AV GUIDANCE DOCUMENT

Replay is an opt-in, automated lecture recording service at Oxford University which runs on a cloud-based instantiation of commercial software called Panopto. The service is centrally managed but the day-to-day recording activity in lecture rooms is devolved to local departmental AV and IT support teams. ThePanopto recording software can be installed on Mac, PC or tablet,will record a combination of audio, slides and videos sources, and deliver the recording to the students immediately after the lecture.

Key features:

  • Academics can easily record their teaching sessions.
  • Students registered on the course can then access the recordings via the central virtual learning environment (VLE) (WebLearn) under Oxford single-signonauthentication. A student can search and replay part of the lecture to reinforce their understanding of concepts and revise for examination purposes.
  • Recordings can be triggered remotely over the network and therefore suites of rooms in a departmentcan be monitored and controlled from a central point.
  • Recording sessions can be timetabled within the software so an academic does not need to initiate the start of the recording or change their lecturing behaviour.

In designing AV infrastructure for automatic lecture capture,it is helpful to group rooms into two categories: small seminar rooms and larger lecture rooms. In both cases, the softwareautomatically synchronises all the inputs so that the viewer has a seamless experience later when viewing the recording.

Small seminar rooms

A typical simple use of the software is to record Powerpoint slides, plus audio commentaryusing a simple USB microphone. There is one presentation computer at the front of the room,which has the software installed, and a USB microphone plugged into the USB port. The software will capture audio, together with what is shown onthe presentation screen (usuallyslides). If video is required (optional), a webcam can be attached to the presentation computer via USB.

Large lecture rooms

Two computers are optimal in large lecture rooms: a front presentation computer and a second computer in an AV boothat the back of the room,each with the Panopto software installed. Thefront PCcapturesPowerpointslides,while simultaneousfeeds from the projector, microphones and room camera(s) canbe captured on thePC at the back.The back PC could also take input from a wall- or roof-mounted camera.The back PC has the advantage that it is less likely to be tampered with or powered down;it can also be set up with a timetable of daily recordings that will be triggeredautomatically. Any front laptop or visualiser going into the projectors can also be wired into the back PCthrough an input card,along with a mixed audio feed coming from the public address systemin the room.


Audio
Audio is usually the most important consideration when creating a recording, but is often the most overlooked. /
  • Replay accepts only a single audio input, so all microphones must be pre-mixed before being fed into the Replay capture PC. As of Panopto version 5.0 (released December 2015), Replaycan also capture the PC audio directly, in addition to the microphone audio input. This is useful for capturing YouTube videos or other demonstrations where the PC audio output is important.
  • Often in larger teaching spaces there will be an existing amplification system. Depending on the location of the Replay 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 wireless lavalier (tie clip) microphones and flat boundary microphones. Lavalier microphones generally offer better sound quality by virtue of them being very close to the presenter’s mouth at all times, even if they walk around the stage. 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 Replay will fail to record at all if there is no audio source.
  • Boundary microphones 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).
  • The golden rule is to get the microphone as close as possible to the presenter’s mouth. A £50 microphone placed a metre from the presenter will sound far better than a £1000 microphone placed at the back of the room.


Cameras
Although audio and screen capture is often sufficient, a camera is required to capture blackboard or whiteboard writing. /
  • Replay is compatible with a wide range of cameras, from internal or 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 Replay, 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 manned by a member of staff.
  • Instead, a permanent, wall-mounted solution is recommended. Pan-tilt-zoom (PTZ) cameras are fully controllable via either a web interface or remote control, and usually have zoom lenses with a long range (10x or 20x) so these are ideal for placing at the back of a large teaching space. However, they tend to be quite expensive, in the region of £2-5k each depending on resolution, features and zoom range.
  • Bullet or dome-style network IP cameras are typically cheaper and more discrete than PTZ cameras, but have a smaller zoom range so are better suited to smaller teaching spaces, or should be mounted closer to the stage area.
  • PTZ cameras usually connect to the capture PC via SDI or HDMI so a video capture card is required, though IP video transfer (via an Ethernet cable) is becoming more common on these cameras. Network IP cameras transmit the video signal over the network via an Ethernet cable, which means the capture PC does not require a video capture card. Network IP cameras are usually powered via the same Ethernet cable used for video transfer, whereas PTZ cameras tend to require a separate power supply. As“power over ethernet” (POE) IP cameras require only the network cable, they are easier to install in difficult-to-reach places.
  • Provision for cabling and network points in the ceiling or at the back of the room for wall-mounted cameras. Cameras should ideally be placed centrally rather than at an angle, and cameras should not be pointed at students. A single camera per room is preferable as Replay can only display one camera at any one time, and multiple cameras force the viewer to constantly flip between camera views.


Physical space /
  • 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.


Boards for writing on /
  • Black/white/smart boards should not be located in a wide/horizontal/panoramic layout, since for automated lecture capture the camera is fixed. Although capable of panning across the room, a manual camera control requires additional staff resources.
  • Whilst the camera can be zoomed out, this will make the text smaller and often illegible. Vertical sliding boards located directly behind the lecturer are preferable.

Above: The use of wide horizontal boards (left image) necessitate that the camera remains zoomed out to ensure all writing is captured, often resulting in 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 causing the blackboard to be underexposed. Students’ heads and laptop screens are also creeping into shot, which is a privacy concern. The use of floor-to-ceiling blackboards (right image) utilise the camera frameto 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 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 (dancing dots) 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 in particular are prone to reflections of spotlights and board lights, creating a halo effect that can make writing unreadable not only on the video, but also for a live audience.

Above: Examples of board lights or spot lights making the text difficult to read (left & centre images) compared to flat, even lighting of a blackboard (right image).


IT equipment
The Panopto recorder software comes in two flavours: manual and remote.
The manual recorder can be installed on either Windows 7+ or Mac OS X 10.8+. The remote recorder can be installed on Windows 7+. /
  • Minimum specifications are:
  • Intel Core i5 quad-core (Core i7 quad-core recommended)
  • 8GB RAM (16GB recommended)
  • 500GB hard drive (1TB recommended)
  • Video capture card(s) – see below
  • Many 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. Thus 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 Replay 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 schedule information and to upload recordings. It
  • The remote recorder is scheduled and configured via a web interface, and the presenter does not need to remember to start the recording. 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 to synchronise two capture PCs running the remote recorder software to record to the same session. An example of this would be a primary instance of the recorder installed on the dedicated Replay capture PC) with audio and (optional) video inputs, and a secondary instance installed on the presentation PC or laptop to capture the screen and/or slides.
  • 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 dedicated Replay capture PC to take a feed directly from the projector. The advantage of using a secondary recording instance rather than simply capturing the projector feed is that if PowerPoint is used, the slide transitions and text are captured and automatically used as chapter markers in the recording.


Network points
Plenty of network sockets need to be provided at the front of the room and in the AV booth at the back (if there is one) /
  • Recording sessions can be in the region of 1-2GB/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 mandatory.
  • Replay always records locally to the capture PC before 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 is able to function quite well in an offline environment. The recording will upload to the server automatically once the network connection is restored.
  • The OS X manual recorder can always record offline and 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.


Cabling /
  • Cabling often needs to be changed as display technology moves from one digital format to another; it’s important to provide access conduits that allow cables to be easily changed or moved.


Other AV requirements /
  • Panel sessions often take place in large lecture rooms and it’s important to provide additional table and audience microphones for such situations.
  • Make sure that extra XLR balanced audio outputs from PA mixing boards can be provided for other recording equipment.


Control systems /
  • Front control systems simplify the job of switching on projectors, lights, and room PA by having commonly used settings as default touch-pad buttons. However they tend be quite complex and expensive to program after initial set-up, so care needs to be taken on training support staff in how to use them.
  • Guest presenters usually bring their own laptops and it needs to be easy for them to switch the projector to this input via a control pad. The projector feed from the laptop would need to captured by the PC at the back of the lecture room.

Maintenance and upgrades to AV/IT equipment

Equipment such as PC’s and laptops need to be maintained to an appropriate technological standard. This is to ensure computers function properly when being used by academics and speakers and reduce down time when setting up a computer ready for a presentation.

PC’s, laptops and projectors

-PC’s and Laptop’s should have a life cycle of 3 to 4 years. The processing speed of the laptop needs to be quick enough to handle loading and running applications smoothly such as Microsoft Office.

-Operating systems should be current or no older than 3 versions previous. Currently all laptops and PC’s 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 for this MS Office 2016.

-All computers should have at least 2 USB inputs, a HDMI input, power input, an Ethernet socket and a headphone jack. These are used for external devices such as harddrives, projectors, speakers, tablets and internet connections.

-All computers need to have their updates installed on a regular basis so that the drivers are always current when running the latest software.

-Microsoft Security Essentials needs to be installed on all machines to protect them from viruses. This is free and easily downloadable. Computers will need to be scanned once a month to ensure that the computers are free from threats.

-All projectors should be HD ready with HDMI outputs and a power outlet and a minimum colour definition of 2000 lumens.

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