Video technology

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Analogous to Audio technology In video technology, the actual need must be carefully determined, also on sight. Nothing is more annoying than having to sell some of the equipment you have just purchased at a loss because it cannot meet the newly changed requirements.

The components are diverse and the possibilities are many. Here is a selection of the most common devices, their areas of application and technical details that are relevant to the purchase decision.

The respective components must be selected according to the video connection formats used (HDMI, DVI, VGA, Composite, etc.). Multiformat equipment offers connections for multiple formats in one device.

Toggle switch

HDMI

• Connect multiple HDMI video sources to one HDMI output

Switching takes place via buttons on the device, an IR remote control or RS232 interface.

When choosing the HDMI switcher, HDMI and HDCP version (High-bandwidth digital content protection) decisive. If you are looking for an 8k-capable (HDMI 2.1) device, you will not be satisfied with HDMI 2.0 (4k).

More information to HDMI.

DVI

• Connecting DVI sources to a DVI output

Switching takes place using buttons, IR remote control or RS232 interface.

Supports resolutions up to 1920 x 1200 (WUXGA) and 1080p (HDTV). Audio and video signals can usually be switched separately. Attention should be paid to HDCP compliance.

VGA

• Connect up to 32 VGA sources to one VGA output

Switching takes place using buttons, IR remote control or RS232 interface.

Supports resolutions up to 2048 x 1536 60Hz. Audio and video signals can usually be switched separately.

Composite

• Connect up to 4 composite sources to one composite output

Switching is done using buttons.

Only video is shown!

Multiformat

• Simultaneous connection of different input and output formats

Switching takes place automatically or via RS232 interface.

Mutiformat audio-video switchers offer multiple input formats simultaneously, e.g. HDMI, VGA, DVI, Composite, S-Video, YUV/HD, SDI, HDBaseT, DGGKat, DisplayPort, USB-C, Lightning.

If necessary, an integrated scaler ensures that the video signal is adjusted to a uniform output resolution.

HDMI and HDCP versions are again priority one in the decision-making process.

Presentation switcher

• Simultaneous connection of different input and output formats with scaler

Switching takes place via buttons, automatically or via the RS232 interface.

Presentation switchers are equipped with scalers to ensure a consistent output format, regardless of incoming format.

Combination devices combine multiformat switchers, scalers, line amplifiers and matrix switchers in one.

HDMI and HDCP versions must be taken into account when choosing a device.

Distributor

• Distribution of ONE video source to multiple output devices.

They are also divided into the above-mentioned output formats. HDMI and HDCP versions are again the basic selection criteria.

Switching takes place via buttons or automatically.

The differences lie in the number of signal sources that can be connected, usually one, possibly several, and the number of outputs. There is also different support for analog and/or digital audio signals, such as RCA (L/R), SPDIF and Toslink.

Amplifiers/Extensors

For all HDMI devices, HDMI and HDCP versions must be taken into account and form the basic criterion for further selection.

Wired technologies span 30 to 150 m, while devices based on fiber optic technology can also achieve cable lengths of a few hundred meters.

Matrix/Matrix

Matrix switches are used to arbitrarily distribute different audio-video input formats to different target devices (sinks).
You switch by first disconnecting the current video source from the output and then connecting the new input shortly afterwards. This resulted in a briefly black screen. Newer seamless matrix/crossbars can switch “seamlessly”.

As long as the HDMI devices to be connected are located in the immediate vicinity (4 m), so-called permanently configured matrix switchers are sufficient. However, if larger distances have to be bridged, you are better off with an HDMI HDBaseT A/V matrix. In addition to the matrix switch itself, this also includes the necessary signal amplifier, which allows transmission via CAT.7 network cable.

If DVI, VGA, SDI, composite or S-Video signals are to be connected, the permanently configured A/V matrix / matrix switcher mentioned at the beginning is sufficient.
It should be noted that it must be taken into account whether audio signals should also be processed/interconnected and whether HDMI and HDCP compatibility is also desired.

If it is expected that more devices will need to be connected in the future than currently planned, a modular A/V matrix should be built straight away in order to avoid unnecessary investments.

Streaming encoder/decoder

Streaming encoders are used as recording devices for A/V data, such as reports, interviews, etc. They encode the 4k UHD or Full HD video stream, including audio, according to H.264 or H.265 codec. The data can be further processed via storage medium in master quality.

H.264 and H.265 are compression methods that reduce the amount of data required when recording. H.265 compresses twice as much as H.264 while maintaining the same quality and therefore places higher demands on computing power and the budget. H.265 is primarily used for 8k resolutions.

Scalers

Scalers are used to convert an input signal into other formats and signal forms. They are usually part of presentation switches and matrix switches or matrix switches.

processors

Multi-viewer video processors are used to process and play back multiple video sources on individual playback devices, such as monitors or TVs, which are assembled into large screens. In order to obtain a seamless optical image, almost borderless monitors/TVs should always be used. The edge width can be set in the software and thus taken into account mathematically during playback.

Video converter

Video converters convert video signals from analog to digital (A/D converter) and vice versa (D/A converter). Analog signals include VGA, composite video (FBAS), S-Video (Y/V) or component video (YUV, YPbPr), digital DVI and HDMI, or (Mini)DisplayPort.