Video transmitting circuit and signal delay compensation method thereof

A video transmitting circuit configured to transmit a video signal at least composed of a first signal and a second signal, in which the first signal is transmitted through a first transmission path and the second signal is transmitted through a second transmission path to a video receiver, comprising:

• a pre-processing circuit configured to detect whether or not the video transmitting circuit has received a preset pulse, wherein the video transmitting circuit switches to a calibration mode and the pre-processing circuit simultaneously transmits a specific signal to the video receiver through the first transmission path and the second transmission path when the preset pulse is received by the video transmitting circuit;
• a return detection circuit configured to detect a first return signal transmitted through the first transmission path and a second return signal transmitted through the second transmission path from the video receiver to the video transmitting circuit when the video transmitting circuit is in the calibration mode, wherein the first return signal corresponds to the specific signal transmitted through the first transmission path and the second return signal corresponds to the specific signal transmitted through the second transmission path;
• and
• a control circuit coupled to the return detection circuit, and configured to transmit a reset signal for resetting an input index or an output index of the first buffer and an input index or an output index of the second buffer to a first buffer serially connected in the first transmission path or a second buffer serially connected in the second transmission path in the video transmitting circuit when the first return signal transmitted through the first transmission path or the second return signal transmitted through the second transmission path being received by the video transmitting circuit has been detected by the return detection circuit.

A signal delay compensation method used in a video transmitting circuit configured to transmit a video signal at least composed of a first signal and a second signal, and transmit the first signal through a first transmission path and the second signal through a second transmission path to a video receiver, and comprising:

• detecting, by a pre-processing circuit, whether or not a preset pulse has been received by the video transmitting circuit, wherein when the preset pulse has been received by the video transmitting circuit, switching, by the video transmitting circuit, to a calibration mode, and wherein a specific signal is transmitted, by the pre-processing circuit, to the video receiver through the first transmission path and the second transmission path;
• detecting, by a return detection circuit, whether or not a first return signal transmitted through the first transmission path and a second return signal transmitted through the second transmission path from the video receiver have been received by the video transmitting circuit when the video transmitting circuit is in the calibration mode, wherein the first return signal corresponds to the specific signal transmitted through the first transmission path and the second return signal corresponds to the specific signal transmitted through the second transmission path;
• and
• setting, by a control circuit, a first delay circuit serially connected in the first transmission path or a second delay circuit serially connected in the second transmission path in the video transmitting circuit according to a detection result of the return detection circuit, such that the first signal and the second signal can synchronously arrive at the video receiver through the first transmission path and the second transmission path, respectively.