Closed Captioning

A Closed Captioning Stream is a data stream hidden inside a video stream. It represents the audio portion as text.

An MPEG2 elementary video stream sometimes has closed captioning data embedded in it as IEC-608. In such cases the MPEG2 Decoder generates two output streams: Video and Closed Captioning.

Also, the AVI and OGG container formats can have closed captioning data as a separate stream. So if an MPEG2 file with closed captioning is converted to an AVI format, the resulting output file will have three streams: Video, Audio and Closed Captioning.

Functions that can be used to manage closed captioning include:

ltmmCaptureCtrl.CloseCaptionAvailable Property Used to determine whether closed captioning is available.
ltmmCaptureCtrl.CloseCaptioning Property Used to determine whether closed captioning is enabled.
ltmmCaptureCtrl.PreviewingCloseCaption Property Used to determine whether closed captioning can be previewed.
ltmmCaptureCtrl.ToggleCloseCaptioning Method Used to toggle closed captioning on and off.
ltmmPlayCtrl.CloseCaptioning Property Used to determine whether closed captioning is enabled.
ltmmPlayCtrl.ToggleCloseCaptioning Method Used to toggle whether closed captioning on and off.

Additional functions are listed in the See Also section.