[flac-dev] "keep qlp coeff precision such that only 32-bit math is required"

lvqcl lvqcl.mail at gmail.com
Sun Apr 19 13:36:54 PDT 2015

Martijn van Beurden wrote:

> Yes, indeed. I removed the 17-bits part because I just matched
> the code in evaluate_lpc_subframe_ with the process_subframe_
> code. It appears it only makes sense that those two pieces code
> are the same.

A bit of history:

1) The conditional "if(subframe_bps <= 16)" was added to evaluate_lpc_subframe_()
in the commit http://git.xiph.org/?p=flac.git;a=commitdiff;h=20ac2c1cac298b8c0666e191ae913f6481e79879

2) The conditional "if(subframe_bps <= 16)" was added to process_subframe_()
in the commit http://git.xiph.org/?p=flac.git;a=commitdiff;h=c9c0d130c562044e641e2cab09894213c5de4d88

3) The conditional in process_subframe_() was changed to "if(subframe_bps <= 17)"
in the commit http://git.xiph.org/?p=flac.git;a=commitdiff;h=df59845d04a3c43e3caea5d9838d08b9b17ba572

So the question is: why the condition in evaluate_lpc_subframe_() wasn't changed in this commit.
Maybe there were some reasons, but maybe Josh forgot about it.

More information about the flac-dev mailing list