apps/codecs/alac.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2005 Dave Chapman
  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 "libm4a/m4a.h"
  24 #include "libalac/decomp.h"
  25
  26 CODEC_HEADER
  27
  28 int32_t outputbuffer[ALAC_MAX_CHANNELS][ALAC_BLOCKSIZE] IBSS_ATTR;
  29
  30 /* this is the codec entry point */
  31 enum codec_status codec_main(void)
  32 {
  33   size_t n;
  34   demux_res_t demux_res;
  35   stream_t input_stream;
  36   uint32_t samplesdone;
  37   uint32_t elapsedtime;
  38   uint32_t sample_duration;
  39   uint32_t sample_byte_size;
  40   int samplesdecoded;
  41   unsigned int i;
  42   unsigned char* buffer;
  43   alac_file alac;
  44   int retval;
  45
  46   /* Generic codec initialisation */
  47   ci->configure(DSP_SET_STEREO_MODE, STEREO_NONINTERLEAVED);
  48   ci->configure(DSP_SET_SAMPLE_DEPTH, ALAC_OUTPUT_DEPTH-1);
  49
  50   next_track:
  51
  52   if (codec_init()) {
  53     LOGF("ALAC: Error initialising codec\n");
  54     retval = CODEC_ERROR;
  55     goto exit;
  56   }
  57
  58   while (!*ci->taginfo_ready && !ci->stop_codec)
  59     ci->sleep(1);
  60
  61   ci->configure(DSP_SWITCH_FREQUENCY, ci->id3->frequency);
  62   codec_set_replaygain(ci->id3);
  63
  64   stream_create(&input_stream,ci);
  65
  66   /* if qtmovie_read returns successfully, the stream is up to
  67    * the movie data, which can be used directly by the decoder */
  68   if (!qtmovie_read(&input_stream, &demux_res)) {
  69     LOGF("ALAC: Error initialising file\n");
  70     retval = CODEC_ERROR;
  71     goto done;
  72   }
  73
  74   /* initialise the sound converter */
  75   create_alac(demux_res.sound_sample_size, demux_res.num_channels,&alac);
  76   alac_set_info(&alac, demux_res.codecdata);
  77
  78   i=0;
  79   samplesdone=0;
  80   /* The main decoding loop */
  81   while (i < demux_res.num_sample_byte_sizes) {
  82     ci->yield();
  83     if (ci->stop_codec || ci->new_track) {
  84       break;
  85     }
  86
  87     /* Deal with any pending seek requests */
  88     if (ci->seek_time) {
  89       if (alac_seek(&demux_res, &input_stream,
  90                     ((ci->seek_time-1)/10) * (ci->id3->frequency/100),
  91                     &samplesdone, (int *)&i)) {
  92         elapsedtime=(samplesdone*10)/(ci->id3->frequency/100);
  93         ci->set_elapsed(elapsedtime);
  94       }
  95       ci->seek_complete();
  96     }
  97
  98     /* Lookup the length (in samples and bytes) of block i */
  99     if (!get_sample_info(&demux_res, i, &sample_duration,
 100                          &sample_byte_size)) {
 101       LOGF("ALAC: Error in get_sample_info\n");
 102       retval = CODEC_ERROR;
 103       goto done;
 104     }
 105
 106     /* Request the required number of bytes from the input buffer */
 107
 108     buffer=ci->request_buffer(&n,sample_byte_size);
 109     if (n!=sample_byte_size) {
 110         retval = CODEC_ERROR;
 111         goto done;
 112     }
 113
 114     /* Decode one block - returned samples will be host-endian */
 115     ci->yield();
 116     samplesdecoded=alac_decode_frame(&alac, buffer, outputbuffer, ci->yield);
 117
 118     /* Advance codec buffer n bytes */
 119     ci->advance_buffer(n);
 120
 121     /* Output the audio */
 122     ci->yield();
 123     ci->pcmbuf_insert(outputbuffer[0], outputbuffer[1], samplesdecoded);
 124
 125     /* Update the elapsed-time indicator */
 126     samplesdone+=sample_duration;
 127     elapsedtime=(samplesdone*10)/(ci->id3->frequency/100);
 128     ci->set_elapsed(elapsedtime);
 129
 130     /* Keep track of current position - for resuming */
 131     ci->set_offset(elapsedtime);
 132
 133     i++;
 134   }
 135   retval = CODEC_OK;
 136
 137 done:
 138   LOGF("ALAC: Decoded %ld samples\n",samplesdone);
 139
 140   if (ci->request_next_track())
 141    goto next_track;
 142
 143 exit:
 144   return retval;
 145 }