Status calls

All status calls are called with a pointer to the desired data. The driver should dereference this pointer to get at the structure or field in order to return the required data.

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GetVideoEnable (csCode = 2)

This call is used to determine whether the zoomed video data stream is enabled or not. If the zoomed video data stream is enabled, the GetVideoEnable call returns a value of true, otherwise it returns a value of false.

OSErr err = Status ( driverRefNum, cscGetVideoEnable, &theZVFlagRecord )

<-- csFlag

Indicates whether Zoomed Video is disabled (false) or enabled (true)

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GetCurrentAnalogValue (csCode = 3)

This call is used to get the current value for various analog controls. The whichControl field specifies which of the analog control settings should be returned in the value field.

OSErr err = Status ( driverRefNum, cscZVGetCurrentAnalogValue,&theZVAnalogControlRecord )

--> whichControl	Which control is referenced
<-- value	Current value of the whichControl

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GetDefaultAnalogValue (csCode = 4)

This call is used to get the default value for various analog controls. The whichControl field specifies which of the default analog control settings should be returned in the value field.

OSErr err = Status ( driverRefNum, cscZVGetDefaultAnalogValue, &theZVAnalogControlRecord )

--> whichControl	Which control is referenced
<-- value	Default value of the whichControl

This call is used by the decoder component to initialize the hardware to its default values.

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GetVerticalSyncState (csCode =5)

This routine is used to report whether the input signal is currently in the vertical sync interval of the video signal. The driver should return a value of false in the csFlag field when the signal is not in the vertical sync region, and a value of true when the signal is in the vertical sync region .

OSErr err = Status ( driverRefNum, cscGetVSyncState, &theZVFlagRecord )

<-- csFlag

Vertical sync state

This call is used by the ZV decoder component to determine when a complete frame has been transferred into the frame buffer.

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GetZoomedVideoInfo (csCode = 6)

This call is used to report information about the capabilities of the ZV driver. The currentFlags parameter returns information about the current settings.

OSErr err = Status (driverRefNum, cscZVGetZVInfo, &theZVInfoRecord)

<-- features	A UInt32 with bits indicating the capabilities of the ZV card (e.g. hasContrast, hasBrightness)
<-- currentFlags	A Uint32 with bits indicating which of the flags specified in the GetInputFlags status call are currently valid
<-- activeRect	The crop rectangle supported by the ZV card (See Figure 2)
<-- isInterlaced	Indicates whether the input signal is putting interlaced video on the ZV bus

Figure 2 shows how the activeRect is defined. It parallels the QuickTime Video Digitizer active source rectangle definition. The Maximum Source Rectangle defines the maximum source area that the Zoomed Video card is capable of showing. Typically, this area includes all the horizontal and vertical blanking. The Active Source Rectangle is the region of the maximum source rectangle that contains the actual video images. The coordinates shown in the diagram are only sample coordinates.

Figure 2 Zoomed Video Driver Rectangles

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GetInputFlags (csCode =7)

This called is used to return the input capabilities of the hardware. It mirrors the QuickTime Video Digitizer call that reports the input capabilities: Inside Macintosh: QuickTime Components, pages 8-14 and 8-15.

OSErr err = Status ( driverRefNum, cscZVGetInputFlags, &theUInt32 )

<-- theUInt32

A UInt32 with bits indicating the input capabilities of the Zoomed Video card

A Zoomed Video driver might set the digiInDoesNTSC, digiInDoesColor, and digiInDoesComposite flags.

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GetNumberOfInputs (csCode =8)

This call returns the number of input video sources that the PC Card supports.

OSErr err = Status ( driverRefNum, cscZVGetNumberOfInputs, &theUInt16 )

<-- theUInt16

Contains the number of inputs supported by the Zoomed Video card

Note: The Zoomed Video Driver should number the video sources sequentially, starting at 0. So, if a PC Card supports two inputs, the field should be set to 1! If it only supports one input, then it should return a 0. This unconventional enumeration is done to preserve compatibility with the Quicktime Video Digitizer API.

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GetInput (csCode =9)

This call returns data that identifies the currently active video port.

OSErr err = Status ( driverRefNum, cscZVGetInput, &theUInt16 )

<-- theUInt16

Returns the enumerated active input (zero-based)

Note: The Zoomed Video Driver should number the video sources sequentially, starting at 0. So, if the first input is active, then this call should return 0.

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GetInputFormat (csCode =10)

This call returns the format of the video signal provided by a specified input source.

OSErr err = Status ( driverRefNum, cscZVGetInputFormat, &theUInt16 )

<-- theUInt16

Returns the format for the currently active input (e.g. compositeIn, sVideoIn)