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 <stdlib.h>
  24 #include <ctype.h>
  25 #include <inttypes.h>
  26
  27 #include "system.h"
  28 #include "metadata.h"
  29 #include "metadata_common.h"
  30 #include "metadata_parsers.h"
  31 #include "logf.h"
  32
  33 static const unsigned char bitspersamples[28] = {
  34     0,
  35     8,  /* G.711 MULAW */
  36     8,  /* 8bit  */
  37     16, /* 16bit */
  38     24, /* 24bit */
  39     32, /* 32bit */
  40     32, /* 32bit */
  41     64, /* 64bit */
  42     0,  /* Fragmented sample data */
  43     0,  /* DSP program */
  44     0,  /* 8bit fixed point */
  45     0,  /* 16bit fixed point */
  46     0,  /* 24bit fixed point */
  47     0,  /* 32bit fixed point */
  48     0,
  49     0,
  50     0,
  51     0,
  52     0,  /* 16bit linear with emphasis */
  53     0,  /* 16bit linear compressed */
  54     0,  /* 16bit linear with emphasis and compression */
  55     0,  /* Music kit DSP commands */
  56     0,
  57     0,  /* G.721 MULAW */
  58     0,  /* G.722 */
  59     0,  /* G.723 3bit */
  60     0,  /* G.723 5bit */
  61     8,  /* G.711 ALAW */
  62 };
  63
  64 static int get_au_bitspersample(unsigned int encoding)
  65 {
  66     if (encoding > 27)
  67         return 0;
  68     return bitspersamples[encoding];
  69 }
  70
  71 bool get_au_metadata(int fd, struct mp3entry* id3)
  72 {
  73     /* Use the trackname part of the id3 structure as a temporary buffer */
  74     unsigned char* buf = (unsigned char *)id3->path;
  75     unsigned long totalsamples = 0;
  76     unsigned long channels = 0;
  77     unsigned long bitspersample = 0;
  78     unsigned long numbytes = 0;
  79     int read_bytes;
  80     int offset;
  81
  82     id3->vbr = false;   /* All Sun audio files are CBR */
  83     id3->filesize = filesize(fd);
  84
  85     if ((lseek(fd, 0, SEEK_SET) < 0) || ((read_bytes = read(fd, buf, 24)) < 0))
  86         return false;
  87
  88     if (read_bytes < 24 || (memcmp(buf, ".snd", 4) != 0))
  89     {
  90         /* no header */
  91         numbytes = id3->filesize;
  92         bitspersample = 8;
  93         id3->frequency = 8000;
  94         channels = 1;
  95     }
  96     else
  97     {
  98         /* data offset */
  99         offset = get_long_be(buf + 4);
 100         if (offset < 24)
 101         {
 102             DEBUGF("CODEC_ERROR: sun audio offset size is small: %d\n", offset);
 103             return false;
 104         }
 105         /* data size */
 106         numbytes = get_long_be(buf + 8);
 107         if (numbytes == (uint32_t)0xffffffff)
 108             numbytes = id3->filesize - offset;
 109         /* bitspersample */
 110         bitspersample = get_au_bitspersample(get_long_be(buf + 12));
 111         /* sample rate */
 112         id3->frequency = get_long_be(buf + 16);
 113         channels = get_long_be(buf + 20);
 114     }
 115
 116     totalsamples = numbytes / ((((bitspersample - 1) / 8) + 1) * channels);
 117
 118     /* Calculate track length (in ms) and estimate the bitrate (in kbit/s) */
 119     id3->length = ((int64_t) totalsamples * 1000) / id3->frequency;
 120
 121     return true;
 122 }