[HowTo]: joining multi-part movies files with MKVtoolnix GUI

You are a god among men, thank you for making this guide.

Can anyone help me with an error please? Trying to merge LOTR and I’m getting a height difference error.
They were both transferred from DVD using the same program (DVDFab) and the same settings, so I don’t understand the error. I seem to get the error regardless of what files I’m trying to stitch. Any ideas what I’m doing wrong?
Since Plex is now broken, I don’t seem to have any more options…

The track number 0 from the file ā€˜E:\Videos\Movies\The Lord of the Rings The Fellowship of the Ring (2001)\The Lord of the Rings The Fellowship of the Ring (2001) - pt2.mkv’ cannot be appended to the track number 0 from the file ā€˜E:\Videos\Movies\The Lord of the Rings The Fellowship of the Ring (2001)\The Lord of the Rings The Fellowship of the Ring (2001) - pt1.mkv’. The height of the two tracks is different: 304 and 300

DVDfab is not transferring the data straight to file. It first tries to cut off the black borders (the width of which is automatically determined) and then re-encodes the video stream. It may determine a different height of the blackbars between discs, which then leads to the video files having different dimensions.

I recommend you to rip the discs with MakeMKV (which doesn’t change the data in any way)
then merge the files of the two discs
then send the resulting file through Handbrake, if you want it being smaller (and the black border cut off).

Thank you for the info, I will give it a go, but I have also found that the Plex stitching works on the LG TV app.
It seems it is just iOS platforms that have the problem with playback of multi-part movies. I wonder if it is on their buglist?
I hope that they can fix it soon, I don’t want to have to re-rip too many of my movies, DVDFab is really simple (most of the time!).

Thanks again!

So I am trying to merge two video files and this is the warning I am getting any help would be appreciated.

— Warnings emitted by job ā€˜Multiplexing to file ā€œDances with wolves.mkvā€ in directory ā€œC:\Users\Andrew\Videosā€ā€™ started on 2019-02-26 13:31:07 —

The track number 0 from the file ā€˜C:\Users\Andrew\Videos\Disc 2.mp4’ can probably not be appended correctly to the track number 0 from the file ā€˜C:\Users\Andrew\Videos\Disc 1.mp4’: The codec’s private data does not match (lengths: 48 and 48). Please make sure that the resulting file plays correctly the whole time. The author of this program will probably not give support for playback issues with the resulting file.

That’s a warning, not an error. So the merged file should still get made.

You are trying to merge files which have already been compressed down (contrary to ā€œraw ripsā€ [usually called ā€˜remuxes’] which are unmodified ).
When you do that, there is always the danger that the files have been compressed using different parameters. (e.g. often seen: the picture of disc 1 was cropped differently than the picture of disc 2. Which results in the 2 video streams having different dimensions. Which then prevents a successful merging.)

Therefore: if you want to merge 2 files, you want to use unmodified, ā€œrawā€ rips.
Only perform the compression as a second step.

it does merger them but… the first video is fine and the second one audio is fine but the video is all scrambled and you can’t even see the picture at all

I just made two parts of a movie, 3gb each, into the first part of the movie that’s 6gb. Instead of a 2 hour 6 gb movie, I made a 1 hour 6gb movie.

Oh, use it to Append. (In your best Zoolander voice)

I just use ffmpeg with concat command from the command line. Very fast.
If you are running a Linux variant just make a file called mylist.txt (or whatever)
In that txt file add the names of the videos you want to connect. Can be however many you want. And named whatever. Such as:

file ā€˜1.mkv’ # can be .mp4 or any video format
file ā€˜2.mkv’
etc

Then save that file and in same directory in the terminal run the following command with whatever you want it named as.

ffmpeg -safe 0 -f concat -i mylist.txt -map 0 -c copy ā€œWhateverā€.mkv

or if you prefer mp4 container

ffmpeg -safe 0 -f concat -i mylist.txt -map 0 -c copy -movflags +faststart ā€œWhateverā€.mp4

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Great app and great guide. Many thanks.

Thanks for this! It worked perfectly…don’t even care about the gap.

Hello, I am trying to merge 13 short films from the Pixar shot film collection and cannot for the life of me work out how to do it. I have both MakeMKV and MKVToolNix but the first doesn’t purport to manage mergers of two MKV files, let alone 13, whilst the second is too complicated to get it right (plus the file size of two supposedly merged files is smaller than either file on its own. Help! I also want to merge existing two part films as I didn’t know some players can’t handle pt1 and pt2 elements.

I have looked everywhere and a pulling out what little hair I have left! I don’t want command line stuff, by the way. Loving Plex, by the way, with nearly 2,000 films loaded so far.

It won’t get any easier than what is described in detail in the first post above.

Thank you, and I agree - a very helpful post but it simply doesn’t work for me with more than two files to join, and I’m neither a ā€œPlex Ninjaā€ nor an ā€œIT Idiotā€!

Edit: I have now gone with Faasoft Video Converter and have successfully joined 13 MKV files into one. I have issues with multiple audio tracks (two at 5.1 reduced to one in stereo), which I have raised with developer.

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Hi, can i ask, I have problem : episode from witch i extract audio have 22:06 minutes, but Hd episode where i want stick" that audio have 22:11 minutes…soo problem is every audio track is shorter than movie file witch i want fit that audio track… when episodes was 1-2 second different it was not problem and audio and picture look synchronised… i was help with ā€œdelay in msā€ … but if is it more than 3 second ,after is imposible synchronise to watch…
how can i do this ?
thank you

Compare the video frame rate of the SD and the HD version. They may be different.

You then either have to adapt the frame rate of the HD version to the frame rate of the SD version (I don’t know how to do that, but it is probably lossless),

or you’ll have to adapt the playback speed of the audio track (lossy option).
Take a look at eac3to

frame rate is same 23.976 booth version,
with option is ā€œloosy optionā€ in program?

There is no such ā€œmenuā€.

I’m currently working on joining LOTR Extended edition blurays. These are MakeMKV rips. I’m getting the following warning:

ā€œThe track number 0 from the file ā€˜F:\MKV Staging\THE LORD OF THE RINGS- THE TWO TOWERS (EXT.) PT. 2_t00.mkv’ can probably not be appended correctly to the track number 0 from the file ā€˜F:\MKV Staging\THE LORD OF THE RINGS- THE TWO TOWERS (EXT.) PT. 1_t00.mkv’: The codec’s private data does not match. Both have the same length (72) but different content. Please make sure that the resulting file plays correctly the whole time. The author of this program will probably not give support for playback issues with the resulting file.ā€

What is it trying to tell me here?

It says you should play the merged file (particularly the time around the switchover) to see if it still plays. If it does, all is well.

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