jack sink

cmh714

I ways back I was using Audiophile linux on a pc before they went 64bit. IIRC it was using a jack sink to get the audio out to the DAC. jackd was made for pro audio fwiw: http://trac.jackaudio.org/wiki/jackd(1)

Curious on thoughts...

TIA, I am loving this and just want it to be even better

ACX

JACK audio is already on our radar

We count to do some tests in the future and see if any performance gain could be obtained from such setup.

cmh714

Thanks ACX, I'm down for testing when you get there.

cmh714

I'm sure you Guys are aware but if not....
http://wiki.linuxaudio.org/wiki/raspberrypi

ACX

cmh714 wroteI'm sure you Guys are aware but if not....
http://wiki.linuxaudio.org/wiki/raspberrypi

You guessed it right, we already know that

But thanks for proposing that again here. It could be useful for those who want to attempt and give us their feedback...

cmh714

Thats what I thought too. And I will make the attempt as well. Unfortunately, I lent my spare Pi to some friends to enjoy Rune. So testing will be a little slower than normal.

ACX

cmh714 wroteUnfortunately, I lent my spare Pi to some friends to enjoy Rune.

You deployed the trojan horse

cmh714

Exactly!!

cmh714

So just starting small and one baby step at a time.....I changed the governor per the link to performance and I do seem to be getting better performance, or so I think.

top was reporting in the 30+% range for cpu with ondemand, and with performance I havent seen anything above 23% and generally its in the low teens. so far so good.

cmh714

ok, maybe I spoke too soon. I changed the radio station and my cpu went back into the 30s....

Midnight

ACX wroteJACK audio is already on our radar We count to do some tests in the future and see if any performance gain could be obtained from such setup.

JACK won't give a performance gain. It still has to use ALSA for it's output. See what JACK is made for (http://jackaudio.org/):

“system for handling real-time, low latency audio (and MIDI).
...
It can connect a number of different applications to an audio device, as well as allowing them to share audio between themselves.”

* you don't need low latency for playback. Low latency is important for recording.
* you don't need to share audio between different applications

Midnight

cmh714 wrotetop was reporting in the 30+% range for cpu with ondemand, and with performance I havent seen anything above 23% and generally its in the low teens. so far so good.

Ondemand governor lowers your CPU clock. Of course while the clock is lower, CPU usage seems to be higher until clock frequency is raised again

cmh714

Thanks for all the info Midnight!! I guess I wont jack with jack

As for the CPU, I see its also dependent on what the source is. From USB I stay mostly below 20%, from radio if the stream is higher then CPU also goes up in relation. So far I have kept the performance setting, but cant really tell if its "better".

I set it in rc.local as well as doing a bunch of other things to try and make for better performance....as best I can.

gearhead

Dredging up an old thread...

i have been reading about Jackd and my idea is to have multiple runes (I have 2 now and a 3rd on the way) and be able to have a single rune pipe audio to other slave devices. Also, since I run Linux, I was looking at removing Pulse from my laptops/desktops and install jack so I can pipe audio from them to whatever device I want to (A la AirPlay or Roku Sound Bridge)

This may be a bit much for a B+, but couldn't a B2 handle it?

Thoughts? Am I way off base with the capabilities of the raspberry or Jack?

Keith

bevlar

Unless you have a wired connection to all of your devices you're going to run into latency issues.

Also I've yet to find a guide to getting jack to play nice with the RPI. I keep looking in the hope of somebody figuring it out.

gearhead

bevlar wroteUnless you have a wired connection to all of your devices you're going to run into latency issues.

Also I've yet to find a guide to getting jack to play nice with the RPI. I keep looking in the hope of somebody figuring it out.

Well, I cannot get it to work with my hifiberry. my hardware looks like this:

# aplay -l
**** List of PLAYBACK Hardware Devices ****
card 1: sndrpihifiberry [snd_rpi_hifiberry_dac], device 0: HifiBerry DAC HiFi pcm5102a-hifi-0 []
  Subdevices: 1/1
  Subdevice #0: subdevice #0

When I start it I get:

jackd -r -d alsa -d hw:0
jackd 0.124.1
Copyright 2001-2009 Paul Davis, Stephane Letz, Jack O'Quinn, Torben Hohn and others.
jackd comes with ABSOLUTELY NO WARRANTY
This is free software, and you are welcome to redistribute it
under certain conditions; see the file COPYING for details

could not open driver .so '/usr/lib/jack/jack_firewire.so': libffado.so.2: cannot open shared object file: No such file or directory

JACK compiled with System V SHM support.
loading driver ..
creating alsa driver ... hw:0|hw:0|1024|2|48000|0|0|nomon|swmeter|-|32bit
ALSA: Cannot open PCM device alsa_pcm for playback. Falling back to capture-only mode
configuring for 48000Hz, period = 1024 frames (21.3 ms), buffer = 2 periods
ALSA: final selected sample format for capture: 16bit little-endian
ALSA: use 2 periods for capture

but this does not seem right because I can do this with MPD playing or not. If I use hw:1, it will not try to connect and tell me that something is using the hardware:

ATTENTION: The playback device "hw:1" is already in use. Please stop the application using it and run JACK again
cannot load driver module alsa

When I try it with mpd stopped, I get:

# jackd -r -d alsa -d hw:1
jackd 0.124.1
Copyright 2001-2009 Paul Davis, Stephane Letz, Jack O'Quinn, Torben Hohn and others.
jackd comes with ABSOLUTELY NO WARRANTY
This is free software, and you are welcome to redistribute it
under certain conditions; see the file COPYING for details

could not open driver .so '/usr/lib/jack/jack_firewire.so': libffado.so.2: cannot open shared object file: No such file or directory

JACK compiled with System V SHM support.
loading driver ..
creating alsa driver ... hw:1|hw:1|1024|2|48000|0|0|nomon|swmeter|-|32bit
ALSA: Cannot open PCM device alsa_pcm for capture. Falling back to playback-only mode
configuring for 48000Hz, period = 1024 frames (21.3 ms), buffer = 2 periods
ALSA: mmap-based access is not possible for the playback stream of this audio interface
ALSA: cannot configure playback channel
cannot load driver module alsa

It looks like mmap is missing from the i2s driver.
Keith

gearhead

So, I was able to get it going on the pi with some info from this post:

https://www.raspberrypi.org/forums/viewtopic.php?f=41&t=5787&p=751387#p751387

I unpacked the deb and manually placed the folders and rebooted. It now will get to teh point where it is looking for a signal. I am new to Jack and will need to figure out how to get it running to see how good/bad it is.

~ # jackd -r -d alsa -d hw:0  
jackd 0.124.1
Copyright 2001-2009 Paul Davis, Stephane Letz, Jack O'Quinn, Torben Hohn and others.
jackd comes with ABSOLUTELY NO WARRANTY
This is free software, and you are welcome to redistribute it
under certain conditions; see the file COPYING for details

could not open driver .so '/usr/lib/jack/jack_firewire.so': libffado.so.2: cannot open shared object file: No such file or directory

JACK compiled with System V SHM support.
loading driver ..
creating alsa driver ... hw:0|hw:0|1024|2|48000|0|0|nomon|swmeter|-|32bit
ALSA: Cannot open PCM device alsa_pcm for capture. Falling back to playback-only mode
configuring for 48000Hz, period = 1024 frames (21.3 ms), buffer = 2 periods
ALSA: final selected sample format for playback: 32bit integer little-endian
ALSA: use 2 periods for playback

Keith