AV and lecture capture: guidance for teaching spaces

COVID-19

This document has been updated in the summer of 2020 to address specific requirements of pandemic-time teaching.

 

Introduction

The Panopto recorder software comes in two flavours: remote and manual. The manual recorder for ad-hoc recordings can be installed on either Windows 7+ or macOS 10.13+. The remote recorder for scheduled recordings is only available for Windows. The remote recorder is recommended for all teaching spaces.

In designing AV (audio-visual) infrastructure for automatic lecture capture, it is helpful to group rooms into two categories: small seminar rooms and larger lecture rooms.

Small seminar rooms (<50 students)

For a room with limited space for AV or limited budget, a standard use-case would one computer at the front of the room used by the presenter to show PowerPoint slides and other content, which also records the computer’s screen and microphone audio using Panopto. This is typically a Windows laptop with a USB microphone attached. Often no camera video is captured, though occasionally a USB webcam is connected to the laptop, or a fixed IP camera is mounted on the ceiling facing the presenter. There may also be some portable equipment brought into the room for specific situations (e.g. guest lectures or panel discussions) such as extra cameras and tripods.

The computer would have Panopto remote recorder installed (for scheduled recordings), Panopto manual recorder, or both. A typical USB microphone is the MXL AC-404 boundary mic. For a USB webcam we recommend Logitech C920/C922 or a laptop’s integrated webcam may suffice. A ceiling mounted IP camera such as the Axis P1448-LE can be an affordable alternative to a higher-end PTZ (pan-tilt-zoom) model.

The computer would need to be of sufficient specification to cope with presenting and recording simultaneously, as this has demands on the processor, memory etc. Also, if a presenter wishes to use an external laptop to present, this will require additional setup in order to record as well: i.e. Panopto manual recorder installed, USB mic and camera attached and tested, sufficient processor and storage, and so on.

Larger lecture theatres (>50 students)

Two capture computers are optimal in large lecture rooms: a front presentation computer as in the small seminar room, but also a second computer, often located in an AV rack or booth at the back of the theatre. Both would be Windows PCs, each with the Panopto remote recorder installed, which allows for simultaneous dual recording from two computers to a single Panopto session. Located in a booth or rack, the rear PC is less likely to be accidentally powered down. Using the remote recorder, Panopto recordings can be scheduled in advance.

The presentation PC would capture PowerPoint slides, whilst the rear PC would capture camera video (usually from a ceiling-mounted or wall-mounted PTZ camera), audio (usually from multiple wireless and boundary microphones mixed through an audio mixer and/or DSP) and a video feed from the projector and/or visualiser.

Equipment

Audio

Audio is usually the most important consideration when creating a recording yet is often the most overlooked.

Panopto accepts only a single microphone audio input, so if using multiple microphones, they must be pre-mixed before being fed into the Panopto capture PC. In addition to the mic audio input, Panopto can also capture the PC audio directly. This is useful for capturing YouTube videos or other demonstrations where the PC audio output is important. (NB: it’s important to stop the YouTube video when finished, rather than just turning down the room speakers, as unwanted PC audio cannot be separated later from the mic audio and could ruin a recording.)

Often in larger teaching spaces there will be an existing amplification system. Depending on the location of the Panopto PC, it may be possible to take an audio feed from this to use as the audio source. Most teaching spaces employ a combination of a gooseneck microphone attached to the lectern, wireless lavalier (tie clip) microphones for presenters who wish to walk around, and flat boundary microphones used as a backup audio and to pick up audience questions. Lavalier microphones generally offer better audio quality primarily because they are very close to the presenter’s mouth at all times. An expensive microphone placed far from the presenter will not sound as good as a cheap microphone place much closer. However, presenters will often forget to wear them or to unmute them, and in these situations, it can be useful to have a boundary microphone as a backup, particularly since Panopto will fail to record at all if there is no audio source.

The most common lavalier system at Oxford is the Sennheiser EW112p G4 system, operating in the licenced 606-614MHz range (or less commonly, the licence-free 863-865MHz range). The G4 system is compatible with the earlier G3 system. Aside from excellent audio quality, an advantage of the G4 system is that it is commonly used by videographers allowing them to use a compatible wireless receiver to capture audio to external equipment (e.g. during VIP lectures), without the need to connect their camera via a cable to the sound system in the room.

Boundary microphones (e.g. MXL AC-404) may be sufficient for smaller spaces and have the advantage of being ‘always-on' but are adequate only if the presenter stands close to it throughout the lecture. Boundary microphones also tend to pick up more audience audio which can be both useful (audience questions and discussions) and detrimental (coughs).

In the case of large group meetings in medium-sized rooms, or panel discussions that have multiple speakers including the audience, then it may be necessary to consider a more advanced microphone set-up. Traditionally rooms often have roving mics used for audience questions - but if roving mics cannot be passed around, another option would be to use either table microphones or ceiling-mounted array microphones. An option is the Sennheiser TeamConnect solution, which comes in two versions: the portable TeamConnect Wireless features a series of wireless table mics suitable for smaller spaces, and the TeamConnect Ceiling 2 which is a ceiling mic which can be flush-mounted into standard false ceilings, suitable for medium to large spaces.  

An alternative popular supplier is ClearOne with a single array suitable for smaller spaces, and the individual ceiling array mics more suitable for larger spaces.

Both ClearOne and Sennheiser systems are Dante (audio over Ethernet)-compatible and allow multiple microphones to be daisy-chained together within large spaces. They use beamforming to focus and improve the wireless connection. Other options include Stem audio, Shure MXA910, and a variety of ceiling mounted/hanging microphones from other AV companies.

Cameras & video I/O devices

Although audio and screen capture are often sufficient, a camera is required to capture blackboard or whiteboard writing.

Panopto is compatible with a wide range of cameras, from internal laptop or external USB webcams, to network IP cameras, to professional video cameras with SDI or HDMI outputs. Whilst webcams can be an ideal way to get started using Panopto, the positions in which they can be placed is limited, and they are more likely to be knocked or the cable accidentally unplugged during a recording. Similarly, professional video cameras on a tripod can provide a high-quality image but can also be knocked and cables typically need to be trailed across the floor to the capture PC. They also need to be set up and operated by a member of staff.

Instead, a permanent, wall-mounted solution is recommended. Pan-tilt-zoom (PTZ) cameras are fully controllable over a network via either a web interface or remote control, and usually have optical zoom lenses with a long range (10-30x) and are therefore ideal for placing at the back of a large teaching space. However, they tend to be quite expensive, in the region of £2-5k depending on resolution, features and zoom range. Two brands of PTZ cameras that work well with Panopto are Panasonic and Axis. Axis also produces a large range of dome and bullet-style cameras that tend to be cheaper and more discrete, but which have a fixed field-of-view, and are better suited to smaller spaces. Examples of Panasonic cameras typically found in lecture theatres are the AW-HE40, AW-HE42 and the AW-UE70. An example of an Axis PTZ camera is the V5915.

PTZ cameras are traditionally connected to PCs via HDMI or, for longer cable runs, SDI, and a video capture card or USB capture dongle would be required. Recommended brands of capture card for Panopto are Magewell or DataPath. Magewell offers dual-HDMI or dual-SDI capture cards, which are useful if you wish to capture more than one camera (or a camera plus an additional device such as a visualiser), as well as reliable single-input HDMI and SDI to USB 3.0 dongles. It is not recommended to use two dongles on the same machine due to USB bandwidth limitations. Blackmagic Design Decklink cards and Ultrastudio boxes do not work well with Panopto and are not recommended, although their latest vision mixers – the ATEM Mini and ATEM Mini Pro – allow multiple HDMI devices to be connected and can be used to live mix between sources as well as creating effects such as Picture-in-Picture. These ATEM devices output a Program signal via USB-C. At the time of writing (July 2020) these remain untested at Oxford. However, they look like a promising option.

In spaces where it is difficult to retrofit HDMI or SDI cabling, such as in listed buildings, a simpler and often cheaper alternative is to use IP network cameras, with IP video transfer over the local network via a standard Ethernet cable. In these scenarios, the capture PC does not require a video capture card, but instead requires additional control software to be installed on the Panopto capture PC. For Axis cameras, the free Axis Streaming Assistant is necessary, and the version (32-bt or 64-bit) must match the Panopto version. The 32-bit version of the Streaming Assistant is available from the Axis website and a beta of the 64-bit version is available from the Replay downloads and resources page.

Panasonic cameras are also compatible over IP with Panopto either using the free Panasonic Virtual USB Driver or using the Network Device Interface (NDI) protocol that Panasonic cameras support. Generally, NDI is considered more stable with Panopto but requires an additional licence per camera costing around £300.

Another advantage of IP cameras is that they can be powered via the same Ethernet cable that is used to send the data signal, provided the network switch can deliver PoE+ (Power-over-Ethernet). Provision for cabling and network points should be provided in the ceiling or at the back of the room.

It may be necessary to install two cameras – one for capturing the presenter and another for capturing the whiteboard/blackboard writing. A single camera could be used, positioned at a wider angle to capture the entire stage area, but, although modern cameras are capable of capturing images at very high resolutions (1080p or 2160p), the primary video stream capture within Panopto is generally limited to 720p and will be scaled down accordingly. At a wide angle this resolution may be too low to resolve the whiteboard/backboard text. Dedicated capture devices such as the Matrox Maevex 6020, which can be used instead of a Windows PC, do allow 1080p capture within the primary stream. The Maevex is discussed later in this document. Alternatively, the latest Panasonic cameras feature autotracking and will follow the presenter around the stage, though this is very new technology and has not been extensively tested at Oxford. Autotracking capabilities require an additional paid licence.

Physical spaces

Automatic lecture capture does not require a camera operator to be present, and as such there are no specific space requirements for cameras. However, a dedicated area at the back of the room is often useful for manned cameras on tripods for VIP events.

Typical requirements include one or two PCs, a microphone audio system (often linked to a mixer and amplifier), an optional camera, and a visualiser. Some of this equipment may be housed on or underneath the podium, some may be housed in an AV rack within the teaching space, or in a separate nearby projection booth.

Black/white/smart boards should not be located in a very wide horizontal or panoramic layout, since for automated lecture capture the camera is usually fixed. Although capable of panning across the room, manual camera control requires additional staff resources and is impractical for day-to-day lecture capture. The use of wide horizontal boards (Fig. 1) necessitate that a single camera remains zoomed out to ensure all writing is captured, resulting in smaller, often illegible writing. Also, the unnecessary capture of the projection screens (already captured separately by the software) can force the camera to automatically adjust its exposure resulting in the blackboard being underexposed. Students’ heads and laptop screens are also creeping into shot, which is a privacy concern.

A lecturer presenting in front of a wide horizontal blackboard.

Fig. 1. Wide horizontal blackboards are more difficult to capture in Panopto.

 

Instead, vertical sliding boards located directly behind the lecturer are preferable (Fig. 2).

A lecturer writing on vertical blackboards.

Fig. 2. The use of floor-to-ceiling blackboards utilise the camera frame to best advantage.

Lighting

Lighting should be controllable so that it is not too dim for camera work.

Camera sensors have a limited ability to see within both highlights and shadows at the same time (known as the dynamic range of the sensor) and so diffused, even lighting is highly beneficial. Many cameras will auto-adjust to low light but in doing so, the video noise may be increased. If the projector screen is being filmed (or even partly in shot), then the camera may automatically adjust exposure for the brightness of the screen, and if the rest of the stage area is not correctly lit it may appear too dark in the video.

Over-reliance on spotlights can create harsh shadows which can be unflattering to the presenter. Similarly, the use of board lights on blackboards and whiteboards can create areas of extreme brightness and shadow that the camera is not well equipped to deal with. Whiteboards are prone to reflections of spotlights and board lights, creating a halo effect that can make writing unreadable on the video (Fig. 3).

Overexposed areas on writing surfaces caused by inadequate lighting.

Fig. 3. Hotspots on blackboards or whiteboards caused by spotlights can make writing difficult to see in the recording.

IT equipment

The Panopto recorder software comes in two flavours: manual and remote. The manual recorder can be installed on either Windows 7+ or macOS 10.13+. The remote recorder for scheduled recordings can be installed on Windows 7+. In teaching spaces, it is recommended to use the remote recorder.

Minimum specifications can be found on the Panopto website. If the capture of video and additional devices (e.g. visualiser, projector feed) is necessary, then consider the recommended specifications:

  • Intel Core i7 4-core processor
  • 16GB memory
  • 256GB solid state hard drive
  • Two USB 3.0 or USB-C ports
  • HDMI 2.0 or higher

The majority of teaching spaces are already equipped with a Windows desktop or laptop and this may be sufficient for basic recording, particularly if only audio and screen capture are required. However, as this PC would also be simultaneously used for presenting, there are limitations as to where it can be positioned in the room. It may be difficult to get audio and video feeds into this PC and does not account for situations where a presenter would wish to present from their own laptop.

An alternative and preferred solution would be a dedicated Panopto PC running Windows 7+ and the Panopto remote recorder software. This could be positioned in a discrete location, e.g. an existing AV rack or projection booth, and receive an audio feed from the room. It would require a network connection (ideally wired) to receive the recording schedule information and to upload recordings.

The remote recorder is scheduled and configured via a web interface, usually by a departmental administrator or IT/AV officer, and the presenter does not need to remember to start the recording manually. Videos are recorded locally and uploaded automatically at the end of each session, before being automatically deleted from the local hard drive to conserve space.

Another advantage of using the remote recorder over the manual recorder is the ability Panopto has to synchronise two remote recorders to record simultaneously to the same session. The “primary” recorder receives the audio and (optional) video inputs and is often housed in an AV rack or booth, whilst the “secondary” recorder is usually the presentation PC and does not require a microphone input.

For situations where the recorder software cannot be installed on the presentation PC, e.g. it is not running Windows, or the presenter has brought their own laptop, a VGA or HDMI capture card can be installed in the primary recorder PC to take a feed directly from the projector. The disadvantage of this method over recording directly on the presentation PC is that PowerPoint slide timings are not captured as metadata and thus cannot be used as automatic chapter markers in the recording.

PCs and laptops need to be maintained to an appropriate standard to ensure computers function properly when being used by academics and presenters, and reduce down-time when setting up a computer ready for a presentation. PCs and laptops have an average life cycle of 3 to 4 years. The processing speed of the laptop needs to be sufficient to handle loading and running applications smoothly, such as Microsoft Office.

Operating systems should be current or no older than three earlier versions. Currently all laptops and PCs should be running either Windows 7, 8.1 or 10. The latest version of Microsoft Office should be installed on all computers to make sure that they are compatible with the latest file types. The current version is MS Office 2019. All computers should have at least two USB inputs, a HDMI output, a gigabit Ethernet socket, and a microphone-in jack. These are used for external devices such as hard drives, projectors, speakers, tablets, and internet connections.

Security updates and drivers should be installed on a regular basis. Pending Windows system updates have been known, in some circumstances, to prevent the remote recorder from successfully recording.

Dedicated hardware recorders

There are also standalone, dedicated hardware remote recorders which can be used as alternatives to Windows PCs. Although these cannot as easily be repurposed, they do have the advantage of needing minimal interaction and maintenance from staff, and do not require Windows updates. They are typically more expensive than a Windows PC but feature dedicated capture hardware which would need to be factored into the cost of building a Windows PC. The Matrox Maevex 6020, for example, costs around £1800 + VAT and includes dual-HDMI inputs. The cost of an equivalent Magewell dual-HDMI capture card for a Windows PC would be around £500. The Maevex also facilitates primary video capture at 1080p, unlike a PC which is limited to 720p, and the additional resolution can be useful in an environment with a single camera and a large whiteboard/blackboard. However, these devices do not currently work with IP cameras.

Panopto-certified hardware

Manufacturer Device Specifications
Seneca (Arrow Systems) Video Capture Appliance https://www.senecadata.com/industry-solutions/broadcast/scribe/
Matrox Maevex 6020 https://www.matrox.com/graphics/en/products/video_over_ip/maevex-6020/remote-recorder/

Non-certified hardware also compatible with Panopto

Network infrastructure

Recording sessions can be in the region of 1-2 GB/hour depending on the video quality and number of video streams used, so a fast, reliable connection from the capture PC is critical, and a wired connection is highly recommended.

Panopto records locally to the capture PCs before automatically uploading to the cloud server at the end of the session, so if the network is unavailable for a short period, the recording will not be lost and it will be uploaded once the network connection is restored.

If there is a sustained network outage, the Windows remote recorder will function offline provided it has already received instructions from the server whilst the network was active. The remote recorder stores a copy of all schedule information locally so can function quite well in an offline environment. The recording will upload to the server automatically once the network connection is restored. The macOS manual recorder can always record offline and the session can be uploaded once the network connection is restored. The Windows manual recorder can record offline only if the user is already logged in (which can only be done if there is a network connection).

If using IP cameras, additional network points are required at suitable locations around the teaching space.

Additional AV requirements

Cabling often needs to be changed as display technology moves from one digital format to another; it is important to provide access conduits that allow cables to be easily changed or moved. For Health and Safety purposes, cables need to be fixed or taped down wherever possible and should never be exposed in public spaces.

Panel sessions often take place in large lecture rooms and it is important to provide additional table and audience microphones for such situations. Ensure extra XLR balanced audio outputs from PA mixing boards can be provided for other recording equipment and to future proof the set-up.

All projectors should be at least Full HD (1080p) though some modern projectors now offer Ultra HD (4K or 2160p), with HDMI outputs, and a minimum brightness specification of 2000 lumens.

Control systems

AV control systems on or near the lectern simplify the job of switching on projectors, lights, and room audio by having commonly used settings as presets on touch-pad buttons, small touchscreens or via an app on a tablet. A good control system can, with the appropriate training for academic staff, often remove the requirement for AV staff to be present at the beginning of lectures. However, some control systems can be quite complex and expensive to program after initial set-up. Subsequent changes (e.g. reprogramming based on user experience and requests) usually has further costs associated, though some modern control systems can be adapted without additional programming.

Guest presenters often bring their own laptops and it needs to be easy for them to switch the projector to this input via a control pad, small touchscreen, or tablet app. A common solution is to split the projector feed and capture via HDMI or VGA using the primary Panopto remote recorder, together with the camera feed and audio from the room PA.

Broadcasting a lecture

Due to COVID-19, there may be a requirement for broadcasting a live lecture to a remote set of students. Panopto recordings can be easily broadcast near-live (with a 60-90s delay) by checking an additional box when scheduling. A common use case of this is for overspill rooms. Due to the delay and lack of supporting tools, Panopto is not suitable for two-way communication and in situations where the presenter and live audience need to be able to communicate with the remote audience, the recommended centrally-supported solution for this is Microsoft Teams.

This style of “hybrid” teaching requires additional focus by the presenter and can be very challenging. It is recommended that, for hybrid lectures, an IT or AV officer is present at the start to ensure the technology is set up and working correctly. A Teams call could be started on the presentation PC, and the screen shared with the remote audience. A simple USB boundary microphone could be attached to the presentation PC, and if necessary, a USB webcam on a light stand or discrete tripod.

To allow the presenter to directly see and communicate with the remote students, without needing to constantly minimize their presentation, a portable AV trolley could be used, housing a TV screen and laptop which could be connected to the same MS Teams call as the presentation PC.

Get support


Local IT and administration staff provide your first line of Lecture Capture support

Local Lecture Capture support

 

For more complex queries, contact the central Replay Lecture Capture team

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