In need to convert many hundreds of short videos from MOV to MP4. All the products I have found for performing this conversion in batch have worked, but with my particular videos they frequently result in MP4's that end with a blank white screen, which will be very disconcerting to my readers (these are videos of sign language sentences to be viewed from inside PDFs by people who are just learning the language, and it facilitates their comprehension for the last frame of the actual event to remain visible, not a white screen that wipes their minds clear so to speak). I can fix each one by simply loading it to Vegas and re-saving it as MP4, but I could as easily have done that just by converting the original MOV's one at a time in the first place. Does anyone understand what the problem could be, and how to solve it? (My suspicion is it may have something to do with the number of actual frames present in the file being less than what the file header claims to be present?.)
A recommendation I found on your site (which I can't find again) suggested a .BAT file using FFmpeg, which I found hard to implement, so I employed the GUI interface in QWinFF. It did the conversion just fine, but about the same proportion ended with a blank white screen as the other apps I've tried (Handbrake, and ZAMZAR), namely about half of them have this problem Success half the time is better than none, but...
While this info may help in its diagnosis if not in its current solution, it may help to know that perhaps 1/3 were originally produced in the 1970's on a black-and-white reel-to-reel Sony VTR, excerpted from there on Sony floor models, then digitized, then further excerpted using Vegas. The other 2/3 were produced in the 2000's on a Sony handheld VTR in AVI, converted to MPG, and excerpted using Vegas either from the AVI's or the MPG's. Thanks in advance for your help.