apps/metadata/wavpack.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id:$
   9  *
  10  * Copyright (C) 2007 David Bryant
  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 #include <stdio.h>
  20 #include <string.h>
  21 #include <stdlib.h>
  22 #include <ctype.h>
  23 #include <inttypes.h>
  24
  25 #include "system.h"
  26 #include "id3.h"
  27 #include "metadata_common.h"
  28 #include "logf.h"
  29
  30 #define ID_UNIQUE               0x3f
  31 #define ID_LARGE                0x80
  32 #define ID_SAMPLE_RATE          0x27
  33
  34 static const long wavpack_sample_rates [] =
  35 {
  36      6000,  8000,  9600, 11025, 12000, 16000,  22050, 24000,
  37     32000, 44100, 48000, 64000, 88200, 96000, 192000
  38 };
  39
  40 /* A simple parser to read basic information from a WavPack file. This
  41  * now works with self-extrating WavPack files and also will scan the
  42  * metadata for non-standard sampling rates. This no longer fails on
  43  * WavPack files containing floating-point audio data because these are
  44  * now converted to standard Rockbox format in the decoder.
  45  */
  46
  47 bool get_wavpack_metadata(int fd, struct mp3entry* id3)
  48 {
  49     /* Use the trackname part of the id3 structure as a temporary buffer */
  50     unsigned char* buf = (unsigned char *)id3->path;
  51     uint32_t totalsamples, blocksamples;
  52     int i;
  53
  54     for (i = 0; i < 256; ++i) {
  55
  56         /* at every 256 bytes into file, try to read a WavPack header */
  57
  58         if ((lseek(fd, i * 256, SEEK_SET) < 0) || (read(fd, buf, 32) < 32))
  59             return false;
  60
  61         /* if valid WavPack 4 header version, break */
  62
  63         if (memcmp (buf, "wvpk", 4) == 0 && buf [9] == 4 &&
  64             (buf [8] >= 2 && buf [8] <= 0x10))
  65                 break;
  66     }
  67
  68     if (i == 256) {
  69         logf ("Not a WavPack file");
  70         return false;
  71     }
  72
  73     id3->vbr = true;   /* All WavPack files are VBR */
  74     id3->filesize = filesize (fd);
  75     totalsamples = get_long_le(&buf[12]);
  76     blocksamples = get_long_le(&buf[20]);
  77
  78     if (blocksamples && totalsamples != (uint32_t) -1) {
  79         int srindx = ((buf [26] >> 7) & 1) + ((buf [27] << 1) & 14);
  80
  81         if (srindx == 15) {
  82             uint32_t meta_bytes = buf [4] + (buf [5] << 8) + (buf [6] << 16) - 24;
  83             uint32_t meta_size;
  84
  85             id3->frequency = 44100;
  86
  87             while (meta_bytes >= 6) {
  88                 if (read(fd, buf, 2) < 2)
  89                     break;
  90
  91                 if (buf [0] & ID_LARGE) {
  92                     if (read(fd, buf + 2, 2) < 2)
  93                         break;
  94
  95                     meta_size = (buf [1] << 1) + (buf [2] << 9) + (buf [3] << 17);
  96                     meta_bytes -= meta_size + 4;
  97                 }
  98                 else {
  99                     meta_size = buf [1] << 1;
 100                     meta_bytes -= meta_size + 2;
 101
 102                     if ((buf [0] & ID_UNIQUE) == ID_SAMPLE_RATE) {
 103                         if (meta_size == 4 && read(fd, buf + 2, 4) == 4)
 104                             id3->frequency = buf [2] + (buf [3] << 8) + (buf [4] << 16);
 105
 106                         break;
 107                     }
 108                 }
 109
 110                 if (meta_size > 0 && lseek(fd, meta_size, SEEK_CUR) < 0)
 111                     break;
 112             }
 113         }
 114         else
 115             id3->frequency = wavpack_sample_rates[srindx];
 116
 117         id3->length = ((int64_t) totalsamples * 1000) / id3->frequency;
 118         id3->bitrate = filesize (fd) / (id3->length / 8);
 119     }
 120
 121     return true;
 122 }