100% cpu usage

[george13]

Hello mchinen,

Those two screenshots are both after using the "generate" menu. In the first case it went well, in the second case cpu went to (and stayed at) 100%. Yes, it could be that I loaded a file before using generate (in the 'benign' case). I found that once a file has been loaded and the cpu hasn't gone up it stays down subsequently.

Your second question: I have never seen any striped blocks. File loading hasn't changed (the waveform shows when the file is fully loaded)

import.png (20.85 KiB) Viewed 2097 times

Btw.: Importing a file just after startup of audacity and then cancelling the import while it is underway, seems to be a sure way to get the 100% cpu issue.

As to your third question, my computer is a 1.6Ghz PPC with one cpu, so not very fast, but shouldn't be too slow either.

Anyway, thanks for your work (I'm not complaining, just trying to be helpful).

[george13]

O.k. Now I have seen the blocked stripes for the first time. You have to enable "load uncompressed audio files directly" in the preferences. This is very cool. An 1 hour long wav file that normally takes 5 Minutes to load plays right away!

About the crash: ffmpeg library is not installed here, so maybe that caused the crash, but it shouldn't crash anyway.

[mchinen]

When the next alpha comes out on August 1st or 2nd, that bug *should* be fixed.

You'll also be able to control the loading point of the striped blocks.

[george13]

Hi! I just tried the latest Alpha version and I'd like to report that this bug is gone for me. No more 100%!

Not related, I read in the developer mailling list (I'm no subscriber so I can't respond there) about a "exporting
silence" bug: Have you checked if you have turned off dither? I get no noise when turning dither off (when exporting 16 bit wav).

[george13]

Oh, I'm afraid, sometimes it happens again. In the status bar it says something like "2 on demand tasks running. 0% completed." although there is nothing to do.

[Gale Andrews]

I read in the developer mailling list (I'm no subscriber so I can't respond there) about a "exporting silence" bug: Have you checked if you have turned off dither? I get no noise when turning dither off (when exporting 16 bit wav).

Hi George - you're quite right the dither (the point of which is adding noise to hide quantisation errors when downsampling) is causing the noise. We'll have to see if there is some way to handle silence better.

If Michael does not notice this, I'll ask him to drop by.

Thanks

Gale

[mchinen]

There were a lot of changes, so it may be fixed now, but the changes won't be propagated down till the new alpha on the 18th. Anyway, I haven't seen it, please let me know if there is some set of reproducible steps I can take to recreate it. If it was related to saving, or after saving, that used to be broken.

Thanks-

[Gale Andrews]

There were a lot of changes, so it may be fixed now, but the changes won't be propagated down till the new alpha on the 18th.

Actually you could help us sooner by trying one of the nightly builds here:
http://www.audacity.homerow.net/index.php?dir=mac%2F

A build dated the 10th August or later from the bottom of the list (still waiting for one at time of writing) should incorporate Michael's latest threading fixes.


Gale

[george13]

Hi,
I tried today's build and the issue is still there, unfortunately. Importing worked o.k with many smaller files (even in parallel), but with a very large file the on-demand thing went wrong again (it's a 900MB 24bit 48Khz aiff File, 55 Minutes, to be precise). I could play and edit the file, but it never showed the waveform, it said 'calculating waveform 0% complete'; cpu went to 100% and stayed there, plus I had to force-quit Audacity each time I tried this.

[Gale Andrews]

Hi George

Thanks for the report. Just to clarify, when you were importing the MP3 in your screenshot, you would not see the on-demand loading stripes, because on-demand does not work for MP3s. Nor should you have been seeing any messages about waveform calculations in the Status Bar.

When you were importing the AIFF, you would see the stripy waveform and the Status Bar messages (but no import AIFF dialogue box), if the Import/Export Preference is set to read uncompressed files directly. But if that Preference is set to make a copy, you should simply get the normal import AIFF dialogue and no "waveform calculation" messages.

So when you saw those messages when you were importing the AIFF, are you still sure that Preference is set to "make a copy"?

Thanks

Gale