VuoQtListener Class Reference

Description

Manages receiving video frames via a QTCaptureSession.

Instance Methods
(BOOL)	- initWithDevice:callback:
	Initialize a QTListener with the device name or id. More...
(BOOL)	- isInitialized
	Returns true if the capture session has been initialized. More...
(BOOL)	- isRunning
	Reflects the actual running status of mCaptureSession, not whether or not the user wants isRunning. More...
(void)	- setInputDevice:
	Set the input device - does not start or stop recording, just changes what the input device is. More...
(void)	- startRunning
	Begins receiving frames. More...
(void)	- stopRunning
	Stops receiving frames (starts ignoring/dropping them). More...
(void)	- devicesDidChange:
	When a device is connected or disconnected, check if the device we're interested in has been found or lost. More...
(void)	- refreshDevices
	Iterate through available input devices and search for one matching the desired device name or id, then set the input device (but don't start recording - only do that in startListening). More...
(void)	- setCaptureDevice:
	Set the capture device. More...
(void)	- setCallback:
	Set the callback to be triggered when a new image is available. More...
(void)	- setWidth:height:
	Specifies the desired image size. More...

Class Methods
(char *)	+ formatTypeString:
	Returns a C string describing the specified pixel format. More...

Protected Attributes
QTMovie *	mMovie
	? More...
QTCaptureSession *	mCaptureSession
	Manages a list of frame receivers. More...
QTCaptureDeviceInput *	mCaptureDeviceInput
	The device from which to receive frames. More...
QTCaptureDecompressedVideoOutput *	mCaptureDecompressedVideoOutput
	A frame receiver. More...
CVImageBufferRef	mCurrentImageBuffer
	The latest received frame. More...
void(*	callback )(VuoVideoFrame)
	Called when a frame is received. More...
double	lastFrameReceived
	The timestamp at which the last frame was received. More...
NSArray *	mVideoInputDevices
	All available video input devices. More...
VuoVideoInputDevice	desiredDevice
	The device the user has requested. More...
BOOL	userWantsRunning
	Was startRunning called (without calling stopRunning)? More...
CVOpenGLTextureCacheRef	textureCache
	GL_TEXTURE_RECTANGLEs from the video feed. More...
CIContext *	ciContext
	Fallback for when CVOpenGLTextureCacheRef fails. More...

Method Documentation

devicesDidChange:()

- (void) devicesDidChange:

(NSNotification *)

notification

When a device is connected or disconnected, check if the device we're interested in has been found or lost.

formatTypeString:()

+ (char *) formatTypeString:

(int)

key

Returns a C string describing the specified pixel format.

initWithDevice:callback:()

- (BOOL) initWithDevice:		(VuoVideoInputDevice)	device
callback:		(void(*)(VuoVideoFrame))	receivedFrame

Initialize a QTListener with the device name or id.

Initializes for listening to a specific device.

The listener will attempt to find the device first using ID, then name. If a matching device is not found, the listener will wait for a device matching the description until it is either registered, or told to stop.

initialize texture cache for creating gl textures from CVPixelBuffer

https://developer.apple.com/library/mac/documentation/QuartzCore/Reference/CVPixelFormatDescriptionRef/#//apple_ref/doc/constant_group/Pixel_Format_Types

isInitialized()

- (BOOL) isInitialized

Returns true if the capture session has been initialized.

Does not reflect the status of capture session isRun

isRunning()

- (BOOL) isRunning

Reflects the actual running status of mCaptureSession, not whether or not the user wants isRunning.

refreshDevices()

- (void) refreshDevices

Iterate through available input devices and search for one matching the desired device name or id, then set the input device (but don't start recording - only do that in startListening).

If both name and id are empty strings, the first valid device is used. If name or id is set, a nil device will be set as the input until a matching device is detected.

setCallback:()

- (void) setCallback:

(void(*)(VuoVideoFrame))

receivedFrame

Set the callback to be triggered when a new image is available.

setCaptureDevice:()

- (void) setCaptureDevice:

(QTCaptureDevice*)

device

Set the capture device.

setInputDevice:()

- (void) setInputDevice:

(VuoVideoInputDevice)

device

Set the input device - does not start or stop recording, just changes what the input device is.

setWidth:height:()

- (void) setWidth:		(VuoInteger)	width
height:		(VuoInteger)	height

Specifies the desired image size.

startRunning()

- (void) startRunning

Begins receiving frames.

stopRunning()

- (void) stopRunning

Stops receiving frames (starts ignoring/dropping them).

Member Data Documentation

callback

- (void(* callback) (VuoVideoFrame))

protected

Called when a frame is received.

ciContext

- (CIContext*) ciContext

protected

Fallback for when CVOpenGLTextureCacheRef fails.

desiredDevice

- (VuoVideoInputDevice) desiredDevice

protected

The device the user has requested.

lastFrameReceived

- (double) lastFrameReceived

protected

The timestamp at which the last frame was received.

mCaptureDecompressedVideoOutput

- (QTCaptureDecompressedVideoOutput*) mCaptureDecompressedVideoOutput

protected

A frame receiver.

mCaptureDeviceInput

- (QTCaptureDeviceInput*) mCaptureDeviceInput

protected

The device from which to receive frames.

mCaptureSession

- (QTCaptureSession*) mCaptureSession

protected

Manages a list of frame receivers.

mCurrentImageBuffer

- (CVImageBufferRef) mCurrentImageBuffer

protected

The latest received frame.

mMovie

- (QTMovie*) mMovie

protected

?

mVideoInputDevices

- (NSArray*) mVideoInputDevices

protected

All available video input devices.

Todo:

Make this a singleton?

textureCache

- (CVOpenGLTextureCacheRef) textureCache

protected

GL_TEXTURE_RECTANGLEs from the video feed.

userWantsRunning

- (BOOL) userWantsRunning

protected

Was startRunning called (without calling stopRunning)?

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The documentation for this class was generated from the following files:

• node/vuo.video/VuoQtListener.h
• node/vuo.video/VuoQtListener.m