Inside Macintosh: QuickTime Components /

Chapter 6 - Sequence Grabber Channel Components / Sequence Grabber Channel Components Reference

Functions / Configuration Functions for All Channel Components

SGGetDataRate

The sequence grabber component calls your component's SGGetDataRate function in order to determine how much recording time is left. The sequence grabber calls your component when an application calls the sequence grabber component's SGGetTimeRemaining function (see the chapter "Sequence Grabber Components" in this book for details).

pascal ComponentResult SGGetDataRate (SGChannel c, 
                                       long *bytesPerSecond);

c

Identifies the channel connection for this operation.

bytesPerSecond

Contains a pointer to a long integer that is to receive a value indicating the number of bytes your component is recording per second. Your component calculates this value based on its current operational parameters.

DESCRIPTION

Your component should calculate and return a value indicating the number of bytes of data your component is recording per second. The sequence grabber component uses this information, along with similar information gathered from other channels being used in the recording operation, to determine how many seconds of data may be recorded given the amount of space remaining.

SPECIAL CONSIDERATIONS

The sequence grabber component calls the SGGetDataRate function during the recording operation. Consequently, your component should service the request as quickly as possible.