libavcodec/pcm.c

   1 /*
   2  * PCM codecs
   3  * Copyright (c) 2001 Fabrice Bellard.
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 /**
  23  * @file pcm.c
  24  * PCM codecs
  25  */
  26
  27 #include "avcodec.h"
  28 #include "bitstream.h" // for ff_reverse
  29 #include "bytestream.h"
  30
  31 #define MAX_CHANNELS 64
  32
  33 /* from g711.c by SUN microsystems (unrestricted use) */
  34
  35 #define         SIGN_BIT        (0x80)      /* Sign bit for a A-law byte. */
  36 #define         QUANT_MASK      (0xf)       /* Quantization field mask. */
  37 #define         NSEGS           (8)         /* Number of A-law segments. */
  38 #define         SEG_SHIFT       (4)         /* Left shift for segment number. */
  39 #define         SEG_MASK        (0x70)      /* Segment field mask. */
  40
  41 #define         BIAS            (0x84)      /* Bias for linear code. */
  42
  43 /*
  44  * alaw2linear() - Convert an A-law value to 16-bit linear PCM
  45  *
  46  */
  47 static int alaw2linear(unsigned char a_val)
  48 {
  49         int t;
  50         int seg;
  51
  52         a_val ^= 0x55;
  53
  54         t = a_val & QUANT_MASK;
  55         seg = ((unsigned)a_val & SEG_MASK) >> SEG_SHIFT;
  56         if(seg) t= (t + t + 1 + 32) << (seg + 2);
  57         else    t= (t + t + 1     ) << 3;
  58
  59         return ((a_val & SIGN_BIT) ? t : -t);
  60 }
  61
  62 static int ulaw2linear(unsigned char u_val)
  63 {
  64         int t;
  65
  66         /* Complement to obtain normal u-law value. */
  67         u_val = ~u_val;
  68
  69         /*
  70          * Extract and bias the quantization bits. Then
  71          * shift up by the segment number and subtract out the bias.
  72          */
  73         t = ((u_val & QUANT_MASK) << 3) + BIAS;
  74         t <<= ((unsigned)u_val & SEG_MASK) >> SEG_SHIFT;
  75
  76         return ((u_val & SIGN_BIT) ? (BIAS - t) : (t - BIAS));
  77 }
  78
  79 /* 16384 entries per table */
  80 static uint8_t linear_to_alaw[16384];
  81 static uint8_t linear_to_ulaw[16384];
  82
  83 static void build_xlaw_table(uint8_t *linear_to_xlaw,
  84                              int (*xlaw2linear)(unsigned char),
  85                              int mask)
  86 {
  87     int i, j, v, v1, v2;
  88
  89     j = 0;
  90     for(i=0;i<128;i++) {
  91         if (i != 127) {
  92             v1 = xlaw2linear(i ^ mask);
  93             v2 = xlaw2linear((i + 1) ^ mask);
  94             v = (v1 + v2 + 4) >> 3;
  95         } else {
  96             v = 8192;
  97         }
  98         for(;j<v;j++) {
  99             linear_to_xlaw[8192 + j] = (i ^ mask);
 100             if (j > 0)
 101                 linear_to_xlaw[8192 - j] = (i ^ (mask ^ 0x80));
 102         }
 103     }
 104     linear_to_xlaw[0] = linear_to_xlaw[1];
 105 }
 106
 107 static int pcm_encode_init(AVCodecContext *avctx)
 108 {
 109     avctx->frame_size = 1;
 110     switch(avctx->codec->id) {
 111     case CODEC_ID_PCM_ALAW:
 112         build_xlaw_table(linear_to_alaw, alaw2linear, 0xd5);
 113         break;
 114     case CODEC_ID_PCM_MULAW:
 115         build_xlaw_table(linear_to_ulaw, ulaw2linear, 0xff);
 116         break;
 117     default:
 118         break;
 119     }
 120
 121     switch(avctx->codec->id) {
 122     case CODEC_ID_PCM_S32LE:
 123     case CODEC_ID_PCM_S32BE:
 124     case CODEC_ID_PCM_U32LE:
 125     case CODEC_ID_PCM_U32BE:
 126         avctx->block_align = 4 * avctx->channels;
 127         break;
 128     case CODEC_ID_PCM_S24LE:
 129     case CODEC_ID_PCM_S24BE:
 130     case CODEC_ID_PCM_U24LE:
 131     case CODEC_ID_PCM_U24BE:
 132     case CODEC_ID_PCM_S24DAUD:
 133         avctx->block_align = 3 * avctx->channels;
 134         break;
 135     case CODEC_ID_PCM_S16LE:
 136     case CODEC_ID_PCM_S16BE:
 137     case CODEC_ID_PCM_U16LE:
 138     case CODEC_ID_PCM_U16BE:
 139         avctx->block_align = 2 * avctx->channels;
 140         break;
 141     case CODEC_ID_PCM_S8:
 142     case CODEC_ID_PCM_U8:
 143     case CODEC_ID_PCM_MULAW:
 144     case CODEC_ID_PCM_ALAW:
 145         avctx->block_align = avctx->channels;
 146         break;
 147     default:
 148         break;
 149     }
 150
 151     avctx->coded_frame= avcodec_alloc_frame();
 152     avctx->coded_frame->key_frame= 1;
 153
 154     return 0;
 155 }
 156
 157 static int pcm_encode_close(AVCodecContext *avctx)
 158 {
 159     av_freep(&avctx->coded_frame);
 160
 161     return 0;
 162 }
 163
 164 /**
 165  * \brief convert samples from 16 bit
 166  * \param bps byte per sample for the destination format, must be >= 2
 167  * \param le 0 for big-, 1 for little-endian
 168  * \param us 0 for signed, 1 for unsigned output
 169  * \param samples input samples
 170  * \param dst output samples
 171  * \param n number of samples in samples buffer.
 172  */
 173 static inline void encode_from16(int bps, int le, int us,
 174                                short **samples, uint8_t **dst, int n) {
 175     int usum = us ? 0x8000 : 0;
 176     if (bps > 2)
 177         memset(*dst, 0, n * bps);
 178     if (le) *dst += bps - 2;
 179     for(;n>0;n--) {
 180         register int v = *(*samples)++;
 181         v += usum;
 182         if (le) AV_WL16(*dst, v);
 183         else    AV_WB16(*dst, v);
 184         *dst += bps;
 185     }
 186     if (le) *dst -= bps - 2;
 187 }
 188
 189 static int pcm_encode_frame(AVCodecContext *avctx,
 190                             unsigned char *frame, int buf_size, void *data)
 191 {
 192     int n, sample_size, v;
 193     short *samples;
 194     unsigned char *dst;
 195
 196     switch(avctx->codec->id) {
 197     case CODEC_ID_PCM_S32LE:
 198     case CODEC_ID_PCM_S32BE:
 199     case CODEC_ID_PCM_U32LE:
 200     case CODEC_ID_PCM_U32BE:
 201         sample_size = 4;
 202         break;
 203     case CODEC_ID_PCM_S24LE:
 204     case CODEC_ID_PCM_S24BE:
 205     case CODEC_ID_PCM_U24LE:
 206     case CODEC_ID_PCM_U24BE:
 207     case CODEC_ID_PCM_S24DAUD:
 208         sample_size = 3;
 209         break;
 210     case CODEC_ID_PCM_S16LE:
 211     case CODEC_ID_PCM_S16BE:
 212     case CODEC_ID_PCM_U16LE:
 213     case CODEC_ID_PCM_U16BE:
 214         sample_size = 2;
 215         break;
 216     default:
 217         sample_size = 1;
 218         break;
 219     }
 220     n = buf_size / sample_size;
 221     samples = data;
 222     dst = frame;
 223
 224     switch(avctx->codec->id) {
 225     case CODEC_ID_PCM_S32LE:
 226         encode_from16(4, 1, 0, &samples, &dst, n);
 227         break;
 228     case CODEC_ID_PCM_S32BE:
 229         encode_from16(4, 0, 0, &samples, &dst, n);
 230         break;
 231     case CODEC_ID_PCM_U32LE:
 232         encode_from16(4, 1, 1, &samples, &dst, n);
 233         break;
 234     case CODEC_ID_PCM_U32BE:
 235         encode_from16(4, 0, 1, &samples, &dst, n);
 236         break;
 237     case CODEC_ID_PCM_S24LE:
 238         encode_from16(3, 1, 0, &samples, &dst, n);
 239         break;
 240     case CODEC_ID_PCM_S24BE:
 241         encode_from16(3, 0, 0, &samples, &dst, n);
 242         break;
 243     case CODEC_ID_PCM_U24LE:
 244         encode_from16(3, 1, 1, &samples, &dst, n);
 245         break;
 246     case CODEC_ID_PCM_U24BE:
 247         encode_from16(3, 0, 1, &samples, &dst, n);
 248         break;
 249     case CODEC_ID_PCM_S24DAUD:
 250         for(;n>0;n--) {
 251             uint32_t tmp = ff_reverse[*samples >> 8] +
 252                            (ff_reverse[*samples & 0xff] << 8);
 253             tmp <<= 4; // sync flags would go here
 254             bytestream_put_be24(&dst, tmp);
 255             samples++;
 256         }
 257         break;
 258     case CODEC_ID_PCM_S16LE:
 259         for(;n>0;n--) {
 260             v = *samples++;
 261             bytestream_put_le16(&dst, v);
 262         }
 263         break;
 264     case CODEC_ID_PCM_S16BE:
 265         for(;n>0;n--) {
 266             v = *samples++;
 267             bytestream_put_be16(&dst, v);
 268         }
 269         break;
 270     case CODEC_ID_PCM_U16LE:
 271         for(;n>0;n--) {
 272             v = *samples++;
 273             v += 0x8000;
 274             bytestream_put_le16(&dst, v);
 275         }
 276         break;
 277     case CODEC_ID_PCM_U16BE:
 278         for(;n>0;n--) {
 279             v = *samples++;
 280             v += 0x8000;
 281             bytestream_put_be16(&dst, v);
 282         }
 283         break;
 284     case CODEC_ID_PCM_S8:
 285         for(;n>0;n--) {
 286             v = *samples++;
 287             *dst++ = v >> 8;
 288         }
 289         break;
 290     case CODEC_ID_PCM_U8:
 291         for(;n>0;n--) {
 292             v = *samples++;
 293             *dst++ = (v >> 8) + 128;
 294         }
 295         break;
 296     case CODEC_ID_PCM_ZORK:
 297         for(;n>0;n--) {
 298             v= *samples++ >> 8;
 299             if(v<0)   v = -v;
 300             else      v+= 128;
 301             *dst++ = v;
 302         }
 303         break;
 304     case CODEC_ID_PCM_ALAW:
 305         for(;n>0;n--) {
 306             v = *samples++;
 307             *dst++ = linear_to_alaw[(v + 32768) >> 2];
 308         }
 309         break;
 310     case CODEC_ID_PCM_MULAW:
 311         for(;n>0;n--) {
 312             v = *samples++;
 313             *dst++ = linear_to_ulaw[(v + 32768) >> 2];
 314         }
 315         break;
 316     default:
 317         return -1;
 318     }
 319     //avctx->frame_size = (dst - frame) / (sample_size * avctx->channels);
 320
 321     return dst - frame;
 322 }
 323
 324 typedef struct PCMDecode {
 325     short table[256];
 326 } PCMDecode;
 327
 328 static int pcm_decode_init(AVCodecContext * avctx)
 329 {
 330     PCMDecode *s = avctx->priv_data;
 331     int i;
 332
 333     switch(avctx->codec->id) {
 334     case CODEC_ID_PCM_ALAW:
 335         for(i=0;i<256;i++)
 336             s->table[i] = alaw2linear(i);
 337         break;
 338     case CODEC_ID_PCM_MULAW:
 339         for(i=0;i<256;i++)
 340             s->table[i] = ulaw2linear(i);
 341         break;
 342     default:
 343         break;
 344     }
 345     return 0;
 346 }
 347
 348 /**
 349  * \brief convert samples to 16 bit
 350  * \param bps byte per sample for the source format, must be >= 2
 351  * \param le 0 for big-, 1 for little-endian
 352  * \param us 0 for signed, 1 for unsigned input
 353  * \param src input samples
 354  * \param samples output samples
 355  * \param src_len number of bytes in src
 356  */
 357 static inline void decode_to16(int bps, int le, int us,
 358                                uint8_t **src, short **samples, int src_len)
 359 {
 360     int usum = us ? -0x8000 : 0;
 361     register int n = src_len / bps;
 362     if (le) *src += bps - 2;
 363     for(;n>0;n--) {
 364         register int v;
 365         if (le) v = AV_RL16(*src);
 366         else    v = AV_RB16(*src);
 367         v += usum;
 368         *(*samples)++ = v;
 369         *src += bps;
 370     }
 371     if (le) *src -= bps - 2;
 372 }
 373
 374 static int pcm_decode_frame(AVCodecContext *avctx,
 375                             void *data, int *data_size,
 376                             uint8_t *buf, int buf_size)
 377 {
 378     PCMDecode *s = avctx->priv_data;
 379     int c, n;
 380     short *samples;
 381     uint8_t *src, *src2[MAX_CHANNELS];
 382
 383     samples = data;
 384     src = buf;
 385
 386     n= av_get_bits_per_sample(avctx->codec_id)/8;
 387     if(n && buf_size % n){
 388         av_log(avctx, AV_LOG_ERROR, "invalid PCM packet\n");
 389         return -1;
 390     }
 391     if(avctx->channels <= 0 || avctx->channels > MAX_CHANNELS){
 392         av_log(avctx, AV_LOG_ERROR, "PCM channels out of bounds\n");
 393         return -1;
 394     }
 395
 396     buf_size= FFMIN(buf_size, *data_size/2);
 397     *data_size=0;
 398
 399     n = buf_size/avctx->channels;
 400     for(c=0;c<avctx->channels;c++)
 401         src2[c] = &src[c*n];
 402
 403     switch(avctx->codec->id) {
 404     case CODEC_ID_PCM_S32LE:
 405         decode_to16(4, 1, 0, &src, &samples, buf_size);
 406         break;
 407     case CODEC_ID_PCM_S32BE:
 408         decode_to16(4, 0, 0, &src, &samples, buf_size);
 409         break;
 410     case CODEC_ID_PCM_U32LE:
 411         decode_to16(4, 1, 1, &src, &samples, buf_size);
 412         break;
 413     case CODEC_ID_PCM_U32BE:
 414         decode_to16(4, 0, 1, &src, &samples, buf_size);
 415         break;
 416     case CODEC_ID_PCM_S24LE:
 417         decode_to16(3, 1, 0, &src, &samples, buf_size);
 418         break;
 419     case CODEC_ID_PCM_S24BE:
 420         decode_to16(3, 0, 0, &src, &samples, buf_size);
 421         break;
 422     case CODEC_ID_PCM_U24LE:
 423         decode_to16(3, 1, 1, &src, &samples, buf_size);
 424         break;
 425     case CODEC_ID_PCM_U24BE:
 426         decode_to16(3, 0, 1, &src, &samples, buf_size);
 427         break;
 428     case CODEC_ID_PCM_S24DAUD:
 429         n = buf_size / 3;
 430         for(;n>0;n--) {
 431           uint32_t v = bytestream_get_be24(&src);
 432           v >>= 4; // sync flags are here
 433           *samples++ = ff_reverse[(v >> 8) & 0xff] +
 434                        (ff_reverse[v & 0xff] << 8);
 435         }
 436         break;
 437     case CODEC_ID_PCM_S16LE:
 438         n = buf_size >> 1;
 439         for(;n>0;n--) {
 440             *samples++ = bytestream_get_le16(&src);
 441         }
 442         break;
 443     case CODEC_ID_PCM_S16LE_PLANAR:
 444         for(n>>=1;n>0;n--)
 445             for(c=0;c<avctx->channels;c++)
 446                 *samples++ = bytestream_get_le16(&src2[c]);
 447         src = src2[avctx->channels-1];
 448         break;
 449     case CODEC_ID_PCM_S16BE:
 450         n = buf_size >> 1;
 451         for(;n>0;n--) {
 452             *samples++ = bytestream_get_be16(&src);
 453         }
 454         break;
 455     case CODEC_ID_PCM_U16LE:
 456         n = buf_size >> 1;
 457         for(;n>0;n--) {
 458             *samples++ = bytestream_get_le16(&src) - 0x8000;
 459         }
 460         break;
 461     case CODEC_ID_PCM_U16BE:
 462         n = buf_size >> 1;
 463         for(;n>0;n--) {
 464             *samples++ = bytestream_get_be16(&src) - 0x8000;
 465         }
 466         break;
 467     case CODEC_ID_PCM_S8:
 468         n = buf_size;
 469         for(;n>0;n--) {
 470             *samples++ = *src++ << 8;
 471         }
 472         break;
 473     case CODEC_ID_PCM_U8:
 474         n = buf_size;
 475         for(;n>0;n--) {
 476             *samples++ = ((int)*src++ - 128) << 8;
 477         }
 478         break;
 479     case CODEC_ID_PCM_ZORK:
 480         n = buf_size;
 481         for(;n>0;n--) {
 482             int x= *src++;
 483             if(x&128) x-= 128;
 484             else      x = -x;
 485             *samples++ = x << 8;
 486         }
 487         break;
 488     case CODEC_ID_PCM_ALAW:
 489     case CODEC_ID_PCM_MULAW:
 490         n = buf_size;
 491         for(;n>0;n--) {
 492             *samples++ = s->table[*src++];
 493         }
 494         break;
 495     default:
 496         return -1;
 497     }
 498     *data_size = (uint8_t *)samples - (uint8_t *)data;
 499     return src - buf;
 500 }
 501
 502 #ifdef CONFIG_ENCODERS
 503 #define PCM_ENCODER(id,name)                    \
 504 AVCodec name ## _encoder = {                    \
 505     #name,                                      \
 506     CODEC_TYPE_AUDIO,                           \
 507     id,                                         \
 508     0,                                          \
 509     pcm_encode_init,                            \
 510     pcm_encode_frame,                           \
 511     pcm_encode_close,                           \
 512     NULL,                                       \
 513 };
 514 #else
 515 #define PCM_ENCODER(id,name)
 516 #endif
 517
 518 #ifdef CONFIG_DECODERS
 519 #define PCM_DECODER(id,name)                    \
 520 AVCodec name ## _decoder = {                    \
 521     #name,                                      \
 522     CODEC_TYPE_AUDIO,                           \
 523     id,                                         \
 524     sizeof(PCMDecode),                          \
 525     pcm_decode_init,                            \
 526     NULL,                                       \
 527     NULL,                                       \
 528     pcm_decode_frame,                           \
 529 };
 530 #else
 531 #define PCM_DECODER(id,name)
 532 #endif
 533
 534 #define PCM_CODEC(id, name)                     \
 535 PCM_ENCODER(id,name) PCM_DECODER(id,name)
 536
 537 PCM_CODEC  (CODEC_ID_PCM_S32LE, pcm_s32le);
 538 PCM_CODEC  (CODEC_ID_PCM_S32BE, pcm_s32be);
 539 PCM_CODEC  (CODEC_ID_PCM_U32LE, pcm_u32le);
 540 PCM_CODEC  (CODEC_ID_PCM_U32BE, pcm_u32be);
 541 PCM_CODEC  (CODEC_ID_PCM_S24LE, pcm_s24le);
 542 PCM_CODEC  (CODEC_ID_PCM_S24BE, pcm_s24be);
 543 PCM_CODEC  (CODEC_ID_PCM_U24LE, pcm_u24le);
 544 PCM_CODEC  (CODEC_ID_PCM_U24BE, pcm_u24be);
 545 PCM_CODEC  (CODEC_ID_PCM_S24DAUD, pcm_s24daud);
 546 PCM_CODEC  (CODEC_ID_PCM_S16LE, pcm_s16le);
 547 PCM_DECODER(CODEC_ID_PCM_S16LE_PLANAR, pcm_s16le_planar);
 548 PCM_CODEC  (CODEC_ID_PCM_S16BE, pcm_s16be);
 549 PCM_CODEC  (CODEC_ID_PCM_U16LE, pcm_u16le);
 550 PCM_CODEC  (CODEC_ID_PCM_U16BE, pcm_u16be);
 551 PCM_CODEC  (CODEC_ID_PCM_S8, pcm_s8);
 552 PCM_CODEC  (CODEC_ID_PCM_U8, pcm_u8);
 553 PCM_CODEC  (CODEC_ID_PCM_ALAW, pcm_alaw);
 554 PCM_CODEC  (CODEC_ID_PCM_MULAW, pcm_mulaw);
 555 PCM_CODEC  (CODEC_ID_PCM_ZORK, pcm_zork);