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  * All files in this archive are subject to the GNU General Public License.
  13  * See the file COPYING in the source tree root for full license agreement.
  14  *
  15  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  16  * KIND, either express or implied.
  17  *
  18  ****************************************************************************/
  19
  20 #include "codeclib.h"
  21 #include "libm4a/m4a.h"
  22 #include "libalac/decomp.h"
  23
  24 CODEC_HEADER
  25
  26 int32_t outputbuffer[ALAC_MAX_CHANNELS][ALAC_BLOCKSIZE] IBSS_ATTR;
  27
  28 /* this is the codec entry point */
  29 enum codec_status codec_main(void)
  30 {
  31   size_t n;
  32   demux_res_t demux_res;
  33   stream_t input_stream;
  34   uint32_t samplesdone;
  35   uint32_t elapsedtime;
  36   uint32_t sample_duration;
  37   uint32_t sample_byte_size;
  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(CODEC_SET_FILEBUF_WATERMARK, 1024*512);
  46   ci->configure(CODEC_SET_FILEBUF_CHUNKSIZE, 1024*128);
  47
  48   ci->configure(DSP_SET_STEREO_MODE, STEREO_NONINTERLEAVED);
  49   ci->configure(DSP_SET_SAMPLE_DEPTH, ALAC_OUTPUT_DEPTH-1);
  50
  51   next_track:
  52
  53   if (codec_init()) {
  54     LOGF("ALAC: Error initialising codec\n");
  55     retval = CODEC_ERROR;
  56     goto exit;
  57   }
  58
  59   while (!*ci->taginfo_ready && !ci->stop_codec)
  60     ci->sleep(1);
  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   /* if qtmovie_read returns successfully, the stream is up to
  68    * the movie data, which can be used directly by the decoder */
  69   if (!qtmovie_read(&input_stream, &demux_res)) {
  70     LOGF("ALAC: Error initialising file\n");
  71     retval = CODEC_ERROR;
  72     goto done;
  73   }
  74
  75   /* initialise the sound converter */
  76   create_alac(demux_res.sound_sample_size, demux_res.num_channels,&alac);
  77   alac_set_info(&alac, demux_res.codecdata);
  78
  79   i=0;
  80   samplesdone=0;
  81   /* The main decoding loop */
  82   while (i < demux_res.num_sample_byte_sizes) {
  83     ci->yield();
  84     if (ci->stop_codec || ci->new_track) {
  85       break;
  86     }
  87
  88     /* Deal with any pending seek requests */
  89     if (ci->seek_time) {
  90       if (alac_seek(&demux_res, &input_stream,
  91                     ((ci->seek_time-1)/10) * (ci->id3->frequency/100),
  92                     &samplesdone, (int *)&i)) {
  93         elapsedtime=(samplesdone*10)/(ci->id3->frequency/100);
  94         ci->set_elapsed(elapsedtime);
  95       }
  96       ci->seek_complete();
  97     }
  98
  99     /* Lookup the length (in samples and bytes) of block i */
 100     if (!get_sample_info(&demux_res, i, &sample_duration,
 101                          &sample_byte_size)) {
 102       LOGF("ALAC: Error in get_sample_info\n");
 103       retval = CODEC_ERROR;
 104       goto done;
 105     }
 106
 107     /* Request the required number of bytes from the input buffer */
 108
 109     buffer=ci->request_buffer(&n,sample_byte_size);
 110     if (n!=sample_byte_size) {
 111         retval = CODEC_ERROR;
 112         goto done;
 113     }
 114
 115     /* Decode one block - returned samples will be host-endian */
 116     ci->yield();
 117     samplesdecoded=alac_decode_frame(&alac, buffer, outputbuffer, ci->yield);
 118
 119     /* Advance codec buffer n bytes */
 120     ci->advance_buffer(n);
 121
 122     /* Output the audio */
 123     ci->yield();
 124     ci->pcmbuf_insert(outputbuffer[0], outputbuffer[1], samplesdecoded);
 125
 126     /* Update the elapsed-time indicator */
 127     samplesdone+=sample_duration;
 128     elapsedtime=(samplesdone*10)/(ci->id3->frequency/100);
 129     ci->set_elapsed(elapsedtime);
 130
 131     /* Keep track of current position - for resuming */
 132     ci->set_offset(elapsedtime);
 133
 134     i++;
 135   }
 136   retval = CODEC_OK;
 137
 138 done:
 139   LOGF("ALAC: Decoded %ld samples\n",samplesdone);
 140
 141   if (ci->request_next_track())
 142    goto next_track;
 143
 144 exit:
 145   return retval;
 146 }