Shrinking MKV files

[handscombmp]

I've got some MKV files which have the video in the MPEG2 codec and i wouldn't mind shrinking them down as they're taking up quite a bit of space on my HDD.

Ideally i'd like to have them using one of the newer codecs live x264 so they have the same quality but take up less space.

Now i'd normally search on google but you come up with so many results i'm not sure which programs i can trust.

So any help would be greatly appreciated.

[Terbinator]

Unless you know this already, MPEG-2 isn't very efficient and so needs high Bit-rates for decent qaulity in comparison too X/H.264. If you convert from MPEG-2 too x264 then you are going to lose some picture quality, no matter what bit-rate you want to use.

However: You could try using any old video converter or use a demuxer which will split your .mkv into seperate audio, video and subtitle streams for you to then remux into a format of your choice. The remuxing process may result in the video being transcoding/converted so be prepared for quality loss!

Looking at your system spec you may as well go for 2-pass encoding for better results, rather than the faster 1-pass techniques.

[jim]

I've been informed that for x264 encoding the tools you need is handbrake - had a brief look myself and seems a very handy tool.

[arthurleung]

Unless your original MPEG2 stream is really clean and/or have very high bitrate (as in >8Mbps) there is really no point transcoding. At basic settings x264 is only fractionally better than MPEG2.

Depending on your source quality you will be taking a 10% quality impact immediately for encoding to the same size, and much more as you go down to a lower bitrate.

Using some video filters can help but will take a fair amount to time (and learning) tuning it to get the best quality output.

Handbrake is good but it won't do magic. The main use for such tools is transcoding to put it on PMPs / phones and archiving DVD/BD to harddrive, assumed that the source file is of very high quality.

[SiM]

I wouldn't bother... unless you are an experienced encoder you will just end up raping the picture quality. Just buy a new hard drive...

[cookie365]

I get good results from Mediacoder transcoding mpeg2 to h264 1000kbs - about half the filesize with no real quality loss.

However, these are from the original DVB transport streams. If there's been any other encoding inbetween I wouldn't bother either just as SiM says.

[lfcfan_uk]

video editing is a fine art..
simple 1 click solutions have made life easy but still a lot of filters need to be run especially for dark colours..

[Lee H]

I've been informed that for x264 encoding the tools you need is handbrake - had a brief look myself and seems a very handy tool.

handbrake is really good at converting media files and I use this myself at home to convert stuff to MKV so my media player is able to play it from a large pen-drive. I ripped my Aliens DVD to my HDD and converted it from DVD to MKV (HQ) resulting in a 980 Mb file and the time was just over 39 mins and this is on a system running a Q6600 overclocked (450 Mhz x 8)

If you've got a CUDA supported graphics card, then it may also be worth having a quick look at this software as well as this uses the GPU to speed-up the conversion ;

http://www.mediacoderhq.com/dlfull.htm

HTH

[Lourdes]

The CUDA encoders are poor and not really much faster than multiple cores and x264 which gives much better quality.