At the trial, you must ask the officer all those questions while the officer is still on the stand. This is called cross-examination.
The officer will take the stand and then the prosecutor will ask for the officers side of the story, which officer will give. Then the JP will ask you if you want to cross-examine the officer. You should say yes and then proceed to get try and get the officer to admit that he saw you go thru a yellow light and not a red light. The charge is RED LIGHT so if you can get the officer to admit that it was not a red light, then you will win.
Once you are done asking the officer questions, the officer will step down and the JP will ask you if you want to call any witnesses. You should say yes, yourself. You can then get on the witness stand and tell your side of the story.
+++ This is not legal advice, only my opinion +++
Former Ontario Police Officer. Advice will become less relevant as the time goes by !