hvirtual/quicktime/libavcodec/pcm.c

   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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18  */
  19 #include "avcodec.h"
  20
  21 /* from g711.c by SUN microsystems (unrestricted use) */
  22
  23 #define SIGN_BIT        (0x80)          /* Sign bit for a A-law byte. */
  24 #define QUANT_MASK      (0xf)           /* Quantization field mask. */
  25 #define NSEGS           (8)             /* Number of A-law segments. */
  26 #define SEG_SHIFT       (4)             /* Left shift for segment number. */
  27 #define SEG_MASK        (0x70)          /* Segment field mask. */
  28
  29 #define BIAS            (0x84)          /* Bias for linear code. */
  30
  31 /*
  32  * alaw2linear() - Convert an A-law value to 16-bit linear PCM
  33  *
  34  */
  35 static int alaw2linear(unsigned char    a_val)
  36 {
  37         int             t;
  38         int             seg;
  39
  40         a_val ^= 0x55;
  41
  42         t = (a_val & QUANT_MASK) << 4;
  43         seg = ((unsigned)a_val & SEG_MASK) >> SEG_SHIFT;
  44         switch (seg) {
  45         case 0:
  46                 t += 8;
  47                 break;
  48         case 1:
  49                 t += 0x108;
  50                 break;
  51         default:
  52                 t += 0x108;
  53                 t <<= seg - 1;
  54         }
  55         return ((a_val & SIGN_BIT) ? t : -t);
  56 }
  57
  58 static int ulaw2linear(unsigned char    u_val)
  59 {
  60         int             t;
  61
  62         /* Complement to obtain normal u-law value. */
  63         u_val = ~u_val;
  64
  65         /*
  66          * Extract and bias the quantization bits. Then
  67          * shift up by the segment number and subtract out the bias.
  68          */
  69         t = ((u_val & QUANT_MASK) << 3) + BIAS;
  70         t <<= ((unsigned)u_val & SEG_MASK) >> SEG_SHIFT;
  71
  72         return ((u_val & SIGN_BIT) ? (BIAS - t) : (t - BIAS));
  73 }
  74
  75 /* 16384 entries per table */
  76 static UINT8 *linear_to_alaw = NULL;
  77 static int linear_to_alaw_ref = 0;
  78
  79 static UINT8 *linear_to_ulaw = NULL;
  80 static int linear_to_ulaw_ref = 0;
  81
  82 static void build_xlaw_table(UINT8 *linear_to_xlaw,
  83                              int (*xlaw2linear)(unsigned char),
  84                              int mask)
  85 {
  86     int i, j, v, v1, v2;
  87
  88     j = 0;
  89     for(i=0;i<128;i++) {
  90         if (i != 127) {
  91             v1 = xlaw2linear(i ^ mask);
  92             v2 = xlaw2linear((i + 1) ^ mask);
  93             v = (v1 + v2 + 4) >> 3;
  94         } else {
  95             v = 8192;
  96         }
  97         for(;j<v;j++) {
  98             linear_to_xlaw[8192 + j] = (i ^ mask);
  99             if (j > 0)
 100                 linear_to_xlaw[8192 - j] = (i ^ (mask ^ 0x80));
 101         }
 102     }
 103     linear_to_xlaw[0] = linear_to_xlaw[1];
 104 }
 105
 106 static int pcm_encode_init(AVCodecContext *avctx)
 107 {
 108     avctx->frame_size = 1;
 109     switch(avctx->codec->id) {
 110     case CODEC_ID_PCM_ALAW:
 111         if (linear_to_alaw_ref == 0) {
 112             linear_to_alaw = av_malloc(16384);
 113             if (!linear_to_alaw)
 114                 return -1;
 115             build_xlaw_table(linear_to_alaw, alaw2linear, 0xd5);
 116         }
 117         linear_to_alaw_ref++;
 118         break;
 119     case CODEC_ID_PCM_MULAW:
 120         if (linear_to_ulaw_ref == 0) {
 121             linear_to_ulaw = av_malloc(16384);
 122             if (!linear_to_ulaw)
 123                 return -1;
 124             build_xlaw_table(linear_to_ulaw, ulaw2linear, 0xff);
 125         }
 126         linear_to_ulaw_ref++;
 127         break;
 128     default:
 129         break;
 130     }
 131
 132     avctx->coded_frame= avcodec_alloc_frame();
 133     avctx->coded_frame->key_frame= 1;
 134
 135     return 0;
 136 }
 137
 138 static int pcm_encode_close(AVCodecContext *avctx)
 139 {
 140     av_freep(&avctx->coded_frame);
 141
 142     switch(avctx->codec->id) {
 143     case CODEC_ID_PCM_ALAW:
 144         if (--linear_to_alaw_ref == 0)
 145             av_free(linear_to_alaw);
 146         break;
 147     case CODEC_ID_PCM_MULAW:
 148         if (--linear_to_ulaw_ref == 0)
 149             av_free(linear_to_ulaw);
 150         break;
 151     default:
 152         /* nothing to free */
 153         break;
 154     }
 155     return 0;
 156 }
 157
 158 static int pcm_encode_frame(AVCodecContext *avctx,
 159                             unsigned char *frame, int buf_size, void *data)
 160 {
 161     int n, sample_size, v;
 162     short *samples;
 163     unsigned char *dst;
 164
 165     switch(avctx->codec->id) {
 166     case CODEC_ID_PCM_S16LE:
 167     case CODEC_ID_PCM_S16BE:
 168     case CODEC_ID_PCM_U16LE:
 169     case CODEC_ID_PCM_U16BE:
 170         sample_size = 2;
 171         break;
 172     default:
 173         sample_size = 1;
 174         break;
 175     }
 176     n = buf_size / sample_size;
 177     samples = data;
 178     dst = frame;
 179
 180     switch(avctx->codec->id) {
 181     case CODEC_ID_PCM_S16LE:
 182         for(;n>0;n--) {
 183             v = *samples++;
 184             dst[0] = v & 0xff;
 185             dst[1] = v >> 8;
 186             dst += 2;
 187         }
 188         break;
 189     case CODEC_ID_PCM_S16BE:
 190         for(;n>0;n--) {
 191             v = *samples++;
 192             dst[0] = v >> 8;
 193             dst[1] = v;
 194             dst += 2;
 195         }
 196         break;
 197     case CODEC_ID_PCM_U16LE:
 198         for(;n>0;n--) {
 199             v = *samples++;
 200             v += 0x8000;
 201             dst[0] = v & 0xff;
 202             dst[1] = v >> 8;
 203             dst += 2;
 204         }
 205         break;
 206     case CODEC_ID_PCM_U16BE:
 207         for(;n>0;n--) {
 208             v = *samples++;
 209             v += 0x8000;
 210             dst[0] = v >> 8;
 211             dst[1] = v;
 212             dst += 2;
 213         }
 214         break;
 215     case CODEC_ID_PCM_S8:
 216         for(;n>0;n--) {
 217             v = *samples++;
 218             dst[0] = v >> 8;
 219             dst++;
 220         }
 221         break;
 222     case CODEC_ID_PCM_U8:
 223         for(;n>0;n--) {
 224             v = *samples++;
 225             dst[0] = (v >> 8) + 128;
 226             dst++;
 227         }
 228         break;
 229     case CODEC_ID_PCM_ALAW:
 230         for(;n>0;n--) {
 231             v = *samples++;
 232             dst[0] = linear_to_alaw[(v + 32768) >> 2];
 233             dst++;
 234         }
 235         break;
 236     case CODEC_ID_PCM_MULAW:
 237         for(;n>0;n--) {
 238             v = *samples++;
 239             dst[0] = linear_to_ulaw[(v + 32768) >> 2];
 240             dst++;
 241         }
 242         break;
 243     default:
 244         return -1;
 245     }
 246     //avctx->frame_size = (dst - frame) / (sample_size * avctx->channels);
 247
 248     return dst - frame;
 249 }
 250
 251 typedef struct PCMDecode {
 252     short table[256];
 253 } PCMDecode;
 254
 255 static int pcm_decode_init(AVCodecContext * avctx)
 256 {
 257     PCMDecode *s = avctx->priv_data;
 258     int i;
 259
 260     switch(avctx->codec->id) {
 261     case CODEC_ID_PCM_ALAW:
 262         for(i=0;i<256;i++)
 263             s->table[i] = alaw2linear(i);
 264         break;
 265     case CODEC_ID_PCM_MULAW:
 266         for(i=0;i<256;i++)
 267             s->table[i] = ulaw2linear(i);
 268         break;
 269     default:
 270         break;
 271     }
 272     return 0;
 273 }
 274
 275 static int pcm_decode_frame(AVCodecContext *avctx,
 276                             void *data, int *data_size,
 277                             UINT8 *buf, int buf_size)
 278 {
 279     PCMDecode *s = avctx->priv_data;
 280     int n;
 281     short *samples;
 282     UINT8 *src;
 283
 284     samples = data;
 285     src = buf;
 286
 287     switch(avctx->codec->id) {
 288     case CODEC_ID_PCM_S16LE:
 289         n = buf_size >> 1;
 290         for(;n>0;n--) {
 291             *samples++ = src[0] | (src[1] << 8);
 292             src += 2;
 293         }
 294         break;
 295     case CODEC_ID_PCM_S16BE:
 296         n = buf_size >> 1;
 297         for(;n>0;n--) {
 298             *samples++ = (src[0] << 8) | src[1];
 299             src += 2;
 300         }
 301         break;
 302     case CODEC_ID_PCM_U16LE:
 303         n = buf_size >> 1;
 304         for(;n>0;n--) {
 305             *samples++ = (src[0] | (src[1] << 8)) - 0x8000;
 306             src += 2;
 307         }
 308         break;
 309     case CODEC_ID_PCM_U16BE:
 310         n = buf_size >> 1;
 311         for(;n>0;n--) {
 312             *samples++ = ((src[0] << 8) | src[1]) - 0x8000;
 313             src += 2;
 314         }
 315         break;
 316     case CODEC_ID_PCM_S8:
 317         n = buf_size;
 318         for(;n>0;n--) {
 319             *samples++ = src[0] << 8;
 320             src++;
 321         }
 322         break;
 323     case CODEC_ID_PCM_U8:
 324         n = buf_size;
 325         for(;n>0;n--) {
 326             *samples++ = ((int)src[0] - 128) << 8;
 327             src++;
 328         }
 329         break;
 330     case CODEC_ID_PCM_ALAW:
 331     case CODEC_ID_PCM_MULAW:
 332         n = buf_size;
 333         for(;n>0;n--) {
 334             *samples++ = s->table[src[0]];
 335             src++;
 336         }
 337         break;
 338     default:
 339         *data_size = 0;
 340         return -1;
 341     }
 342     *data_size = (UINT8 *)samples - (UINT8 *)data;
 343     return src - buf;
 344 }
 345
 346 #define PCM_CODEC(id, name)                     \
 347 AVCodec name ## _encoder = {                    \
 348     #name,                                      \
 349     CODEC_TYPE_AUDIO,                           \
 350     id,                                         \
 351     0,                                          \
 352     pcm_encode_init,                            \
 353     pcm_encode_frame,                           \
 354     pcm_encode_close,                           \
 355     NULL,                                       \
 356 };                                              \
 357 AVCodec name ## _decoder = {                    \
 358     #name,                                      \
 359     CODEC_TYPE_AUDIO,                           \
 360     id,                                         \
 361     sizeof(PCMDecode),                          \
 362     pcm_decode_init,                            \
 363     NULL,                                       \
 364     NULL,                                       \
 365     pcm_decode_frame,                           \
 366 };
 367
 368 PCM_CODEC(CODEC_ID_PCM_S16LE, pcm_s16le);
 369 PCM_CODEC(CODEC_ID_PCM_S16BE, pcm_s16be);
 370 PCM_CODEC(CODEC_ID_PCM_U16LE, pcm_u16le);
 371 PCM_CODEC(CODEC_ID_PCM_U16BE, pcm_u16be);
 372 PCM_CODEC(CODEC_ID_PCM_S8, pcm_s8);
 373 PCM_CODEC(CODEC_ID_PCM_U8, pcm_u8);
 374 PCM_CODEC(CODEC_ID_PCM_ALAW, pcm_alaw);
 375 PCM_CODEC(CODEC_ID_PCM_MULAW, pcm_mulaw);
 376
 377 #undef PCM_CODEC