NaSTAvision

At a Glance

Hardware:

  • Blackmagic ATEMs
  • HD Broadcast Studio
  • Makito Encoder
  • Wowza Server
  • Grass Valley T2

Software:

  • Final Cut Pro X
  • Edius 6
  • JWPlayer
  • WordPress
  • MXLight
  • VLC

My Roles:

  • Producer
  • Web Player Development
  • Broadcast Engineer
  • Editor

Project Overview

NaSTAvision 2013 was the first ever live music competition between student TV stations in the UK. Staffs TV was one of the two hosts stations meaning that they had to handle the organisation and production of the show.

It was an extremely ambitious project that would include the show being split between two studios on different sides of the country and having entries both send in via VT and by live stream in some cases.

Workflow Overview

The system that allowed NaSTAvision to go live was designed by myself and included a method of splitting the broadcast between the two stations, having an outside broadcast at the Staffs TV end and having the external stations stream their entries in.

The first step was to build a transmission centre, in which all the various feeds would be received and then mixed down into the final stream. This was built around a Blackmagic ATEM Television Studio with various laptops connected to it via HDMI. Each laptop would be decoding an input stream using VLC media player. An additional HD-SDI input was used to directly bring in the footage from the Staffs Studio.

The input streams received by the Transmission centre were:

  1. SonarTV (co-hosts) Transmission
  2. Outside Broadcast
  3. External Stations A
  4. External Stations B

The outside broadcast system was also designed using a Blackmagic ATEM Television Studio. However, this time each of the inputs was one of our Panasonic HMC-151 cameras, along with an audio mix down of the venue.

The OB feed was streamed back to the studio over the university’s network, however this did not require an external encoder. Instead, the ATEM has an internal H.264 encoder and using the MXLight software I was able to set the encoder to make a 5Mb/s 1080i stream that was both recorded and streamed.

The final transmission was encoded at two qualities in the encoder (HD and SD) and sent to our Wowza Server. The server generated both a RTMP and HLS stream that were received inside JWPlayer. This allowed the show to be watched on both Flash capable devices and iOS devices.

I also wrote a Javascript file that could control JWPlayer to carry out the following two functions:

  • Split the audience between the two streaming servers based on random number generation
  • Automatically switch the viewer to the other server if they lose their connection

Once the broadcast was finished, each station that had taken part sent across their high quality recordings of whatever they had broadcast. These were then taken into Final Cut Pro X and the show was re-edited together using the full quality material. This allowed us to upgrade the on-demand show to be full HD (when possible) but also much smoother as any mistakes and delays could easily be removed.

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