[opus] SPEEX and OPUS questions and minor issues

[Tristan Matthews]

Hi,

On Fri, Jul 29, 2016 at 1:50 PM, dos386 <dos386 at gmail.com> wrote:
> I recently stumbled upon <speex/speex_resampler.h> and made a chain of
> discoveries:
>
> - "http://speex.org/downloads" some links are broken ("rarewares" and git)

What do you mean by broken? Those links seem to work here.

> - there is some (minor) development (whitespace and more) of the "dead" Speex
> codec ... will there be a release? (I don't really need such myself)

Eventually, yes.

> - there is some (more useful?) development of the "Speex DSP" part
> split off in 2009 ... will there be a release? Maybe the page should
> document the Speex codec is deprecated but "Speex DSP" is not? Maybe
> "Speex DSP" could have a better "home" than in "shadow" of the dead
> Speex codec?

Development has mostly focused on the resampler, as this is the most
widely used module in speexdsp. There was talk of splitting the
resampler into its own lib, however it's not clear if it would really
be worth it.

> - documentation of "Speex DSP" ... the latest release
> "speexdsp-1.2rc3.tar.gz" from 2015 still contains "The Speex Codec
> Manual Version 1.2 Beta 3" from 2007 ... it documents the codec part,
> not the DSP part ... maybe the documentation should be updated and
> split off too?

This is on my TODO, however since it doesn't involve coding this would
be an easy-ish task for a newcomer to tackle.

>
> - file "resample.c"
> - - note "This resampler is relatively new" maybe no longer true

Relative to other resamplers I guess it's still "relatively new".

> - - link "http://www-ccrma.stanford.edu/~jos/resample" broken (delete "www-")

Fixed, thanks.

> - - is "FIXED_POINT" supposed to work? There seems to be some "semi-translated"
> code ...

It should work, are you having bugs with fixed-point?

> - the resample code from "Speex DSP" is used in OPUS TOOLS ...version
> 0.1.9 from 2014 contains an outdated version of the resampling code
> from 2009 with minimal modifications ... maybe it should be
> synchronized with the code inside "Speex DSP"?

This is also on my TODO. Thanks for your feedback.

Best,
Tristan