The interface of video acquisition card includes the interface between video and PC and the interface with analog video equipment. At present, the video capture card usually uses 32-bit PCI bus interface, which is inserted into the expansion slot of PC main board to realize the communication and data transmission between the capture card and PC. The acquisition card shall have at least one composite video interface (video in) to connect with the analog video device. High performance acquisition card generally has a composite video interface and an S-Video interface. Note: the former TV card is not a video acquisition card. Generally, the image acquisition card does not have a TV antenna interface and an audio input interface. It is not allowed to collect TV RF signals directly with the acquisition card, nor can it directly collect the audio signals in the analog video. There are also previous image acquisition cards (simultaneous real-time acquisition performance of non audio and video signals) to acquire the sound, the PC must be equipped with sound card, the image acquisition card obtains the digital sound through the sound card on the PC and synchronizes the sound and the collected digital video together.