[Nymashock] Fake lag frames

[ThunderAxe31]

I've always thought that the point of lag frames is pointing out that the core isn't reading the inputs during that frame. However, I stumbled more than once in lag in which the provided inputs are actually read and resulted in the relative game acting accordingly. Here is my example:
Emulator version: 2.8
Game: Time Crisis (USA) http://redump.org/disc/1871/
.tasproj file: Time Crisis (USA)_nonlag.zip
Incriminated frame: 27693
Repro: just try removing the "1" input from frame 27693, you'll see that the player gun doesn't shot. Set it again to have the gun shooting again. Clearing the greenzone doesn't change the outcome. You even get the game result if you play back as a .bk2 file.

[CasualPokePlayer]

A look at guncon code seems to say there is nothing wrong for the lag detection code per se. The issue seems to more due to how guncon works (at least according to mednafen's code). The trigger being pressed variable is not cleared until after the input poll and if the trigger button is not pressed. So while the frame you press the trigger button may be a lag frame, the guncon remembers that until the input poll actually occurs. (i.e. the input meant for a non-polling frame is "stored" until the next polling frame.) Not really any way to fix this.

[Spikestuff]

I can switch this out from being a GunCon issue by mentioning that Salary Man Champ: Tatakau Salary Man also has this exact same issue where it polls false lag frames every other frame for whatever reason.

[CasualPokePlayer]

With what controller? Do you have a repro movie?

[Spikestuff]

Any standard controller (dpad, dualanalog/dualshock), I don't have a movie but it'll happen instantaneously in the first mini-game regardless (and carries throughout the rest of the game), it's extremely noticeable since it drops lag every other frame.

[CasualPokePlayer]

How are these lag frames false lag frames? The game is not responding to inputs on these frames. As far as I can tell the emulator is correctly reporting lag frames here.

[CasualPokePlayer]

Please provide a repro movie that contains "fake lag frames" where input on those fake lag frames have the game do something.

[Spikestuff]

I read the repo wrong apparently. The issue is that the lag frames shouldn't exist in SMC.

[CasualPokePlayer]

Why not? Is there no "lag" on actual console? Or is this based on another emulator (which itself has as much claim to "accurate lag" as Nymashock)?

[Spikestuff]

Actual console.