I am creating an experiment in python. It includes the presentation of many mp4 videos, that include both image and sound. The sound is timed so that it appears at the exact same time as a certain visual image in the video. For the presentation of videos, I am using psychopy, namely the visual.MovieStim3 function.
Because I do not know much about technical sound issues, I am not sure if I should/can take measures to improve possible latencies. I know that different sound settings make a difference for the presentation for sound stimuli alone in python, but is this also the case, if the sound is embedded in the video? And if so, can I improve this by choosing a different sound library?
Thank you for any input.
Juliane
Ultimately, yes, the issues are the same for audio-visual sync whether or not they are embedded in a movie file. By the time the computer plays them they are simply visual images on a graphics card and an audio stream on a sound card. The streams just happen to be bundled into a single (mp4) file.
Improving sound latencies for video presentation in python