Question about cutting video

[Mike89]

I had a two hour video and I wanted to cut 1 1/2 hours off of it. I did that and ended up with a video of 30 minutes long. Problem is even though the video is now 30 minutes long, when playing it back in a player, the player is still showing it as 2 hours long and the slider moves like it is still two hours long which it isn't. Right clicking on that 30 minute vid and clicking properties/details also still shows it as 2 hours long. Any way I can fix this?


Edit:

When I did this the original vid was a .mp4. I had changed the cut to mkv remux. Is this why? Cause I did it again and left it .mp4 and this time the player and properties did show it at 30 minutes.

[Claire]

I think you are right it probably has to do with the fact you used MKV Remux but also related to the source file. Doing the same with another source file might not have this problem.

[Mike89]

I used the same .mp4 video both times. Used it once to cut out a part then converting the rest of it to mkv remux. Did it again using the same original .mp4 video to make the same cut but left it the original .mp4.

For some reason the converted mkv remux still showed the full length of the original when playing it instead of showing the corrected 1/3 of what I had after the cut, as I said even the properties still showed it full size also.

The cut I didn't convert, just left it .mp4 showed the correct size after cut both in the player and in the properties.

Any idea why changing to mkv remux caused this behavior?


I wonder if cutting and changing to any other formats other than what the original one was is going to this.

[Claire]

When converted the file is formatted differently and also a new header is created with correct information written there in regards to the file created.

I tried to explain in my previous post that the remux problem will not happen with all files just some it depends on how their were originally encoded.