Question / Help Webcam feed and microphone audio independently desynchronizing with my game footage.

[DarpiestShezbot]

Is anyone else having this issue? I use a hauppauge HD PVR2 and while I believe many here would be quick to point out the PVR2's 'variable delay' as the root cause of these desyching issues, tonight I discovered that, mid-stream (I've noticed over time that it will either happen between 10 minutes to an hour during my stream), both my webcam footage and microphone audio will gradually desynchronize from my game footage.

How is this possible? To my knowledge, there's no latency caused by the webcam itself and I'll begin my streams with both the Mic Syc offset for my microphone and Use Buffering for my webcam both set to 1800 (or 1200 sometimes because it looks and sounds better for some reason sometimes when set to this amount) milliseconds. With both of those sources set to delay at the exact same time, how do they de-sync from each other and, eventually, de-sync from my game feed creating a huge desynchronized mess out of my stream?

Tonight I ran my stream for over an hour for testing purposes to hopefully find a solution to this problem.
During this stream the game preview feed in hauppauge's software did not experience any fluctuations with its delay. Every few minutes I constantly checked if the delay between my television and preview in the hauppauge software had changed but the delay remained at a constant 2 - 2.4 seconds. The differences between the 2 and 2.4 are negligible considering I was gauging this time with an iPhone stopwatch.
There is virtually no delay between OBS and the preview screen of the hauppauge software so it doesn't explain why my microphone and webcam will de-synchronize (at different rates too) from the game footage when the delay from the hauppauge remains at a constant fixed rate. I should also mention that during this entire session my stream did not drop any frames or take too long to encode and my upload speed is about 10-12 Mbps.

This gets frustrating really quickly for me. Especially when I've been streaming for awhile already and then suddenly the delay mixup will cause my voice to play over the in-game voices making it near impossible for my viewers to understand what anyone is saying anymore and having my reactions and commentary not match up with what's happening in the game.
Is anyone else having this issue? Have the OBS devs acknowledged this problem or is there some sort of self-correcting method that I am unaware of?

Would really appreciate any help.
Thanks.

 

[Lain]

Most likely you're delaying your webcam and mic with 'use buffering'. The problem however is that they're delayed on system time, and system time may not always be 100% accurate or synced with the hauppauge's timing, so I would guess that might be the culprit or related to it. I'm just guessing though to be perfectly honest. In the newer version (few months out) this may not be an issue because you'll be able to use the hauppauge directly and it'll be on the same timing, but right now in the current version of OBS you're sort of stuck with capturing the window.

Again though, just speculation based upon the description.

 

[DarpiestShezbot]

To be honest, I don't really know what you mean by system time but I'm guessing it's something that has more to do with the limitations of my hardware rather than something I can control, right? I just find it puzzling that even if my microphone and webcam are set to 'use buffering' at the same exact rate they still de-sync from each other at different rates even when checking their respective settings shows that the entered amount on both are the same.

But getting official confirmation from a dev that hauppauge supports is coming to OBS is certainly reassuring. I know you didn't mention an exact release date but do you think we could maybe get it by the end of the year?
Also thanks for your input.

 

[Lain]

Hopefully, yes. For device support we really need things like webcam delay, deinterlacing, as well as optional audio delay. After that it will be completely usable for devices. Then there's also things like game capture and a number of other minor things.