I hope this is the right thread.
I am annotating a video in Elan5.4 and analysing the same video in FaceReader. It is really important that these videos be the same length to the millisecond for when I put them together in another software but they are not the same length! They are also a slightly different length in QuickTime and Adobe Premiere. Each one is different by a few seconds ranging from 03.00.03.012 to 03.00.16.086 (hh.mm.ss.mss). Again to clarify, I am using the exact same video but even when I separated the audio as a wav. file from the video mp4. They are different lengths. Is this normal? Can someone please explain why and is there anything I can do?
+ Reply to Thread
Results 1 to 3 of 3
It's not abnormal. The video and audio in a file don't have to start at the same time, end at the same time, or be the same length. Then you can have variable frame rates. With VFR you may need to parse the entire file to determine how long it really is. And often the header has the wrong information. Programs that only look at the headers will report that wrong information.
You should be able to use ffprobe to get that information to 6 place accuracy. You can list all frames with each frame duration, time code, etc or just length. I cannot say how accurate this info is since I do not have the code but it appears to be accurate to at least 0.0001 during all my tests.