Disabling low power/power management while audio recording

[ljones]

Hello all !

Just got a small problem here. I can record with my pandora and audacity without problem - but it dosen't seem to work with longer recordings. After roughly ~12 mins, (I'm guessing here) the screen blanks out (can be brought back btw!) and I am guessing that the pandora is entering some sort of low power mode via power management.

Unfortunatly this seems to upset audacity/recording and nothing gets recorded once the pandora enters low power mode - even if I press a screen and the pandora returns to normal mode. Is there any way to suspend low power/power managment temporarily at all?

thanks

ljones

 

[levi]

Usually, disabling the screensaver sorts out many of these issues, but I'm not currently sure what the correct incantation is for that.

 

[canseco]

Check out Pandora Settings-> Video Settings -> Enable/disable screen blanking.

Another option would be to execute this commands on a terminal:

xset s off
xset -dpms

To enable again

xset s on
xset +dpms

 

[notaz]

Unfortunatly this seems to upset audacity/recording and nothing gets recorded once the pandora enters low power mode - even if I press a screen and the pandora returns to normal mode.

Hmm this doesn't happen to me, it happily continues recording after blanking.

There is a different known bug though - if you play any kind of audio while recording is going on, the recording will get interrupted.

 

[elw3]

No problems here either.
This sounds like its going to sleep rather just blanking the screen. Not a default setting.

 

[ljones]

Anyone know how to stop the pandora from going to sleep then at all?

 

[notaz]

Use the "xset s off" command.

But are you sure the issue is really caused by sleep?

 

[ljones]

Ok, I gave that a go but it didn't seem to work. The screen didn't blank out, but recording in audacity did not work properly after around 12 mins. I managed to take some pictures/videos btw of what is going on. This looks more intresting - prehaps I'm experiencing either some sort of weird SD card read/write error, or maybe audacity or something else is misreporting or writing into somewhere there isn't much space? (Not sure).

FIrstly Here is the pandora and audacity recording normally. No problems here.

Roughly ~12 mins though this seems to happen. That recorded waveform dosen't look quite right!

(I know it says "out of disk space" but I'm pretty sure the SD card isn't). -- Update: df -h from the command line reports in /media/ROOT (the SD card I booted from) reports ~1.9GB free).

This is a picture of what I got when I stopped the recording and moved back from the end of the recording a little. I also sometimes got this; note the weird gap in the recording. Apon saving the file, closing down audacity, reloading and reopening I get this - audio recorded after roughly 12 mins is gone - !

Not sure what is going on! Why would audacity misreport the amount of free space like that? Either that, or I have a bad SD card. I guess I might have been wrong about it being about power management and it might be to do with free space - it just seemed to happen around the time the screen went off (so making me think 2+2=6!), but maybe it's audacity being weird?

ljones

 

[edgex004]

Is /media/ROOT/ the partition your PND is saved on? My guess is you have your PND saved to another partition and that one is running out of space.
[doublepost=1466353926,1466353534][/doublepost]Also, if you are running SZ from an SD with the standard BOOT, ROOT, and swap partitions, you will probably be saving and running PNDs in BOOT. ROOT is for your non-PND home directory. Each PND has its own home directory in /media/BOOT/pandora/appdata. When I install SZ to an SD, I also create an extra partition for my PNDs and mount it to /media/APPS/ since I like to have BOOT be FAT, but like to run PND's from ext2/3 formatted partitons.

 

[ljones]

I'm not sure how to choose where PNDs (such as for audacity) mount themselves, but while I ran audacity I found this:

$ df -h

/dev/loop0     7.3G     1.9G    5.0G     28% /mnt/utmp/audacity-2.0.2-dave18
/none          7.3G     1.9G    5.0G     28% /mnt/utmp/audacity-2.0.2-dave18

Don't quite know how to change it from /mnt/utmp. But it seems to say it has almost 2G of free space!

ljones

 

[Yoyobuae]

Change the temporary files directory:
http://manual.audacityteam.org/man/directories_preferences.html

On Pandora Audacity PND it defaults to /var/tmp/audacity-user, but /var/tmp/ is a RAM filesystem so it only has around 250MB free. So your recording is probably stopping when that gets full.

 

[Farox]

If you want to test another program to record...try mhWaveEdit

 

[levi]

I think I used arecord last time I recorded on my Pandora. I never checked the waveform so it might have had weird errors like that, but I found them inaudible on that mp4, so perhaps it did and I missed them.

 

[ljones]

I'll have to give mhWaveEdit and others a go -- I must admit I've never even really tried it before. But changing the temporary files directory seems to have worked -- the pandora has been recording audio for almost an hour now and been ok. Guess it just looked "like" it was connected with power management because it was running out of space *and* the screen was blanking at around the same time!

ljones