Joining MKV files
correctly is not is not that simple. In order to join MKVs or for that matter join any 2 files with structures like movie files (VOB,TS,etc). You really need to "fix" them 1st. But let me start from the beginning.
DVDs,blurays,etc all support delays in both the audio and Video.
DVDs,blurays,etc all support support having a longer video Or audio stream then the other. Meaning you audio stream can last longer then the video stream or vise versa.
The MKV supports join any too files into what looks like a 1 clean long MKV. But this is due to the structuring of the MKV format. What really happens is that the MKV treats each joined file as separate "item" with it's own run times, delays, etc. But after the joining if you where to reopen the MKV and view the info. You wouldn't see 2+ joined files any more but 1. And while this will play just fine, you'll not me able to cleanly demux any of the streams. As the demuxing will out put only 1 file per stream. Not remembering to noting the needed delays between segments.
This same issue is true to software that claims to joins VOBs, or Mpegs together. They join to do it right, but in the end almost all of them basically just do a.
Code: Select all
copy /b file1.vob+file2.vob combined.vob
And while said file will appear to play cleanly, you never be able to covert it to anything else with out audio sync issues. Unless all the joined files where either fixed OR never had any run over or delays in them.
My favorite example of this is the lord of the rings extended edition. With these 6 discs you ended up having ALL the above issues. For example with discs 1 and 2 you had a longer audio stream then video. So you had to add a "delay" to the second DVD or lengthen the video stream of DVD 1 or cut the audio stream down on DVD 1.
So joining MKV while simple is only advisable, if you not ever going to want to cover it to anything else ever again. This includes simply just wanting to convert the video stream to h264 from mpeg2, or the audio stream to mp3, etc. Or even just wanting to convert it back to a normal DVD(s). I'll do a write up on how to go about "fixing" the files before joining them as soon as i get a chance.