Wednesday, June 01, 2011

Post processing mp4 with Subler Mac OS X

Subler is an open-source mp4 muxer and editor software on Mac OS X. I use it to edit soft subtitles, chapter information and add movie (or video) information.

What is soft subtitles? 

Soft subtitles are subtitles that are not embedded in the video or image. It can be turn on ond off by the software.

In VLC player, enable from main menu - Video - Subtitle track. In Quicktime player, enable from main menu - View - Subtitles.

In iPhone/iPod video player, there is an extra icon if the mp4 video has soft subtitles.

If the mp4 video does not have soft subtitles, the icon will not appear.

The subtitles can be added into the mp4 video when you create or convert the video. Or it can be added after the mp4 video was created.

I have tried to use muxo and iHex editor to add in the subtitles. Using Subler is much easier.

Subler quick tutorial 

Add soft subtitles

To add a soft subtitles, click on the (+) button, choose the external subtitles (current support srt format). If you are using double byte subtitles file, prefer to save it as UTF-8 encoding.

If the subtitle not sync with the audio, you may need to adjust the offset of the subtitle. Select the subtitle track, menu - edit - offset. Adjust the time with +/- value (in milliseconds). eg. +1000ms will delay the subtitle by 1 second.

Movie info and artwork

You can add your video (or movie) description into the mp4 file, by clicking the (+) button at the bottom. The information will be displayed at iOS players or iTunes software.

To make your job easier, you can get movie information online, from menu - File - Import Search metadata online. Search the movie information by name, if the movie is found, the information and artwork can be downloaded from the internet.

Create chapter info

The last function I want to show here is to create chapter information using Subler.

Chapter information supported by VLC, Quicktime and iOS player. The chapter information can be added in when you create the mp4 file. 

create chapter info with handbrake software

Sometimes chapter information is not available, you can add in using Subler, from menu - Edit - Insert a Chapter Every (nn minutes).

If the chapter information created by the software (eg. handbrake) is not supported by Quicktime or iOS players, save the mp4 file with Subler again will solve the problem.


Subler is powerful and easy to use open-source software. I just show a few feature of the software. There are more features and functions came with Subler, you need to explore it yourself.


deelight said...

you don't actually say how to output a movie

this program does not output an mp4 with an added set even when you have added them all into the programme for processing - you just get an unsubtitled mp4

no doubt there is a way but the programme remains a total mystery

fuyichin said...

You don't have to output the movie. The subtitle and information will be saved into the movie.