1. The capture card is divided into built-in capture card and external capture card
Image acquisition cards can be divided into external acquisition cards (boxes) and built-in boards according to the installation link method. The acquisition card in the form of a plug-in card is called a built-in acquisition card. The advantage of this form is that it can support the simultaneous access of multiple cameras. Most of them can realize multi-tasking under the Windows system. Generally, we insert it into the PCIE card of the desktop top of the slot.
Secondly, its price is much cheaper than external ones, and it will not take up external desktop space. Now there are too many peripherals on the computer desk, and it would be annoying if there are too many peripherals.
In addition, the built-in video card does not need an external power supply, which not only saves the position of a power plug, but also reduces the messy situation caused by too many power cables, and also avoids video failure caused by unstable mains voltage. A drop in quality occurs.
2. Need to distinguish whether it is USB2.0 or USB3.0
All computers are equipped with USB2.0 interface, which is convenient for connection and does not require a capture card.
The camera with USB2.0 interface is one of the earliest digital interfaces used. It has a short development cycle and low cost. It is the most common type at present. The disadvantage is that its transmission rate is relatively slow, and the theoretical speed is only 480Mb (60MB).
During the transmission process, the CPU participates in the management, occupying and consuming a lot of resources. The USB2.0 interface is unstable, and the camera usually does not have strong screws, so there may be a risk of loosening on devices that are often moved. The transmission distance is short, and the signal is easy to attenuate.
The design of USB 3.0 adds two sets of data buses on the basis of USB 2.0. In order to ensure backward compatibility, USB 3.0 retains a set of transmission buses of USB 2.0.
In terms of transmission protocols, in addition to supporting the traditional BOT protocol, USB 3.0 has added the USB Attached SCSI Protocol (USAP), which can fully utilize the advantages of 5Gbps high-speed bandwidth. USB 3.0 has the plug-and-play advantages of USB 2.0, while also allowing for higher data transfer rates.
The advantages of the USB 3.0 interface are bandwidth higher than 350Mbps, no additional cost of a separate frame grabber, widely available plug-and-play hardware, and low CPU load. Most new devices—from PCs to the smallest PC cards—offer USB 3.0 embedded connectivity.
Generally speaking, USB2.0 transmits compressed images, so the image quality will be damaged, while 3.0 capture cards can transmit uncompressed images, so the image quality will be better. The USB 3.0 interface standard has become a widespread standard in the consumer market, and most hardware currently supports the USB 3.0 interface.
A 4k capture card is an output that captures 4K video, and it functions very similarly to other USB capture cards, allowing you to capture uncompressed video anytime, anywhere, without configuration or special drivers. The difference from this product is that it can capture video in 4K resolution, but basically all live broadcast platforms can’t use 4K at present, so when doing live broadcast, a 1080p capture card is enough.