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 /* The maximum buffer size handled. This amount of bytes is buffered for each
  29  * frame. */
  30 #define ALAC_BYTE_BUFFER_SIZE 32768
  31
  32 static int32_t outputbuffer[ALAC_MAX_CHANNELS][ALAC_BLOCKSIZE] IBSS_ATTR;
  33
  34 /* this is the codec entry point */
  35 enum codec_status codec_main(enum codec_entry_call_reason reason)
  36 {
  37     if (reason == CODEC_LOAD) {
  38         /* Generic codec initialisation */
  39         ci->configure(DSP_SET_STEREO_MODE, STEREO_NONINTERLEAVED);
  40         ci->configure(DSP_SET_SAMPLE_DEPTH, ALAC_OUTPUT_DEPTH-1);
  41     }
  42
  43     return CODEC_OK;
  44 }
  45
  46 /* this is called for each file to process */
  47 enum codec_status codec_run(void)
  48 {
  49     size_t n;
  50     demux_res_t demux_res;
  51     stream_t input_stream;
  52     uint32_t samplesdone;
  53     uint32_t elapsedtime = 0;
  54     int samplesdecoded;
  55     unsigned int i;
  56     unsigned char* buffer;
  57     alac_file alac;
  58     intptr_t param;
  59
  60     /* Clean and initialize decoder structures */
  61     memset(&demux_res , 0, sizeof(demux_res));
  62     if (codec_init()) {
  63         LOGF("ALAC: Error initialising codec\n");
  64         return CODEC_ERROR;
  65     }
  66
  67     ci->configure(DSP_SWITCH_FREQUENCY, ci->id3->frequency);
  68     codec_set_replaygain(ci->id3);
  69
  70     ci->seek_buffer(0);
  71
  72     stream_create(&input_stream,ci);
  73
  74     /* Read from ci->id3->offset before calling qtmovie_read. */
  75     samplesdone = (uint32_t)(((uint64_t)(ci->id3->offset) * ci->id3->frequency) /
  76                   (ci->id3->bitrate*128));
  77
  78     /* if qtmovie_read returns successfully, the stream is up to
  79      * the movie data, which can be used directly by the decoder */
  80     if (!qtmovie_read(&input_stream, &demux_res)) {
  81         LOGF("ALAC: Error initialising file\n");
  82         return CODEC_ERROR;
  83     }
  84
  85     /* initialise the sound converter */
  86     create_alac(demux_res.sound_sample_size, demux_res.num_channels,&alac);
  87     alac_set_info(&alac, demux_res.codecdata);
  88
  89     /* Set i for first frame, seek to desired sample position for resuming. */
  90     i=0;
  91     if (samplesdone > 0) {
  92         if (m4a_seek(&demux_res, &input_stream, samplesdone,
  93                       &samplesdone, (int*) &i)) {
  94             elapsedtime = (samplesdone * 10) / (ci->id3->frequency / 100);
  95             ci->set_elapsed(elapsedtime);
  96         } else {
  97             samplesdone = 0;
  98         }
  99     }
 100
 101     /* The main decoding loop */
 102     while (i < demux_res.num_sample_byte_sizes) {
 103         enum codec_command_action action = ci->get_command(&param);
 104
 105         if (action == CODEC_ACTION_HALT)
 106             break;
 107
 108         /* Request the required number of bytes from the input buffer */
 109         buffer=ci->request_buffer(&n, ALAC_BYTE_BUFFER_SIZE);
 110
 111         /* Deal with any pending seek requests */
 112         if (action == CODEC_ACTION_SEEK_TIME) {
 113             if (m4a_seek(&demux_res, &input_stream,
 114                          (param/10) * (ci->id3->frequency/100),
 115                          &samplesdone, (int *)&i)) {
 116                 elapsedtime=(samplesdone*10)/(ci->id3->frequency/100);
 117             }
 118             ci->set_elapsed(elapsedtime);
 119             ci->seek_complete();
 120         }
 121
 122         /* Request the required number of bytes from the input buffer */
 123         buffer=ci->request_buffer(&n, ALAC_BYTE_BUFFER_SIZE);
 124
 125         /* Decode one block - returned samples will be host-endian */
 126         samplesdecoded=alac_decode_frame(&alac, buffer, outputbuffer, ci->yield);
 127         ci->yield();
 128
 129         /* Advance codec buffer by amount of consumed bytes */
 130         ci->advance_buffer(alac.bytes_consumed);
 131
 132         /* Output the audio */
 133         ci->pcmbuf_insert(outputbuffer[0], outputbuffer[1], samplesdecoded);
 134
 135         /* Update the elapsed-time indicator */
 136         samplesdone+=samplesdecoded;
 137         elapsedtime=(samplesdone*10)/(ci->id3->frequency/100);
 138         ci->set_elapsed(elapsedtime);
 139
 140         i++;
 141     }
 142
 143     LOGF("ALAC: Decoded %lu samples\n",(unsigned long)samplesdone);
 144     return CODEC_OK;
 145 }