[LAU] Creating a very long audio file?

[Paul Davis]

On Tue, Apr 2, 2013 at 3:12 PM, Paul Davis <paul at linuxaudiosystems.com>wrote:

>
>
> On Tue, Apr 2, 2013 at 2:35 PM, Monty Montgomery <xiphmont at gmail.com>wrote:
>
>> Regular WAV at ~CD rate is limited to about 5 hours because the length
>> encoding fields are 32 bit.  You need to generate an extended WAV with
>> the WAVEFORMATEXTENSIBLE struct that allows a 16 exabyte data chunk.
>> I'm a little surprised sox doesn't do that by default.
>>
>
> I wasn't aware that WAVEFORMATEXTENSIBLE covered file sizes - the spec
> seems to be mostly about "higher resolution" sample formats. what did i
> miss?
>

Specifically:

   "The WAVE_FORMAT_EXTENSIBLE format code indicates that there is an
extension to the Format chunk. The extension has one field which declares
the number of "valid" bits/sample (wValidBitsPerSample). Another field (
dwChannelMask) contains a bits which indicate the mapping from channels to
loudspeaker positions. The last field (SubFormat) is a 16-byte globally
unique identifier (GUID)."

it does not change the size of the size field of the RIFF or data chunks,
which is what matters here.
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