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
  22 #include "libavutil/intreadwrite.h"
  23 #include "avcodec.h"
  24
  25 #include "truespeech_data.h"
  26 /**
  27  * @file libavcodec/truespeech.c
  28  * TrueSpeech decoder.
  29  */
  30
  31 /**
  32  * TrueSpeech decoder context
  33  */
  34 typedef struct {
  35     /* input data */
  36     int16_t vector[8];  //< input vector: 5/5/4/4/4/3/3/3
  37     int offset1[2];     //< 8-bit value, used in one copying offset
  38     int offset2[4];     //< 7-bit value, encodes offsets for copying and for two-point filter
  39     int pulseoff[4];    //< 4-bit offset of pulse values block
  40     int pulsepos[4];    //< 27-bit variable, encodes 7 pulse positions
  41     int pulseval[4];    //< 7x2-bit pulse values
  42     int flag;           //< 1-bit flag, shows how to choose filters
  43     /* temporary data */
  44     int filtbuf[146];   // some big vector used for storing filters
  45     int prevfilt[8];    // filter from previous frame
  46     int16_t tmp1[8];    // coefficients for adding to out
  47     int16_t tmp2[8];    // coefficients for adding to out
  48     int16_t tmp3[8];    // coefficients for adding to out
  49     int16_t cvector[8]; // correlated input vector
  50     int filtval;        // gain value for one function
  51     int16_t newvec[60]; // tmp vector
  52     int16_t filters[32]; // filters for every subframe
  53 } TSContext;
  54
  55 static av_cold int truespeech_decode_init(AVCodecContext * avctx)
  56 {
  57 //    TSContext *c = avctx->priv_data;
  58
  59     avctx->sample_fmt = SAMPLE_FMT_S16;
  60     return 0;
  61 }
  62
  63 static void truespeech_read_frame(TSContext *dec, const uint8_t *input)
  64 {
  65     uint32_t t;
  66
  67     /* first dword */
  68     t = AV_RL32(input);
  69     input += 4;
  70
  71     dec->flag = t & 1;
  72
  73     dec->vector[0] = ts_codebook[0][(t >>  1) & 0x1F];
  74     dec->vector[1] = ts_codebook[1][(t >>  6) & 0x1F];
  75     dec->vector[2] = ts_codebook[2][(t >> 11) &  0xF];
  76     dec->vector[3] = ts_codebook[3][(t >> 15) &  0xF];
  77     dec->vector[4] = ts_codebook[4][(t >> 19) &  0xF];
  78     dec->vector[5] = ts_codebook[5][(t >> 23) &  0x7];
  79     dec->vector[6] = ts_codebook[6][(t >> 26) &  0x7];
  80     dec->vector[7] = ts_codebook[7][(t >> 29) &  0x7];
  81
  82     /* second dword */
  83     t = AV_RL32(input);
  84     input += 4;
  85
  86     dec->offset2[0] = (t >>  0) & 0x7F;
  87     dec->offset2[1] = (t >>  7) & 0x7F;
  88     dec->offset2[2] = (t >> 14) & 0x7F;
  89     dec->offset2[3] = (t >> 21) & 0x7F;
  90
  91     dec->offset1[0] = ((t >> 28) & 0xF) << 4;
  92
  93     /* third dword */
  94     t = AV_RL32(input);
  95     input += 4;
  96
  97     dec->pulseval[0] = (t >>  0) & 0x3FFF;
  98     dec->pulseval[1] = (t >> 14) & 0x3FFF;
  99
 100     dec->offset1[1] = (t >> 28) & 0x0F;
 101
 102     /* fourth dword */
 103     t = AV_RL32(input);
 104     input += 4;
 105
 106     dec->pulseval[2] = (t >>  0) & 0x3FFF;
 107     dec->pulseval[3] = (t >> 14) & 0x3FFF;
 108
 109     dec->offset1[1] |= ((t >> 28) & 0x0F) << 4;
 110
 111     /* fifth dword */
 112     t = AV_RL32(input);
 113     input += 4;
 114
 115     dec->pulsepos[0] = (t >> 4) & 0x7FFFFFF;
 116
 117     dec->pulseoff[0] = (t >> 0) & 0xF;
 118
 119     dec->offset1[0] |= (t >> 31) & 1;
 120
 121     /* sixth dword */
 122     t = AV_RL32(input);
 123     input += 4;
 124
 125     dec->pulsepos[1] = (t >> 4) & 0x7FFFFFF;
 126
 127     dec->pulseoff[1] = (t >> 0) & 0xF;
 128
 129     dec->offset1[0] |= ((t >> 31) & 1) << 1;
 130
 131     /* seventh dword */
 132     t = AV_RL32(input);
 133     input += 4;
 134
 135     dec->pulsepos[2] = (t >> 4) & 0x7FFFFFF;
 136
 137     dec->pulseoff[2] = (t >> 0) & 0xF;
 138
 139     dec->offset1[0] |= ((t >> 31) & 1) << 2;
 140
 141     /* eighth dword */
 142     t = AV_RL32(input);
 143     input += 4;
 144
 145     dec->pulsepos[3] = (t >> 4) & 0x7FFFFFF;
 146
 147     dec->pulseoff[3] = (t >> 0) & 0xF;
 148
 149     dec->offset1[0] |= ((t >> 31) & 1) << 3;
 150
 151 }
 152
 153 static void truespeech_correlate_filter(TSContext *dec)
 154 {
 155     int16_t tmp[8];
 156     int i, j;
 157
 158     for(i = 0; i < 8; i++){
 159         if(i > 0){
 160             memcpy(tmp, dec->cvector, i * 2);
 161             for(j = 0; j < i; j++)
 162                 dec->cvector[j] = ((tmp[i - j - 1] * dec->vector[i]) +
 163                                    (dec->cvector[j] << 15) + 0x4000) >> 15;
 164         }
 165         dec->cvector[i] = (8 - dec->vector[i]) >> 3;
 166     }
 167     for(i = 0; i < 8; i++)
 168         dec->cvector[i] = (dec->cvector[i] * ts_230[i]) >> 15;
 169
 170     dec->filtval = dec->vector[0];
 171 }
 172
 173 static void truespeech_filters_merge(TSContext *dec)
 174 {
 175     int i;
 176
 177     if(!dec->flag){
 178         for(i = 0; i < 8; i++){
 179             dec->filters[i + 0] = dec->prevfilt[i];
 180             dec->filters[i + 8] = dec->prevfilt[i];
 181         }
 182     }else{
 183         for(i = 0; i < 8; i++){
 184             dec->filters[i + 0]=(dec->cvector[i] * 21846 + dec->prevfilt[i] * 10923 + 16384) >> 15;
 185             dec->filters[i + 8]=(dec->cvector[i] * 10923 + dec->prevfilt[i] * 21846 + 16384) >> 15;
 186         }
 187     }
 188     for(i = 0; i < 8; i++){
 189         dec->filters[i + 16] = dec->cvector[i];
 190         dec->filters[i + 24] = dec->cvector[i];
 191     }
 192 }
 193
 194 static void truespeech_apply_twopoint_filter(TSContext *dec, int quart)
 195 {
 196     int16_t tmp[146 + 60], *ptr0, *ptr1;
 197     const int16_t *filter;
 198     int i, t, off;
 199
 200     t = dec->offset2[quart];
 201     if(t == 127){
 202         memset(dec->newvec, 0, 60 * 2);
 203         return;
 204     }
 205     for(i = 0; i < 146; i++)
 206         tmp[i] = dec->filtbuf[i];
 207     off = (t / 25) + dec->offset1[quart >> 1] + 18;
 208     ptr0 = tmp + 145 - off;
 209     ptr1 = tmp + 146;
 210     filter = (const int16_t*)ts_240 + (t % 25) * 2;
 211     for(i = 0; i < 60; i++){
 212         t = (ptr0[0] * filter[0] + ptr0[1] * filter[1] + 0x2000) >> 14;
 213         ptr0++;
 214         dec->newvec[i] = t;
 215         ptr1[i] = t;
 216     }
 217 }
 218
 219 static void truespeech_place_pulses(TSContext *dec, int16_t *out, int quart)
 220 {
 221     int16_t tmp[7];
 222     int i, j, t;
 223     const int16_t *ptr1;
 224     int16_t *ptr2;
 225     int coef;
 226
 227     memset(out, 0, 60 * 2);
 228     for(i = 0; i < 7; i++) {
 229         t = dec->pulseval[quart] & 3;
 230         dec->pulseval[quart] >>= 2;
 231         tmp[6 - i] = ts_562[dec->pulseoff[quart] * 4 + t];
 232     }
 233
 234     coef = dec->pulsepos[quart] >> 15;
 235     ptr1 = (const int16_t*)ts_140 + 30;
 236     ptr2 = tmp;
 237     for(i = 0, j = 3; (i < 30) && (j > 0); i++){
 238         t = *ptr1++;
 239         if(coef >= t)
 240             coef -= t;
 241         else{
 242             out[i] = *ptr2++;
 243             ptr1 += 30;
 244             j--;
 245         }
 246     }
 247     coef = dec->pulsepos[quart] & 0x7FFF;
 248     ptr1 = (const int16_t*)ts_140;
 249     for(i = 30, j = 4; (i < 60) && (j > 0); i++){
 250         t = *ptr1++;
 251         if(coef >= t)
 252             coef -= t;
 253         else{
 254             out[i] = *ptr2++;
 255             ptr1 += 30;
 256             j--;
 257         }
 258     }
 259
 260 }
 261
 262 static void truespeech_update_filters(TSContext *dec, int16_t *out, int quart)
 263 {
 264     int i;
 265
 266     for(i = 0; i < 86; i++)
 267         dec->filtbuf[i] = dec->filtbuf[i + 60];
 268     for(i = 0; i < 60; i++){
 269         dec->filtbuf[i + 86] = out[i] + dec->newvec[i] - (dec->newvec[i] >> 3);
 270         out[i] += dec->newvec[i];
 271     }
 272 }
 273
 274 static void truespeech_synth(TSContext *dec, int16_t *out, int quart)
 275 {
 276     int i,k;
 277     int t[8];
 278     int16_t *ptr0, *ptr1;
 279
 280     ptr0 = dec->tmp1;
 281     ptr1 = dec->filters + quart * 8;
 282     for(i = 0; i < 60; i++){
 283         int sum = 0;
 284         for(k = 0; k < 8; k++)
 285             sum += ptr0[k] * ptr1[k];
 286         sum = (sum + (out[i] << 12) + 0x800) >> 12;
 287         out[i] = av_clip(sum, -0x7FFE, 0x7FFE);
 288         for(k = 7; k > 0; k--)
 289             ptr0[k] = ptr0[k - 1];
 290         ptr0[0] = out[i];
 291     }
 292
 293     for(i = 0; i < 8; i++)
 294         t[i] = (ts_5E2[i] * ptr1[i]) >> 15;
 295
 296     ptr0 = dec->tmp2;
 297     for(i = 0; i < 60; i++){
 298         int sum = 0;
 299         for(k = 0; k < 8; k++)
 300             sum += ptr0[k] * t[k];
 301         for(k = 7; k > 0; k--)
 302             ptr0[k] = ptr0[k - 1];
 303         ptr0[0] = out[i];
 304         out[i] = ((out[i] << 12) - sum) >> 12;
 305     }
 306
 307     for(i = 0; i < 8; i++)
 308         t[i] = (ts_5F2[i] * ptr1[i]) >> 15;
 309
 310     ptr0 = dec->tmp3;
 311     for(i = 0; i < 60; i++){
 312         int sum = out[i] << 12;
 313         for(k = 0; k < 8; k++)
 314             sum += ptr0[k] * t[k];
 315         for(k = 7; k > 0; k--)
 316             ptr0[k] = ptr0[k - 1];
 317         ptr0[0] = av_clip((sum + 0x800) >> 12, -0x7FFE, 0x7FFE);
 318
 319         sum = ((ptr0[1] * (dec->filtval - (dec->filtval >> 2))) >> 4) + sum;
 320         sum = sum - (sum >> 3);
 321         out[i] = av_clip((sum + 0x800) >> 12, -0x7FFE, 0x7FFE);
 322     }
 323 }
 324
 325 static void truespeech_save_prevvec(TSContext *c)
 326 {
 327     int i;
 328
 329     for(i = 0; i < 8; i++)
 330         c->prevfilt[i] = c->cvector[i];
 331 }
 332
 333 static int truespeech_decode_frame(AVCodecContext *avctx,
 334                 void *data, int *data_size,
 335                 AVPacket *avpkt)
 336 {
 337     const uint8_t *buf = avpkt->data;
 338     int buf_size = avpkt->size;
 339     TSContext *c = avctx->priv_data;
 340
 341     int i, j;
 342     short *samples = data;
 343     int consumed = 0;
 344     int16_t out_buf[240];
 345     int iterations;
 346
 347     if (!buf_size)
 348         return 0;
 349
 350     iterations = FFMIN(buf_size / 32, *data_size / 480);
 351     for(j = 0; j < iterations; j++) {
 352         truespeech_read_frame(c, buf + consumed);
 353         consumed += 32;
 354
 355         truespeech_correlate_filter(c);
 356         truespeech_filters_merge(c);
 357
 358         memset(out_buf, 0, 240 * 2);
 359         for(i = 0; i < 4; i++) {
 360             truespeech_apply_twopoint_filter(c, i);
 361             truespeech_place_pulses(c, out_buf + i * 60, i);
 362             truespeech_update_filters(c, out_buf + i * 60, i);
 363             truespeech_synth(c, out_buf + i * 60, i);
 364         }
 365
 366         truespeech_save_prevvec(c);
 367
 368         /* finally output decoded frame */
 369         for(i = 0; i < 240; i++)
 370             *samples++ = out_buf[i];
 371
 372     }
 373
 374     *data_size = consumed * 15;
 375
 376     return consumed;
 377 }
 378
 379 AVCodec truespeech_decoder = {
 380     "truespeech",
 381     CODEC_TYPE_AUDIO,
 382     CODEC_ID_TRUESPEECH,
 383     sizeof(TSContext),
 384     truespeech_decode_init,
 385     NULL,
 386     NULL,
 387     truespeech_decode_frame,
 388     .long_name = NULL_IF_CONFIG_SMALL("DSP Group TrueSpeech"),
 389 };