The most common sentence encountered when making audio and video optical transmission solutions is: If it can all be transmitted to the control room, why do studios insist on SDI and conference rooms just use HDMI? The difference is not in the image quality rating, but in the interface design and fault performance.
Interface genes determine what they are afraid of
SDI is a native radio and television interface, with 75 ohm coaxial point-to-point transmission. The connector is locked and can be plugged and unplugged thousands of times and is still reliable. The screen will go black if there is an error in the picture. HDMI is a consumer electronics product and is designed for three to five meters from the sofa to the TV. The contacts are fragile and hot-swapping is prone to EDID handshake problems. The first thing to lose over long distances is the high bit rate and color depth. Fiber optics solves the problem of distance, but the tempers of the two signals before entering the optical terminal still need to be adjusted.
The rate is different from the audio carrying method
3G-SDI refers to the 2.97 Gbps speed file, which can carry 1080p50/60. Audio is embedded in the video stream for single-line transmission.1-way 3G-SDI audio and video optical transceiverIt can be transmitted back transparently and de-embedded at the receiving end. HDMI relies on the TMDS channel to carry video and audio. The version and chip compatibility have a great impact. The actual link test shall prevail when selecting the model. If you need to make a call, confirm whether it has an independent two-way audio channel.
Scene mapping: who uses which?
- Live broadcast, broadcast truck, studio camera backhaul: SDI priority, black screen can be expected to be better than flash black
- Conference projection, information release, and computer signals on the big screen: HDMI or DVI are more convenient
- Mixed use site: The optical terminals are used to unify the output, and then converge and switch on the control room side.
Simple note: If the signal is related to broadcast safety, use SDI; if the signal is related to convenient access, use HDMI or DVI. For networking in mixed scenarios, please refer toRadio, television and large-screen audio and video optical fiber transmission solutionsIf you are not sure, you can call EB-LINK technical support 0755-83179002 to confirm.