This section explains how to initialize a video device and display captured images on the user's display. More...

Classes
struct	VideoFormat
	A struct containing the properties of a video capture format. More...

struct	VideoFrame
	A RGB32 image where the pixels can be accessed directly in an allocated frameBuffer. More...

struct	VideoCaptureDevice
	A struct containing the properties of a video capture device. More...

Macros
#define	TT_VIDEOFORMATS_MAX 1024

Typedefs
typedef enum FourCC	FourCC
	The picture format used by a capture device. More...

typedef struct VideoFormat	VideoFormat
	A struct containing the properties of a video capture format. More...

typedef struct VideoFrame	VideoFrame
	A RGB32 image where the pixels can be accessed directly in an allocated frameBuffer. More...

typedef struct VideoCaptureDevice	VideoCaptureDevice
	A struct containing the properties of a video capture device. More...

Enumerations
enum	FourCC { FOURCC_NONE = 0 , FOURCC_I420 = 100 , FOURCC_YUY2 = 101 , FOURCC_RGB32 = 102 }
	The picture format used by a capture device. More...

Functions
TEAMTALKDLL_API TTBOOL	TT_GetVideoCaptureDevices (IN OUT VideoCaptureDevice lpVideoDevices, IN OUT INT32 lpnHowMany)
	Get the list of devices available for video capture. More...

TEAMTALKDLL_API TTBOOL	TT_InitVideoCaptureDevice (IN TTInstance lpTTInstance, IN const TTCHAR szDeviceID, IN const VideoFormat *lpVideoFormat)
	Initialize a video capture device. More...

TEAMTALKDLL_API TTBOOL	TT_CloseVideoCaptureDevice (IN TTInstance *lpTTInstance)
	Close a video capture device. More...

TEAMTALKDLL_API TTBOOL	TT_PaintVideoFrame (IN HDC hDC, IN INT32 XDest, IN INT32 YDest, IN INT32 nDestWidth, IN INT32 nDestHeight, IN VideoFrame *lpVideoFrame)
	Paint user's video frame using a Windows' DC (device context). More...

TEAMTALKDLL_API TTBOOL	TT_PaintVideoFrameEx (IN HDC hDC, IN INT32 XDest, IN INT32 YDest, IN INT32 nDestWidth, IN INT32 nDestHeight, IN INT32 XSrc, IN INT32 YSrc, IN INT32 nSrcWidth, IN INT32 nSrcHeight, IN VideoFrame *lpVideoFrame)
	Paint user's video frame using a Windows' DC (device context). More...

TEAMTALKDLL_API VideoFrame *	TT_AcquireUserVideoCaptureFrame (IN TTInstance *lpTTInstance, IN INT32 nUserID)
	Extract a user's video capture frame for display. More...

TEAMTALKDLL_API TTBOOL	TT_ReleaseUserVideoCaptureFrame (IN TTInstance lpTTInstance, IN VideoFrame lpVideoFrame)
	Delete a user's video frame, acquired through TT_AcquireUserVideoCaptureFrame(), so its allocated resources can be released. More...

Detailed Description

This section explains how to initialize a video device and display captured images on the user's display.

The client is able to capture video and present them to the user application in RGB32-format and transmit the image in encoded format to other users.

Sections:

Initialize Video Capture Device

This section explains how to detect and configure video capture devices.

To capture video the user application must first query the available capture devices by calling TT_GetVideoCaptureDevices. A VideoCaptureDevice supports a certain number of capture formats each described in the videoFormats member of VideoFormat.

Once a device has been chosen the TT_InitVideoCaptureDevice must be called for the client instance to start capturing video frames. Use the szDevice member of VideoCaptureDevice as the device identifier for the video capture device and pass a VideoFormat from the videoFormats array of VideoCaptureDevice. Check out section Audio and Video Codecs on how to configure the video codec.

Display Captured Video

When a video frame becomes available the event CLIENTEVENT_USER_VIDEOCAPTURE is posted to the application and TT_AcquireUserVideoCaptureFrame can be used to extract the RGB32 image. On Windows it's also possible to call TT_PaintVideoFrame to make the client instance paint on a HWND by getting its HDC, otherwise use the VideoFrame's frame buffer pointer to access the bitmap data.

Macro Definition Documentation

◆ TT_VIDEOFORMATS_MAX

#define TT_VIDEOFORMATS_MAX 1024

The maximum number of video formats which will be queried for a VideoCaptureDevice.

Definition at line 101 of file TeamTalk.h.

Typedef Documentation

◆ FourCC

typedef enum FourCC FourCC

The picture format used by a capture device.

See also: VideoFormat; VideoCaptureDevice

◆ VideoFormat

typedef struct VideoFormat VideoFormat

A struct containing the properties of a video capture format.

A struct for holding a supported video capture format by a VideoCaptureDevice.

◆ VideoFrame

typedef struct VideoFrame VideoFrame

A RGB32 image where the pixels can be accessed directly in an allocated frameBuffer.

Use TT_AcquireUserVideoCaptureFrame() to acquire a user's image and remember to call TT_ReleaseUserVideoCaptureFrame() when the image has been processed so TeamTalk can release its resources.

◆ VideoCaptureDevice

typedef struct VideoCaptureDevice VideoCaptureDevice

A struct containing the properties of a video capture device.

The information retrieved from the video capture device is used to initialize the video capture device using the TT_InitVideoCaptureDevice function.

See also: TT_GetVideoCaptureDevices

Enumeration Type Documentation

◆ FourCC

enum FourCC

The picture format used by a capture device.

See also: VideoFormat; VideoCaptureDevice

Enumerator
FOURCC_NONE	Internal use to denote no supported formats.
FOURCC_I420	Prefered image format with the lowest bandwidth usage. A 640x480 pixel image takes up 460.800 bytes.
FOURCC_YUY2	Image format where a 640x480 pixel images takes up 614.400 bytes.
FOURCC_RGB32	The image format with the highest bandwidth usage. A 640x480 pixel images takes up 1.228.880 bytes.

Definition at line 813 of file TeamTalk.h.

Function Documentation

◆ TT_GetVideoCaptureDevices()

TEAMTALKDLL_API TTBOOL TT_GetVideoCaptureDevices	(	IN OUT VideoCaptureDevice *	lpVideoDevices,
		IN OUT INT32 *	lpnHowMany
	)

Get the list of devices available for video capture.

Parameters

lpVideoDevices	Array of VideoCaptureDevice-stucts where lpnHowMany hold the size of the array. Pass NULL to query the number of devices.
lpnHowMany	This is both an input and output parameter. If lpVideoDevices is NULL lpnHowMany will after the call hold the number of devices, otherwise it should hold the size of the lpVideoDevices array.

See also: TT_InitVideoCaptureDevice

◆ TT_InitVideoCaptureDevice()

TEAMTALKDLL_API TTBOOL TT_InitVideoCaptureDevice	(	IN TTInstance *	lpTTInstance,
		IN const TTCHAR *	szDeviceID,
		IN const VideoFormat *	lpVideoFormat
	)

Initialize a video capture device.

To transmit video capture data to a channel call TT_StartVideoCaptureTransmission()

Parameters

lpTTInstance	Pointer to client instance created by TT_InitTeamTalk.
szDeviceID	The device idenfier szDeviceID of VideoCaptureDevice.
lpVideoFormat	The capture format to use, i.e. frame-rate, resolution and picture format.

See also: TT_GetVideoCaptureDevices; TT_CloseVideoCaptureDevice

◆ TT_CloseVideoCaptureDevice()

TEAMTALKDLL_API TTBOOL TT_CloseVideoCaptureDevice ( IN TTInstance * lpTTInstance )

Close a video capture device.

See also: TT_InitVideoCaptureDevice

◆ TT_PaintVideoFrame()

TEAMTALKDLL_API TTBOOL TT_PaintVideoFrame	(	IN HDC	hDC,
		IN INT32	XDest,
		IN INT32	YDest,
		IN INT32	nDestWidth,
		IN INT32	nDestHeight,
		IN VideoFrame *	lpVideoFrame
	)

Paint user's video frame using a Windows' DC (device context).

Same as calling TT_PaintVideoFrameEx() like this:

TT_PaintVideoFrameEx(lpTTInstance, nUserID, hDC, 
                     XDest, YDest, nDestWidth,
                     nDestHeight, 0, 0, 
                     src_bmp_width, src_bmp_height);

src_bmp_width and src_bmp_height are extracted internally from the source image.

◆ TT_PaintVideoFrameEx()

TEAMTALKDLL_API TTBOOL TT_PaintVideoFrameEx	(	IN HDC	hDC,
		IN INT32	XDest,
		IN INT32	YDest,
		IN INT32	nDestWidth,
		IN INT32	nDestHeight,
		IN INT32	XSrc,
		IN INT32	YSrc,
		IN INT32	nSrcWidth,
		IN INT32	nSrcHeight,
		IN VideoFrame *	lpVideoFrame
	)

Paint user's video frame using a Windows' DC (device context).

An application can either paint using TT_AcquireUserVideoCaptureFrame which provides a raw RGB32 array of the image or the application can ask the client instance to paint the image using this function.

Typically this paint operation will be called in the WM_PAINT message. Here is how the client instance paints internally:

StretchDIBits(hDC, nPosX, nPosY, nWidth, nHeight, XSrc, YSrc, 
              nSrcWidth, nSrcHeight, frame_buf, &bmi,
              DIB_RGB_COLORS, SRCCOPY);

Parameters

hDC	The handle to the Windows device context.
XDest	Coordinate of left corner where to start painting.
YDest	Coordinate or top corner where to start painting.
nDestWidth	The width of the image.
nDestHeight	The height of the image.
XSrc	The left coordinate in the source bitmap of where to start reading.
YSrc	The top left coordinate in the source bitmap of where to start reading.
nSrcWidth	The number of width pixels to read from source bitmap.
nSrcHeight	The number of height pixels to read from source bitmap.
lpVideoFrame	Video frame retrieved by TT_AcquireUserVideoCaptureFrame()

See also: TT_AcquireUserVideoCaptureFrame

◆ TT_AcquireUserVideoCaptureFrame()

TEAMTALKDLL_API VideoFrame* TT_AcquireUserVideoCaptureFrame	(	IN TTInstance *	lpTTInstance,
		IN INT32	nUserID
	)

Extract a user's video capture frame for display.

The VideoFrame extracted from the client instance will contain a pointer to the image's frame buffer, so a RGB32 bitmap can be displayed in a window control.

To release the acquired VideoFrame call TT_ReleaseUserVideoCaptureFrame().

A video capture frame comes from a user's STREAMTYPE_VIDEOCAPTURE.

Parameters

lpTTInstance	Pointer to client instance created by TT_InitTeamTalk.
nUserID	The user's ID. 0 for local user.

Returns: Returns video frame which will contain the image data. Note that it's the frameBuffer member of VideoFrame which will contain the image data allocated internally by TeamTalk. Returns NULL if no video frame could be acquired.

See also: TT_ReleaseUserVideoCaptureFrame

◆ TT_ReleaseUserVideoCaptureFrame()

TEAMTALKDLL_API TTBOOL TT_ReleaseUserVideoCaptureFrame	(	IN TTInstance *	lpTTInstance,
		IN VideoFrame *	lpVideoFrame
	)

Delete a user's video frame, acquired through TT_AcquireUserVideoCaptureFrame(), so its allocated resources can be released.

Parameters

lpTTInstance	Pointer to client instance created by TT_InitTeamTalk.
lpVideoFrame	Pointer to VideoFrame which should be deallocated.

Returns: Returns TRUE If a video frame was successfully deallocated.

See also: TT_AcquireUserVideoCaptureFrame

Classes

Macros

Typedefs

Enumerations

Functions

Detailed Description

Initialize Video Capture Device

Display Captured Video

Macro Definition Documentation

◆ TT_VIDEOFORMATS_MAX

Typedef Documentation

◆ FourCC

◆ VideoFormat

◆ VideoFrame

◆ VideoCaptureDevice

Enumeration Type Documentation

◆ FourCC

Function Documentation

◆ TT_GetVideoCaptureDevices()

◆ TT_InitVideoCaptureDevice()

◆ TT_CloseVideoCaptureDevice()

◆ TT_PaintVideoFrame()

◆ TT_PaintVideoFrameEx()

◆ TT_AcquireUserVideoCaptureFrame()

◆ TT_ReleaseUserVideoCaptureFrame()