Slowness With Over an Hour of Audio

Programming and Development General Audio Programming
1

I am currently trying to work on Audacity for a course project and one of the things I would like to do is improve the slowness that occurs when you are dealing with over an hour of audio. I am trying to see if some underlying data structure or functionality could be improved to help this performance. I was wondering if this could have anything to do with the efficiency of the WaveClip or WaveTrack classes and file. Am I correct in understanding that these files handle the storage of the audio? If so, is this is a good place to look when trying to improve this sort of performance?

2

Audacity is a complete slave to the computer running it. I capture multiple hour long performances and cut and edit them just fine. How much memory do you have? What’s the speed of the computer? Windows? Which one?

Which Audacity?

What’s the size of your hard drive and how much space to you have left? When was the last time you did an error check and defragment? Wrong answers to any of these questions will restrict the size of show you can handle in Audacity.

Live audio (and video) is very stressful for a computer. It can’t stop and take a breath or pause while it shuffles files around. Performance sound happens right now and you can tell immediately when the computer isn’t up to it.

Koz

3

Someone else at nd.edu wrote to our feedback address asking the same questions.

With long tracks there is serious slowness on Windows with track redraws, and slowness in non-dialogue edits.

You may see it on Linux with a long enough track, but it may better to debug this on Windows.

Have you read the bug comments:
http://bugzilla.audacityteam.org/show_bug.cgi?id=218
http://bugzilla.audacityteam.org/show_bug.cgi?id=406

for views on what has been diagnosed so far?

Also see Missing features - Audacity Support (waveclip allows multiple clips to be a part of one WaveTrack).

I think the general consensus is that the waveform redrawing is consuming far too much CPU, some argue that Audacity may be saving (or at least reading) too much of the project to rewrite the data (instead of just looking at what changed), and most agree that Audacity may be autosaving too often.

However I am not a developer and they don’t hang out here, so you’d be better to do some research, then subscribe to audacity-devel ( audacity-devel List Signup and Options ) and ask there.


Thanks,


Gale