I am taking some multi-gigabyte video files (m2ts format), and converting them to not-as-many-gigabyte files (MP4 format) using software called Handbrake.
The problem is, my source files have extraneous material at the beginning and the end, and I want to cut it out. Handbrake will do this, although it won't allow material in the middle to be cut. But, one must specify how much to cut. This can be done in seconds, or in frames; everything I am seeing suggests that there are 25 frames per second. (Should be 30 in North America, I think.)
So, how to do it? Convert the m2ts to MP4 format, a process that takes several hours. Then I can watch the MP4, simultaneously watching the clock (which I suspect is not updated with perfect accuracy) and the video, to get an idea of where I want to cut. Note the time, and multiply by 25; that gives me the estimated frame count of the cut point.
If I'm lucky, this will give me a cut point to within ten frames or so. I can then reconvert the video (takes what seems forever), and see how accurate my guesses are. Adjust, and reconvert. Examine, adjust, and convert again. And again. And maybe again. And maybe again after that. Each time takes hours, and the fans on the computer are going at full speed the entire time.
There must be a better way. But what is it?