Im new to TASing and having trouble understanding lag frames in bizHawk. What actually are lag frames? Are these caused by my computer or are they part of the emulation? Im only doing megadrive games so i would be surprised if my computer was lagging. Will these lag frames always be in the same place and can they potentially cause desync for tas?
Thanks anyone that can help with this probably stupid question
Every frame, the game needs to read the controller ports to know what buttons the player has pressed on that particular frame. Bizhawk (and other emulators) detects that process, and will count a lag frame every time the game fails to do that, either because it was too busy or because input polling was disabled, for example when it is loading.
This means that lag frames are part of the emulated game and not of your computer. On any solid emulator (like Bizhawk), they should always happen at the same moments. They can however differ between different emulators and emulator versions due to emulation differences.
When TASing, you should try to keep the number of lag frames as low as possible, as lag frames generally indicate slowdown.
I hope this helped.