libavcodec/dtsdec.c

   1 /*
   2  * dtsdec.c : free DTS Coherent Acoustics stream decoder.
   3  * Copyright (C) 2004 Benjamin Zores <ben@geexbox.org>
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (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
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * 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 "avcodec.h"
  23 #include <dts.h>
  24
  25 #include <stdlib.h>
  26 #include <string.h>
  27
  28 #define BUFFER_SIZE 18726
  29 #define HEADER_SIZE 14
  30
  31 #define CONVERT_LEVEL 1
  32 #define CONVERT_BIAS 0
  33
  34 typedef struct DTSContext {
  35     dts_state_t *state;
  36     uint8_t buf[BUFFER_SIZE];
  37     uint8_t *bufptr;
  38     uint8_t *bufpos;
  39 } DTSContext;
  40
  41 static inline int16_t
  42 convert(sample_t s)
  43 {
  44     return s * 0x7fff;
  45 }
  46
  47 static void
  48 convert2s16_multi(sample_t *f, int16_t *s16, int flags)
  49 {
  50     int i;
  51
  52     switch(flags & (DTS_CHANNEL_MASK | DTS_LFE)){
  53     case DTS_MONO:
  54         for(i = 0; i < 256; i++){
  55             s16[5*i] = s16[5*i+1] = s16[5*i+2] = s16[5*i+3] = 0;
  56             s16[5*i+4] = convert(f[i]);
  57         }
  58     case DTS_CHANNEL:
  59     case DTS_STEREO:
  60     case DTS_DOLBY:
  61         for(i = 0; i < 256; i++){
  62             s16[2*i] = convert(f[i]);
  63             s16[2*i+1] = convert(f[i+256]);
  64         }
  65     case DTS_3F:
  66         for(i = 0; i < 256; i++){
  67             s16[5*i] = convert(f[i+256]);
  68             s16[5*i+1] = convert(f[i+512]);
  69             s16[5*i+2] = s16[5*i+3] = 0;
  70             s16[5*i+4] = convert(f[i]);
  71         }
  72     case DTS_2F2R:
  73         for(i = 0; i < 256; i++){
  74             s16[4*i] = convert(f[i]);
  75             s16[4*i+1] = convert(f[i+256]);
  76             s16[4*i+2] = convert(f[i+512]);
  77             s16[4*i+3] = convert(f[i+768]);
  78         }
  79     case DTS_3F2R:
  80         for(i = 0; i < 256; i++){
  81             s16[5*i] = convert(f[i+256]);
  82             s16[5*i+1] = convert(f[i+512]);
  83             s16[5*i+2] = convert(f[i+768]);
  84             s16[5*i+3] = convert(f[i+1024]);
  85             s16[5*i+4] = convert(f[i]);
  86         }
  87     case DTS_MONO | DTS_LFE:
  88         for(i = 0; i < 256; i++){
  89             s16[6*i] = s16[6*i+1] = s16[6*i+2] = s16[6*i+3] = 0;
  90             s16[6*i+4] = convert(f[i]);
  91             s16[6*i+5] = convert(f[i+256]);
  92         }
  93     case DTS_CHANNEL | DTS_LFE:
  94     case DTS_STEREO | DTS_LFE:
  95     case DTS_DOLBY | DTS_LFE:
  96         for(i = 0; i < 256; i++){
  97             s16[6*i] = convert(f[i]);
  98             s16[6*i+1] = convert(f[i+256]);
  99             s16[6*i+2] = s16[6*i+3] = s16[6*i+4] = 0;
 100             s16[6*i+5] = convert(f[i+512]);
 101         }
 102     case DTS_3F | DTS_LFE:
 103         for(i = 0; i < 256; i++){
 104             s16[6*i] = convert(f[i+256]);
 105             s16[6*i+1] = convert(f[i+512]);
 106             s16[6*i+2] = s16[6*i+3] = 0;
 107             s16[6*i+4] = convert(f[i]);
 108             s16[6*i+5] = convert(f[i+768]);
 109         }
 110     case DTS_2F2R | DTS_LFE:
 111         for(i = 0; i < 256; i++){
 112             s16[6*i] = convert(f[i]);
 113             s16[6*i+1] = convert(f[i+256]);
 114             s16[6*i+2] = convert(f[i+512]);
 115             s16[6*i+3] = convert(f[i+768]);
 116             s16[6*i+4] = 0;
 117             s16[6*i+5] = convert(f[i+1024]);
 118         }
 119     case DTS_3F2R | DTS_LFE:
 120         for(i = 0; i < 256; i++){
 121             s16[6*i] = convert(f[i+256]);
 122             s16[6*i+1] = convert(f[i+512]);
 123             s16[6*i+2] = convert(f[i+768]);
 124             s16[6*i+3] = convert(f[i+1024]);
 125             s16[6*i+4] = convert(f[i]);
 126             s16[6*i+5] = convert(f[i+1280]);
 127         }
 128     }
 129 }
 130
 131 static int
 132 channels_multi(int flags)
 133 {
 134     switch(flags & (DTS_CHANNEL_MASK | DTS_LFE)){
 135     case DTS_CHANNEL:
 136     case DTS_STEREO:
 137     case DTS_DOLBY:
 138         return 2;
 139     case DTS_2F2R:
 140         return 4;
 141     case DTS_MONO:
 142     case DTS_3F:
 143     case DTS_3F2R:
 144         return 5;
 145     case DTS_MONO | DTS_LFE:
 146     case DTS_CHANNEL | DTS_LFE:
 147     case DTS_STEREO | DTS_LFE:
 148     case DTS_DOLBY | DTS_LFE:
 149     case DTS_3F | DTS_LFE:
 150     case DTS_2F2R | DTS_LFE:
 151     case DTS_3F2R | DTS_LFE:
 152         return 6;
 153     }
 154
 155     return -1;
 156 }
 157
 158 static int
 159 dts_decode_frame(AVCodecContext * avctx, void *data, int *data_size,
 160                  uint8_t * buff, int buff_size)
 161 {
 162     DTSContext *s = avctx->priv_data;
 163     uint8_t *start = buff;
 164     uint8_t *end = buff + buff_size;
 165     int16_t *out_samples = data;
 166     int sample_rate;
 167     int frame_length;
 168     int flags;
 169     int bit_rate;
 170     int len;
 171     level_t level;
 172     sample_t bias;
 173     int nblocks;
 174     int i;
 175
 176     *data_size = 0;
 177
 178     while(1) {
 179         int length;
 180
 181         len = end - start;
 182         if(!len)
 183             break;
 184         if(len > s->bufpos - s->bufptr)
 185             len = s->bufpos - s->bufptr;
 186         memcpy(s->bufptr, start, len);
 187         s->bufptr += len;
 188         start += len;
 189         if(s->bufptr != s->bufpos)
 190             return start - buff;
 191         if(s->bufpos != s->buf + HEADER_SIZE)
 192             break;
 193
 194         length = dts_syncinfo(s->state, s->buf, &flags, &sample_rate,
 195                               &bit_rate, &frame_length);
 196         if(!length) {
 197             av_log(NULL, AV_LOG_INFO, "skip\n");
 198             for(s->bufptr = s->buf; s->bufptr < s->buf + HEADER_SIZE - 1; s->bufptr++)
 199                 s->bufptr[0] = s->bufptr[1];
 200             continue;
 201         }
 202         s->bufpos = s->buf + length;
 203     }
 204
 205     level = CONVERT_LEVEL;
 206     bias = CONVERT_BIAS;
 207
 208     flags |= DTS_ADJUST_LEVEL;
 209     if(dts_frame(s->state, s->buf, &flags, &level, bias)) {
 210         av_log(avctx, AV_LOG_ERROR, "dts_frame() failed\n");
 211         goto end;
 212     }
 213
 214     avctx->sample_rate = sample_rate;
 215     avctx->channels = channels_multi(flags);
 216     avctx->bit_rate = bit_rate;
 217
 218     nblocks = dts_blocks_num(s->state);
 219
 220     for(i = 0; i < nblocks; i++) {
 221         if(dts_block(s->state)) {
 222             av_log(avctx, AV_LOG_ERROR, "dts_block() failed\n");
 223             goto end;
 224         }
 225
 226         convert2s16_multi(dts_samples(s->state), out_samples, flags);
 227
 228         out_samples += 256 * avctx->channels;
 229         *data_size += 256 * sizeof(int16_t) * avctx->channels;
 230     }
 231
 232 end:
 233     s->bufptr = s->buf;
 234     s->bufpos = s->buf + HEADER_SIZE;
 235     return start - buff;
 236 }
 237
 238 static int
 239 dts_decode_init(AVCodecContext * avctx)
 240 {
 241     DTSContext *s = avctx->priv_data;
 242     s->bufptr = s->buf;
 243     s->bufpos = s->buf + HEADER_SIZE;
 244     s->state = dts_init(0);
 245     if(s->state == NULL)
 246         return -1;
 247
 248     return 0;
 249 }
 250
 251 static int
 252 dts_decode_end(AVCodecContext * avctx)
 253 {
 254     DTSContext *s = avctx->priv_data;
 255     dts_free(s->state);
 256     return 0;
 257 }
 258
 259 AVCodec dts_decoder = {
 260     "dts",
 261     CODEC_TYPE_AUDIO,
 262     CODEC_ID_DTS,
 263     sizeof(DTSContext),
 264     dts_decode_init,
 265     NULL,
 266     dts_decode_end,
 267     dts_decode_frame,
 268 };