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
  22 #include <limits.h>
  23 #include "codeclib.h"
  24 #include "inttypes.h"
  25 #include "math.h"
  26 #include "lib/fixedpoint.h"
  27
  28 CODEC_HEADER
  29
  30 /* Maximum number of bytes to process in one iteration */
  31 #define WAV_CHUNK_SIZE (1024*2)
  32
  33 /* Number of times to loop looped tracks when repeat is disabled */
  34 #define LOOP_TIMES 2
  35
  36 /* Length of fade-out for looped tracks (milliseconds) */
  37 #define FADE_LENGTH 10000L
  38
  39 /* Default high pass filter cutoff frequency is 500 Hz.
  40  * Others can be set, but the default is nearly always used,
  41  * and there is no way to determine if another was used, anyway.
  42  */
  43 static const long cutoff = 500;
  44
  45 static int16_t samples[WAV_CHUNK_SIZE] IBSS_ATTR;
  46
  47 /* this is the codec entry point */
  48 enum codec_status codec_main(void)
  49 {
  50     int channels;
  51     int sampleswritten, i;
  52     uint8_t *buf;
  53     int32_t ch1_1, ch1_2, ch2_1, ch2_2; /* ADPCM history */
  54     size_t n;
  55     int endofstream; /* end of stream flag */
  56     uint32_t avgbytespersec;
  57     int looping; /* looping flag */
  58     int loop_count; /* number of loops done so far */
  59     int fade_count; /*  countdown for fadeout */
  60     int fade_frames; /* length of fade in frames */
  61     off_t start_adr, end_adr; /* loop points */
  62     off_t chanstart, bufoff;
  63     /*long coef1=0x7298L,coef2=-0x3350L;*/
  64     long coef1, coef2;
  65
  66     /* Generic codec initialisation */
  67     /* we only render 16 bits */
  68     ci->configure(DSP_SET_SAMPLE_DEPTH, 16);
  69
  70 next_track:
  71     DEBUGF("ADX: next_track\n");
  72     if (codec_init()) {
  73         return CODEC_ERROR;
  74     }
  75     DEBUGF("ADX: after init\n");
  76
  77     /* init history */
  78     ch1_1=ch1_2=ch2_1=ch2_2=0;
  79
  80     /* wait for track info to load */
  81     if (codec_wait_taginfo() != 0)
  82         goto request_next_track;
  83
  84     codec_set_replaygain(ci->id3);
  85
  86     /* Get header */
  87     DEBUGF("ADX: request initial buffer\n");
  88     ci->seek_buffer(0);
  89     buf = ci->request_buffer(&n, 0x38);
  90     if (!buf || n < 0x38) {
  91         return CODEC_ERROR;
  92     }
  93     bufoff = 0;
  94     DEBUGF("ADX: read size = %lx\n",(unsigned long)n);
  95
  96     /* Get file header for starting offset, channel count */
  97
  98     chanstart = ((buf[2] << 8) | buf[3]) + 4;
  99     channels = buf[7];
 100
 101     /* useful for seeking and reporting current playback position */
 102     avgbytespersec = ci->id3->frequency * 18 * channels / 32;
 103     DEBUGF("avgbytespersec=%ld\n",(unsigned long)avgbytespersec);
 104
 105     /* calculate filter coefficients */
 106
 107     /**
 108      * A simple table of these coefficients would be nice, but
 109      * some very odd frequencies are used and if I'm going to
 110      * interpolate I might as well just go all the way and
 111      * calclate them precisely.
 112      * Speed is not an issue as this only needs to be done once per file.
 113      */
 114     {
 115         const int64_t big28 = 0x10000000LL;
 116         const int64_t big32 = 0x100000000LL;
 117         int64_t frequency = ci->id3->frequency;
 118         int64_t phasemultiple = cutoff*big32/frequency;
 119
 120         long z;
 121         int64_t a;
 122         const int64_t b = (M_SQRT2*big28)-big28;
 123         int64_t c;
 124         int64_t d;
 125
 126         fp_sincos((unsigned long)phasemultiple,&z);
 127
 128         a = (M_SQRT2*big28)-(z*big28/LONG_MAX);
 129
 130         /**
 131          * In the long passed to fsqrt there are only 4 nonfractional bits,
 132          * which is sufficient here, but this is the only reason why I don't
 133          * use 32 fractional bits everywhere.
 134          */
 135         d = fp_sqrt((a+b)*(a-b)/big28,28);
 136         c = (a-d)*big28/b;
 137
 138         coef1 = (c*8192) >> 28;
 139         coef2 = (c*c/big28*-4096) >> 28;
 140         DEBUGF("ADX: samprate=%ld ",(long)frequency);
 141         DEBUGF("coef1 %04x ",(unsigned int)(coef1*4));
 142         DEBUGF("coef2 %04x\n",(unsigned int)(coef2*-4));
 143     }
 144
 145     /* Get loop data */
 146
 147     looping = 0; start_adr = 0; end_adr = 0;
 148     if (!memcmp(buf+0x10,"\x01\xF4\x03\x00",4)) {
 149         /* Soul Calibur 2 style (type 03) */
 150         DEBUGF("ADX: type 03 found\n");
 151         /* check if header is too small for loop data */
 152         if (chanstart-6 < 0x2c) looping=0;
 153         else {
 154             looping = (buf[0x18]) ||
 155                       (buf[0x19]) ||
 156                       (buf[0x1a]) ||
 157                       (buf[0x1b]);
 158             end_adr = (buf[0x28]<<24) |
 159                       (buf[0x29]<<16) |
 160                       (buf[0x2a]<<8) |
 161                       (buf[0x2b]);
 162
 163             start_adr = (
 164               (buf[0x1c]<<24) |
 165               (buf[0x1d]<<16) |
 166               (buf[0x1e]<<8) |
 167               (buf[0x1f])
 168               )/32*channels*18+chanstart;
 169         }
 170     } else if (!memcmp(buf+0x10,"\x01\xF4\x04\x00",4)) {
 171         /* Standard (type 04) */
 172         DEBUGF("ADX: type 04 found\n");
 173         /* check if header is too small for loop data */
 174         if (chanstart-6 < 0x38) looping=0;
 175         else {
 176             looping = (buf[0x24]) ||
 177                       (buf[0x25]) ||
 178                       (buf[0x26]) ||
 179                       (buf[0x27]);
 180             end_adr = (buf[0x34]<<24) |
 181                       (buf[0x35]<<16) |
 182                       (buf[0x36]<<8) |
 183                       buf[0x37];
 184             start_adr = (
 185               (buf[0x28]<<24) |
 186               (buf[0x29]<<16) |
 187               (buf[0x2a]<<8) |
 188               (buf[0x2b])
 189               )/32*channels*18+chanstart;
 190         }
 191     } else {
 192         DEBUGF("ADX: error, couldn't determine ADX type\n");
 193         return CODEC_ERROR;
 194     }
 195
 196     if (looping) {
 197         DEBUGF("ADX: looped, start: %lx end: %lx\n",start_adr,end_adr);
 198     } else {
 199         DEBUGF("ADX: not looped\n");
 200     }
 201
 202     /* advance to first frame */
 203     DEBUGF("ADX: first frame at %lx\n",chanstart);
 204     bufoff = chanstart;
 205
 206     /* get in position */
 207     ci->seek_buffer(bufoff);
 208
 209
 210     /* setup pcm buffer format */
 211     ci->configure(DSP_SWITCH_FREQUENCY, ci->id3->frequency);
 212     if (channels == 2) {
 213         ci->configure(DSP_SET_STEREO_MODE, STEREO_INTERLEAVED);
 214     } else if (channels == 1) {
 215         ci->configure(DSP_SET_STEREO_MODE, STEREO_MONO);
 216     } else {
 217         DEBUGF("ADX CODEC_ERROR: more than 2 channels\n");
 218         return CODEC_ERROR;
 219     }
 220
 221     endofstream = 0;
 222     loop_count = 0;
 223     fade_count = -1; /* disable fade */
 224     fade_frames = 1;
 225
 226     /* The main decoder loop */
 227
 228     while (!endofstream) {
 229         ci->yield();
 230         if (ci->stop_codec || ci->new_track) {
 231             break;
 232         }
 233
 234         /* do we need to loop? */
 235         if (bufoff > end_adr-18*channels && looping) {
 236             DEBUGF("ADX: loop!\n");
 237             /* check for endless looping */
 238             if (ci->global_settings->repeat_mode==REPEAT_ONE) {
 239                 loop_count=0;
 240                 fade_count = -1; /* disable fade */
 241             } else {
 242                 /* otherwise start fade after LOOP_TIMES loops */
 243                 loop_count++;
 244                 if (loop_count >= LOOP_TIMES && fade_count < 0) {
 245                     /* frames to fade over */
 246                     fade_frames = FADE_LENGTH*ci->id3->frequency/32/1000;
 247                     /* volume relative to fade_frames */
 248                     fade_count = fade_frames;
 249                     DEBUGF("ADX: fade_frames = %d\n",fade_frames);
 250                 }
 251             }
 252             bufoff = start_adr;
 253             ci->seek_buffer(bufoff);
 254         }
 255
 256         /* do we need to seek? */
 257         if (ci->seek_time) {
 258             uint32_t newpos;
 259
 260             DEBUGF("ADX: seek to %ldms\n",ci->seek_time);
 261
 262             endofstream = 0;
 263             loop_count = 0;
 264             fade_count = -1; /* disable fade */
 265             fade_frames = 1;
 266
 267             newpos = (((uint64_t)avgbytespersec*(ci->seek_time - 1))
 268                       / (1000LL*18*channels))*(18*channels);
 269             bufoff = chanstart + newpos;
 270             while (bufoff > end_adr-18*channels) {
 271                 bufoff-=end_adr-start_adr;
 272                 loop_count++;
 273             }
 274             ci->seek_buffer(bufoff);
 275             ci->seek_complete();
 276         }
 277
 278         if (bufoff>ci->filesize-channels*18) break; /* End of stream */
 279
 280         sampleswritten=0;
 281
 282         while (
 283                 /* Is there data left in the file? */
 284                 (bufoff <= ci->filesize-(18*channels)) &&
 285                 /* Is there space in the output buffer? */
 286                 (sampleswritten <= WAV_CHUNK_SIZE-(32*channels)) &&
 287                 /* Should we be looping? */
 288                 ((!looping) || bufoff <= end_adr-18*channels))
 289         {
 290             /* decode first/only channel */
 291             int32_t scale;
 292             int32_t ch1_0, d;
 293
 294             /* fetch a frame */
 295             buf = ci->request_buffer(&n, 18);
 296
 297             if (!buf || n!=18) {
 298                 DEBUGF("ADX: couldn't get buffer at %lx\n",
 299                         bufoff);
 300                 return CODEC_ERROR;
 301             }
 302
 303             scale = ((buf[0] << 8) | (buf[1])) +1;
 304
 305             for (i = 2; i < 18; i++)
 306             {
 307                 d = (buf[i] >> 4) & 15;
 308                 if (d & 8) d-= 16;
 309                 ch1_0 = d*scale + ((coef1*ch1_1 + coef2*ch1_2) >> 12);
 310                 if (ch1_0 > 32767) ch1_0 = 32767;
 311                 else if (ch1_0 < -32768) ch1_0 = -32768;
 312                 samples[sampleswritten] = ch1_0;
 313                 sampleswritten+=channels;
 314                 ch1_2 = ch1_1; ch1_1 = ch1_0;
 315
 316                 d = buf[i] & 15;
 317                 if (d & 8) d -= 16;
 318                 ch1_0 = d*scale + ((coef1*ch1_1 + coef2*ch1_2) >> 12);
 319                 if (ch1_0 > 32767) ch1_0 = 32767;
 320                 else if (ch1_0 < -32768) ch1_0 = -32768;
 321                 samples[sampleswritten] = ch1_0;
 322                 sampleswritten+=channels;
 323                 ch1_2 = ch1_1; ch1_1 = ch1_0;
 324             }
 325             bufoff+=18;
 326             ci->advance_buffer(18);
 327
 328             if (channels == 2) {
 329                 /* decode second channel */
 330                 int32_t scale;
 331                 int32_t ch2_0, d;
 332
 333                 buf = ci->request_buffer(&n, 18);
 334
 335                 if (!buf || n!=18) {
 336                     DEBUGF("ADX: couldn't get buffer at %lx\n",
 337                             bufoff);
 338                     return CODEC_ERROR;
 339                 }
 340
 341                 scale = ((buf[0] << 8)|(buf[1]))+1;
 342
 343                 sampleswritten-=63;
 344
 345                 for (i = 2; i < 18; i++)
 346                 {
 347                     d = (buf[i] >> 4) & 15;
 348                     if (d & 8) d-= 16;
 349                     ch2_0 = d*scale + ((coef1*ch2_1 + coef2*ch2_2) >> 12);
 350                     if (ch2_0 > 32767) ch2_0 = 32767;
 351                     else if (ch2_0 < -32768) ch2_0 = -32768;
 352                     samples[sampleswritten] = ch2_0;
 353                     sampleswritten+=2;
 354                     ch2_2 = ch2_1; ch2_1 = ch2_0;
 355
 356                     d = buf[i] & 15;
 357                     if (d & 8) d -= 16;
 358                     ch2_0 = d*scale + ((coef1*ch2_1 + coef2*ch2_2) >> 12);
 359                     if (ch2_0 > 32767) ch2_0 = 32767;
 360                     else if (ch2_0 < -32768) ch2_0 = -32768;
 361                     samples[sampleswritten] = ch2_0;
 362                     sampleswritten+=2;
 363                     ch2_2 = ch2_1; ch2_1 = ch2_0;
 364                 }
 365                 bufoff+=18;
 366                 ci->advance_buffer(18);
 367                 sampleswritten--; /* go back to first channel's next sample */
 368             }
 369
 370             if (fade_count>0) {
 371                 fade_count--;
 372                 for (i=0;i<(channels==1?32:64);i++) samples[sampleswritten-i-1]=
 373                   ((int32_t)samples[sampleswritten-i-1])*fade_count/fade_frames;
 374                 if (fade_count==0) {endofstream=1; break;}
 375             }
 376         }
 377
 378         if (channels == 2)
 379             sampleswritten >>= 1; /* make samples/channel */
 380
 381         ci->pcmbuf_insert(samples, NULL, sampleswritten);
 382
 383         ci->set_elapsed(
 384            ((end_adr-start_adr)*loop_count + bufoff-chanstart)*
 385            1000LL/avgbytespersec);
 386     }
 387
 388 request_next_track:
 389     if (ci->request_next_track())
 390         goto next_track;
 391
 392     return CODEC_OK;
 393 }