libavcodec/truespeech.c

   1 /*
   2  * DSP Group TrueSpeech compatible decoder
   3  * Copyright (c) 2005 Konstantin Shishkov
   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 #include "avcodec.h"
  22
  23 #include "truespeech_data.h"
  24 /**
  25  * @file truespeech.c
  26  * TrueSpeech decoder.
  27  */
  28
  29 /**
  30  * TrueSpeech decoder context
  31  */
  32 typedef struct {
  33     /* input data */
  34     int16_t vector[8];  //< input vector: 5/5/4/4/4/3/3/3
  35     int offset1[2];     //< 8-bit value, used in one copying offset
  36     int offset2[4];     //< 7-bit value, encodes offsets for copying and for two-point filter
  37     int pulseoff[4];    //< 4-bit offset of pulse values block
  38     int pulsepos[4];    //< 27-bit variable, encodes 7 pulse positions
  39     int pulseval[4];    //< 7x2-bit pulse values
  40     int flag;           //< 1-bit flag, shows how to choose filters
  41     /* temporary data */
  42     int filtbuf[146];   // some big vector used for storing filters
  43     int prevfilt[8];    // filter from previous frame
  44     int16_t tmp1[8];    // coefficients for adding to out
  45     int16_t tmp2[8];    // coefficients for adding to out
  46     int16_t tmp3[8];    // coefficients for adding to out
  47     int16_t cvector[8]; // correlated input vector
  48     int filtval;        // gain value for one function
  49     int16_t newvec[60]; // tmp vector
  50     int16_t filters[32]; // filters for every subframe
  51 } TSContext;
  52
  53 static av_cold int truespeech_decode_init(AVCodecContext * avctx)
  54 {
  55 //    TSContext *c = avctx->priv_data;
  56
  57     return 0;
  58 }
  59
  60 static void truespeech_read_frame(TSContext *dec, const uint8_t *input)
  61 {
  62     uint32_t t;
  63
  64     /* first dword */
  65     t = AV_RL32(input);
  66     input += 4;
  67
  68     dec->flag = t & 1;
  69
  70     dec->vector[0] = ts_codebook[0][(t >>  1) & 0x1F];
  71     dec->vector[1] = ts_codebook[1][(t >>  6) & 0x1F];
  72     dec->vector[2] = ts_codebook[2][(t >> 11) &  0xF];
  73     dec->vector[3] = ts_codebook[3][(t >> 15) &  0xF];
  74     dec->vector[4] = ts_codebook[4][(t >> 19) &  0xF];
  75     dec->vector[5] = ts_codebook[5][(t >> 23) &  0x7];
  76     dec->vector[6] = ts_codebook[6][(t >> 26) &  0x7];
  77     dec->vector[7] = ts_codebook[7][(t >> 29) &  0x7];
  78
  79     /* second dword */
  80     t = AV_RL32(input);
  81     input += 4;
  82
  83     dec->offset2[0] = (t >>  0) & 0x7F;
  84     dec->offset2[1] = (t >>  7) & 0x7F;
  85     dec->offset2[2] = (t >> 14) & 0x7F;
  86     dec->offset2[3] = (t >> 21) & 0x7F;
  87
  88     dec->offset1[0] = ((t >> 28) & 0xF) << 4;
  89
  90     /* third dword */
  91     t = AV_RL32(input);
  92     input += 4;
  93
  94     dec->pulseval[0] = (t >>  0) & 0x3FFF;
  95     dec->pulseval[1] = (t >> 14) & 0x3FFF;
  96
  97     dec->offset1[1] = (t >> 28) & 0x0F;
  98
  99     /* fourth dword */
 100     t = AV_RL32(input);
 101     input += 4;
 102
 103     dec->pulseval[2] = (t >>  0) & 0x3FFF;
 104     dec->pulseval[3] = (t >> 14) & 0x3FFF;
 105
 106     dec->offset1[1] |= ((t >> 28) & 0x0F) << 4;
 107
 108     /* fifth dword */
 109     t = AV_RL32(input);
 110     input += 4;
 111
 112     dec->pulsepos[0] = (t >> 4) & 0x7FFFFFF;
 113
 114     dec->pulseoff[0] = (t >> 0) & 0xF;
 115
 116     dec->offset1[0] |= (t >> 31) & 1;
 117
 118     /* sixth dword */
 119     t = AV_RL32(input);
 120     input += 4;
 121
 122     dec->pulsepos[1] = (t >> 4) & 0x7FFFFFF;
 123
 124     dec->pulseoff[1] = (t >> 0) & 0xF;
 125
 126     dec->offset1[0] |= ((t >> 31) & 1) << 1;
 127
 128     /* seventh dword */
 129     t = AV_RL32(input);
 130     input += 4;
 131
 132     dec->pulsepos[2] = (t >> 4) & 0x7FFFFFF;
 133
 134     dec->pulseoff[2] = (t >> 0) & 0xF;
 135
 136     dec->offset1[0] |= ((t >> 31) & 1) << 2;
 137
 138     /* eighth dword */
 139     t = AV_RL32(input);
 140     input += 4;
 141
 142     dec->pulsepos[3] = (t >> 4) & 0x7FFFFFF;
 143
 144     dec->pulseoff[3] = (t >> 0) & 0xF;
 145
 146     dec->offset1[0] |= ((t >> 31) & 1) << 3;
 147
 148 }
 149
 150 static void truespeech_correlate_filter(TSContext *dec)
 151 {
 152     int16_t tmp[8];
 153     int i, j;
 154
 155     for(i = 0; i < 8; i++){
 156         if(i > 0){
 157             memcpy(tmp, dec->cvector, i * 2);
 158             for(j = 0; j < i; j++)
 159                 dec->cvector[j] = ((tmp[i - j - 1] * dec->vector[i]) +
 160                                    (dec->cvector[j] << 15) + 0x4000) >> 15;
 161         }
 162         dec->cvector[i] = (8 - dec->vector[i]) >> 3;
 163     }
 164     for(i = 0; i < 8; i++)
 165         dec->cvector[i] = (dec->cvector[i] * ts_230[i]) >> 15;
 166
 167     dec->filtval = dec->vector[0];
 168 }
 169
 170 static void truespeech_filters_merge(TSContext *dec)
 171 {
 172     int i;
 173
 174     if(!dec->flag){
 175         for(i = 0; i < 8; i++){
 176             dec->filters[i + 0] = dec->prevfilt[i];
 177             dec->filters[i + 8] = dec->prevfilt[i];
 178         }
 179     }else{
 180         for(i = 0; i < 8; i++){
 181             dec->filters[i + 0]=(dec->cvector[i] * 21846 + dec->prevfilt[i] * 10923 + 16384) >> 15;
 182             dec->filters[i + 8]=(dec->cvector[i] * 10923 + dec->prevfilt[i] * 21846 + 16384) >> 15;
 183         }
 184     }
 185     for(i = 0; i < 8; i++){
 186         dec->filters[i + 16] = dec->cvector[i];
 187         dec->filters[i + 24] = dec->cvector[i];
 188     }
 189 }
 190
 191 static void truespeech_apply_twopoint_filter(TSContext *dec, int quart)
 192 {
 193     int16_t tmp[146 + 60], *ptr0, *ptr1;
 194     const int16_t *filter;
 195     int i, t, off;
 196
 197     t = dec->offset2[quart];
 198     if(t == 127){
 199         memset(dec->newvec, 0, 60 * 2);
 200         return;
 201     }
 202     for(i = 0; i < 146; i++)
 203         tmp[i] = dec->filtbuf[i];
 204     off = (t / 25) + dec->offset1[quart >> 1] + 18;
 205     ptr0 = tmp + 145 - off;
 206     ptr1 = tmp + 146;
 207     filter = (const int16_t*)ts_240 + (t % 25) * 2;
 208     for(i = 0; i < 60; i++){
 209         t = (ptr0[0] * filter[0] + ptr0[1] * filter[1] + 0x2000) >> 14;
 210         ptr0++;
 211         dec->newvec[i] = t;
 212         ptr1[i] = t;
 213     }
 214 }
 215
 216 static void truespeech_place_pulses(TSContext *dec, int16_t *out, int quart)
 217 {
 218     int16_t tmp[7];
 219     int i, j, t;
 220     const int16_t *ptr1;
 221     int16_t *ptr2;
 222     int coef;
 223
 224     memset(out, 0, 60 * 2);
 225     for(i = 0; i < 7; i++) {
 226         t = dec->pulseval[quart] & 3;
 227         dec->pulseval[quart] >>= 2;
 228         tmp[6 - i] = ts_562[dec->pulseoff[quart] * 4 + t];
 229     }
 230
 231     coef = dec->pulsepos[quart] >> 15;
 232     ptr1 = (const int16_t*)ts_140 + 30;
 233     ptr2 = tmp;
 234     for(i = 0, j = 3; (i < 30) && (j > 0); i++){
 235         t = *ptr1++;
 236         if(coef >= t)
 237             coef -= t;
 238         else{
 239             out[i] = *ptr2++;
 240             ptr1 += 30;
 241             j--;
 242         }
 243     }
 244     coef = dec->pulsepos[quart] & 0x7FFF;
 245     ptr1 = (const int16_t*)ts_140;
 246     for(i = 30, j = 4; (i < 60) && (j > 0); i++){
 247         t = *ptr1++;
 248         if(coef >= t)
 249             coef -= t;
 250         else{
 251             out[i] = *ptr2++;
 252             ptr1 += 30;
 253             j--;
 254         }
 255     }
 256
 257 }
 258
 259 static void truespeech_update_filters(TSContext *dec, int16_t *out, int quart)
 260 {
 261     int i;
 262
 263     for(i = 0; i < 86; i++)
 264         dec->filtbuf[i] = dec->filtbuf[i + 60];
 265     for(i = 0; i < 60; i++){
 266         dec->filtbuf[i + 86] = out[i] + dec->newvec[i] - (dec->newvec[i] >> 3);
 267         out[i] += dec->newvec[i];
 268     }
 269 }
 270
 271 static void truespeech_synth(TSContext *dec, int16_t *out, int quart)
 272 {
 273     int i,k;
 274     int t[8];
 275     int16_t *ptr0, *ptr1;
 276
 277     ptr0 = dec->tmp1;
 278     ptr1 = dec->filters + quart * 8;
 279     for(i = 0; i < 60; i++){
 280         int sum = 0;
 281         for(k = 0; k < 8; k++)
 282             sum += ptr0[k] * ptr1[k];
 283         sum = (sum + (out[i] << 12) + 0x800) >> 12;
 284         out[i] = av_clip(sum, -0x7FFE, 0x7FFE);
 285         for(k = 7; k > 0; k--)
 286             ptr0[k] = ptr0[k - 1];
 287         ptr0[0] = out[i];
 288     }
 289
 290     for(i = 0; i < 8; i++)
 291         t[i] = (ts_5E2[i] * ptr1[i]) >> 15;
 292
 293     ptr0 = dec->tmp2;
 294     for(i = 0; i < 60; i++){
 295         int sum = 0;
 296         for(k = 0; k < 8; k++)
 297             sum += ptr0[k] * t[k];
 298         for(k = 7; k > 0; k--)
 299             ptr0[k] = ptr0[k - 1];
 300         ptr0[0] = out[i];
 301         out[i] = ((out[i] << 12) - sum) >> 12;
 302     }
 303
 304     for(i = 0; i < 8; i++)
 305         t[i] = (ts_5F2[i] * ptr1[i]) >> 15;
 306
 307     ptr0 = dec->tmp3;
 308     for(i = 0; i < 60; i++){
 309         int sum = out[i] << 12;
 310         for(k = 0; k < 8; k++)
 311             sum += ptr0[k] * t[k];
 312         for(k = 7; k > 0; k--)
 313             ptr0[k] = ptr0[k - 1];
 314         ptr0[0] = av_clip((sum + 0x800) >> 12, -0x7FFE, 0x7FFE);
 315
 316         sum = ((ptr0[1] * (dec->filtval - (dec->filtval >> 2))) >> 4) + sum;
 317         sum = sum - (sum >> 3);
 318         out[i] = av_clip((sum + 0x800) >> 12, -0x7FFE, 0x7FFE);
 319     }
 320 }
 321
 322 static void truespeech_save_prevvec(TSContext *c)
 323 {
 324     int i;
 325
 326     for(i = 0; i < 8; i++)
 327         c->prevfilt[i] = c->cvector[i];
 328 }
 329
 330 static int truespeech_decode_frame(AVCodecContext *avctx,
 331                 void *data, int *data_size,
 332                 const uint8_t *buf, int buf_size)
 333 {
 334     TSContext *c = avctx->priv_data;
 335
 336     int i, j;
 337     short *samples = data;
 338     int consumed = 0;
 339     int16_t out_buf[240];
 340     int iterations;
 341
 342     if (!buf_size)
 343         return 0;
 344
 345     iterations = FFMIN(buf_size / 32, *data_size / 480);
 346     for(j = 0; j < iterations; j++) {
 347         truespeech_read_frame(c, buf + consumed);
 348         consumed += 32;
 349
 350         truespeech_correlate_filter(c);
 351         truespeech_filters_merge(c);
 352
 353         memset(out_buf, 0, 240 * 2);
 354         for(i = 0; i < 4; i++) {
 355             truespeech_apply_twopoint_filter(c, i);
 356             truespeech_place_pulses(c, out_buf + i * 60, i);
 357             truespeech_update_filters(c, out_buf + i * 60, i);
 358             truespeech_synth(c, out_buf + i * 60, i);
 359         }
 360
 361         truespeech_save_prevvec(c);
 362
 363         /* finally output decoded frame */
 364         for(i = 0; i < 240; i++)
 365             *samples++ = out_buf[i];
 366
 367     }
 368
 369     *data_size = consumed * 15;
 370
 371     return consumed;
 372 }
 373
 374 AVCodec truespeech_decoder = {
 375     "truespeech",
 376     CODEC_TYPE_AUDIO,
 377     CODEC_ID_TRUESPEECH,
 378     sizeof(TSContext),
 379     truespeech_decode_init,
 380     NULL,
 381     NULL,
 382     truespeech_decode_frame,
 383     .long_name = "DSP Group TrueSpeech",
 384 };