apps/codecs/adx.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  *
   9  * Copyright (C) 2006-2008 Adam Gashlin (hcs)
  10  * Copyright (C) 2006 Jens Arnold
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public License
  14  * as published by the Free Software Foundation; either version 2
  15  * of the License, or (at your option) any later version.
  16  *
  17  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  18  * KIND, either express or implied.
  19  *
  20  ****************************************************************************/
  21 #include "codeclib.h"
  22 #include "inttypes.h"
  23 #include "math.h"
  24 #include "lib/fixedpoint.h"
  25
  26 CODEC_HEADER
  27
  28 /* Maximum number of bytes to process in one iteration */
  29 #define WAV_CHUNK_SIZE (1024*2)
  30
  31 /* Number of times to loop looped tracks when repeat is disabled */
  32 #define LOOP_TIMES 2
  33
  34 /* Length of fade-out for looped tracks (milliseconds) */
  35 #define FADE_LENGTH 10000L
  36
  37 /* Default high pass filter cutoff frequency is 500 Hz.
  38  * Others can be set, but the default is nearly always used,
  39  * and there is no way to determine if another was used, anyway.
  40  */
  41 const long cutoff = 500;
  42
  43 static int16_t samples[WAV_CHUNK_SIZE] IBSS_ATTR;
  44
  45 /* this is the codec entry point */
  46 enum codec_status codec_main(void)
  47 {
  48     int channels;
  49     int sampleswritten, i;
  50     uint8_t *buf;
  51     int32_t ch1_1, ch1_2, ch2_1, ch2_2; /* ADPCM history */
  52     size_t n;
  53     int endofstream; /* end of stream flag */
  54     uint32_t avgbytespersec;
  55     int looping; /* looping flag */
  56     int loop_count; /* number of loops done so far */
  57     int fade_count; /*  countdown for fadeout */
  58     int fade_frames; /* length of fade in frames */
  59     off_t start_adr, end_adr; /* loop points */
  60     off_t chanstart, bufoff;
  61     /*long coef1=0x7298L,coef2=-0x3350L;*/
  62     long coef1, coef2;
  63
  64     /* Generic codec initialisation */
  65     /* we only render 16 bits */
  66     ci->configure(DSP_SET_SAMPLE_DEPTH, 16);
  67
  68 next_track:
  69     DEBUGF("ADX: next_track\n");
  70     if (codec_init()) {
  71         return CODEC_ERROR;
  72     }
  73     DEBUGF("ADX: after init\n");
  74
  75     /* init history */
  76     ch1_1=ch1_2=ch2_1=ch2_2=0;
  77
  78     /* wait for track info to load */
  79     while (!*ci->taginfo_ready && !ci->stop_codec)
  80         ci->sleep(1);
  81
  82     codec_set_replaygain(ci->id3);
  83
  84     /* Get header */
  85     DEBUGF("ADX: request initial buffer\n");
  86     ci->seek_buffer(0);
  87     buf = ci->request_buffer(&n, 0x38);
  88     if (!buf || n < 0x38) {
  89         return CODEC_ERROR;
  90     }
  91     bufoff = 0;
  92     DEBUGF("ADX: read size = %lx\n",(unsigned long)n);
  93
  94     /* Get file header for starting offset, channel count */
  95
  96     chanstart = ((buf[2] << 8) | buf[3]) + 4;
  97     channels = buf[7];
  98
  99     /* useful for seeking and reporting current playback position */
 100     avgbytespersec = ci->id3->frequency * 18 * channels / 32;
 101     DEBUGF("avgbytespersec=%ld\n",(unsigned long)avgbytespersec);
 102
 103     /* calculate filter coefficients */
 104
 105     /**
 106      * A simple table of these coefficients would be nice, but
 107      * some very odd frequencies are used and if I'm going to
 108      * interpolate I might as well just go all the way and
 109      * calclate them precisely.
 110      * Speed is not an issue as this only needs to be done once per file.
 111      */
 112     {
 113         const int64_t big28 = 0x10000000LL;
 114         const int64_t big32 = 0x100000000LL;
 115         int64_t frequency = ci->id3->frequency;
 116         int64_t phasemultiple = cutoff*big32/frequency;
 117
 118         long z;
 119         int64_t a;
 120         const int64_t b = (M_SQRT2*big28)-big28;
 121         int64_t c;
 122         int64_t d;
 123
 124         fp_sincos((unsigned long)phasemultiple,&z);
 125
 126         a = (M_SQRT2*big28)-(z*big28/LONG_MAX);
 127
 128         /**
 129          * In the long passed to fsqrt there are only 4 nonfractional bits,
 130          * which is sufficient here, but this is the only reason why I don't
 131          * use 32 fractional bits everywhere.
 132          */
 133         d = fp_sqrt((a+b)*(a-b)/big28,28);
 134         c = (a-d)*big28/b;
 135
 136         coef1 = (c*8192) >> 28;
 137         coef2 = (c*c/big28*-4096) >> 28;
 138         DEBUGF("ADX: samprate=%ld ",(long)frequency);
 139         DEBUGF("coef1 %04x ",(unsigned int)(coef1*4));
 140         DEBUGF("coef2 %04x\n",(unsigned int)(coef2*-4));
 141     }
 142
 143     /* Get loop data */
 144
 145     looping = 0; start_adr = 0; end_adr = 0;
 146     if (!memcmp(buf+0x10,"\x01\xF4\x03\x00",4)) {
 147         /* Soul Calibur 2 style (type 03) */
 148         DEBUGF("ADX: type 03 found\n");
 149         /* check if header is too small for loop data */
 150         if (chanstart-6 < 0x2c) looping=0;
 151         else {
 152             looping = (buf[0x18]) ||
 153                       (buf[0x19]) ||
 154                       (buf[0x1a]) ||
 155                       (buf[0x1b]);
 156             end_adr = (buf[0x28]<<24) |
 157                       (buf[0x29]<<16) |
 158                       (buf[0x2a]<<8) |
 159                       (buf[0x2b]);
 160
 161             start_adr = (
 162               (buf[0x1c]<<24) |
 163               (buf[0x1d]<<16) |
 164               (buf[0x1e]<<8) |
 165               (buf[0x1f])
 166               )/32*channels*18+chanstart;
 167         }
 168     } else if (!memcmp(buf+0x10,"\x01\xF4\x04\x00",4)) {
 169         /* Standard (type 04) */
 170         DEBUGF("ADX: type 04 found\n");
 171         /* check if header is too small for loop data */
 172         if (chanstart-6 < 0x38) looping=0;
 173         else {
 174             looping = (buf[0x24]) ||
 175                       (buf[0x25]) ||
 176                       (buf[0x26]) ||
 177                       (buf[0x27]);
 178             end_adr = (buf[0x34]<<24) |
 179                       (buf[0x35]<<16) |
 180                       (buf[0x36]<<8) |
 181                       buf[0x37];
 182             start_adr = (
 183               (buf[0x28]<<24) |
 184               (buf[0x29]<<16) |
 185               (buf[0x2a]<<8) |
 186               (buf[0x2b])
 187               )/32*channels*18+chanstart;
 188         }
 189     } else {
 190         DEBUGF("ADX: error, couldn't determine ADX type\n");
 191         return CODEC_ERROR;
 192     }
 193
 194     if (looping) {
 195         DEBUGF("ADX: looped, start: %lx end: %lx\n",start_adr,end_adr);
 196     } else {
 197         DEBUGF("ADX: not looped\n");
 198     }
 199
 200     /* advance to first frame */
 201     DEBUGF("ADX: first frame at %lx\n",chanstart);
 202     bufoff = chanstart;
 203
 204     /* get in position */
 205     ci->seek_buffer(bufoff);
 206
 207
 208     /* setup pcm buffer format */
 209     ci->configure(DSP_SWITCH_FREQUENCY, ci->id3->frequency);
 210     if (channels == 2) {
 211         ci->configure(DSP_SET_STEREO_MODE, STEREO_INTERLEAVED);
 212     } else if (channels == 1) {
 213         ci->configure(DSP_SET_STEREO_MODE, STEREO_MONO);
 214     } else {
 215         DEBUGF("ADX CODEC_ERROR: more than 2 channels\n");
 216         return CODEC_ERROR;
 217     }
 218
 219     endofstream = 0;
 220     loop_count = 0;
 221     fade_count = -1; /* disable fade */
 222     fade_frames = 1;
 223
 224     /* The main decoder loop */
 225
 226     while (!endofstream) {
 227         ci->yield();
 228         if (ci->stop_codec || ci->new_track) {
 229             break;
 230         }
 231
 232         /* do we need to loop? */
 233         if (bufoff > end_adr-18*channels && looping) {
 234             DEBUGF("ADX: loop!\n");
 235             /* check for endless looping */
 236             if (ci->global_settings->repeat_mode==REPEAT_ONE) {
 237                 loop_count=0;
 238                 fade_count = -1; /* disable fade */
 239             } else {
 240                 /* otherwise start fade after LOOP_TIMES loops */
 241                 loop_count++;
 242                 if (loop_count >= LOOP_TIMES && fade_count < 0) {
 243                     /* frames to fade over */
 244                     fade_frames = FADE_LENGTH*ci->id3->frequency/32/1000;
 245                     /* volume relative to fade_frames */
 246                     fade_count = fade_frames;
 247                     DEBUGF("ADX: fade_frames = %d\n",fade_frames);
 248                 }
 249             }
 250             bufoff = start_adr;
 251             ci->seek_buffer(bufoff);
 252         }
 253
 254         /* do we need to seek? */
 255         if (ci->seek_time) {
 256             uint32_t newpos;
 257
 258             DEBUGF("ADX: seek to %ldms\n",ci->seek_time);
 259
 260             endofstream = 0;
 261             loop_count = 0;
 262             fade_count = -1; /* disable fade */
 263             fade_frames = 1;
 264
 265             newpos = (((uint64_t)avgbytespersec*(ci->seek_time - 1))
 266                       / (1000LL*18*channels))*(18*channels);
 267             bufoff = chanstart + newpos;
 268             while (bufoff > end_adr-18*channels) {
 269                 bufoff-=end_adr-start_adr;
 270                 loop_count++;
 271             }
 272             ci->seek_buffer(bufoff);
 273             ci->seek_complete();
 274         }
 275
 276         if (bufoff>ci->filesize-channels*18) break; /* End of stream */
 277
 278         sampleswritten=0;
 279
 280         while (
 281                 /* Is there data left in the file? */
 282                 (bufoff <= ci->filesize-(18*channels)) &&
 283                 /* Is there space in the output buffer? */
 284                 (sampleswritten <= WAV_CHUNK_SIZE-(32*channels)) &&
 285                 /* Should we be looping? */
 286                 ((!looping) || bufoff <= end_adr-18*channels))
 287         {
 288             /* decode first/only channel */
 289             int32_t scale;
 290             int32_t ch1_0, d;
 291
 292             /* fetch a frame */
 293             buf = ci->request_buffer(&n, 18);
 294
 295             if (!buf || n!=18) {
 296                 DEBUGF("ADX: couldn't get buffer at %lx\n",
 297                         bufoff);
 298                 return CODEC_ERROR;
 299             }
 300
 301             scale = ((buf[0] << 8) | (buf[1])) +1;
 302
 303             for (i = 2; i < 18; i++)
 304             {
 305                 d = (buf[i] >> 4) & 15;
 306                 if (d & 8) d-= 16;
 307                 ch1_0 = d*scale + ((coef1*ch1_1 + coef2*ch1_2) >> 12);
 308                 if (ch1_0 > 32767) ch1_0 = 32767;
 309                 else if (ch1_0 < -32768) ch1_0 = -32768;
 310                 samples[sampleswritten] = ch1_0;
 311                 sampleswritten+=channels;
 312                 ch1_2 = ch1_1; ch1_1 = ch1_0;
 313
 314                 d = buf[i] & 15;
 315                 if (d & 8) d -= 16;
 316                 ch1_0 = d*scale + ((coef1*ch1_1 + coef2*ch1_2) >> 12);
 317                 if (ch1_0 > 32767) ch1_0 = 32767;
 318                 else if (ch1_0 < -32768) ch1_0 = -32768;
 319                 samples[sampleswritten] = ch1_0;
 320                 sampleswritten+=channels;
 321                 ch1_2 = ch1_1; ch1_1 = ch1_0;
 322             }
 323             bufoff+=18;
 324             ci->advance_buffer(18);
 325
 326             if (channels == 2) {
 327                 /* decode second channel */
 328                 int32_t scale;
 329                 int32_t ch2_0, d;
 330
 331                 buf = ci->request_buffer(&n, 18);
 332
 333                 if (!buf || n!=18) {
 334                     DEBUGF("ADX: couldn't get buffer at %lx\n",
 335                             bufoff);
 336                     return CODEC_ERROR;
 337                 }
 338
 339                 scale = ((buf[0] << 8)|(buf[1]))+1;
 340
 341                 sampleswritten-=63;
 342
 343                 for (i = 2; i < 18; i++)
 344                 {
 345                     d = (buf[i] >> 4) & 15;
 346                     if (d & 8) d-= 16;
 347                     ch2_0 = d*scale + ((coef1*ch2_1 + coef2*ch2_2) >> 12);
 348                     if (ch2_0 > 32767) ch2_0 = 32767;
 349                     else if (ch2_0 < -32768) ch2_0 = -32768;
 350                     samples[sampleswritten] = ch2_0;
 351                     sampleswritten+=2;
 352                     ch2_2 = ch2_1; ch2_1 = ch2_0;
 353
 354                     d = buf[i] & 15;
 355                     if (d & 8) d -= 16;
 356                     ch2_0 = d*scale + ((coef1*ch2_1 + coef2*ch2_2) >> 12);
 357                     if (ch2_0 > 32767) ch2_0 = 32767;
 358                     else if (ch2_0 < -32768) ch2_0 = -32768;
 359                     samples[sampleswritten] = ch2_0;
 360                     sampleswritten+=2;
 361                     ch2_2 = ch2_1; ch2_1 = ch2_0;
 362                 }
 363                 bufoff+=18;
 364                 ci->advance_buffer(18);
 365                 sampleswritten--; /* go back to first channel's next sample */
 366             }
 367
 368             if (fade_count>0) {
 369                 fade_count--;
 370                 for (i=0;i<(channels==1?32:64);i++) samples[sampleswritten-i-1]=
 371                   ((int32_t)samples[sampleswritten-i-1])*fade_count/fade_frames;
 372                 if (fade_count==0) {endofstream=1; break;}
 373             }
 374         }
 375
 376         if (channels == 2)
 377             sampleswritten >>= 1; /* make samples/channel */
 378
 379         ci->pcmbuf_insert(samples, NULL, sampleswritten);
 380
 381         ci->set_elapsed(
 382            ((end_adr-start_adr)*loop_count + bufoff-chanstart)*
 383            1000LL/avgbytespersec);
 384     }
 385
 386     if (ci->request_next_track())
 387         goto next_track;
 388
 389     return CODEC_OK;
 390 }