apps/metadata/au.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2010 Yoshihisa Uchida
  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 #include <stdio.h>
  22 #include <string.h>
  23 #include <inttypes.h>
  24
  25 #include "system.h"
  26 #include "metadata.h"
  27 #include "metadata_common.h"
  28 #include "metadata_parsers.h"
  29 #include "logf.h"
  30
  31 static const unsigned char bitspersamples[9] = {
  32     0,  /* encoding */
  33     8,  /* 1:  G.711 MULAW      */
  34     8,  /* 2:  Linear PCM 8bit  */
  35     16, /* 3:  Linear PCM 16bit */
  36     24, /* 4:  Linear PCM 24bit */
  37     32, /* 5:  Linear PCM 32bit */
  38     32, /* 6:  IEEE float 32bit */
  39     64, /* 7:  IEEE float 64bit */
  40         /* encoding 8 - 26 unsupported. */
  41     8,  /* 27: G.711 ALAW       */
  42 };
  43
  44 static inline unsigned char get_au_bitspersample(unsigned int encoding)
  45 {
  46     if (encoding < 8)
  47         return bitspersamples[encoding];
  48     else if (encoding == 27)
  49         return bitspersamples[8];
  50
  51     return 0;
  52 }
  53
  54 bool get_au_metadata(int fd, struct mp3entry* id3)
  55 {
  56     /* temporary buffer */
  57     unsigned char* buf = (unsigned char *)id3->path;
  58     unsigned long numbytes = 0;
  59     int offset;
  60
  61     id3->vbr      = false;   /* All Sun audio files are CBR */
  62     id3->filesize = filesize(fd);
  63     id3->length   = 0;
  64
  65     lseek(fd, 0, SEEK_SET);
  66     if ((read(fd, buf, 24) < 24) || (memcmp(buf, ".snd", 4) != 0))
  67     {
  68         /*
  69          * no header
  70          *
  71          * frequency:       8000 Hz
  72          * bits per sample: 8 bit
  73          * channel:         mono
  74          */
  75         numbytes = id3->filesize;
  76         id3->frequency = 8000;
  77         id3->bitrate   = 8;
  78     }
  79     else
  80     {
  81         /* parse header */
  82
  83         /* data offset */
  84         offset = get_long_be(buf + 4);
  85         if (offset < 24)
  86         {
  87             DEBUGF("CODEC_ERROR: sun audio offset size is small: %d\n", offset);
  88             return false;
  89         }
  90         /* data size */
  91         numbytes = get_long_be(buf + 8);
  92         if (numbytes == (uint32_t)0xffffffff)
  93             numbytes = id3->filesize - offset;
  94
  95         id3->frequency = get_long_be(buf + 16);
  96         id3->bitrate = get_au_bitspersample(get_long_be(buf + 12)) * get_long_be(buf + 20)
  97                                                                    * id3->frequency / 1000;
  98     }
  99
 100     /* Calculate track length [ms] */
 101     if (id3->bitrate)
 102         id3->length = (numbytes << 3) / id3->bitrate;
 103
 104     return true;
 105 }