Re: [Audacity-devel] Reassigned spectrograms

[Paul L. <pau...@gm...>]

On Tue, Aug 18, 2015 at 8:02 AM, James Crook <cr...@in...> wrote:

> Spectral reassignment is in for 2.1.2.
>
> It is a super feature, and 'local' in that bugs in it are unlikely to
> affect anything else.  Its bugs are mostly likely to be around quality of
> its own display, i.e. not reassigning as finely as we might like.  It was
> being worked on already in 2.1.1 rather than being completely new.
>
>
> The track menu changes now give us something better than we had in 2.1.1,
> and (as RM) that's good enough to justify making them.  As me, I think
> there is still something not as good as it should be in how we select track
> options, but I can't put my finger on it, and it does not scream enough to
> me to worry about it for 2.1.2.
>
>
> I think Steve you are right to worry.  We have a tremendous amount of
> technical debt caused by the wx change.  3P1s, and 8 DEVEL-FIX-MADE P1s
> which are pending confirmation that they have been fixed (without breaking
> something else important).  Any changes as big as spectral reassignment
> intended for 2.1.2 from here on need to ask "Is it OK?" on this list and
> the answer is probably no.  Minor features/improvements are definitely OK
> and in particular picks for these ones from Gale's wishlist:
>
>
>    - Option to turn off backwards scrubbing OR a modified click that
>    automatically plays forward from the seek point. This is to reduce
>    un-necessary RSI after seek.
>    - Some TLC for those who do large amount of daily export and import:
>       - Bug 550 – Add Directories Preference to export to directory the
>       file came from
>       <http://bugzilla.audacityteam.org/show_bug.cgi?id=550>
>       - Related to above, easier one-step overwrite of the same file you
>       imported.
>       - Bug 549 – Add missing export formats to Chains
>       <http://bugzilla.audacityteam.org/show_bug.cgi?id=549> and Chains
>       export format parameters and sample rate
>       <http://wiki.audacityteam.org/wiki/Feature_Requests#Improvements_to_the_.22Chains.22_.28batch_processing.29_feature>
>       - Bug 551 – Export Multiple: Pass through common metadata to next
>       window <http://bugzilla.audacityteam.org/show_bug.cgi?id=551>
>       - Support per-track metadata so that if you import multiple files
>       you can export multiple using each file's metadata instead of export all
>       files with only the last file's metadata
>       - Bug 701 - Embedded album art and lyrics discarded
>       <http://bugzilla.audacityteam.org/show_bug.cgi?id=701>.
>
>
> I would like to see some more work on noise reduction to make it
> better/easier to use.  I would like Paul to set a colour for spectral
> selection that he is happy with to replace the yellow.  We are leaving
> 'rough edges'.  We do have until 30th August before Semifreddo.
>

Oh, the colors?  I had hoped to see Luciano's work in this release, but it
sounds like it's disqualified for now.

I never liked the yellow highlights much, and if we did have Luciano's
different palettes, then the yellowing might not be right for every one of
them.  Originally I just used two degrees of dimming.  We could return to
that, but I recall that didn't satisfy everyone either.  Or, I think it was
also suggested that the bold and dashed lines are enough.


>
> Steve, does this answer your concerns?
>
> --James.
>
>
>
> On 18/08/2015 11:39, Steve the Fiddle wrote:
>
> I'm just wondering why we are seeing so many new features introduced
> for the 2.1.2 release. I thought that this release was about updating
> to Wx3. My concern with so many changes in this release is that either
> quality suffers or the release is seriously delayed. Perhaps James can
> comment and reassure us that it is all in hand?
>
> Steve
>
> On 17 August 2015 at 15:40, Paul Licameli <pau...@gm...> <pau...@gm...> wrote:
>
> I don't think it's "experimental" any more, I think I got all the math right
> now.
>
> There are opportunities for more efficiency.  It is true that caching of
> results leaves something to be desired for some changes of view, but that is
> already true of spectrograms generally.  There is no caching of any
> spectrograms for changes of zoom level.  There is some caching only for
> scrolling left and right without changing the zoom, and that much won't work
> now with reassignment.
>
> I consider any such effort for performance a future project.
>
> PRL
>
>
> On Mon, Aug 17, 2015 at 10:28 AM, Steve the Fiddle<ste...@gm...> <ste...@gm...> wrote:
>
> Is this an experimental feature?
>
> Steve
>
> On 17 August 2015 at 15:18, Paul Licameli <pau...@gm...> <pau...@gm...> wrote:
>
> As of
> https://github.com/audacity/audacity/commit/3ddbbd375d6963838b91fe2f54c91df96d90e79a
>
> Now reassignment is a third algorithm choice in spectrograms preferences
> and
> view settings.
>
> This is an algorithm that sharpens the results of a spectrogram.  It
> works
> by computing two extra FFTs using different windowing functions.  The
> contributions that the usual FFT makes to pixels on the screen, are in
> effect moved slightly using results of the other FFTs.  This can
> counteract
> both the "time smearing" and "frequency smearing" effects.
>
> But not only is this spectrogram about three times as costly to compute
> -- I
> also had to disable the caching that allows horizontal scrolling of
> spectrograms to go faster.  This sort of caching is important for
> scroll-scrub with spectrogram on.
>
> The zero padding of spectrograms that I implemented in the last version
> was
> meant to accompany this.
>
> Try it out with tones and chirps -- you will find just a thin bright
> line,
> even if your window size is small!
>
> Try it with an impulse -- you will find a bright vertical line, even if
> your
> window size is large!
>
> Try it with real world examples -- and it is true there are strange
> artifacts from "cross terms" if you have two or more sources of sound,
> or
> inharmonic sounds, which make a sort of gauzy pattern as in this
> article.https://en.wikipedia.org/wiki/Reassignment_method
>
>
> PRL
>
>
>
>
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