Convert MKV to MP4 (Lossless) using MKVExtractGUI + MyMP4Box GUI

[ilimitus]

I believe I have done this correct and I was able to convert MKV to Mp4 but am I doing it correctly?

1. Use MKVExtractGUI to open MKV video and extract into .h264 video, .audio, .chapter/txt

(Here is where I am iffy about)
2. Use My Mp4Box GUI:
A) MUX => Add .h264 video=> MUX into video.MP4 (Default settings- same FPS)
B) Then MUX add .Audio=> audio.MP4 (Default settings, same FPS)
C) Then click on Join and join Video.mp4 + Audio.mp4 => Finished converted MP4 video

It seems to work, but when I click on Join, it says "Formats do not match, errors may occur." So this is where I am wondering... Am I doing it correctly?

Thanks in advance.

[Bonie81]

steps you mentioned are correct, and already worked for me without problems, and i hv converted lots of mkv videos to mp4 to upload to youtube.

[ilimitus]

steps you mentioned are correct, and already worked for me without problems, and i hv converted lots of mkv videos to mp4 to upload to youtube.

Hey thanks, What I am doing is lossless (no re-encoding), rt?

Also I think I found an easier way. Once in My MP4Box, I just go to MUX and add both 1. video and 2. audio and simply click on MUX and it works pretty fast. (Instead of seperately creating video.mp4 and audio.mp4 and joining.)

[adom]

I just started playing with all those programs but I think it should be like this:

MUX -> add -> choose video
MUX -> add -> choose audio
then click on SAVE AS -> type a name
then click on MUX
that's all (do not use JOIN tab)

edit:
cross-post

[Bonie81]

I just tried the reverse process MP4 --> MKV by reversing above steps.
it also worked like a charm.
1) Use My Mp4Box GUI
DeMux Video and Audio out of MP4 container.
2) Use MKVToolnix and Mux demuxed video and audio into MKV.

So following tools are MKV <==> MP4 <==> MKV bi-directional lossless conversion.
1) MKVToolnix
2) MYMP4Box
3) MKVExtractGUI/MKVMergeCLI.

[bat999]

I just tried the reverse process MP4 --> MKV by reversing above steps.
it also worked like a charm.
1) Use My Mp4Box GUI
DeMux Video and Audio out of MP4 container.
2) Use MKVToolnix and Mux demuxed video and audio into MKV.

I don't think it's necessary to do that.
MKVmergeGUI will accept mp4 files without demuxing.

[Lazare Londaridze]

I have a problem, got some anime mkv videos, I extract video and audio tracks but mp4box won't mux it. Any thoughts ?