StreamLabs ALPHA Plus PCI-E YUV Capture / Playout Card with SDK

StreamLabs ALPHA Plus PCI-E YUV Capture / Playout Card with SDK
Stream ALPHA Plus PCI-E YUV is designed to work with Composite or S-Video by-pass signal whether using PAL, SECAM or NTSC. It also has a separate RGB (YUV) + Key Component output on the board to work with computer graphics without mixing it with the video. Stream ALPHA Plus has all-digital image formation chain which guarantees perfect quality of generated signal and its better binding to the input signal.

The board overlays graphics over live video signal using alpha-channel that allows setting the transparency level of each pixel of the image and changing it while playing.

Stream ALPHA Plus PCI-E is equipped with internal synch generator that switches on automatically if the input signal is missing. If computer power supply is switched off or BYPASS mode is activated, the output is directly connected to the input through relay contacts, and 75 Ohm load on the board is disconnected. The board can overlay computer graphics over video signal whether inside itself or on the external mixer. To work with external mixer the board has a special KEY output. It is possible to switch on/off multiplication of generated image by alpha-channel.

In addition to the common for Stream ALPHA boards analog mixing performed without any delay, the board has digital mode that enables decoding of the input video signal. The decoding and subsequent coding delays the video signal (about 10 mks). Digital mixing makes it possible to change standards of output signal relative to input signal (PAL<->SECAM, CVBS<->S-Video). Besides, it allows decreasing requirements to the quality of input signal, keeping the high quality of output signal. Composite signal is decoded using color combine filter to divide brightness and chrominance.

The possibility of grabbing and hardware scaling of video signal from the board's inputs allows changing the size of incoming video and overlay titles in BY-PASS mode using minimal resources of central processor.

Due to the usage of PCI-Express bus on Stream ALPHA Plus Express, interface and board bandwidth enables overlaying full screen titles through alpha channel and grabbing input video signal at the same time.

All the graphics generated by the card passes through the active digital filter. It is possible to enable/disable the insertion of the sync into the "Green" signal of the component output and alpha-channel. Component YUV output and alpha-channel (Key) output allows working with the mixer, that has appropriate input and DSK input.


Fully digital video image composing. Can operate in both, the digital and analog video mix modes that provide better quality of output video based on source video signal.

Digital video mix mode. Stream Alpha Plus video card has on-board video decoder which uses the "color combine filter" to separate the color and brightness components of the video signal.

Analog video mix mode. Input video signal goes through the video processor without coding. It saves parameters related to frequency of video signal and secondary information like tele-text.

Automatic pass-through mode.

New features of Stream ALPHA Plus board :
- Dr, Db frame color synchronization for SECAM mode.
- capture mode with scaling using direct memory access (DMA);
- sync signal embedding into Alpha channel output;
- binding black level to zero on Red, Green, Blue and Alpha channel output;
- on/off sync pulses in Y (green) and KEY (alpha channel) signal's modes are made, i.e. proper operation with various external mixers over YUV/RGB+Key;
- active filtration of output signals;
- interface to memory performance extended due to PCI-Express bus;
- lower power consumption.


Dimensions 188x126 mm
Bus PCI-Express 1x
Inputs (1,0 v / 75 Ohm) Composite, S-Video: PAL, SECAM, NTSC
Outputs (1,0 v / 75 Ohm) Composite, S-Video: PAL, SECAM, NTSC; YUV+DSK
Analog mixing bandwidth > 10 mHz
Differential nonlinearity < 0,2%
Alpha-channel 256 degrees of transparency
Alpha-channel delay
adjustment from -127 up +127 1/4 pixel each
Chrominance subcarrier
phase adjustment 0 - 360o (256 values)


In the Box

Stream ALPHA Plus PCI-E Composite Board
SDK (Software Development Kit)


Compatible Products