How can I crop a MKV video?

[devyhevy]

Hey guys,
I have this huge 4 hour MKV video with over 8GB of size. I need to crop it in different bits. However, QuickTime won't open it. Neither will Final Cut pro X, Premiere CS5 nor iMovie.

I've tried converting it to MP4, MOV, AVI and many other file formats but every time I do so, by the end of the video the audio starts to get out of sync. So I'm really running out of options here.

How can I crop this bloody huge MKV file?
Can anyone help?

Thank you in advance.

 

[simsaladimbamba]

.mkv, as .mov and .m4v and .mp4 and .avi are just containers using a variety of codecs, thus simply transcoding (converting) the .mkv to a .mov or .avi will not help, as the codec used is still important.

I tested MPEG Streamclip (latest BETA) and it worked opening the .mkv sample file I downloaded. You also have to have Perian installed to make that work.
To crop the opened video, you have to export it, I used the "Export as QuickTime" option (CMD+E) and used the H.264 codec as Compressor and then set the cropping dimensions and clicked "Make Movie".

To trim a video (trimming is the shortening of a clip's length by taking away something from the end and/or beginning), I opened the .mkv in MPEG Streamclip too and used the I and O keys to make an IN and an OUT mark, thus shortening the actual clip.
Then I can continue to export it via the way described above in the CROPPING section.