Cons & Pros of buffering vs no buffering

[vagrant]

Something I've been meaning to ask about is the effects of buffering vs no buffering.

My usual setup is 50hz + low latency vsync + minimum sound buffer + no buffering.

With no buffering set it produce absolute minimum input lag, however on occasion, 1 video frame seems doubled which I presume is fail safe for audio buffer?

If I set triple buffering, there is of course more input lag, however I think there are never any doubled frames & the audio seems to have even less latency then with buffer disabled.

Is this about right?
My main reason for asking is the possibility of 'triple buffering' being the best option for video recording - since there are no doubled frames, tighter audio & input lag is irrelevant.

[Toni Wilen]

Video recording should never skip any frames, it records everything that custom chipset emulation creates (both sound and video), even if it frame is not shown or it gets doubled (due to vsync issues).

I'd recommend not to use vsync or any other "special" options when recording, it can only cause extra slowdowns.

Above is only true if capture before filtering is enabled and fastest possible CPU is not enabled. Other config: not supported, too many odd things can happen with recording.

[vagrant]

I use external software for recording anyway, so I mean running winuae in it's normal state.

The occasional double frame is noticeable on smooth scrolls (I remember reading some thread where you said a double frame was a better option then the sound skipping.)
Can this be stopped by disabling sound emulation or enabling buffering, or is unavoidable due to vsync in general?

And is there slightly less sound latency with buffering enabled? (or is just my imagination )

[SquawkBox]

Try your usual setup with double buffering maybe

[vagrant]

Have tried double buffering.

Also I've just discovered that double framing still happens with sound emulation disabled and buffering on.
Toni is there any way to avoid this so there is never any doubled frames, or is it some inevitable vsync issue

[mark_k]

They may not be any solution to skipped or doubled frames if you're using an external program (which?) to record WinUAE instead of having WinUAE create the video file itself.

[Toni Wilen]

Sorry but that is unsupported, especially in vsync mode. It would need totally different and incompatible sync method.

[vagrant]

Ok np, but to be clear I'm talking about occasional double frames during normal usage - not while recording. Does it make any difference?

[SquawkBox]

It wasn't clear at first whether you were speaking about video recording or normal usage,
but I think you made your point, meaning answer would be the same (unsupported) for both scenarios.
Should you have a few minutes to experiment, I'd go and ask the following :
Is the glitch you just described still noticeable if you simply plug a PS/2 keyboard
(or analog gamepad, having in mind this kind of gear belongs to a bygone era)
and play said smoothly scrolling game (or demo) with absolutely no USB device plugged in / configured ?
As for the sound buffer increment VS input lag, I assume you're used to allowing merely the minimal acceptable value,
but 1, even 2 might be a bit overkill, just saying.

Good luck!

[Toni Wilen]

Originally Posted by ED-209

Ok np, but to be clear I'm talking about occasional double frames during normal usage - not while recording. Does it make any difference?

It shouldn't happen but it can still happen, it depends on drivers, hardware, everything..