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• Windows (x64) 87.8 MB
• Linux (x64) 80.6 MB

Why is the application size so big?

What is Subtitle Merger?

It is a desktop application that allows you to merge two subtitles into one. It is helpful if you learn a new language and want to see bilingual subtitles or if you watch videos with someone who wants to see subtitles in a different language.
The main feature of the application is the ability to work with videos - you can select one or several videos, see the list of subtitles for each video, merge selected subtitles and inject the result right back into the videos or save to external files nearby.

Table of Contents

• What formats are supported?
• Hot to use it?
  • To merge two subtitle files into a third
  • To work with videos
• Other questions
  • What merge mode should I choose?
  • Why are there question marks instead of subtitle sizes?
  • What about the encoding?
  • Why is the the application size so big?
• Additional features
  • Mark merged subtitles as default
  • Merge subtitles in plain text

What formats are supported?

Currently the application supports SubRip subtitles (.srt) and Matroska videos (.mkv). It also supports SubStation Alpha subtitles (.ssa, .ass) if they are already in videos and will convert them with Ffmpeg to SubRip internally.

How to use it?

First of all, you need to download the archive with the application. After downloading the archive you should unpack it to any folder of your choice. After unpacking to start the application you should launch:

• subtitle-merger.exe on Windows
• run.sh on Linux.

The application has two main tabs to work with subtitles, the first one simply merges subtitles from two files into a third one. The second tab is much more powerful and allows to work with videos.

To merge two subtitle files into a third

Open the first tab called "Subtitle files". On that tab you just need to select a file with subtitles that will be displayed at the top of the video and another file with subtitles that will go at the bottom. You also need to select the file where the result will be written.
Note that there are three eye icons, clicking them will open the preview windows.
What about the encoding?

To work with videos

Open the second tab called "Videos". When you open the tab for the first time you will see that three required settings are missing. After setting them (what merge mode should I choose?) you will be able to open one or several files (better for movies) or the whole directory (better for TV shows with many episodes). After you see the videos you should do the following:

1. If you've chosen the whole directory you will need to mark the files you want to work with directly.
2. The next step is to select the subtitles to merge for each video, you can do so either by
   • Pressing the "Auto-select subtitles" button. The application will try to select subtitles for merging based on the preferred languages that you've set on the settings tab. If there are more than one subtitles for one of the preferred languages, the application will load them and choose the biggest one.
   • Clicking the radio buttons next to the subtitles if auto-selecting is not possible for some videos or if you want to select subtitles manually. Note that initially you can't see the subtitle sizes (the reasons for that are described here) but you can always load the subtitles by pressing the corresponding buttons.
3. Press the "Merge" button, this is the final step.

Other questions

Below are the most expected questions about the application.

What merge mode should I choose?

There are two merge options:

1. Modify original videos. With this option the application will inject merged subtitles into original video files. It is the most convenient option since everything will look as before except for the new merged subtitles in the subtitle list. This approach requires extra disk space during the merging process (equal to the size of the largest video to process) because the application will create a temporary video first and then will overwrite the original video with this temporary one. Note that the original files will be overwritten! And if something goes wrong during the merge you may lose your video files.
2. Create separate subtitle files. With this option the application will create separate subtitle files next to the videos. This option is not so convenient because after merging you will have to select the subtitle files manually when watching videos. But this option is safe because the original videos won't be modified in any way. And it also doesn't require almost any extra disk space.

Why are there question marks instead of subtitle sizes?

You may have noticed that table with videos and subtitle lists are loaded pretty fast but there are question marks instead of subtitle sizes. That's because with Ffmpeg it's very fast to get the basic video information including a list of subtitles with their languages and titles but unfortunately, size of subtitles isn't returned among the basic information about the video. So the application has to load the whole subtitle stream and that takes much more time (around 10 seconds for each of the subtitles for a several gigabyte video) and because of that loading the subtitles happens only on demand.

What about the encoding?

By default all input files are considered to be UTF8-encoded. If that's not the case you can change the encoding to the one you like in the preview window after pressing the eye icon. Feel free to do it because that's safe and does not modify files. Application encodes resulting files with UTF8, it's not configurable. Also note that you can't change the encoding of subtitles that are already in the video, they are always UTF8-encoded.

Why is the application size so big?

The size of the application varies from 80 megabytes (the Linux version) to almost 90 megabytes (the Windows version) although the application itself is relatively simple.
There are two main reasons for it:

1. 40 megabytes are taken by the custom Java Runtime Environment (JRE) which is included because starting from version 9 Java no longer has JREs, only development kits, so we can't ask users to install Java by themselves.
2. 35-45 megabytes are taken by Ffmpeg. It is a very useful open source utility that the application uses internally to work with videos.

The "pure" jar with the application takes approximately 350 KB. After adding required libraries and making a "fat" jar, the size rises up to 5.5 MB. All other space is taken by the JRE and Ffmpeg.

Additional features

The application has several additional features that can be managed through settings.

Mark merged subtitles as default

The application can mark merged subtitles as default which means that they will be selected by video players by default automatically so you don't need to select them manually when watching videos. It works only if you select the "Modify original videos" mode.

Merge subtitles in plain text

If you want subtitles to be "pure", without any colors, different font sizes and so on you can choose that option on the settings tab.