Having problems trying to split MPEG-4 file

[Xax]

I'm trying to use MP4Box/YAMB to split an already-encoded .M4V file into 4 parts. The first part splits fine. I'm having problems with the second part, however; either the video starts by showing a frozen frame from about 5 seconds into the clip, or the clip is starting earlier in the video than I specify.

In the latter case, when I try to split using MP4Box from the command line, here's what it looks like:

C:\Users\Main\AppData\Roaming\Yamb>mp4box video.m4v -split-chunk 385:682
Adjusting chunk start time to previous random access at 377.18 sec
Extracting chunk video_377_682.m4v - duration 304.82 seconds
Warning: Edit list doesn't look like a track delay scheme - ignoring

It looks like it's starting the video at 377 seconds instead of 385 as I specify. I don't understand why that is.

Any ideas? Is there a better tool for what I'm trying to do?

[olyteddy]

377 seconds is likely the nearest I frame.

[poisondeathray]

Just to clarify what olyteddy is saying: you can't cut with frame accuracy, only on I-frames (actually right before an I-frame, or end of the GOP). This is true for all applications that do not re-encode at least the GOP

You could try avidemux. But to ensure the freezing errors do not occur, navigate and cut on keyframes, not P or B.

[Xax]

I appreciate your responses. It sounds like I need to split during the encode if I want precision. I found no way to do this with Handbrake; is there a program you could recommend?

[Baldrick]

What is your source?

You can use avidemux to cut and convert to mp4 with h264 video.

[Xax]

Source is a .VOB from a DVD.

[poisondeathray]

You can cut it before you encode with frame accuracy

Either the vob beforehand with something like videoredo, womble mpeg dvd , or through an avisynth script using trim()

[Xax]

I like Avidemux and it's doing the trick; thanks very much for the help and suggestions.