[ecasound] Re: W64 format conversion correctness

From: Free Lunch <freelunch@email-addr-hidden>
Date: Sat May 28 2005 - 18:27:48 EEST


Any thoughts on this? This should be bit-correct, right?

My alternative to being able to use W64 is, apparently, to write some
kludgey scripts to try and get ecasound to split files while recording
but not losing any data. Any hints on how to do that in an un-kludgey
fashion would be appreciated.



On 5/20/05, Free Lunch <freelunch@email-addr-hidden> wrote:
> Hello,
> I have been looking at using W64 to get around the 2 GB file limits
> when recording to WAV with ecasound. I would prefer to have automatic
> splits with WAV but don't think it is supported.
> I ran some tests converting an 8 MB CD format WAV file to W64 and back
> to WAV. I then compared the original and new WAV via phase inversion.
> The results were more noisy than I expected. Baudline reported around
> 15dB at low frequencies.
> When I repeat this test using a copy of the original WAV in place of
> the W64 converted version, the inverted result appears perfect (no
> sound). So I don't think this is a sox issue.
> I considered that my AMD64 system might be part of the problem but
> received similar results on an Athlon XP. Both systems run Gentoo.
> I'm wondering why this conversion isn't perfect and whether it could be?
> On a more positive note, ecasound has been working great.
> Thank you!
> FL
> Command history for test cases
> "Control case"
> cp orig.wav orig.copy.wav
> # Phase invert copy of original
> sox orig.copy.wav -v -1.0 orig.copy.invert.wav
> # Mix original and inverted. Should cancel.
> soxmix orig.wav orig.copy.invert.wav orig.copy.invert.mix.wav
> # Review result
> baudline orig.copy.invert.mix.wav
> "Test case"
> # Convert original to W64
> ecaconvert .w64 orig.wav
> # Convert W64 back to WAV
> ecaconvert .wav orig.wav.w64
> # Mix inverted copy of original with test file
> soxmix orig.copy.invert.wav orig.wav.w64.wav orig.wav.w64.mix.wav
> # Review result
> baudline orig.wav.w64.mix.wav

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Received on Sat May 28 20:15:09 2005

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