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Run ahead debate: a journey 4 input lag reduction #117752 08/29/20 07:29 PM
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Shideravan Offline OP
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Just opening this thread to discuss about new ways to reduce input lag in software emulation and what can be done in MAME that can't need a massive rewrite of every drive manually.
As every one of us know, generally the software emulation has a larger input lag compared with the original hardware with the same conditions, which isn't the ideal when we think about hardware preservation, and this stands as a considerable issue.
Recently, BSNES brought a new way of thinking about how to reduce this input lag, using a method that was known as "run-ahead". What do the devs think about this solution? Is it possible to be implemented in some way on the MAME in order to bring more significant benefits than losses in accuracy? If not, is there a better way to overcome the input lag issue?


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Re: Run ahead debate: a journey 4 input lag reduction [Re: Shideravan] #117753 08/29/20 07:58 PM
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R. Belmont Offline
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Runahead isn't from bsnes (it's from retroarch) and as currently implemented it actually eliminates real latency that existed in the real machine, which is not exactly compatible with MAME's goals. With the recently added MAME low latency mode switch, you can get as low as 4 ms of latency while using a VRR monitor (Gsync/Freesync), which is quite good.

Re: Run ahead debate: a journey 4 input lag reduction [Re: Shideravan] #117754 08/29/20 08:14 PM
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basically it's the technique that's made every emulated world record attempt completely invalid as people are playing with 'less lag than real hardware' without even knowing it, or knowing it and insisting it is correct when it isn't. since nobody will disclose it, nothing can be trusted now if it's recorded in emulators with support for it.


Re: Run ahead debate: a journey 4 input lag reduction [Re: Shideravan] #117755 08/29/20 08:30 PM
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Shideravan Offline OP
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It's not from retroarch. The run-ahead is a feature from standalone BSNES. Unfortunatelly byuu removed his own channel in his retirement, but there was a video in he himself explained about the feature.
But you can take a look in a standalone BSNES for this feature (not higan): https://github.com/bsnes-emu/bsnes/releases
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Last edited by Shideravan; 08/29/20 08:42 PM.

"A user interface is like a joke. If you have to explain it, it's not that good."
Re: Run ahead debate: a journey 4 input lag reduction [Re: Shideravan] #117756 08/29/20 10:23 PM
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R. Belmont Offline
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I know standalone bsnes has it, but it originated from retroarch.

Re: Run ahead debate: a journey 4 input lag reduction [Re: R. Belmont] #117757 08/29/20 11:08 PM
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Shideravan Offline OP
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Originally Posted by R. Belmont
I know standalone bsnes has it, but it originated from retroarch.

I didn't know it had first appeared on RetroArch. It is not a kind of project that I follow, but anyway, it is interesting to know. smile


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