IT: How does it work

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General Background
Echo360 is centrally managed lecture capture system which offers three different ways of recording lecture material, Personal Capture, Podium Capture and Capture Appliance.

Personal Capture software allows users to record material on their own laptop or desktop wherever they might be located and publish it via the same path as their classroom recordings. It can record the screen content, video from a webcam and audio but it cannot be scheduled in advance.

Podium Capture software runs on the PC classroom machine. It can record any content presented on the computer as well as audio and it can be scheduled in advance.

The Capture Appliance is an external box that can accept VGA, Composite/S-Video and audio inputs and it can be scheduled in advanced.

During this trial we are testing all three recording options, however our highest priority has been focused on the Capture Appliance solution and it is this solution that is explained in greater detail below. That said, the server and playback processes are the same for all three, it is really just the recording experience that is different.

Recording
The Echo360 Capture Appliance is a one rack unit sized external box which accepts pre-existing feeds from our smart classroom console. It has an internal 80GB hard drive and runs an embedded Linux operating system. It has VGA, Composite/S-Video and RCA/TRS 1/4” audio inputs (see image below of the back panel of the Echo360 Appliance Box).

Image of back of Echo 360 appliance box

The projector feed is directed into the box via the VGA input. Any material that is presented on the projector is recorded (for our dual-screen rooms, only whatever is presented on the stage left projector is recorded). Although we do not use it in this way, the box can be setup as a pass through as it also has a VGA output. The VGA input is captured in MPEG-4 AVC/H.264 at up to 5fps, encoded at 1024kbps Constant Bit Rate (CBR). It can capture at resolutions up to 1920×1200.

Any video camera or switcher that can output a S-video or composite video can be fed into the appliance box. Although the box has a USB jack, this is used for software installs and cannot be used with a webcam. To use a webcam the feed either needs to be converted to S-video or composite or the camera needs to run through the console computer. Video is captured in MPEG-4 AVC/H.264 at 15fps, encoded at 512kbps CBR. The image is captures at a resolution of 320×240.

The RCA/TRS 1/4” audio inputs accept a line level signal. We have configured our console mixers to allow for two signals in the classroom with one going to the room and the other into the Capture Appliance. This allows the professor to mute the microphone to the room and still record into the box, which works well in rooms where the speaker does not need amplification. Audio is captured in AAC, sampled at 22kHz mono and encoded at 64kbps CBR.

The total file size per hour of the recording is roughly 400MB. The VGA input requires about 200MB, the audio 50MB and the video 150MB per hour.

Once the box is installed in the room, connected to the internet and powered on it will contact the Echo System Server (ESS) to retrieve scheduling, security and static IP information. With this information, the box can begin recording and can be monitored via a web browser interface. The ethernet connection also allows the console’s Crestron touchscreen controller to talk with the box. This allows recording feedback on the controller.

Recordings can be pre-scheduled or ad-hoc. Scheduling takes place in the ESS and can be setup as a repetitive or single recording. Metadata for the recording can also be assigned in the ESS scheduling. Once a schedule is made in the ESS, an update is sent to the Capture Appliance box containing all the information for the recording. This process takes place as soon as the schedule is created which means the box should never be more then a few minutes out of sync with the full schedule.

For scheduled recordings, a countdown clock will appear in the lower right hand corner of the Crestron controller 5 minutes before the start of the recording (as shown in the image below). Once the recording begins, the countdown clock turns into a ‘Recording’ button which, if pressed, pauses the recording. The Echo360 system is synced to the UT time server, which allows pre-scheduled recordings to start and end within a few seconds of the bell system.

Crestron Record button

Once the recording is finished, it is automatically uploaded to the ESS for processing. The box can upload and record simultaneously so no extended breaks are needed.

Server
Once files are uploaded to the ESS the processing begins. During the scheduling procedure, a workflow is setup for each course which includes different options for playback including mp3 (podcast) and flash (streaming presentation). The ESS will process the uploaded files to match the options selected for the course. If a different type of playback file is wanted, recordings can be reprocessed.

During processing the AAC course audio and H.264 video and VGA files are converted to whatever output option is desired. For most of our recordings, we use the streaming flash presentation. Processing takes between 1-3 hours per recording depending on the number of recordings being processed at the time and the length of each recording.

Once processed the file is published. The ESS supports a number of different publishing options including Blackboard, Moodle, iTunes U, RSS feeds or email notification. Publishing can happen automatically or manually.

Playback
Once a recording is published, a notification is sent to the student. For most of our courses, students receive this notification announcement within Blackboard. The announcement contains a link to the recording. Once a student clicks on that link, a background authentication check takes place. If the student is enrolled in the course, a new page opens and loads the recording. This background authentication check works via a secured handshake between the ESS and Blackboard.

The flash streaming presentations are handled by a Wowza server (software provided by Echo360).

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