Sox generates WAV files which the Tascam DP32SD multitrack recorder can not understand

[Sam Trenholme <strenholme.usenet@gmail.com>]

Without modifying the header, the Tascam DP-32SD (a stand-alone
digital multitrack recorder) is unable to “grok” (acknowledge as a
valid .WAV file) a 24-bit 44.1khz monophonic .WAV file generated by
sox.

Because of this, the Tascam DP-32SD is unable to import 24-bit/44.1
SoX-generated files via the “Audio Depot” unless the .WAV header is
altered.

==Steps to reproduce==

Use the SoX program to generate a 24-bit wav file. For example:

sox foo.wav -b24 bar.wav gain -9

Put the resulting bar.wav file in the “Audio Depot” folder, and
attempt to import the file in to the DP32SD.

==Expected results==

The file is visible and can be imported in to the DP-32SD.

==Actual results==

WAV files generated by Sox are not visible in the DP-32SD until they
are altered.

Technical details

A Tascam DP-32SD has, for an “audio depot” 24/44.1 file header, the
following bytes (this is “hexdump” format; the numbers on the left are
hexadecimal numbers; the ASCII that follows is a representation of the
data):

00000000 52 49 46 46 XX XX XX XX 57 41 56 45 66 6d 74 20 |RIFF....WAVEfmt |
00000010 10 00 00 00 01 00 01 00 44 ac 00 00 cc 04 02 00 |........D.......|
00000020 03 00 18 00 64 61 74 61 WW WW WW WW WW WW WW WW |....data........|

The “XX” bytes above are a 32-bit little-endian representation of the
length of the file, and vary depending on the file length. “WW” is
audio data.

SoX, on the other hand, generates a 24/44.1 wav file with the following header:

00000000 52 49 46 46 XX XX XX XX 57 41 56 45 66 6d 74 20 |RIFF....WAVEfmt |
00000010 28 00 00 00 fe ff 01 00 44 ac 00 00 cc 04 02 00 |(.......D.......|
00000020 03 00 18 00 16 00 18 00 04 00 00 00 01 00 00 00 |................|
00000030 00 00 10 00 80 00 00 aa 00 38 9b 71 66 61 63 74 |.........8.qfact|
00000040 04 00 00 00 14 f5 5f 00 64 61 74 61 WW WW WW WW |......_.data....|

Again “XX” is length, and “WW” is audio data.

The following C program takes a Sox-generated 24/44.1 Wav file on the
standard input, and outputs a DP-32SD compatible file:

// Public Domain 2015 Sam Trenholme

// The DP32SD can not grok 24-bit/44.1 WAV files generated by SOX. This
// fixes the headers so that Tascam's DP32SD can understand them.

// Standard input: SOX-generated WAV file
// Standard output: DP32SD-comparible WAV file

#include <stdio.h>

main() {
int b;
int a;
for(a=0;a<16;a++) {
b = getc(stdin);
printf("%c",b);
}
int c;
printf("%c%c%c%c%c%c%c%c",0x10,0,0,0,1,0,1,0);
printf("%c%c%c%c%c%c%c%c",0x44,0xac,0,0,0xcc,4,2,0);
printf("%c%c%c%cdata",3,0,0x18,0);
for(a=0;a<60;a++) { getc(stdin); }
while(!feof(stdin)) {
b=getc(stdin);
if(!feof(stdin)) {printf("%c",b);}
}
}

- Sam

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