How to convert an MKV to MP4 file and an MP4 to MKV file

[carlmart]

I would appreciate some help on the following questions?

1) How to convert an MKV file to MP4, and viceversa, without converting the video?

2) How to select the video codec when converting an avi file to mp4?

3) Is it possible to convert an avi codec into another one?

The questions about the codecs is because I want to import an avi file into Sony Vegas and the program does not recognize the codec.

I did use Videocoder to convert the avi file into an MP4 file, and I have the same codec error.

The avi codec is mp42 (isom/iso2/avc1/mp41)

I am aware avi, mkv and mp4 are just containers. So I wonder if there's some way to convert the codecs

Thanks

[carlmart]

I was now having another look at the original AVI codec, which seems to be DX50. So the mp42 coded was Videocoder that changed the original to.

But both seem not to be recognized by Sony Vegas.

Perhaps the problem is not the codec really.

[carlmart]

Oh, I forgot to say.

Vegas does import part of the file from the Videocoder processed mp4: the audio tracks. It doe NOT import the video.

[jagabo]

Remux only:
MKV to MP4: MKVtoMP4 (may reencode audio)
MP4 to MKV: MKVMerge

[carlmart]

OK, the MKV to MP4 conversion went fine. Thank you.

The other one I forgot.

Any options for the codecs question? Maybe it's a Vegas problem really.

[jagabo]

Install a VFW decoder for MP42. FFDShow, for example. That should allow Vegas to open the AVI file.

[carlmart]

OK, now I can't try that because I am rendering the MP4 file I converted the MKV file to.

Even if I just installed the latest FFDshow version, I already had FFDshow installed.

Let's see if the new one works better.

[jagabo]

Even if I just installed the latest FFDshow version, I already had FFDshow installed.

Enable the VFW MP42 decoder. If you're using 32 bit Vegas use 32 bit ffdshow. If you're using 64 bit Vegas use 64 bit ffdshow. You don't need a new version. The MP42 decoder has been around for many years.

[carlmart]

OK, this time I could import the video part of the avi file, not the audio. Any special trick to do that?

Both Vegas and ffdshow are 64-bit. I don't know how to enable MP42 in ffdshow. It's there, but I don't see any box to tick and enable it.

I will look into the Vegas tutorial to see if there's any way to open the video full-screen, so I can see properly what I'm doing.

[jagabo]

Select Start -> All Programs -> ffdshow x64 -> VFW Configuration 64. At the configuration dialog select the Decoder tab near the top left. Just below that highlight Codecs in the list. To the right of that click on the Decoder column next to MP42. Use the pulldown to make it say libavcodec, not disabled.


[Attachment 48670 - Click to enlarge]

Also check the Audio Decoder Configuration and make sure the appropriate audio decoder is enabled.

[carlmart]

All that you show is exactly the same on my ffdshow.

The audio configuration is all enabled with libavcodec. The files audio codec is Dolby digital. I tried another one and Vegas only opens the video, no audio track.

[jagabo]

All that you show is exactly the same on my ffdshow.

Which is why:

OK, this time I could import the video part of the avi file

The audio configuration is all enabled with libavcodec. The files audio codec is Dolby digital. I tried another one and Vegas only opens the video, no audio track.

I don't use Vegas so I can't give you specific instructions. But you can probably demux the audio from the video and import that audio file into Vegas.

[carlmart]

Of course I did that, but it's completely out of sync.

I would have to learn how to move the whole audio track to sync it.

Another thing is how to export it, because the file is 25fps. Going to 30fps would imply a full re-conversion, with frames added and all that.

So on my test I exported to AVCHD 1440 x 1080 50i, and I got a 25fps video as a result (do not ask my how).

The format is m2ts. so the file is enormous, x6 the original size, but the movements are much smoother than the original too. Do not ask me how either, but it does.

What I wanted to add was a light sharpening, which ended up perfect. But all the image looks much better than the original, and I have a trained eye.

This film is from '48, and was never released in Blu Ray, but does show possibilities on DVDs that also were not.

I also have a film that had been originally released in DVD, but this time they re-released it in BD. A complete disappointment! The images might have more resolution, but it's much darker and lifeless. Perhaps I can process the BD version with Vegas and get closer to the original look.

[carlmart]

Well, the only way to do it was to convert the audio tracks to pcm, re-merge it, then convert it to mp4.

This time I could import the file to Vegas.

[jagabo]

I would have to learn how to move the whole audio track to sync it.

In an NLE that usually as simple as dragging the track left or right in the timeline. Or right clicking on it and selecting something like properties, delay, start time from the context menu.

https://www.youtube.com/watch?v=LeXUgOUJUus

I think he said CTRL + U.

[ashokcool2636]

you can easliy from mkv to mp4 without re-encoding using ffmpeg to switch container
from mkv to mp4 via this command:
ffmpeg -i filename.mkv -vcodec copy 1.mp4

and for mp4 to mkv you can use below command
ffmpeg -i filename.mp4 -codec copy filename.mkv

[carlmart]

Please forgive my ignorance, but I'm not used to working with ffmpeg.

Where do I load and execute the change command?

[jagabo]

If you already have an MKV with suitable codecs you can remux to MP4 with MKVtoMP4.
https://www.videohelp.com/software/MkvToMp4

[Cauptain]

Please forgive my ignorance, but I'm not used to working with ffmpeg.

Where do I load and execute the change command?

Create a folder in C: named 'Video'

Download FFMPEG from here: https://ffmpeg.zeranoe.com/builds/

Make like a screenshot




Claudio