- Subtitles? Closed Captions? Is There a Difference?
- Subtitle Formats
- Subtitle Editors
- Using Aegisub
A great description comes from the Wikipedia article on Closed-Captions:
The term "closed" in closed captioning indicates that not all viewers see the captions—only those who choose to decode or activate them. This distinguishes from "open captions" (sometimes called "burned-in" or "hardcoded" captions), which are visible to all viewers.
Most of the world does not distinguish captions from subtitles. In the United States and Canada, these terms do have different meanings, however: "subtitles" assume the viewer can hear but cannot understand the language or accent, or the speech is not entirely clear, so they only transcribe dialogue and some on-screen text. "Captions" aim to describe to the deaf and hard of hearing all significant audio content—spoken dialogue and non-speech information such as the identity of speakers and, occasionally, their manner of speaking—along with music or sound effects using words or symbols.
The United Kingdom, Ireland, and most other countries do not distinguish between subtitles and closed captions, and use "subtitles" as the general term—the equivalent of "captioning" is usually referred to as "Subtitles for the hard of hearing". Their presence is referenced on screen by notation which says "Subtitles", or previously "Subtitles 888" or just "888" (the latter two are in reference to the conventional teletext channel for captions).
In this support document, we’ll just call them all subtitles.
Viddler supports the “SubRip” .srt subtitle standard. They are easy to create, and you don’t have to worry about the “style” of the text (fonts, colors).
Our player HTML5 (Arpeggio) supports the following carriage returns formats:
- carriage return character (0D)
- carriage return and line feed (0D 0A)
- line feed (0A)
You may run into MPEG 4 Timed Text subtitles inside .mp4/.m4v files – We don’t support this directly, but there are methods to convert this.
The program in our example uses the SubStationAlpha (.ssa) and the Advanced SubStation (.ass) formats that can do a lot of extra things like animation, fonts, colors, and positioning, all things that require considerably more processor usage on the viewer’s side, so currently we do not support this format. It will easily export to a supported .srt file
While you can use a standard text editor, one of the best programs to use is Aegisub, which works on Windows, Mac (Alpha quality; may crash often—make sure to save often!) and Linux. Special programs for subtitling allow you to time based on the audio waveform (and video) and get near-instant preview on changes. This overview will be targeted to Aegisub.
For a list of other programs, see the Wikipedia article on subtitle editors.
Using Aegisub to create subtitles is a relatively easy process, but timing the subtitles is itself a time-intensive task, so be sure to set aside enough time. It took about an hour to properly time the video on our front page.
The first time you start a “project” You’ll need to open both the video and audio streams separately.
To load the video: “Video” menu -> Open Video…
To load the audio from the video: “Audio” menu -> Open Audio from Video
Note: If the video track has the audio built-in, you can use the same file for both options. Using Windows, you may also need to change the file types from “Video Formats” to “All Files” in order to load some formats like QuickTime .mov.
In order to have the subtitles appear at the right time, you’ll need to work through your video and align the text to timeframes—In many cases, one sentence will be one line
In Aegisub, you can drag the red start marker and the orange end marker to the beginning and end of the section you’d like to have as one line (Number 1 in the above image). To play back the selection to make sure you have the entire section you’d like, you can click the Play Selection Button (Number 2 in the above image).
Once the timing is complete, you can enter the text in the text box (3 in the above screenshot)
Once you are finished, Press the Enter/Return key on your keyboard, which will enter your changes and create a new line for you.
Repeat this process until you’ve reached the end of the file.
If the line runs too long, you may need to force it to create two lines. Use \N in the text editor where you would like the break to happen. If it’s larger than two lines, you should consider splitting the line into two or more sections
You will want to make sure to save early and often to not lose your work. Aegisub does save backup copies hidden in your home directory just in case, but they aren’t in the easiest location to access by default—these options can be changed in the “File save/load” in the Options menu (View->Options)
The normal Save/Save As… Options will save only to the Advanced SubStation (.ass) format – We don’t support these, but it is a good format for editing. To Export the File as an SRT, choose the “Export” Option from the File menu.
At the Export dialog box, you can safely ignore all the options, and then click the “Export. . .” Button, then name the file. Make sure to add the .srt extension to the end of the file. You can then upload the Closed Captioning File to your video.
Here's a list of potential error messages you may receive if a .srt file isn't formatted correctly.
- "Invalid sequence number - 1 expected" - This generally means that there is an invalid character at the beginning of the file. The .srt should start with "1" at the top. Many times it is due to an invisible character or a nonstandard line break. Many times just backspacing from before the "1" to the beginning of the file will fix it.