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   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     retval = CODEC_OK;
  52
  53   /* Clean and initialize decoder structures */
  54    memset(&demux_res , 0, sizeof(demux_res));
  55   if (codec_init()) {
  56     LOGF("ALAC: Error initialising codec\n");
  57     retval = CODEC_ERROR;
  58     goto exit;
  59   }
  60
  61   if (codec_wait_taginfo() != 0)
  62     goto done;
  63
  64   ci->configure(DSP_SWITCH_FREQUENCY, ci->id3->frequency);
  65   codec_set_replaygain(ci->id3);
  66
  67   stream_create(&input_stream,ci);
  68
  69   /* Read from ci->id3->offset before calling qtmovie_read. */
  70   samplesdone = (uint32_t)(((uint64_t)(ci->id3->offset) * ci->id3->frequency) /
  71                 (ci->id3->bitrate*128));
  72
  73   /* if qtmovie_read returns successfully, the stream is up to
  74    * the movie data, which can be used directly by the decoder */
  75   if (!qtmovie_read(&input_stream, &demux_res)) {
  76     LOGF("ALAC: Error initialising file\n");
  77     retval = CODEC_ERROR;
  78     goto done;
  79   }
  80
  81   /* initialise the sound converter */
  82   create_alac(demux_res.sound_sample_size, demux_res.num_channels,&alac);
  83   alac_set_info(&alac, demux_res.codecdata);
  84
  85   /* Set i for first frame, seek to desired sample position for resuming. */
  86   i=0;
  87   if (samplesdone > 0) {
  88     if (alac_seek(&demux_res, &input_stream, samplesdone,
  89                   &samplesdone, (int*) &i)) {
  90         elapsedtime = (samplesdone * 10) / (ci->id3->frequency / 100);
  91         ci->set_elapsed(elapsedtime);
  92     } else {
  93         samplesdone = 0;
  94     }
  95   }
  96
  97   /* The main decoding loop */
  98   while (i < demux_res.num_sample_byte_sizes) {
  99     ci->yield();
 100     if (ci->stop_codec || ci->new_track) {
 101       break;
 102     }
 103
 104     /* Deal with any pending seek requests */
 105     if (ci->seek_time) {
 106       if (alac_seek(&demux_res, &input_stream,
 107                     ((ci->seek_time-1)/10) * (ci->id3->frequency/100),
 108                     &samplesdone, (int *)&i)) {
 109         elapsedtime=(samplesdone*10)/(ci->id3->frequency/100);
 110         ci->set_elapsed(elapsedtime);
 111       }
 112       ci->seek_complete();
 113     }
 114
 115     /* Lookup the length (in samples and bytes) of block i */
 116     if (!get_sample_info(&demux_res, i, &sample_duration,
 117                          &sample_byte_size)) {
 118       LOGF("ALAC: Error in get_sample_info\n");
 119       retval = CODEC_ERROR;
 120       goto done;
 121     }
 122
 123     /* Request the required number of bytes from the input buffer */
 124
 125     buffer=ci->request_buffer(&n,sample_byte_size);
 126     if (n!=sample_byte_size) {
 127         retval = CODEC_ERROR;
 128         goto done;
 129     }
 130
 131     /* Decode one block - returned samples will be host-endian */
 132     ci->yield();
 133     samplesdecoded=alac_decode_frame(&alac, buffer, outputbuffer, ci->yield);
 134
 135     /* Advance codec buffer n bytes */
 136     ci->advance_buffer(n);
 137
 138     /* Output the audio */
 139     ci->yield();
 140     ci->pcmbuf_insert(outputbuffer[0], outputbuffer[1], samplesdecoded);
 141
 142     /* Update the elapsed-time indicator */
 143     samplesdone+=sample_duration;
 144     elapsedtime=(samplesdone*10)/(ci->id3->frequency/100);
 145     ci->set_elapsed(elapsedtime);
 146
 147     i++;
 148   }
 149
 150 done:
 151   LOGF("ALAC: Decoded %lu samples\n",(unsigned long)samplesdone);
 152
 153   if (ci->request_next_track())
 154    goto next_track;
 155
 156 exit:
 157   return retval;
 158 }