Now the screen projection protocol used by Android Phones / tablets / windows computers / TVs / Android boxes and some projection software can be said to be miracast.
Miracast was introduced in 2012 as a wireless connection standard from devices (such as laptops, tablets or smartphones) to monitors (such as TVs, monitors or projectors). It can be roughly described as “HDMI over Wi Fi,” replacing the cable from the device to the monitor.
The Wi Fi Alliance launched the miracast certification program at the end of 2012. Regardless of the device manufacturer, miracast certified devices can communicate with each other. The adapter can be used to plug into an HDMI or USB port, allowing devices without built-in miracast support to connect through miracast.
Miracast adopts the point-to-point wi fidirect standard. It allows sending up to 1080p HD video (H.264 codec) and 5.1 surround sound (AAC and AC3 are optional codecs, and mandatory codecs are lpcm – 16 bit 48khz2 channels). Connections are created through WPS, so WPA2 is used for protection. IPv4 is used for the Internet layer. At the transport layer, use TCP or UDP. In the application layer, through RTSP, RTP starts and controls the flow for data transmission.
Miracast has the following problems:
1. Nomenclature not standardized
Android phone manufacturers have not standardized the naming of miracastsource. When users use it, they don’t know where to find it. Some mobile phones are called wireless projection, others are called multi screen interaction.
2. The poor experience of screen projection is mainly manifested in the following aspects: long connection time, easy automatic disconnection, delay, mosaic, insufficient clarity, etc.
At present, the access compatibility of miracastsink is relatively poor, which is reflected in the fact that the mobile phone cannot be connected / the mobile phone is connected for a long time.
The stability of the existing miracastsink is relatively poor, which is reflected in: after many times of use, the screen projection device is no longer connected / will be disconnected after a long time of connection, etc.
The current experience of miracastsink needs to be optimized, which is reflected in: audio and video will be stuck or mosaic / picture is not clear / picture delay is relatively large.