YAMB (Yet another MP4 Box utility), allows you to do many things with your MP4 files. I needed it to chop a long video into 10 minute pieces so that I could upload it to YouTube. YAMB can do it, but it does not have any documentation. So when it came to setting a value into the “Split by duration” box, I had no idea what kind of value it takes.
Well, after a whole lot of tries, I figured out that to split my video into 10 minutes pieces, the value had to be 600 (10 minutes x 60 seconds). Ah! so the value it accepts is in seconds.
But, after spending at least 5 minutes, trying various values, I found that YAMB has tool-tips (only if the delay to display them was not so high, I might have found them a long time ago!). And it turns out the values you can specify for the “Split by Duration” box are
1. In seconds
2. Using the format hh:mm:ss.ccc (when using this format – be sure to add the values for ccc – otherwise YAMB will freak out. eg: 10 minutes = 00:10:00.000)
Here is a good tutorial on how to manipulate and edit your MP4 files: http://www.digital-digest.com/articles/MP4_Usage_Guide_page1.html (page 5, goes into how you can use the YAMB tool).