Search found 299 matches

by Drumfix
Wed May 19, 2021 7:04 am
Forum: The Producer's Area
Topic: (Solved!) Windows Audio vs. Linux Audio
Replies: 88
Views: 60544

Re: Windows Audio vs. Linux Audio

I don't know in what parallel universe you guys are living, but i known not a single version of the Windows audio stack that would be suitable for low latency audio. WDM, no. DirectSound, no. WASAPI (shared) no. WASAPI exclusive (maybe). But wit WASAPI exclusiveonly one audio client can use the soun...
by Drumfix
Sat May 15, 2021 1:18 pm
Forum: Computer Related Hardware
Topic: Ultralite AVB
Replies: 892
Views: 2764059

Re: Ultralite AVB

What am I doing wrong? Maybe the channel count of from/to computer in the web gui is set to a value <= 32. In this situation the Motu is using a "low bandwiidth" mode where it transfers only 32 instead of 64 channels at 44,1/48kHz. The driver doesn't know about that (yet). If you like tha...
by Drumfix
Sat May 15, 2021 6:58 am
Forum: Computer Related Hardware
Topic: Ultralite AVB
Replies: 892
Views: 2764059

Re: Ultralite AVB

Thanks for the pointer. So the alsa devs change to formats inside usbaudio.h and midi.h whenever they want. It's a shame that these include files are not in the include directory (and therefor would be available in the kernel headers). So apparently we have to copy them over from the kernel we want ...
by Drumfix
Tue May 11, 2021 9:35 pm
Forum: Linux Distributions & Other Software
Topic: AVL MXE Linux and Touchscreens?
Replies: 6
Views: 8590

Re: AVL MXE Linux and Touchscreens?

They provide a DisplayLink binary driver for Ubuntu here and notes on how to compile the opensource part for other distros:

https://www.synaptics.com/products/disp ... ads/ubuntu
by Drumfix
Sun May 09, 2021 9:36 pm
Forum: Computer Related Hardware
Topic: Ultralite AVB
Replies: 892
Views: 2764059

Re: Ultralite AVB

Since page 40 we talk USB only. I have uploaded the driver code and some pseudo structs of the USB bulk messages (psseudo structs because the strings in there are of variable lemgth) on github https://github.com/Drumfix/motu-avb-usb. I have not yet implemented the protocol though. So, for now, for t...
by Drumfix
Tue Apr 27, 2021 7:12 pm
Forum: Computer Related Hardware
Topic: Ultralite AVB
Replies: 892
Views: 2764059

Re: Ultralite AVB

I'm using CONFIG_PREEMPT=y (low-latency desktop) If this doesn't help you maybe better off using the snd-usb-audio driver. For that to work in 64 channel mode on the brand new 5.12 kernel: 1. disable the duplicate endpont check in drivers/usb/core/config.c as described further up this thread 2. Add ...
by Drumfix
Tue Apr 27, 2021 6:55 am
Forum: Computer Related Hardware
Topic: Ultralite AVB
Replies: 892
Views: 2764059

Re: Ultralite AVB

My advice is to run a low-latency kernel with irqthreads disabled instead of a rt-kernel and set the irq affinities so that the USB interrupt has its own core. Also, you don't necessarily disable hyperthreading. The driver does 8000 interrupts/sec, so the rt-kernel does 16000 task switches/per secon...
by Drumfix
Mon Apr 26, 2021 6:45 am
Forum: Computer Related Hardware
Topic: Ultralite AVB
Replies: 892
Views: 2764059

Re: Ultralite AVB

As mentioned earlier in this thread i use my own driver based on the ua101 driver. Modify in drivers/usb/core/config.c the function config_endpoint_is_duplicate so that it always returns false (just remove everything in this function except the "return false" statement at the end). Blackli...
by Drumfix
Fri Apr 23, 2021 3:41 pm
Forum: Computer Related Hardware
Topic: Ultralite AVB
Replies: 892
Views: 2764059

Re: Ultralite AVB

Just did another look at the 4 mystery bytes. They are indeed a standard CRC32 caculated over the remainder of the message starting with UTOM.
by Drumfix
Tue Apr 20, 2021 10:12 pm
Forum: Computer Related Hardware
Topic: Ultralite AVB
Replies: 892
Views: 2764059

Re: Ultralite AVB

64 channel mode is working just fine when the necessary kernel changes are applied and the curl command executed. However executing the curl command must be done over the ethernet connection. Unfortunately the USB connection uses in its commands some unknown 4 bytes, my guess it is some crc32, and t...
by Drumfix
Thu Apr 15, 2021 10:46 am
Forum: Computer Related Hardware
Topic: Ultralite AVB
Replies: 892
Views: 2764059

Re: Ultralite AVB

1. Do you have any references to Mac-Users that experienced the hopping with USB or did you perhaps experience that yourself on a Mac? Here for example. https://www.motunation.com/forum/viewtopic.php?f=2&t=65227&start=15 2. Would it be possible to use the libusb-based userspace program on a ...
by Drumfix
Thu Apr 15, 2021 6:41 am
Forum: Computer Related Hardware
Topic: Ultralite AVB
Replies: 892
Views: 2764059

Re: Ultralite AVB

The channel hopping is there on MacOS as well when used with USB. Its just that most Macies run the 828ES via thunderbolt. Btw early in this thread i posted a userspace program using libusb to copying what is received from the inputs directly to the outputs without alsa being involved at all. And it...
by Drumfix
Tue Mar 23, 2021 11:45 am
Forum: System Tuning and Configuration
Topic: JACK is Hannibal Lector with an ear fetish
Replies: 42
Views: 10200

Re: JACK is Hannibal Lector with an ear fetish

JACK was the best, while not perfect, thing that was developed in the Linux audio world. The reason that it is not the standard today is very simple: The author did not work for any of the commercial linux vendors (SUSe/Redhat), so they cannot control its development. Alsa, this utter piece of rubbi...
by Drumfix
Sun Mar 21, 2021 5:33 pm
Forum: Computer Related Hardware
Topic: Audient iD44
Replies: 11
Views: 4488

Re: Audient iD44

Provided the output of "lsusb -v" of the ID44 is the same as here https://windows-hexerror.linestarve.com/q/so62981281-Audio-waveform-output-errors-in-Ubuntu-1804-snd_usb_audio i see 2 problems: 1. the ID44 is using endpoint 1 in three places. Due to a major bug in the Linux' USB core it w...
by Drumfix
Tue Mar 16, 2021 9:10 pm
Forum: Computer Related Hardware
Topic: USB sound card "freezes" the system
Replies: 9
Views: 2488

Re: USB sound card "freezes" the system

I'm pretty sure its the problem and is a long standing bug in the Linux USB core.
If you know how to compile your kernel you can try to disable the duplicate endpoint checking.

in drivers/usb/core/config.c

make the function config_endpoint_is_duplicate always return false