Re: [ecasound] lossless conversion broken?

From: Kai Vehmanen <kvehmanen@email-addr-hidden>
Date: Thu Nov 04 2010 - 23:02:45 EET

Hi,

On Wed, 3 Nov 2010, Dan Muresan wrote:

> I looked at the code. I'm surprised at a different asymmetry -- the
> one between eca_sample_convert_float_to_s32 vs.
> eca_sample_convert_s32_to_float:
>
> int32_t eca_sample_convert_float_to_s32(float inval) {
> if (inval < 0.0f)
> return((int32_t)((float)(inval * (INT32_MAX))));
>
> return((int32_t)((float)(inval * INT32_MAX) - 0.5f));
> }

oh yes, thanks, I've been blind to that completely, that's not right at
all. Definitely a bug. It sure is depressing to find such stuff... :P

> I agree with the jackit threads -- introducing a nonlinear
> transformation in a chain is not a good thing (from a signals &
> systems POV). Sounds like 0x8000, symmetrical would be best for the
> future. I assume this breaks existing files, which is why you'd have
> to wait for a major release.

Yes, agreed.

------------------------------------------------------------------------------
The Next 800 Companies to Lead America's Growth: New Video Whitepaper
David G. Thomson, author of the best-selling book "Blueprint to a
Billion" shares his insights and actions to help propel your
business during the next growth cycle. Listen Now!
http://p.sf.net/sfu/SAP-dev2dev
_______________________________________________
Ecasound-list mailing list
Ecasound-list@email-addr-hidden
https://lists.sourceforge.net/lists/listinfo/ecasound-list
Received on Fri Nov 5 00:15:03 2010

This archive was generated by hypermail 2.1.8 : Fri Nov 05 2010 - 00:15:03 EET