JackAudio August 2019

jackaudio@lists.linuxaudio.org

15 participants
18 discussions

[Jack-Devel] Cannot callback the server in notification thread!

by Ethan Funk

In an application I am writing, I am getting an error message out stderr (see email subject), and a connection failure return result, when I try to use jack_connect() from inside a jack_set_port_registration_callback function, using Jack2. My goal is to have the application remember and re-connect to a disconnected port if/when it "comes back." Am I going to need to create a mostly sleeping thread just for port re-connections attempts, or is there something obvious I am missing? Thanks, Ethan...

4 years, 9 months

[Jack-Devel] Time for a separate jack-users list?

by John Rigg

A lot of the traffic on jack-devel lately has been routine linux audio user questions, often concerning problems that aren't anything to do with JACK. This makes it difficult to follow actual JACK development posts as they tend to get buried. Would a separate jack-users list be a good idea? John

4 years, 9 months

[Jack-Devel] Would alsa_in reading from SPDIF input inject have pops and crackles into audio?

by crocket

alsa_in reading from ALSA loopback often injects pops and crackles into audio when vivaldi web browser has difficulty with real-time audio processing. ALSA loopback's clock is fed from audio signal of ALSA applications which cannot have a regular clock. I haven't tried alsa_in on any hardware soundcard, yet. I don't see actual xruns from alsa_in or alsa_out, but I hear pops and crackles. Would the following setup cause pops and crackles? 1. Vivaldi web browser, mpv, mplayer, ... --> ALSA dmix --> onboard SPDIF Out --> SPDIF In of Creative Sound Blaster X-Fi HD USB --(alsa_in) --> netjack1 ==(ethernet)==> Jack ALSA backend --> HiFiBerry Amp2 --> Speakers 2. netjack1 --(alsa_out)--> headphone jack of X-Fi HD USB --> headphones -----On Raspberry Pi 3B+ jackd -P 90 -d alsa -d HiFiBerryAmp2 -p 512 -n 2 -P -r 48000 jack_netsource -H 192.168.30.2 -o 0 -i 2 -O 0 -I 0 -n 2 -N guardian -----On This Computer jackd -P 90 -d netone -p 512 -n 2 -r 48000 alsa_out -j headphones -d headphones -p 512 -n 3 -q 2 alsa_in -j spdif-in -d spdif-in -p 512 -n 3 -q 2

4 years, 9 months

[Jack-Devel] What about the number of buffers?

by Holger Marzen

What is the difference between jackd -n2 -p192 and jackd -n3 -p128 Both give a total of 384 samples in buffers. What's the difference for jackd? Regards Holger

4 years, 9 months

Re: [Jack-Devel] Sudden problem Jack refuses to start.

by John Rigg

On Tue, Aug 06, 2019 at 01:06:31AM -0400, liebrecht(a)grossmann-venter.com wrote: > It looks to me like it is and ALSA problem.... What happens if you do the following? 1. Disable Pulseaudio 2. Look in /proc/asound/ to see which hw device (hw:0, hw:1 etc) your 1818 is 3. Start jackd from command line with -dhw:0 (or whichever one is the 1818) instead of the "fancy" name John

4 years, 9 months

[Jack-Devel] Hello, total Jackaudio Newbie

by Nathan Reddancer

Hello, I do not know if this is the correct and appropriate location to post this question, I was looking for a Jackaudio forum and this is the first page that came up. SOooo, here's my delimmna, as a musician and part time geek: If I buy an 8 Channel USB Audio interface, will Jackaudio controll/ bypass Alsa, and then allow 8 channel inputs record directly to 8 SIMULTANEOUS tracks of a live band into Traction Waveform or Ardour? Or does Jackaudio just work as a plugin with extra functions to the Alsa drivers, and merely allow the DAW software and hardware interface work together at the same time? I am NOT gonna be programming a midi drumset, but I am gonna be recording an actual real live drumset, with bass guitar, lead guitar, and a temporary vocal track to record the foundation of each song for an upcoming album project. THEN my musicians will go back and punch in any mistakes and dub over them. So, IS Jackaudio capable of SIMULTANEOUS Channel to Track recording of more than two channel/ tracks? That is all I need to know before I make my hardware and software purchases over the next couple of weeks. Thank you for the answers to my questions. And if this ISN"T the correct forum, please send me a link to the correct one so I don't trouble the wrong teams that are busy working on pure code work. Thank you again for your patience. OH and for the record, If/ when Jackaudio can do this task for us, I'll be bragging on everybody involved for the rest of my career. thanks again, and have a wonderful week. Fraternally, Nathan.

4 years, 9 months

[Jack-Devel] How do I eliminate pops between alsa_in and alsa loopback?

by crocket

I made ALSA applications output audio to jack by applying instructions on https://alsa.opensrc.org/Jack_and_Loopback_device_as_Alsa-to-Jack_bridge # Gentoo Linux aarch64 on Raspberry Pi 3 B+ jackd -P 90 -d alsa -d speakers -p 512 -n 3 -P -r 48000 jack_netsource -H 192.168.30.2 -o 0 -i 2 -O 0 -I 0 -n 3 -N guardian # Gentoo Linux amd64 on my desktop computer jackd -P 90 -d netone -p 512 -n 3 -r 48000 alsa_out -j headphones -d headphones -c 2 -p 512 -n 3 -q 3 alsa_in -j cloop -d cloop -c 2 -p 1024 -n 2 -q 3 jackd, jack_netsource, alsa_in, and alsa_out belong to audio cgroup which allocates 95% of CPU time to its group members. While youtube videos are played in vivaldi web browser, chrome web browser, and firefox web browser, I occasionally hear audible pops. It seems all pops come from `alsa_in`. I also tried alsa_in -p 1024 -n 3 -q 2|3|4, but it doesn't eliminate pops. Here's a part of ~/.asoundrc on my desktop computer. pcm.loophw00 { type hw card Loopback device 0 subdevice 0 format S16_LE rate 48000 channels 2 } pcm.lmix { type dmix ipc_key 219347 slave { pcm "loophw00" period_time 0 period_size 512 periods 4 format S16_LE rate 48000 channels 2 } bindings { 0 0 1 1 } } pcm.cloop { type hw card Loopback device 1 subdevice 0 format S16_LE rate 48000 channels 2 } pcm.!default { type plug slave { pcm "lmix" format S16_LE channels 2 rate 48000 } rate_converter "samplerate_best" } Is it impossible to eliminate pops from alsa_in running on cloop which is just alsa loopback?

4 years, 9 months

[Jack-Devel] advice on xruns

by liebrecht＠grossmann-venter.com

Anyone have an in depth treatise on xruns and how to minimize them. By that I dont mean just adjusting the buffer size, I mean really getting into the gears of why xruns happen and how to potentially minimize them. Reason I ask is that I use jack on a live music basis amd it is crucial for me to get no more than 2.9ms latency. I can hear and feel every latency above above that. I am lucky with mixbus and jack on Linux to get 2.9ms with the occasional xrun every 2 minutes, but I want to see if I cannot eliminate them. Any advice or point to very relevant reference material will be appreciated. Thanks

4 years, 9 months

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JackAudio August 2019