Potato: Delay between audio + video output - how to synchronise?

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inetdude
Posts: 9
Joined: Sun Mar 31, 2019 11:08 am

Potato: Delay between audio + video output - how to synchronise?

Post by inetdude »

Hi,

I have installed VM Potato and first I had only wired audio outputs (onboard realtek sound, soundblaster, hdmi sound and dvi sound) connected to my pc.

Some weeks ago I decided to extend sound with 2 similar bluetooth devices (2.1). Now I have 5 outputs (realtek, soundblaster and hdmi as before) connected to potato.

At the beginning I had some delay between the wired and the bluetooth devices, so there were echoes in earing sound. I found out the possibility of "synchro delay" in the vm settings... By setting various values to this option, I got satisfactory results when delaying the wired devices to 300ms (see attached picture).

The next problem is now: there is a delay when watching a video/movie stream and the sound!

And, there were often "brokes" in the sync of the audio devices, so I had to "restart audio engine" manualy, so the devices sync again. In a youtube video I got some input about changing default values of buffering WDM, engine mode, WDM input mode and preferred sample rate (see attached picture)... Now the device syncs are much more stable (although the bluetooth devices do not support 48000 Hz sample rate)!

I did not find out how I can now sync the video with the audio output... Is there also a solution for this issue by changing some vm settings?
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Vincent Burel
Site Admin
Posts: 2121
Joined: Sun Jan 17, 2010 12:01 pm

Re: Potato: Delay between audio + video output - how to synchronise?

Post by Vincent Burel »

first of of all, we do not recommend the WDM Input Exclusive mode and the Swift Engine Mode.
it's not normal your 3 hardware input are not working (please deselect device if not working properly).

About audio / video sync, 512 sample buffer is usually enough (and you will get a more stable stream)
if you have to delay video, you will have to check your Video Player (Voicemeeter cannot delay video, but audio only).
inetdude
Posts: 9
Joined: Sun Mar 31, 2019 11:08 am

Re: Potato: Delay between audio + video output - how to synchronise?

Post by inetdude »

Vincent Burel wrote:first of of all, we do not recommend the WDM Input Exclusive mode and the Swift Engine Mode.
OK, according to your input I changed both to default values... Connections still stable! Thank you... :-)
Vincent Burel wrote:it's not normal your 3 hardware input are not working (please deselect device if not working properly).
Now I only have one input --> SB Audigy (the others were not connected, e.g. headset micro).
Vincent Burel wrote:About audio / video sync, 512 sample buffer is usually enough (and you will get a more stable stream)
I tried the default value (512) as you recommend - but the bluetooth devices lose sometimes the synch and I get the echos (it happens often, when I walk between the devices)... With 256 the synch is very stable, even when I walk across the room. I did not try other values above 256 yet, but will do it soon! ;)
Vincent Burel wrote:if you have to delay video, you will have to check your Video Player (Voicemeeter cannot delay video, but audio only).
What video player??? I have this delay when I stream through browsers (firefox and/or chome or opera - didn't try edge yet) and also when using VLC and Kodi... Has someone an idea if there are video settings in Win10?
Vincent Burel
Site Admin
Posts: 2121
Joined: Sun Jan 17, 2010 12:01 pm

Re: Potato: Delay between audio + video output - how to synchronise?

Post by Vincent Burel »

ok, so you talk about delay between audio device only.
in this case you may find the best settings and use Synchro delay (applied to A1 , because A1 is always in advance compared to A2 or A3).

the problem of bluetooth is that latency delay may change in the time...
chaosgrid
Posts: 4
Joined: Fri May 10, 2019 3:41 pm

Re: Potato: Delay between audio + video output - how to synchronise?

Post by chaosgrid »

Just a hint for bluetooth connection: You need to use aptx low latency devices which guarantee a 45ms latency (I think the delay is constant so it's also not changing over time based on radio quality).
inetdude
Posts: 9
Joined: Sun Mar 31, 2019 11:08 am

Re: Potato: Delay between audio + video output - how to synchronise?

Post by inetdude »

chaosgrid wrote:Just a hint for bluetooth connection: You need to use aptx low latency devices which guarantee a 45ms latency (I think the delay is constant so it's also not changing over time based on radio quality).
@chaosgrid Just came to this (my) post per accident some months later now and saw your reply... Thank you for your hint!

Now I tried to get more info about "aptx low latency" on the web... I learnd it is supported by Win10. But cannot find if it is on or off (have searched in device manager and sound settings)... Only got the name of the driver: bth.inf

How can I manage settings for aptx low latency within Win10 and/or VM Potato?
chaosgrid
Posts: 4
Joined: Fri May 10, 2019 3:41 pm

Re: Potato: Delay between audio + video output - how to synchronise?

Post by chaosgrid »

inetdude wrote:
chaosgrid wrote:Just a hint for bluetooth connection: You need to use aptx low latency devices which guarantee a 45ms latency (I think the delay is constant so it's also not changing over time based on radio quality).
@chaosgrid Just came to this (my) post per accident some months later now and saw your reply... Thank you for your hint!

Now I tried to get more info about "aptx low latency" on the web... I learnd it is supported by Win10. But cannot find if it is on or off (have searched in device manager and sound settings)... Only got the name of the driver: bth.inf

How can I manage settings for aptx low latency within Win10 and/or VM Potato?
You cannot set this up in Windows, the devices need to support it. Check here: https://www.aptx.com/products?field_aptx_type_tid=484

For example, you can use this: https://www.aptx.com/products/fiio-blue ... fier-btr1k
With this: https://www.aptx.com/products/creative- ... ransceiver
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