case CODEC_ID_PCM_U32BE:
223 sample_size = 4;
224 break;
225 case CODEC_ID_PCM_S24LE:
226 case CODEC_ID_PCM_S24BE:
227 case CODEC_ID_PCM_U24LE:
228 case CODEC_ID_PCM_U24BE:
229 case CODEC_ID_PCM_S24DAUD:
230 sample_size = 3;
231 break;
232 case CODEC_ID_PCM_S16LE:
233 case CODEC_ID_PCM_S16BE:
234 case CODEC_ID_PCM_U16LE:
235 case CODEC_ID_PCM_U16BE:
236 sample_size = 2;
237 break;
238 default:
239 sample_size = 1;
240 break;
241 }
242 n = buf_size / sample_size;
243 samples = data;
244 dst = frame;
245
246 switch(avctx->codec->id) {
247 case CODEC_ID_PCM_S32LE:
248 encode_from16(4, 1, 0, &samples, &dst, n);
249 break;
250 case CODEC_ID_PCM_S32BE:
251 encode_from16(4, 0, 0, &samples, &dst, n);
252 break;
253 case CODEC_ID_PCM_U32LE:
254 encode_from16(4, 1, 1, &samples, &dst, n);
255 break;
256 case CODEC_ID_PCM_U32BE:
257 encode_from16(4, 0, 1, &samples, &dst, n);
258 break;
259 case CODEC_ID_PCM_S24LE:
260 encode_from16(3, 1, 0, &samples, &dst, n);
261 break;
262 case CODEC_ID_PCM_S24BE:
263 encode_from16(3, 0, 0, &samples, &dst, n);
264 break;
265 case CODEC_ID_PCM_U24LE:
266 encode_from16(3, 1, 1, &samples, &dst, n);
267 break;
268 case CODEC_ID_PCM_U24BE:
269 encode_from16(3, 0, 1, &samples, &dst, n);
270 break;
271 case CODEC_ID_PCM_S24DAUD:
272 for(;n>0;n--) {
273 uint32_t tmp = ff_reverse[*samples >> 8] +
274 (ff_reverse[*samples & 0xff] << 8);
275 tmp <<= 4; // sync flags would go here
276 dst[2] = tmp & 0xff;
277 tmp >>= 8;
278 dst[1] = tmp & 0xff;
279 dst[0] = tmp >> 8;
280 samples++;
281 dst += 3;
282 }
283 break;
284 case CODEC_ID_PCM_S16LE:
285 for(;n>0;n--) {
286 v = *samples++;
287 dst[0] = v & 0xff;
288 dst[1] = v >> 8;
289 dst += 2;
290 }
291 break;
292 case CODEC_ID_PCM_S16BE:
293 for(;n>0;n--) {
294 v = *samples++;
295 dst[0] = v >> 8;
296 dst[1] = v;
297 dst += 2;
298 }
299 break;
300 case CODEC_ID_PCM_U16LE:
301 for(;n>0;n--) {
302 v = *samples++;
303 v += 0x8000;
304 dst[0] = v & 0xff;
305 dst[1] = v >> 8;
306 dst += 2;
307 }
308 break;
309 case CODEC_ID_PCM_U16BE:
310 for(;n>0;n--) {
311 v = *samples++;
312 v += 0x8000;
313 dst[0] = v >> 8;
314 dst[1] = v;
315 dst += 2;
316 }
317 break;
318 case CODEC_ID_PCM_S8:
319 for(;n>0;n--) {
320 v = *samples++;
321 dst[0] = v >> 8;
322 dst++;
323 }
324 break;
325 case CODEC_ID_PCM_U8:
326 for(;n>0;n--) {
327 v = *samples++;
328 dst[0] = (v >> 8) + 128;
329 dst++;
330 }
331 break;
332 case CODEC_ID_PCM_ALAW:
333 for(;n>0;n--) {
334 v = *samples++;
335 dst[0] = linear_to_alaw[(v + 32768) >> 2];
336 dst++;
337 }
338 break;
339 case CODEC_ID_PCM_MULAW:
340 for(;n>0;n--) {
341 v = *samples++;
342 dst[0] = linear_to_ulaw[(v + 32768) >> 2];
343 dst++;
344 }
345 break;
346 default:
347 return -1;
348 }
349 //avctx->frame_size = (dst - frame) / (sample_size * avctx->channels);
350
351 return dst - frame;
352}
353
354typedef struct PCMDecode {
355 short table[256];
356} PCMDecode;
357
358static int pcm_decode_init(AVCodecContext * avctx)
359{
360 PCMDecode *s = avctx->priv_data;
361 int i;
362
363 switch(avctx->codec->id) {
364 case CODEC_ID_PCM_ALAW:
365 for(i=0;i<256;i++)
366 s->table[i] = alaw2linear(i);
367 break;
368 case CODEC_ID_PCM_MULAW:
369 for(i=0;i<256;i++)
370 s->table[i] = ulaw2linear(i);
371 break;
372 default:
373 break;
374 }
375 return 0;
376}
377
378/**
379 * \brief convert samples to 16 bit
380 * \param bps byte per sample for the source format, must be >= 2
381 * \param le 0 for big-, 1 for little-endian
382 * \param us 0 for signed, 1 for unsigned input
383 * \param src input samples
384 * \param samples output samples
385 * \param src_len number of bytes in src
386 */
387static inline void decode_to16(int bps, int le, int us,
388 uint8_t **src, short **samples, int src_len)
389{
390 register int n = src_len / bps;
391 if (le) *src += bps - 2;
392 for(;n>0;n--) {
393 *(*samples)++ = ((*src)[le] << 8 | (*src)[1 - le]) - (us?0x8000:0);
394 *src += bps;
395 }
396 if (le) *src -= bps - 2;
397}
398
399static int pcm_decode_frame(AVCodecContext *avctx,
400 void *data, int *data_size,
401 uint8_t *buf, int buf_size)
402{
403 PCMDecode *s = avctx->priv_data;
404 int n;
405 short *samples;
406 uint8_t *src;
407
408 samples = data;
409 src = buf;
410
411 if(buf_size > AVCODEC_MAX_AUDIO_FRAME_SIZE/2)
412 buf_size = AVCODEC_MAX_AUDIO_FRAME_SIZE/2;
413
414 switch(avctx->codec->id) {
415 case CODEC_ID_PCM_S32LE:
416 decode_to16(4, 1, 0, &src, &samples, buf_size);
417 break;
418 case CODEC_ID_PCM_S32BE:
419 decode_to16(4, 0, 0, &src, &samples, buf_size);
420 break;
421 case CODEC_ID_PCM_U32LE:
422 decode_to16(4, 1, 1, &src, &samples, buf_size);
423 break;
424 case CODEC_ID_PCM_U32BE:
425 decode_to16(4, 0, 1, &src, &samples, buf_size);
426 break;
427 case CODEC_ID_PCM_S24LE:
428 decode_to16(3, 1, 0, &src, &samples, buf_size);
429 break;
430 case CODEC_ID_PCM_S24BE:
431 decode_to16(3, 0, 0, &src, &samples, buf_size);
432 break;
433 case CODEC_ID_PCM_U24LE:
434 decode_to16(3, 1, 1, &src, &samples, buf_size);
435 break;
436 case CODEC_ID_PCM_U24BE:
437 decode_to16(3, 0, 1, &src, &samples, buf_size);
438 break;
439 case CODEC_ID_PCM_S24DAUD:
440 n = buf_size / 3;
441 for(;n>0;n--) {
442 uint32_t v = src[0] << 16 | src[1] << 8 | src[2];
443 v >>= 4; // sync flags are here
444 *samples++ = ff_reverse[(v >> 8) & 0xff] +
445 (ff_reverse[v & 0xff] << 8);
446 src += 3;
447 }
448 break;
449 case CODEC_ID_PCM_S16LE:
450 n = buf_size >> 1;
451 for(;n>0;n--) {
452 *samples++ = src[0] | (src[1] << 8);
453 src += 2;
454 }
455 break;
456 case CODEC_ID_PCM_S16BE:
457 n = buf_size >> 1;
458 for(;n>0;n--) {
459 *samples++ = (src[0] << 8) | src[1];
460 src += 2;
461 }
462 break;
463 case CODEC_ID_PCM_U16LE:
464 n = buf_size >> 1;
465 for(;n>0;n--) {
466 *samples++ = (src[0] | (src[1] << 8)) - 0x8000;
467 src += 2;
468 }
469 break;
470 case CODEC_ID_PCM_U16BE:
471 n = buf_size >> 1;
472 for(;n>0;n--) {
473 *samples++ = ((src[0] << 8) | src[1]) - 0x8000;
474 src += 2;
475 }
476 break;
477 case CODEC_ID_PCM_S8:
478 n = buf_size;
479 for(;n>0;n--) {
480 *samples++ = src[0] << 8;
481 src++;
482 }
483 break;
484 case CODEC_ID_PCM_U8:
485 n = buf_size;
486 for(;n>0;n--) {
487 *samples++ = ((int)src[0] - 128) << 8;
488 src++;
489 }
490 break;
491 case CODEC_ID_PCM_ALAW:
492 case CODEC_ID_PCM_MULAW:
493 n = buf_size;
494 for(;n>0;n--) {
495 *samples++ = s->table[src[0]];
496 src++;
497 }
498 break;
499 default:
500 return -1;
501 }
502 *data_size = (uint8_t *)samples - (uint8_t *)data;
503 return src - buf;
504}
505
506#define PCM_CODEC(id, name) \
507AVCodec name ## _encoder = { \
508 #name, \
509 CODEC_TYPE_AUDIO, \
510 id, \
511 0, \
512 pcm_encode_init, \
513 pcm_encode_frame, \
514 pcm_encode_close, \
515 NULL, \
516}; \
517AVCodec name ## _decoder = { \
518 #name, \
519 CODEC_TYPE_AUDIO, \
520 id, \
521 sizeof(PCMDecode), \
522 pcm_decode_init, \
523 NULL, \
524 NULL, \
525 pcm_decode_frame, \
526}
527
528PCM_CODEC(CODEC_ID_PCM_S32LE, pcm_s32le);
529PCM_CODEC(CODEC_ID_PCM_S32BE, pcm_s32be);
530PCM_CODEC(CODEC_ID_PCM_U32LE, pcm_u32le);
531PCM_CODEC(CODEC_ID_PCM_U32BE, pcm_u32be);
532PCM_CODEC(CODEC_ID_PCM_S24LE, pcm_s24le);
533PCM_CODEC(CODEC_ID_PCM_S24BE, pcm_s24be);
534PCM_CODEC(CODEC_ID_PCM_U24LE, pcm_u24le);
535PCM_CODEC(CODEC_ID_PCM_U24BE, pcm_u24be);
536PCM_CODEC(CODEC_ID_PCM_S24DAUD, pcm_s24daud);
537PCM_CODEC(CODEC_ID_PCM_S16LE, pcm_s16le);
538PCM_CODEC(CODEC_ID_PCM_S16BE, pcm_s16be);
539PCM_CODEC(CODEC_ID_PCM_U16LE, pcm_u16le);
540PCM_CODEC(CODEC_ID_PCM_U16BE, pcm_u16be);
541PCM_CODEC(CODEC_ID_PCM_S8, pcm_s8);
542PCM_CODEC(CODEC_ID_PCM_U8, pcm_u8);
543PCM_CODEC(CODEC_ID_PCM_ALAW, pcm_alaw);
544PCM_CODEC(CODEC_ID_PCM_MULAW, pcm_mulaw);
545
546#undef PCM_CODEC
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