Compared with the current mainstream projection protocols of
, we all know that miracast, airplay, DLNA and widi. Among them, miracast protocol mainly has the vast majority of user base. The screen image of airplay is only used by IOS system (Apple device). At present, DLNA is more commonly used in video app. Although we don’t know much about widi protocol, we actually use it more.
widi (wireless home digital interface) widi supports high-definition transmission within 7-15 meters. It is composed of a transmitter and a receiver. The transmitter is connected to playback devices such as computers, notebooks, Blu ray disc players, high-definition players, PS3, etc., and the receiver is connected to display devices such as large screen LCD, high-definition TV, high-definition projector, home theater or simple speakers.
widi enables the majority of users to no longer be entangled by cables and easily establish a wireless audio-visual center, which is widely used in conference rooms, lecture halls, lecture halls, literary and artistic stages, home audio-visual entertainment, KTV entertainment and other places. Widi enables you to realize the wireless HD audio and video feast of zero trouble, long-distance wireless transmission, automatic frequency switching, plug and play and uncompressed 1080p in the enjoyment of home entertainment! The system architecture of
screen projectors on the market is mainly divided into Android and Linux architecture. Most Android boxes adopt miracast screen projection technology. The advantages of
whdi technology are as follows:
① uncompressed video transmission
widi technology is essentially different from other wireless technologies in that it can transmit Full HD audio and video streams completely uncompressed. There are two main ways to transmit video wirelessly: one is to transmit video wirelessly through compressed audio and video streams at the transmitting end and decompress and restore images at the receiving end, represented by WiFi and UWB technologies. The other is to directly transmit the video frequency stream output by the video source to the receiving end and output the image through wireless mode, represented by widi. Only widi technology can be implemented in the industry.
② no delay in transmission
because widi technology provides sufficient wireless bandwidth, there is no need to transmit by compression, which saves the time spent in the process of video compression and decompression, so as to ensure that the transmitted video has no delay at all.
③ resolution up to 1080p
whdi technology supports video resolution up to 1920x1080p. The subsequent software upgrade can support the resolution of 2kx4k. Equivalent to 4 times 1080p.
④ support 7.1-channel
in addition to transmitting Full HD video, widi technology can support 7.1-channel (PCM) audio transmission, with sampling rate up to 24bit and 192Khz.
⑤ 100k return channel
widi technology itself not only can transmit audio and video, but also provides 100k return channel. The purpose of setting the return channel is to enable the control protocol of HDCP to verify each other between the transmitting end and the receiving end. At present, the domestic widi module manufacturer SHIMENG company has realized the return function of USB keyboard and mouse through this channel, that is, uwtc (usbwirelesstransmission control) technology, and mastered the remote control technology of multi touch.
⑥ supports hdcp2 0 technology
HDCP organization has separately set hdcp2 for whdi technology Technical standard of 0. HDCP2. 0 allows users to realize one to many and many to many HDCP interactive authentication through whdi technology. Hdcp2 0 technology allows a video source with content protection protocol to be displayed at multiple display terminals at the same time. This is in hdmi1 2 standard is completely impossible to achieve.
⑦ the disadvantage of widi technology
is that they are not universal enough. Because our mobile phones and computers do not support whdi protocol, widi protocol can not have a broad user base like miracast projection technology. However, with the gradual maturity of wireless screen projector and wireless screen software, widi technology has also been well compatible. It is not impossible that it will be familiar to everyone in the future.