The easiest way to add open captions to your media file is to use our Video Encoding service. But if you need to do it yourself, this article will show you how.
Open captioning is essentially forcing the captions onto the video screen so that they are always visible -- they become part of the video signal itself. The advantage to open captioning is that it doesn't require any inherent captioning support on the playback device. Any device that can play video will display open captions. You can learn more about the differences between Closed Captioning/Subtitling and Open Captioning here.
First, you need to complete all the steps laid down in our Displaying captions on the QuickTime player article. Next, open the Window menu, and click Show Movie Inspector. Look at the Data Rate field, and note the value you see there. In this case, it's 1390 kbits/sec.
Now, close the Movie Inspector window, open the File menu, and click Export. On the Save Exported File As... dialog box, choose Movie to MPEG-4 on the Export drop-down menu. Next, choose the output directory and the name of the file. Then click on the Options button.
On the Export Settings dialog box, you can choose the appropriate settings, considering your ultimate goal. In this case, the goal is to have an open captioned movie, with a quality as close as possible to the original movie, and the same size. So, the chosen settings are: MP4 on the File Format field, MPEG-4 Improved on the Video Format field, and Current on the Image Size field and the Frame Rate field. On the Data Rate field, a higher value than the original (1390 kbits/sec) was chosen, to make sure quality was maintained, while keeping the overall size of the file similar to the original one.
Now, close the Export Settings dialog box, and click Save on the Save Exported File As... dialog box.
Your media file will be transcoded and saved as a new MP4 movie. This is what the open captioned MP4 looks like:
- If you are experiencing problems making the results work on this program, check out these troubleshooting tips.