Cropping an MKV file

[alexp2000]

Hi there, just wondering if there is a simple way to crop an mkv file? For example, when using vlc it is possible to crop a 16:9 image to 5:3 (1.66) or 4:3 but is there a program that can make a permanent change? Thinking of using something like this for a coupel of projects I have in mind...

[deblock]

I don't know of a simple way, but I think it's possible (depending on codec/container) to do this losslessly because supposedly there are retail DVDs that can show full-screen and widescreen off of the same video data. I've never seen a DVD like this, but *I think* the MPEG-2/DVD spec even defines this possibility. It's shameful it wasn't/isn't used.

[Feallan]

It's possible of course, but for lossy formats, not without reencoding.

You can do it in Handbrake for example. Command-line x264 probably has this option as well.

[deblock]

And on the other hand, depending on container/codec it should possible to do this losslessly with no reencoding, however I've never viewed a video (DVD) that's done this.

It's possible of course, but for lossy formats, not without reencoding.

You can do it in Handbrake for example. Command-line x264 probably has this option as well.

[PDB]

I was going to recommend Handbrake also. Its pretty the easy to use.

[Stamper]

You can crop any video using mkvtoolnix. Then it will display direct widescreen on your TV using a WDTV for example, without reencoding

[deblock]

Do all MKV software/hardware players support lossless cropping for all video codecs (that MKV supports)?

I would beware and verify the software/hardware MKV player you're using supports the MKV lossless cropping for the video codec you're using because (I could be wrong), however, I would think MKV's lossless cropping doesn't work with every type of video codec and on every MKV player.

You can crop any video using mkvtoolnix. Then it will display direct widescreen on your TV using a WDTV for example, without reencoding

[spoRv]

MKV is a container (like AVI, M2TS etc.) and, unless it contains a lossless encoded video, it's impossible to crop it losslessly - read: if it has an h264 video, it's not possible to crop without re-encoding it...

[deblock]

spoRV, I know you're a master and an expert, however I think you're mistaken, but it's ok. I would think MKV does define the use of a viewport separate from resolution, whether this is actually implemented/supported in players for all video codecs is another thing, but for MPEG-2, it's supported with VOB's and I'm assuming MKV's (because MKV's were defined supposedly to support DVD functions very closely, however as we all know the software/implementations don't actually do this). I've always been interested in this because of my previous fullscreen comments, and now I'll look it up when I get a free chance.

A quick search turned up this, which doesn't definitely say lossless MKV cropping supported but does align nicely with my and Stampers opinions and thoughts.
http://forum.doom9.org/archive/index.php/t-138711.html

MKV is a container (like AVI, M2TS etc.) and, unless it contains a lossless encoded video, it's impossible to crop it losslessly - read: if it has an h264 video, it's not possible to crop without re-encoding it...

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[spoRv]

I may be wrong, but try this: take whatever video, in letterbox format, lossy encoded (h264, mpeg2, vc1 etc) and put it in an MKV container; crop out the black borders; compare the same frame before and after; if the cropping is effectively lossless, you will note no difference in the cropped and uncropped frame (apart, obviously, the absence of black bars); let me know if it does occur.