Combining mkv files (video, audio, subtitles) to create a proper episode...

[Cinderwolf]

I wasn't 100% sure if this belonged in "editing" or another category.
I'm facing a bit of a problem.
I've got some video files that weren't compiled/created traditionally (intro and credits to a show are separate files from every episode). The easiest way to break it down is this example:

episode1.mkv (doesn't contain the introduction or the credits to the show
intro.mkv (literally just the opening sequence/credits with subtitle files in the mkv)
credits.mkv (literally just the closing sequence/credits with the subtitle file in the mkv)
If I play the "episode1.mkv" in VLC, it automatically plays the intro with its subtitles and continues into episode1.mkv and then continues into credits.mkv (likely contained within the "chapters" of the episode1.mkv). If I move the intro or credits files or re-name them, of course they don't play when I open "episode1.mkv".

For convenience, I access my media through my Plex home server. This file setup doesn't sit well with Plex as all it does is simply play the episode1.mkv itself without automatically playing the intro at the beginning or credits at the end. Also: the intro and credits all have subtitles due to foreign languages spoken.

What I'm looking to do is find some way to insert the intro.mkv (with its subtitles) and the credits.mkv (with its subtitles) into the episode1.mkv so I get everything in one actual file.
I have a feeling it's not quite as simple as this because the timings will all of a sudden be off/changed due to video stream lengths changing... unless there's a way/program to have the subtitle timings automatically corrected/adjusted? I've got the basic MKVtoolnix installed with the tools that come with that (basic staple of mkv editing) but I have a feeling I'm going to need some pretty step-by-step instructions to do this.

[jagabo]

I've got the basic MKVtoolnix installed with the tools that come with that (basic staple of mkv editing) but I have a feeling I'm going to need some pretty step-by-step instructions to do this.

In 1/10 the time it took you to write that post you could have just tried the program to see if it works.

[Cinderwolf]

I've got the basic MKVtoolnix installed with the tools that come with that (basic staple of mkv editing) but I have a feeling I'm going to need some pretty step-by-step instructions to do this.

In 1/10 the time it took you to write that post you could have just tried the program to see if it works.

Okay- so, thanks for the sarcasm and you know, not actually assisting with any "have you done x, y, z? Try this...". At the time I wrote this, I didn't know about the append feature in the program. Don't assume someone can figure it out just by 'trying' because as you'll find out, I needed more than the toolnix provides to come to the proper resolution.

Bit of a rollercoaster here, but I ended up crash-coursing myself and I've figured it out- AND this might actually be a bit of a road-map for other users given a problem that was created and resolved along the way!

I had to update the toolnix I had (unfortunately was out of date by a year or two).
Tools needed: mkvtoolnix-gui.exe and MKVExtract
1) Opened: mkvtoolnix-gui.exe
2) Inserted intro.mkv
3) Appended with episode1.mkv
4) Appended with credits.mkv
5) Remuxed into "newepisode1.mkv"

**Problem: credits and formatting for the episode1 and credits portion is wonky in new file - but it all plays as a singular file (half-way there!)

6) Opened: gMKVExtractGUI.exe with original episode1 file and extracted just the subtitle file (.ass format)
7) Also extracted subtitle file from my "newepisode1.mkv" file (creating "newepisode.ass")
8) Using Notepad and comparing the [V4+ Styles] section, I noticed 8 lines of "Style:" code missing in the "newepisode.ass" file.... so I copied/pasted the entire [V4+ Styles] block from the original "episode1.ass" into the "newepisode.ass" subtitles file and saved it.
9) Used mkvtoolnix-gui.exe to remove the subtitles from "newepisode" and manually add the updated version of subtitles, remuxing into what is now a perfectly whole episode.

So lessons learned: keep MKVtoolnix up to date and appending multiple parts destroys formatting in subtitles (which can be saved by copying the [V4+ Styles] from the original file's subtitle file!