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

OttoKernerOttoKerner Posts: 25,158Members, Plex Pass, Plex Ninja Plex Ninja
edited January 2016 in Tips, Tricks & How-Tos

The purpose of this HowTo is to join videofiles, when a movie was ripped and split into two or more files.
(This happens usually with very long movies [i.e. LOTR] or more often back in the day when we had Video CD or DIVX CDs)

The ultimate goal is to have the movie back in one file, so there is no trouble in the various Plex clients which do not support multi-part files.

The tool used is MKVtoolnixGUI
it is freely available for all major PC operating systems.

Therefore the container format of the output files will be MKV.
The input format can be a multitude of containers like AVI, MP4, MKV, MPEG, TS, DIVX and several more.
The quality of the files will remain the same, because mkvtoolnix only remuxes the files, it doesn't re-encode them.

This HowTo will use the newer GUI that is available from V8.0.0 of MKVtoolnix on.
(The older MKVmergeGUI has been deprecated and will be unavailable soon.)

Prerequisite:
All parts of the movie must be from the same source, encoded with the same parameters into the same audio/video codecs, or a lossless joining with mkvmerge is not possible!

  • start up MKVtoolnixGUI
    (depending on your operating system this might look a little bit different)

  • drag the first part file into the window marked by my crude arrow

  • the video, audio and subtitle tracks it contains will appear in the window underneath it

  • Right-click on the File name of the first part and choose 'Append files'. Navigate to the file for the second part and select it.
  • Your screen should now look like the screenshot below. Note, how the filename for the second part is 'indented'.
  • you may want to revise the language code that is assigned to the audio track(s) and the language and 'forced' attribute of subtitle tracks so the Plex interface informs you correctly about the languages available. Plex's automatic audio and subtitle track selection feature relies also on these tags to work correctly.

  • Now we correct the 'Output file' name to Plex standards to ensure a successful matching.
    Filmtitle (year) [extraneous info which is not mentioned in the movie naming guide].ext

  • 'Start Muxing'

Done.

Guide for splitting video files with MKVtoolnix GUI

Thanks to @adamskoog who suggested writing this guide.

Help others too - by reporting back with your results!
Have you checked the Documentation before posting a question in the forums?
Use the SEARCH function before starting a new thread!
No PMs unless requested, please! Do not use 'verbose' logging

Comments

  • adamskoogadamskoog Posts: 2,365Members, Plex Pass, Plex Ninja Plex Ninja

    Great write up, this will help quite a few people!!

  • BigFrosty92BigFrosty92 Posts: 1Members

    Hey, this is a great write up! I have a question though. When I append files, there will be a gap of 2 or 3 seconds between the end of one and the beginning of the next. Is there a way I can reduce this or remove it entirely?

  • adamskoogadamskoog Posts: 2,365Members, Plex Pass, Plex Ninja Plex Ninja

    If there is a gap, it's likely because it was there in the source material. You likely need to either trim the end of the first or the beginning of the second (or a bit of both) to remove it. I know when I joined my Lord of the Rings movies there was no gap at least.

  • diJj33E8@gmail.comdiJj33E8@gmail.com Posts: 2Members

    Thanks for sharing. No gap, I found other easy ways to join MP4 files. Just need to load the files and choose the output format, then join the files directly.

  • OttoKernerOttoKerner Posts: 25,158Members, Plex Pass, Plex Ninja Plex Ninja

    @diJj33E8@gmail.com said:
    Thanks for sharing. No gap, I found other easy ways to join MP4 files. Just need to load the files and choose the output format, then join the files directly.

    Would you care to share some more details?
    "Just load the files" - where? Which software?

    Help others too - by reporting back with your results!
    Have you checked the Documentation before posting a question in the forums?
    Use the SEARCH function before starting a new thread!
    No PMs unless requested, please! Do not use 'verbose' logging
  • diJj33E8@gmail.comdiJj33E8@gmail.com Posts: 2Members

    @OttoKerner said:

    @diJj33E8@gmail.com said:
    Thanks for sharing. No gap, I found other easy ways to join MP4 files. Just need to load the files and choose the output format, then join the files directly.

    Would you care to share some more details?
    "Just load the files" - where? Which software?

    Hi, here is the step-by-step tutorial of how to join MP4 files. Just go to check the process and the program you need to use.

  • creation6@me.comcreation6@me.com Posts: 1Members

    Please help. I have followed the instructions above by first adding one mkv file and then right clicking and appending the second file. When I click on "Start multiplexing" I get the error "Files cannot be appended to themselves. The argument for '--append-to' was invalid." As they are separate files, I am confused. Thanks for your help!

  • mlawlor26@icloud.commlawlor26@icloud.com Posts: 10Members, Plex Pass Plex Pass

    Thanks very much - I've got a couple of multi-part movies playing fine on the web player but not on iOS, and this should fix that right up.

  • HonzaHonza Posts: 17Members ✭✭

    Is there a commanline way to do this (mkvmerge?) My video files are on the NAS and I don't wanna pull them to my desktop over the network first to use the GUI.

  • OttoKernerOttoKerner Posts: 25,158Members, Plex Pass, Plex Ninja Plex Ninja

    @Honza said:
    Is there a commanline way to do this (mkvmerge?) My video files are on the NAS and I don't wanna pull them to my desktop over the network first to use the GUI.

    You mean you have mkvmerge installed on your NAS?
    If so, I am sure there is a way to achieve this on the command line. But I can't tell you the exact command since I very rarely dabble in terminal stuff.
    Description of the command line parameters is here http://mkvtoolnix-releases.bunkus.org/doc/mkvmerge.html

    But if you don't have mkvmerge installed on your NAS, you can use files located on a network resource in the GUI version just as well.

    Help others too - by reporting back with your results!
    Have you checked the Documentation before posting a question in the forums?
    Use the SEARCH function before starting a new thread!
    No PMs unless requested, please! Do not use 'verbose' logging
  • HonzaHonza Posts: 17Members ✭✭

    Yep I have mkvmerge installed on my NAS, it's running debian. I'm re-multiplexing all my previously ripped AVIs and MP4s to MKVs, by hand on the cmdline. Using the GUI on a local desktop means the file still gets pulled over the network, edited, and put back over the network. It just does it without the manual copy. I'm trying to avoid the 20 minute wait (the cmdline mkvmerge can replex an 1gb avi in ~20 seconds).
    Anyhow, I figured out how to append (I forgot to do a 'man mkvmerge' :) ), which works from an AV point of view, but the 2nd part subs are not being shifted up. I'll figure it out or manually fix the subs files with Jubler or something. Luckily for me I didn't make many 2-parter rips.

  • stanzanimstanzanim Posts: 2Members

    Thanks for the guide, which I carefulli followed. The issue is that the resulting joined file (descending from 2 AVI files MPEG4-p2 as reported) play with lack video (audio is OK, though)

  • OttoKernerOttoKerner Posts: 25,158Members, Plex Pass, Plex Ninja Plex Ninja

    @stanzanim said:
    Thanks for the guide, which I carefulli followed. The issue is that the resulting joined file (descending from 2 AVI files MPEG4-p2 as reported) play with lack video (audio is OK, though)

    Then the two source files had very likely differently encoded video tracks.
    This method cannot correct that.

    I hope you did trigger a manual re-'Analysis' of the merged file before you did the playback test.
    https://support.plex.tv/hc/en-us/articles/200289336-Analyze-Media

    Help others too - by reporting back with your results!
    Have you checked the Documentation before posting a question in the forums?
    Use the SEARCH function before starting a new thread!
    No PMs unless requested, please! Do not use 'verbose' logging
  • stanzanimstanzanim Posts: 2Members

    Thank but the two files seems to be coded the same way as MPEG-4p2 (codec columns). I see a column 'Force track' in crossed red ...

  • OttoKernerOttoKerner Posts: 25,158Members, Plex Pass, Plex Ninja Plex Ninja

    The codec alone is not the only parameter that defines a video stream.
    Even if the two discs had differently 'cropped' the black borders, the two video streams won't fit anymore.

    The 'forced' flag has no importance for video or audio streams.

    You cannot use this method for your files, I suppose.

    Help others too - by reporting back with your results!
    Have you checked the Documentation before posting a question in the forums?
    Use the SEARCH function before starting a new thread!
    No PMs unless requested, please! Do not use 'verbose' logging
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