PulseAudio mixing at 44.1kHz instead of 48kHz
 

Looking at /etc/pulse/daemon.conf and /etc/pulse/system.pa it seems to me that all audio is upscaled to 48kHz sampling rate. However, since most if not all my music is 44.1kHz, I'd figured, why waste cpu-cycles and quality, let's try to lower the sampling rate.

So... I forced it to 4kHz by changing the default-sample-rate in daemon.conf to 4000 and in system.pa the rate of both sinks also to 4000. Then I restarted pulseaudio (/sbin/initctl restart pulseaudio) and... a very slow system. top learned me that pulseaudio was consuming the entire CPU at high prio (dual core would be nice..) and then... crash. The device came into a boot loop. :eek:
My guess is the hardware doesn't like 4kHz, which caused the driver to $&^%-up, which caused high CPU, which caused a watchdog timer to trip, which caused the reboot.

Using the flasher --enable-rd-mode --set-rd-flags=no-lifeguard-reset the device booted again, because the watchdog is disabled (I guestimated) and I could restore both files. *pfew*

However, I'd still like to know if 44.1kHz sampling rate is indeed a good idea, but before rebricking my phone I'd like to consult the crowd here, which has much more hacking/linux experience than I :)

So,

• does the hardware support native 44.1kHz?
• Does altering the rate in system.pa indeed is the way to achieve this?
• would it be useful?
• or is there a better way to do this?

Re: PulseAudio mixing at 44.1kHz instead of 48kHz
 

But, why did you try 4KHz?? Am I missing something, wasn't it 44.1KHz you're aiming at? Thus, all your 44.1KHz music and sound files had to be downscaled, thus the high CPU consumption?

Best
Sidecar

Re: PulseAudio mixing at 44.1kHz instead of 48kHz
 

I don't think I can hear the difference between 44.1kHz and 48kHz. So in order to verify I'm editing the correct parameters, I changed it to 4kHz so I'm sure I can hear the difference. My plan was that if it worked I change it to 44.1kHz and run some tests.

Re: PulseAudio mixing at 44.1kHz instead of 48kHz
 

Well, I tried again, this time with some more sane settings like 44.1kHz. No crashes anymore, but the music was too fast. Also, CPU usage was even higher. Lowering to 22.05kHz confirmed it: the hardware was still playing at 48kHz, but the audio got mixed at 22.05kHz, alas, all audio was more than twice as fast.

I guess some other bits needs to be changed. Alsa? GStreamer? Or is the hardware simply incapable of anything but 48kHz? Where to look?

Re: PulseAudio mixing at 44.1kHz instead of 48kHz
 

Actually... If you don't mind, could you PM me on how you were changing those settings? I use my N900 to listen to podcasts, and would love to be able to set it to play back 20% faster natively. Would save a lot on remixing. Just download and play. ;)