Avi-Matrix 4 Input Multiviewer

The Architecture of the Avi-Matrix 4 Input Multiviewer

The Avi-Matrix 4 Input Multiviewer is a dedicated signal processing unit designed to aggregate four independent 3G-SDI video feeds into a single monitoring output. Positioned as a critical utility for multi-camera productions, this device functions as a hardware-based scaler and compositor. It features four BNC inputs that support SD, HD, and 3G-SDI signals, automatically detecting the incoming resolution and frame rate for each channel. The output is delivered simultaneously through one 3G-SDI port and one HDMI port, allowing for redundant monitoring or the use of both professional SDI displays and consumer-grade HDMI monitors. Unlike software-based solutions that introduce significant processing overhead, this hardware multiviewer utilizes a dedicated FPGA (Field-Programmable Gate Array) to ensure low-latency signal handling, making it suitable for live broadcast environments where timing is critical.

Designed for DITs (Digital Imaging Technicians), broadcast engineers, and live event videographers, the Avi-Matrix 4 Input Multiviewer sits in the manufacturer’s lineup as a portable yet robust alternative to large, rack-mounted multiviewer systems. It eliminates the need for multiple monitors on set, consolidating the visual data from four cameras into a single screen. The device supports a wide range of SMPTE standards, including SMPTE 259M, 292M, and 424M. This ensures compatibility with a vast array of professional cinema cameras and broadcast equipment, ranging from legacy SD-SDI units to modern 1080p60 3G-SDI systems. Its compact form factor is specifically engineered for field use, where space in a flight case or on a camera cart is at a premium.

Signal Processing and Visual Integrity

The core strength of the Avi-Matrix 4 Input Multiviewer lies in its internal scaling engine. Each of the four SDI inputs is processed independently, allowing the device to accept mixed formats. For example, Input 1 can receive a 1080p 23.98fps signal while Input 2 receives a 1080i 59.94fps signal; the multiviewer will internally scale and frame-rate convert these disparate sources to match the user-defined output resolution. The output can be set to various standard resolutions, including 1080p at 60, 50, 30, 25, or 24 frames per second, as well as 1080i and 720p formats. This ensures that the final composite image remains stable and flicker-free, regardless of the variations in the source signals.

Visual monitoring is enhanced by several on-screen display (OSD) features that provide critical data to the operator. The device supports an 11-segment signal indicator for each input, which provides a visual representation of the signal strength and integrity. Furthermore, it includes Under Monitor Display (UMD) support, allowing users to overlay text labels (up to 13 characters) for each camera feed, such as "CAM 1," "WIDE," or "CLOSE-UP." This is complemented by on-screen audio meters that display the levels of the embedded SDI audio for each channel. The multiviewer also features a global timecode overlay, which is essential for synchronizing takes across multiple cameras during a complex shoot. These overlays are customizable via the control software or the physical DIP switches, ensuring the screen remains as clean or as data-rich as the specific production requires.

Build Quality and Interface Handling

The Avi-Matrix 4 Input Multiviewer is housed in a heavy-duty metal chassis designed to withstand the rigors of professional production environments. The metal casing acts as a passive heat sink, dissipating the thermal energy generated by the high-speed FPGA during continuous operation. This design choice avoids the need for internal fans, resulting in silent operation—a critical requirement for quiet studio sets or intimate event recordings. The unit features a standard 1/4-20 threaded mounting hole on the bottom, allowing it to be easily secured to a monitor arm, a cage, or a specialized DIT rack. Power is supplied via a locking threaded DC jack, which prevents accidental disconnections during a live shoot. The device accepts a wide voltage range from 7V to 24V, making it compatible with various power sources, including professional V-mount or Gold-mount batteries via D-Tap adapters.

Control of the device is handled through two primary methods: physical DIP switches and a LAN-based software interface. On the side of the unit, a bank of 10 DIP switches allows for immediate, driver-free configuration of the most common settings. These switches control the output resolution, the layout mode (Quad Split, Picture-in-Picture, or Full Screen), and the visibility of the OSD elements. For more granular control, the RJ45 Ethernet port allows the multiviewer to be connected to a local network. Using the dedicated Windows-based software, users can customize UMD text, adjust the position and size of the Picture-in-Picture (PiP) windows, and manage advanced signal settings. This dual-control approach ensures that the device can be configured quickly in the field without a computer, while still offering deep customization for permanent installations.

Video Standards and Connectivity Specifications

The connectivity suite of the Avi-Matrix 4 Input Multiviewer is centered around professional SDI standards. The four 3G-SDI inputs utilize high-quality BNC connectors with 75-ohm impedance. These inputs are capable of handling 3G-SDI Level A and Level B signals, ensuring compatibility with different mapping structures used by various camera manufacturers. The SDI output port functions as a mirrored output of the HDMI port, providing a 10-bit 4:2:2 signal that maintains color accuracy for monitoring purposes. The HDMI output is version 1.3 compatible, supporting the full range of HD resolutions up to 1080p60. This allows the multiviewer to drive large-format consumer televisions, which are often used as affordable "client monitors" on set.

The device supports a comprehensive list of video formats. For 3G-SDI, it handles 1080p at 60/59.94/50Hz. For HD-SDI, it supports 1080p at 30/29.97/25/24/23.98Hz, 1080i at 60/59.94/50Hz, and 720p at 60/59.94/50/30/29.97/25/24/23.98Hz. It even maintains support for SD-SDI formats like 525i 59.94 (NTSC) and 625i 50 (PAL). The internal processing ensures that the latency from input to output is kept to a minimum, typically less than two frames, which is vital for directors who need to provide real-time feedback to camera operators. The inclusion of a dedicated USB port for firmware updates ensures that the device can be updated to support new signal variations or to improve OSD features as the manufacturer releases them.

On the Shoot: Practical Indian Production Scenarios

In a high-pressure Bengaluru wedding reception, the Avi-Matrix 4 Input Multiviewer becomes the central hub for the live feed management. With four cameras positioned around the mandap—perhaps two Sony FX6s on sticks, a roaming FX3 on a gimbal, and a fixed wide shot—the videography lead can monitor all four angles on a single 24-inch monitor. By using the Quad Split mode, the lead can ensure that all cameras are in focus and properly exposed before the main ceremony begins. The UMD labels help the director quickly identify which operator to communicate with via intercom, while the audio meters confirm that the wireless lavalier mics are feeding clean audio into the primary camera. The compact size of the multiviewer allows it to be tucked away in a small Pelican case alongside the wireless receivers, keeping the footprint at the venue minimal.

For a Mumbai-based studio product session, such as a high-end jewelry shoot, the multiviewer is used to manage macro and detail shots simultaneously. One input might be dedicated to a 90mm macro lens for tight details of a necklace, another to a 35mm lens for a lifestyle context, and a third for a top-down "flat lay" perspective. The DIT can use the Picture-in-Picture (PiP) mode to keep the primary macro shot full-screen while monitoring the top-down safety shot in a small corner window. This allows the lighting team to see how adjustments to a single key light affect all three angles at once, significantly speeding up the setup time for complex product arrangements. The ability to output to both an SDI production monitor for the DIT and an HDMI television for the client ensures everyone is seeing the same synchronized feed.

During a documentary shoot in the varied terrain of Goa, the multiviewer’s wide voltage input is a significant advantage. Powered by a single V-mount battery via a D-Tap to DC cable, the unit can be used in remote outdoor locations where mains power is unavailable. When filming a multi-person interview on a beach, the crew can monitor three camera angles and a fourth input from a laptop displaying the script or a remote producer's feed via an SDI converter. The 11-segment signal indicators are particularly useful here, as they provide an immediate visual warning if a long SDI cable run is suffering from signal degradation due to environmental interference or cable strain, allowing the crew to swap cables before the recording is compromised.

Compatibility and Essential Pairings

The Avi-Matrix 4 Input Multiviewer is a versatile tool that pairs effectively with a wide range of professional cinema and broadcast gear. For cabling, it requires high-quality 75-ohm RG6 or RG59 BNC cables to maintain signal integrity over longer distances, especially when working with 3G-SDI 1080p60 signals. It is perfectly compatible with industry-standard cameras from Sony (FS7, FX series), Canon (C300, C500), and Blackmagic Design (URSA Mini, Pocket Cinema Camera with SDI converters). For power, pairing the unit with a D-Tap to 2.1mm DC locking cable allows it to draw power from the same large-capacity batteries used to power cameras or monitors, simplifying the power distribution on a complex rig.

In terms of monitoring, the device is frequently paired with professional displays from brands like SmallHD, Atomos, or Flanders Scientific. Because it offers both SDI and HDMI outputs, it can also be used in conjunction with wireless video transmitters like the Teradek Bolt or Hollyland Mars series. By plugging the multiviewer's output into a wireless transmitter, a director can carry a single handheld monitor and see all four camera feeds while moving around the set. For live streaming setups, the multiviewer’s output can be fed into an ATEM Mini (via an SDI-to-HDMI converter) or a Blackmagic Web Presenter, allowing a single-channel switcher to handle a multi-camera composite feed as a single input source.

Limitations and Alternative Considerations

While the Avi-Matrix 4 Input Multiviewer is an exceptional tool for HD workflows, it has specific limitations that may require a different class of equipment. The most significant limitation is the lack of 4K support. This device is strictly limited to 3G-SDI (1080p) and below. For productions requiring 4K or 12G-SDI monitoring, a more advanced multiviewer like the Blackmagic MultiView 4 or a dedicated 4K production switcher would be necessary. Additionally, this unit is a multiviewer, not a seamless switcher. While it can display multiple feeds, it does not have the "cut" or "fade" buttons found on a dedicated video switcher. If the goal is to switch between cameras for a live broadcast or recording, a device like the Avi-Matrix VS0601 or an ATEM switcher is the appropriate choice.

Another consideration is the lack of internal recording or streaming capabilities. The Avi-Matrix 4 Input Multiviewer is purely a signal processor; it does not record the composite feed to an SD card or SSD, nor does it have a built-in H.264/H.265 encoder for direct-to-web streaming. Furthermore, the device does not feature a built-in battery plate, meaning it always requires an external power source. For solo operators looking for an all-in-one monitor, recorder, and multiviewer, a high-end monitor-recorder like the Atomos Sumo 19 might be more suitable, although at a significantly higher weight and power requirement. Finally, the control interface via DIP switches, while reliable, is less intuitive than a touchscreen or a dedicated front-panel button array found on more expensive rack-mount units.