RMS measurement for large files

[steve]

I ran your snippet on Ubuntu 16.04 64-bit on a selection within an hour of mono audio. The extra RAM used by the snippet was not released. When I chose a different selection in the track, almost no additional RAM was used, but none was released. Even when I created audio in a new track and ran the snippet on that, it did not use much more memory and released none.

Could you give some numbers for the amount of RAM used at each stage.

[Gale Andrews]

I ran your snippet on Ubuntu 16.04 64-bit on a selection within an hour of mono audio. The extra RAM used by the snippet was not released. When I chose a different selection in the track, almost no additional RAM was used, but none was released. Even when I created audio in a new track and ran the snippet on that, it did not use much more memory and released none.

Could you give some numbers for the amount of RAM used at each stage.

Select 15 minutes in a 1 hour mono sine tone 44100 Hz.

Open Nyquist Prompt and paste your snippet. Audacity is using 24.2 MB of RAM.

Apply the snippet. By the time I get the dialogue for the returned value, Audacity is using 186.7 MB.

OK the dialogue. Audacity RAM use is now 186.6 MB.

Create new empty track and generate noise into the selection in that track. Open Nyquist Prompt. Audacity memory use still 186.6 MB. Apply the snippet. When the returned dialogue appears, RAM use is 190.8 MB. After OK'ing the dialogue, RAM use is still 190.8 MB.


Gale

[steve]

Open Nyquist Prompt and paste your snippet. Audacity is using 24.2 MB of RAM.

That's a lot lower than my machine. I'm seeing 125 MiB

Select 15 minutes in a 1 hour mono sine tone 44100 Hz.

OK, so that's about 159 MB of data

Open Nyquist Prompt and paste your snippet. Audacity is using 24.2 MB of RAM.
Apply the snippet. By the time I get the dialogue for the returned value, Audacity is using 186.7 MB.

So that's about right for Audacity + 15 minutes of audio.

OK the dialogue. Audacity RAM use is now 186.6 MB.

On my machine, the memory is then released back down to 139 MiB.

Create new empty track and generate noise into the selection in that track. Open Nyquist Prompt. Audacity memory use still 186.6 MB. Apply the snippet. When the returned dialogue appears, RAM use is 190.8 MB. After OK'ing the dialogue, RAM use is still 190.8 MB.

So there's not actually a memory leak. The memory is being managed and reused, but it seems that Ubuntu is reserving that used memory after "OK" rather than releasing it. It could be worth minimizing Audacity at that point and doing something else for an hour or two, then looking to see if the memory is eventually released.

I don't see that we can draw much in the way of meaningful conclusions, other than that memory management is different in Ubuntu 64-bit to Debian 32-bit.

[Gale Andrews]

I don't see that we can draw much in the way of meaningful conclusions, other than that memory management is different in Ubuntu 64-bit to Debian 32-bit.

It's also different to Ubuntu 32-bit, which releases the memory used by Nyquist plugins after processing.

To make clear one point, when I run a new effect after your script, such as ACX-Check, that new effect does not reuse the memory that Nyquist Prompt was using, but uses new memory that is also not released after OK'ing the result.

I draw the conclusion that crashes are more likely on 64-bit Linux , despite having more than 2 GB RAM available, if you use multiple effects that load all the audio data into memory.


Gale

[steve]

What about the code in the first post of this thread? Does 64-bit Ubuntu release memory correctly there?