The embedder/deembedder card for audio in HDSDI video signals

With the XHDI card, audio signals can be extracted from an HDSDI digital video stream, replaced and simultaneously embedded again.

The XHDI card is a combined de-embedder and embedder for audio signals in HDSDI and SDI video signals to SMPTE 259M, 292M and 424M/425M. The card supports automatic format detection of the video data streams and is able to read, exchange and embed all 16 embedded audio signals simultaneously. Various modes are available for this: De-Embed, Embed, Replace, Bypass and Delete allow flexible handling of the embedded audio data. The unpacked channels can be used freely in the NEXUS routing matrix. To be able to adjust the levels as soon as you enter the system, a DSP is provided on the module. The image-sound offset that occurs during separate audio-video processing can be compensated by means of delay. A video delay before re-embedding is also possible.

Requantisation can be activated for audio formats with a different word width, such as 20 or 16 bit. Dithering and noise shaping are of course available. When setting up new systems or troubleshooting, an integrated video test pattern generator that supports the various resolutions and frame rates can be used to connect the XHDI with the XDED or XDEE board using a short cable within the NEXUS base unit for practical integration of Dolby E signals.

The metadata contained in the SD/HD data stream can be read and written. They can be received from or output to external devices via the optional XDEM interface card. Even more convenient when using a NEXUS Dolby E card is the connection via the NEXUS network, e.g. to an XTI serial data transfer card. The XHDI board is available in two versions: with four BNC connectors for Video In, Thru and 2x Video Out and alternatively with a bidirectional SFP port, which connects to an LC-duplex fiber with different modules. Optionally, the board can be equipped with sample rate converters to operate the NEXUS system in a different clock to the audio signals from the video source.

automatic format recognition

The XHDI card supports a variety of SD, HD and 3G formats and recognizes independently which one it is.

Adjustable digital gain in the inputs

The inputs are immediately followed by a digital gain in the range of +/-20dB, which can be adjusted in 1dB steps. In addition, it is possible to reverse the phase for each channel separately.

Adjustable delay for delay compensation compared to the video

To compensate for an image-sound offset that can occur when editing or compressing video, there is an adjustable delay.

Adjustable delay for delay compensation compared to the audio

During extensive processing or routing over long distances, the audio signal may be slightly delayed, so that an adjustable delay restores lip sync.

Integrated test pattern generator

In 425M, 296M, 274M, and 125M SMPTE formats, a color bar or black image can be output for setup and troubleshooting.

Integrated DSP

Dithering is calculated on an integrated DSP to reduce rounding errors during the requesting process. Switchable noise shaping shifts the noise energy to an area to which the human ear is less sensitive.

Optional sample rate converter

An optional sample rate converter module enables the embedding of audio signals that do not comply with the SD standard of 48kHz. On the other hand, audio signals from SD/HD data streams can also be fed into NEXUS systems that operate at other sampling rates such as 96kHz.



BNC 2x SDI, HDSDI, 3G Output
BNC 1x SDI, HDSDI, 3G Input
SFP 1x SDI, HDSDI, 3G bidirektional

Technical specifications


Video data formats compliant w/ SMPTE 259M (270 Mbps),
SMPTE 292M (1485/1483.5 Mbps),
SMPTE 424M/425M (2970/2967 Mbps),
automatic format detection
Embedding and de-embedding SMPTE 272M-AC (SD),
SMPTE 299M (HD/3G)
Audio data 16/20/24 bit-transparent
 transmission of compressed audio,
Dolby E certified
Sample rates 48 kHz according to SDI44
44.1 kHz, 48 kHz, 88.1 kHz, 96 kHz (NEXUS system clock) with optional sampling rate converter
input data rate 270 MBit, 1483,51 MBit, 1485 MBit
notation Due to the high data rate, only high-quality cables with sufficient bandwidth and defined impedance (75 Ohm) should be used.
Interface extension XDEM optional expansion card for feeding or outputting metadata

Electrical input BNC

impedance 75 ohm
return loss min. 15 dB according to SMPTE 292M
cable length max. 300 m at 270 MBit with cable Belden 1694A
max. 140 m at 1485 MBit with cable Belden 1694A

Electrical outputs BNC

impedance 75 ohms
output voltage typ. 800 mVPP
return loss min. 15 dB according to SMPTE 292M

Input optical LC

bloke Single-Mode SM
cable length max. 10 km
optical sensitivity 18 dBm (at 9/125 μm)
max. damping 0...8 dB (total attenuation via cables, connectors, switches, connections)

Output optical LC

bloke Single-Mode SM
cable length max. 10 km
wavelength 1270...1360 μm
optical output 10...-3 dBm (at 9/125 μm)

Operation conditions

Temperature range 0 °C bis +50 °C
max humidity max. 90 %, non-condensing

Storage conditions

Temperature range –35 °C bis +70 °C
max humidity max. 90 %, non-condensing

Power supply

Voltage +4,75…5,25 V
Currrent 1000 mA (BNC only)
1200 mA (optical and BNC)

Mechanical data

Weight 0,26 kg

NEXUS / NEXUS Star Technical specifications




XHDI Technical specifications