Re: [sc-users] [ot] new 24-bit wav file format

[Erik de Castro Lopo <sc-erikd@xxxxxxxxxxxxx>]

Bhob Rainey wrote:

> hey erik et al-
> 
> thanks for offering to help with this.  i put a small example file on 
> my site at http://bhobrainey.net/1015.WAV for anyone who feels like 
> looking at it.
> 
> i'm suspicious, as well, that there is actually a new wav 24bit format. 
>   couldn't find anything on it.  i asked marantz for specs.  they're 
> currently silent on the matter.

This is a standard 24 bit PCM WAV file using the WAVE_FORMAT_EXTENSIBLE
format marker.

Here's what libsndfile (pre-release) says about it:

    erikd@miles > sndfile-info 1015.WAV 
    
    Version : libsndfile-1.0.12pre10
    
    ========================================
    File : 1015.WAV
    Length : 118784
    RIFF : 118776
    WAVE
    fmt  : 40
      Format        : 0xFFFE => WAVE_FORMAT_EXTENSIBLE
      Channels      : 2
      Sample Rate   : 44100
      Block Align   : 6
      Bit Width     : 24
      Bytes/sec     : 264600
      Valid Bits    : 24
      Channel Mask  : 0x3
      Subformat
        esf_field1 : 0x1
        esf_field2 : 0x0
        esf_field3 : 0x10
        esf_field4 : 0x80 0x0 0x0 0xAA 0x0 0x38 0x9B 0x71 
    fact : 1972
      frames  : 0
    data : 116736
    End
    
    ----------------------------------------
    Sample Rate : 44100
    Frames      : 19456
    Channels    : 2
    Format      : 0x00130003
    Sections    : 1
    Seekable    : TRUE
    Duration    : 00:00:00.441
    Signal Max  : 8.38861e+06 (0.00 dB)

Openning it up in Sweep (a Linux audio editor which uses libsndfile
for file I/O) looks like this:

    http://www.mega-nerd.com/tmp/wav24.png

I haven't played the file because I don't want to wake my daughter
who is currently asleep, but it looks right, especially at the
end where there is some real audio.

I also tried the current release version os libsndfile (1.0.11)
and it also opened the file without problems.

Erik
-- 
+-----------------------------------------------------------+
  Erik de Castro Lopo  nospam@xxxxxxxxxxxxx (Yes it's valid)
+-----------------------------------------------------------+
"The problem with using C++ ... is that there's already a strong
tendency in the language to require you to know everything before
you can do anything." -- Larry Wall