Utility Functions8

This section describes two new utility functions that may be supported by some video digitizer components.

The VDGetTimeCode function allows an application to retrieve timecode information.

The VDGetSoundInputSource function allows an application to retrieve information about a digitizer's sound input source.

VDGetTimeCode

The VDGetTimeCode function instructs your video digitizer component to return timecode information for the incoming video signal.



 
pascal VideoDigitizerError VDGetTimeCode (

                     VideoDigitizerComponent ci,

                     TimeRecord *atTime,

                     void *timeCodeFormat,

                     void *timeCodeTime);

ci: Specifies the video digitizer component for the request. Applications obtain this reference from the Component Manager's OpenComponent function.
atTime: Specifies a location to receive the QuickTime movie time value corresponding to the timecode information.
timeCodeFormat: Contains a pointer to a timecode definition structure. Your video digitizer component returns the movie's timecode definition information.
timeCodeTime: Contains a pointer to a timecode record structure. Your video digitizer component returns the time value corresponding to the movie time contained in the atTime parameter.

DISCUSSION

Typically, this function is called once, at the beginning of a capture session. The use of VDGetTimeCode assumes that the timecoding for the entire capture session will be continuous.

For more information about the timecode data structures, see Media Handlers: Timecodes

VDGetSoundInputSource

The VDGetSoundInputSource function instructs your video digitizer component to return the sound input source associated with a particular video input.



 
pascal VideoDigitizerError VDGetSoundInputSource (

                     VideoDigitizerComponent ci,

                     long videoInput,

                     long *soundInput);

ci: Specifies the video digitizer component for the request. Applications obtain this reference from the Component Manager's OpenComponent function.
videoInput: Specifies the input video source for this request. Video digitizer components number video sources sequentially, starting at 0. So, to request information about the first video source, an application sets this parameter to 0. Applications can get the number of video sources supported by a video digitizer component by calling the VDGetNumberOfInputs function.
soundInput: The sound input index to use with the sound input driver returned by VDGetSoundInputDriver .

DISCUSSION

Some video digitizers may associate different sound inputs with each video input. The VDGetSoundInputDriver function returns the name of the sound input driver that the sound input is associated with.