Inside Macintosh: QuickTime Components /

Chapter 5 - Sequence Grabber Components / Sequence Grabber Components Reference

Sequence Grabber Component Functions / Configuring Sequence Grabber Components

SGNewChannel

The SGNewChannel function creates a sequence grabber channel and assigns a channel component to the channel. The channel component is responsible for providing digitized data to the sequence grabber component. You specify the type of channel component to be added to the sequence grabber component.

pascal ComponentResult SGNewChannel (SeqGrabComponent s, 
                                     OSType channelType,
                                     SGChannel *ref);

s

Specifies the component instance that identifies your connection to the sequence grabber component. You obtain this value from the Component Manager's OpenDefaultComponent or OpenComponent function.

channelType

Specifies the type of channel to open. This value corresponds to the component subtype value of the channel component. The following values are valid:

VideoMediaType

Video channel

SoundMediaType

Sound channel

ref

Contains a pointer to the frameChannel field in the sequence grabber information structure that is to receive a reference to the channel that is added to the sequence grabber component. If the sequence grabber component successfully locates and connects to an appropriate
channel component, the sequence grabber component returns a reference to the channel component into the field referred to by this parameter. If the sequence grabber component cannot open a connection, it sets the result code to a nonzero value.

DESCRIPTION

The sequence grabber component locates, and attempts to connect to, an appropriate channel component. If the sequence grabber component cannot locate or connect to
a channel component, it returns a nonzero result code.

RESULT CODES

couldntGetRequiredComponent

-9405

Component not found

Memory Manager errors

SEE ALSO

When you are done with the sequence grabber component, you can dispose of the channels you have used by calling the SGDisposeChannel function, which is described on page 5-32. However, when you close the sequence grabber component, it automatically disposes of all its channels, so this function is usually unnecessary.

If you want to use a specific channel component, you may use the SGNewChannelFromComponent function, which is described next.

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