apps/codecs/wavpack.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2005 David Bryant
  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 "codeclib.h"
  23 #include "libwavpack/wavpack.h"
  24
  25 CODEC_HEADER
  26
  27 #define BUFFER_SIZE 4096
  28
  29 static int32_t temp_buffer [BUFFER_SIZE] IBSS_ATTR;
  30
  31 static int32_t read_callback (void *buffer, int32_t bytes)
  32 {
  33     int32_t retval = ci->read_filebuf (buffer, bytes);
  34     ci->id3->offset = ci->curpos;
  35     return retval;
  36 }
  37
  38 /* this is the codec entry point */
  39 enum codec_status codec_main(void)
  40 {
  41     WavpackContext *wpc;
  42     char error [80];
  43     int bps, nchans, sr_100;
  44     int retval;
  45
  46     /* Generic codec initialisation */
  47     ci->configure(DSP_SET_SAMPLE_DEPTH, 28);
  48
  49 next_track:
  50     retval = CODEC_OK;
  51
  52     if (codec_init()) {
  53         retval = CODEC_ERROR;
  54         goto exit;
  55     }
  56
  57     if (codec_wait_taginfo() != 0)
  58         goto done;
  59
  60     /* Create a decoder instance */
  61     wpc = WavpackOpenFileInput (read_callback, error);
  62
  63     if (!wpc) {
  64         retval = CODEC_ERROR;
  65         goto done;
  66     }
  67
  68     ci->configure(DSP_SWITCH_FREQUENCY, WavpackGetSampleRate (wpc));
  69     codec_set_replaygain(ci->id3);
  70     bps = WavpackGetBytesPerSample (wpc);
  71     nchans = WavpackGetReducedChannels (wpc);
  72     ci->configure(DSP_SET_STEREO_MODE, nchans == 2 ? STEREO_INTERLEAVED : STEREO_MONO);
  73     sr_100 = ci->id3->frequency / 100;
  74
  75     ci->set_elapsed (0);
  76
  77     /* The main decoder loop */
  78
  79     while (1) {
  80         int32_t nsamples;
  81
  82         if (ci->seek_time && ci->taginfo_ready && ci->id3->length) {
  83             ci->seek_time--;
  84             int curpos_ms = WavpackGetSampleIndex (wpc) / sr_100 * 10;
  85             int n, d, skip;
  86
  87             if (ci->seek_time > curpos_ms) {
  88                 n = ci->seek_time - curpos_ms;
  89                 d = ci->id3->length - curpos_ms;
  90                 skip = (int)((int64_t)(ci->filesize - ci->curpos) * n / d);
  91                 ci->seek_buffer (ci->curpos + skip);
  92             }
  93             else {
  94                 n = curpos_ms - ci->seek_time;
  95                 d = curpos_ms;
  96                 skip = (int)((int64_t) ci->curpos * n / d);
  97                 ci->seek_buffer (ci->curpos - skip);
  98             }
  99
 100             wpc = WavpackOpenFileInput (read_callback, error);
 101             ci->seek_complete();
 102
 103             if (!wpc)
 104                 break;
 105
 106             ci->set_elapsed (WavpackGetSampleIndex (wpc) / sr_100 * 10);
 107             ci->yield ();
 108         }
 109
 110         nsamples = WavpackUnpackSamples (wpc, temp_buffer, BUFFER_SIZE / nchans);
 111
 112         if (!nsamples || ci->stop_codec || ci->new_track)
 113             break;
 114
 115         ci->yield ();
 116
 117         if (ci->stop_codec || ci->new_track)
 118             break;
 119
 120         ci->pcmbuf_insert (temp_buffer, NULL, nsamples);
 121
 122         ci->set_elapsed (WavpackGetSampleIndex (wpc) / sr_100 * 10);
 123         ci->yield ();
 124     }
 125
 126 done:
 127     if (ci->request_next_track())
 128         goto next_track;
 129
 130 exit:
 131     return retval;
 132 }