[BUG]: TAS save state undo issue.

[RRX-JP]

Describe the Bug

If a save state is performed during recording in TAS and the state is loaded,
undoing will corrupt the subsequent recording because of the frame gap that occurs at the timing of loading.

i7 10700K
GTX 1070

Game:SLPM-65719
Burnout 3 - Takedown

Reproduction Steps

1. Record TAS.
2. play and Save State.
3. load Save State. (At this point, UndoCount is set to 1.)
4. Complete the recording at any time.
5. play TAS.(Select record file. File generated in 2.)
6. The gap occurs at the timing of the load state.

Video
https://youtu.be/m1VNQpb81UU

Expected Behavior

No response

PCSX2 Revision

v1.7.5922

Operating System

Windows 11

If Linux - Specify Distro

No response

Logs & Dumps

No response

[RRX-JP]

Apparently not a blank,
It appears that a few frames were not recorded.

pcsx2/pcsx2/VMManager.cpp

Line 1813 in 3040474

if (g_InputRecording.isActive())

I feel there is a problem here.

[sestain]

Can confirm this too from my own testing.

[kage2051]

Sounds like a data race between GS and EE threads, which this PR should fix: #10793

However, the generated builds for it lack of any fixes for .p2m2 playback (it does nothing after clicking on Tools > Input Recording > Play) so I am unable to properly test these changes.

[F0bes]

Sounds like a data race between GS and EE threads, which this PR should fix: #10793

However, the generated builds for it lack of any fixes for .p2m2 playback (it does nothing after clicking on Tools > Input Recording > Play) so I am unable to properly test these changes.

I've rebased that PR. Once it builds you should be able to test it with the latest master changes.

[kage2051]

Looks like the PR does not fix the issue. The RNG in most titles seems to be really inconsistent between states.

[RRX-JP]

test from 1.7.5936
If you can give me some hints.
Load state and when it is rewritten.
I deleted the front 2 frames (+18h+18h) and it improved.

Blue: Record before load state.
Black: Deleted from the record before the load state.
Pink: overwritten by load state.

[kage2051]

I should also mention emulation pausing also causes the frame dropping/removal in the recording file.

[RRX-JP]

I should also mention emulation pausing also causes the frame dropping/removal in the recording file.

Yeah.
I confirmed it about 3 minutes ago.

[kage2051]

test from 1.7.5936 If you can give me some hints. Load state and when it is rewritten. I deleted the front 2 frames (+18h+18h) and it improved.

Blue: Record before load state. Black: Deleted from the record before the load state. Pink: overwritten by load state.

How can I determine which frames are fine and which are not because of a state load?

[RRX-JP]

test from 1.7.5936 If you can give me some hints. Load state and when it is rewritten. I deleted the front 2 frames (+18h+18h) and it improved.
Blue: Record before load state. Black: Deleted from the record before the load state. Pink: overwritten by load state.

How can I determine which frames are fine and which are not because of a state load?

Perform a save state while holding down any key, and perform a load state with no key pressed.

[RRX-JP]

This might help.
https://github.com/search?q=repo%3Apocokhc%2Fpcsx2-1.4.0-rr%20%2F%2F--TAS--%2F%2F&type=code

[kage2051]

Real cause of the issue: #11607 (comment)