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Windows => JRiver Media Center 33 for Windows => Topic started by: Nator on February 12, 2025, 12:51:40 pm

Title: Optimising Delay of the JRiver Soundcard
Post by: Nator on February 12, 2025, 12:51:40 pm

Hi,
am using JRiver mostly for convolving. I use KODI for TV stuff and PowerDVD for BluRay with the JRiver Media .."Souncard". It works quit good apart from the quite high delay of more than 600 ms. It is only a problem for PowerDVD since its "lipsync" can only be adjusted to 0,5 Seconds.
Is there a way to optimize the delay? The convolver itself does not make a big difference.
The other, better option would be that i can watch bluRays with JRiver but from what I've read its not a simple task.

EDIT: I just saw that it is possible to route a virtual asio driver into JRiver. Does somebody have a recipe for this? Ideally with a freeware virtual soundcard. Does the WASAPI feature the same quality of ASIO? Why shoul i use ASIO? :)
And do i always have to click "open live"?

regards Han

Title: Re: Optimising Delay of the JRiver Soundcard
Post by: JimH on February 12, 2025, 02:30:59 pm

Try changing the buffers. https://wiki.jriver.com/index.php/WDM_Driver

Title: Re: Optimising Delay of the JRiver Soundcard
Post by: Nator on February 14, 2025, 01:00:43 pm

Hi, thank you!
Are those input adjustments for WDM Driver? I do not see a difference in the shown delay time if i switch between minimum and 50ms.
Sadly i can't lower the output buffer.
Any other ideas?
regards Han

Title: Re: Optimising Delay of the JRiver Soundcard
Post by: mwillems on February 14, 2025, 01:34:45 pm

The "Live Playback Latency" is the input buffer, but if changing it doesn't affect the latency then something else is is causing it.  You mention that you can't lower the output buffer, but what is the output buffer set to?

You also mentioned Convolution and say that you think it doesn't make a big difference, but convolution can contribute quite a bit of fixed input latency depending on the length of your convolution filters.  Have a look at this wiki article and calculate how long your filters are, and that should tell you if convolution is potentially the long pole in the tent:  https://wiki.jriver.com/index.php/Convolution#Latency 

It's possible you could make a set of shorter filters with lower latency depending on how much correction you're doing.

Title: Re: Optimising Delay of the JRiver Soundcard
Post by: Nator on February 15, 2025, 02:58:59 am

I checked my Filters, i need 128k sample count at 48khz (if that is the correct setting for export convolution in REW) to match the desired curve.
I came from 256k so this should get the delay a little lower?!
I have some additional queations to the convolution system:
Does someone know what the setting " Place t=0 at sample index X" means?
How does JRiver handle different sample counts for differenz channels? In my case i would probably not need the 128k for the "normal Stereo" channels but for the sub channels. Does this cause a not synced output between subs and "Stereos"?

regards Han