BATC Forum

I have just upgraded to an RTX A2000 graphics card and switched the FreeStreamCoder to use nVidia hardware acceleration for the encoding instead of the Intel GPU built into the processor.

Used with OBS, FreeStreamCoder now easily copes with H265 with no stuttering. Maybe the A2000's B frame capability helps.

However, the lip sync is awful. The audio lags behind the video by at least a full second.

I've looked at the Easy DATV software, that does have a lip sync adjustment, but so far I've not found a way to make it work with my Portsdown 4 using IPTS in.

Anyone got a suggestion that might fix this?

Clive G3GJA

Dear Clive:
If it is possible, please, send me information about how send IPTS from OBS 28.0.3 to Portsdown4. I have lost the correct configuration.
73,s de Jabi, ea2aru

Hi Clive,

This may or may not help, I had awful lip sync issues feeding from OBS with virtual cam to Portsdown4 via Freestreamcoder. With info from John G7JTT I altered the virtual cam frame buffer to 25. I'm not at home so this may not be 100% but...

Go to tools
Virtual cam
Stop
Advanced settings
Scroll down to frame buffer setting.
Restart Virtual cam

I'm still having lip sync issues now when switching between streaming into 'HV or TXing via the Portsdown but that's a different story.

73 Dave.

Sorry if I have miss-understood the issue but why not just set an appropriate lipsync offset in OBS under the advanced audio properties? You may find it depends on the TS bitrate so you may need to note down what it is for various settings you use.

Mike

Hi Mike,

I used the maximum offset but it still wasn't enough a others have found, altering the frame buffer gives quite a bit more adjustment opportunity.

73 Dave.

That's what I found; it needed more than maximum adjustment -950mS.

I'll try the frame buffer setting to see if that helps. Only just seen that there was a reply to my July enquiry!

Clive

I don't understand this, it seems you can add a lot more than 950mS in OBS. Does it not actually work?

Mike

You missed the minus symbol in front of the 950mS!

Positive correction is not restricted to the same limit.

Clive

Ah - you wanted negative, I didn't realise that. Not sure why it would be so high. Anyway, you can easily fix that, just delay the video with the video delay filter.

Mike