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 static 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   int samplesdecoded;
  39   unsigned int i;
  40   unsigned char* buffer;
  41   alac_file alac;
  42   int retval;
  43
  44   /* Generic codec initialisation */
  45   ci->configure(DSP_SET_STEREO_MODE, STEREO_NONINTERLEAVED);
  46   ci->configure(DSP_SET_SAMPLE_DEPTH, ALAC_OUTPUT_DEPTH-1);
  47
  48   next_track:
  49     retval = CODEC_OK;
  50
  51   /* Clean and initialize decoder structures */
  52    memset(&demux_res , 0, sizeof(demux_res));
  53   if (codec_init()) {
  54     LOGF("ALAC: Error initialising codec\n");
  55     retval = CODEC_ERROR;
  56     goto exit;
  57   }
  58
  59   if (codec_wait_taginfo() != 0)
  60     goto done;
  61
  62   ci->configure(DSP_SWITCH_FREQUENCY, ci->id3->frequency);
  63   codec_set_replaygain(ci->id3);
  64
  65   stream_create(&input_stream,ci);
  66
  67   /* Read from ci->id3->offset before calling qtmovie_read. */
  68   samplesdone = (uint32_t)(((uint64_t)(ci->id3->offset) * ci->id3->frequency) /
  69                 (ci->id3->bitrate*128));
  70
  71   /* if qtmovie_read returns successfully, the stream is up to
  72    * the movie data, which can be used directly by the decoder */
  73   if (!qtmovie_read(&input_stream, &demux_res)) {
  74     LOGF("ALAC: Error initialising file\n");
  75     retval = CODEC_ERROR;
  76     goto done;
  77   }
  78
  79   /* initialise the sound converter */
  80   create_alac(demux_res.sound_sample_size, demux_res.num_channels,&alac);
  81   alac_set_info(&alac, demux_res.codecdata);
  82
  83   /* Set i for first frame, seek to desired sample position for resuming. */
  84   i=0;
  85   if (samplesdone > 0) {
  86     if (alac_seek(&demux_res, &input_stream, samplesdone,
  87                   &samplesdone, (int*) &i)) {
  88         elapsedtime = (samplesdone * 10) / (ci->id3->frequency / 100);
  89         ci->set_elapsed(elapsedtime);
  90     } else {
  91         samplesdone = 0;
  92     }
  93   }
  94
  95   /* The main decoding loop */
  96   while (i < demux_res.num_sample_byte_sizes) {
  97     ci->yield();
  98     if (ci->stop_codec || ci->new_track) {
  99       break;
 100     }
 101
 102     /* Deal with any pending seek requests */
 103     if (ci->seek_time) {
 104       if (alac_seek(&demux_res, &input_stream,
 105                     ((ci->seek_time-1)/10) * (ci->id3->frequency/100),
 106                     &samplesdone, (int *)&i)) {
 107         elapsedtime=(samplesdone*10)/(ci->id3->frequency/100);
 108         ci->set_elapsed(elapsedtime);
 109       }
 110       ci->seek_complete();
 111     }
 112
 113     /* Request the required number of bytes from the input buffer */
 114     buffer=ci->request_buffer(&n, demux_res.sample_byte_size[i]);
 115     if (n!=demux_res.sample_byte_size[i]) {
 116         retval = CODEC_ERROR;
 117         goto done;
 118     }
 119
 120     /* Decode one block - returned samples will be host-endian */
 121     ci->yield();
 122     samplesdecoded=alac_decode_frame(&alac, buffer, outputbuffer, ci->yield);
 123
 124     /* Advance codec buffer by amount of consumed bytes */
 125     ci->advance_buffer(alac.bytes_consumed);
 126
 127     /* Output the audio */
 128     ci->yield();
 129     ci->pcmbuf_insert(outputbuffer[0], outputbuffer[1], samplesdecoded);
 130
 131     /* Update the elapsed-time indicator */
 132     samplesdone+=samplesdecoded;
 133     elapsedtime=(samplesdone*10)/(ci->id3->frequency/100);
 134     ci->set_elapsed(elapsedtime);
 135
 136     i++;
 137   }
 138
 139 done:
 140   LOGF("ALAC: Decoded %lu samples\n",(unsigned long)samplesdone);
 141
 142   if (ci->request_next_track())
 143    goto next_track;
 144
 145 exit:
 146   return retval;
 147 }