Converting MKV to VOB without losing quality

[guy24s]

I have a MKV file that I want to convert to VOB without losing any quality.
I don't know why everyone keeps saying MKV is lossless and the same as VOB. This was taken from a DVD and obviously I can tell by just looking that the quality of the MKV looks much worse. Side by side comparisons makes it even more clear.
Anyway, it says that the MKV is:
H264 716x576 25.00fps ~1150 kbps

How do I convert that to VOB? Preferably something besides FFmpeg or TMPGEnc if possible, unless there is an easy step by step guide to for these programs that explains exactly what I want to do.
I want to convert it without losing further quality other than what has already been lost after it was converted from VOB to MKV.

[noemi7]

MKV is not a video codec but container which accepts any type of video. H264 is not accepted video codec for a DVD but MPEG2 only. Your video was lossy converted from a DVD or it source is a webcast for which H264 is the most common codec now. Any video conversion, like required in this case: H264 back to MPEG2 VOB/DVD is lossy, so no way that the quality will improve. You will end up with a larger file, and depending on conversion setup, a bit or more degraded video.

[lingyi]

To add to the above, an .mkv can be the the same quality as a .vob (which is another container, specifically for use in video DVDs), if the file is remuxed (rewrapped) into the .mkv container. Imagine you have a store bought cake. You take it out of the box (.vob) and place it into a home container (.mkv). The cake is still exactly the same.

[zizouillette]

@noemi7: +1

[guy24s]

OK thanks for replying. So the damage has been done already. Right, but I still need it back to VOB in order to edit in some missing pieces of another VOB file I have that is superior in quality but contains some damaged parts.
So I need the contents of this MKV to VOB, with as least loss of quality as possible. It doesn't matter to me if the VOB file will be larger and I am aware of that it won't look better than the MKV, I just don't want it to look worse.
So what is the easiest way?

[noemi7]

FFMPEG does pretty good job imo, and there are plenty of free GUIs for it with optimized presets for high quality DVD. However, have in mind that to keep maximum quality you need to join both MPEG2 videos in an editor which does not further re-encode them to create the final file / DVD. I use VideoReDo. TMPGEnc, you mentioned, has smart rendering option but I don't trust it - the video has to be 100% compliant with DVD standard but even so Pegasys' programs are sometimes 'smarter' and re-encode 'here & there'. It will be of course necessary at the joint point, with a few frames, but should not be done in other parts.

[DB83]

Unfortunately even converting this H264 to mpeg2 (can not directly edit a vob) will mean two losses of actual quality - first in the conversion and second when you edit since it will be practically impossible to export the edit without a re-encode since both videos will invariably have different parameters. And the H264 is further compromsed at 716 pixels width whereas the dvd/vob will be 720 pixels.


And is your vob 25 fps since if it is not there lies even another problem.

[guy24s]

FFMPEG does pretty good job imo, and there are plenty of free GUIs for it with optimized presets for high quality DVD. However, have in mind that to keep maximum quality you need to join both MPEG2 videos in an editor which does not further re-encode them to create the final file / DVD. I use VideoReDo. TMPGEnc, you mentioned, has smart rendering option but I don't trust it - the video has to be 100% compliant with DVD standard but even so Pegasys' programs are sometimes 'smarter' and re-encode 'here & there'. It will be of course necessary at the joint point, with a few frames, but should not be done in other parts.

OK thank you, I will try FFMPEG. Yes, I use an editor that does not re-encode anything (as long as the different segments are encoded the same way). I am not adding any transitions or altering anything, it's just a very basic cut and paste job of a few frames that are damaged in the MPEG2 file.

And is your vob 25 fps since if it is not there lies even another problem.

Yes both are 25 fps PAL.

[LMotlow]

And chances are that the VOB you have from your DVD is interlaced and the mkv you want to turn into a VOB is not. You can't mix interlaced and non-interlaced video in the DVD format. They both have to be either interlaced or progressive, not one of each.

[manono]

They both have to be either interlaced or progressive, not one of each.

It's especially easy to mix interlaced and progressive content for PAL DVD. You just encode the whole thing as interlaced. No pulldown to worry about.