Abstract: A method for automatic format detection, video decoder and video display devices therefrom. A video input having an algorithm-based first graphics format is received that carries an RGB video signal, Hsync signal and a Vsync signal. From the Hsync signal and Vsync signal, a plurality of different measured timing parameters are generated including a total number of vertical lines per frame, a total number of vertical lines per pulse width of the Vsync signal, a total number of reference clock cycles per vertical line, and measured polarity information for the Vsync and Hsync signal. An algorithm automatically generates a format detection result that represents the first graphics format using the plurality of different measured timing parameters and the measured polarity information, including a plurality of horizontal and vertical timing information for configuring a video display for the algorithm-based first graphics format.

Abstract: A video decoder (10) for receiving an input video signal and producing output signals for a digital display (12), and involving automatic gain control (AGC) functions (20, 28), is disclosed. For each of the front-end and back-end AGC functions (20, 28), the AGC gain value applied is modified according to measurements of several attributes of the video signal, such as sync height, color burst amplitude, composite signal peak amplitude, and luma signal peak amplitude. The measurements are made, and the AGC gains are modified, on a frame-by-frame basis. Preferably, the AGC is modified using the one of the signal attributes that indicates the lowest gain. The back-end AGC function (28) modifies its gain to unity if the front-end AGC function (20) selected the luma signal peak amplitude for modifying its gain. A method for adjusting the rate of change of the AGC gain is also disclosed, in which gain increases are delayed and slowed following an AGC gain decrease because of an image-dependent signal attribute.

Abstract: An apparatus, system and method for clamping a video signal input to a coupling capacitor (215) for providing a clamping voltage. A charging current is applied to the capacitor (215) via an amplifier (225) having a first input (227) coupled with the capacitor output and a second input (226) coupled to a reference potential, the amplifier (225) is responsive to the capacitor output signal and the reference potential for providing the charging current to the capacitor (215). The current has a linearly varying magnitude which is proportional to a difference between the capacitor output and the reference potential.

Abstract: An apparatus, system and method for clamping a video signal input to a coupling capacitor (215) for providing a clamping voltage. A charging current is applied to the capacitor (215) via an amplifier (225) having a first input (227) coupled with the capacitor output and a second input (226) coupled to a reference potential, the amplifier (225) is responsive to the capacitor output signal and the reference potential for providing the charging current to the capacitor (215). The current has a linearly varying magnitude which is proportional to a difference between the capacitor output and the reference potential.

Abstract: An integrated analog to digital interface subsystem for imaging applications includes digital global and digital pixel by pixel offset correction and scaling. The integrated interface 2 includes 3 DAC's 2c1-2c3 that are used to do a rough offset cancellation on the three analog input signals (RGB) in the analog domain. A triple sample/hold circuit 2a samples the RGB signals simultaneously, multiplexes the data and passes the three signals on the ADC 2b sequentially (at about 3 times the data rate). The sample/hold circuit 2a has the capability to operate in fully differential as well as single ended input mode, and can perform correlated double sampling if needed. A high resolution ADC 2b converts the 3 multiplexed signals from simple/hold circuit 2a. A first digital offset correction circuit 2f restores the level of the RGB signals in the digital domain on a pixel by pixel basis.