This report discusses the different processes employed during the preparation and execution of the live stream event conducted as part of the assessment for this module on the 11th of May 2019.
Live streaming involves a couple of steps and processes, this event follows the eight (8) streaming zones or stages namely media content, media transfer, media capture, encoding, uplink, streaming server, broadcast and playback.
The content
Leveraging the Karis Sportfest Outside broadcast event, this live stream used the football match as its content and streamed the game live on the karis website and YouTube. The streamed event had over 300 viewers.
When planning for a live stream, depending on the type of event and budget in place, the following key factors are to be considered.
- The event flow – the running order of the event.
- Video and Audio source – How the event will be captured, types of cameras and microphone to be used.
- Internet – What is the available upload speed for uplink the captured media content to a streaming server for distribution.
- Contingency – What are the plans in place for any technical or internet failure.
During the planning phase of the football match, the site recce of the location “the forest recreation ground” was carried out ahead of time and camera positions decided.
Suitable cameras and microphones (for pitch side effect) for the event were agreed with CloudBass (the OB company).
Days prior to the event pre-match and post-match video graphics were created using Adobe After Effects and encoded using H.264.
The Event
On arrival to the location of the event, a speed test to ascertain the upload speed on the mobile network facility intended to be used for uplink was done, see Figure 1. The results from this test was used to determine a suitable bitrate for the live stream.
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| Figure 1 - Speedtest results at the live stream location |
This event was a four-camera production, after powering up and setting up the production truck, the cameras to be used were positioned as specified in the camera plan contained in the planning sheet see Figure 2.
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| Figure 2 - Event camera plan |
Transfer and Capture
- The cameras were connected to the production truck using Triax cables.
- The video feeds from the cameras were routed to the video mixing desk in the truck.
- A clean PGM output with embedded audio from the pitch side mics patched via the audio mixer also in the truck was routed to an SDI output for ingest into the streaming PC.
Capture and encoding
The streaming PC had a blackmagic capture card onboard and Wirecast installed.
- The clean PGM feed from the OB truck was connected to the streaming PC using an SDI cable via the capture card and added as a video input into Wirecast.
- The two other videos prepared for pre and post-match were also added to Wirecast, see Figure 3.
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| Figure 3 - Wirecast with all video inputs |
Encoder configurations
With the video sources all added to Wirecast, the encode was configured and output destination set. Figure 4 shows the configurations used for the streaming.
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| Figure 4 - Encoder setting used for the live stream |
The choice of Wirecast as the encoder was because the event was sent to two different server destinations at once, a feature readily available in Wirecast among many others.
During the configuration of wirecast, when the software encoder was used the CPU usage hitting almost a 100%, causing massive frame drops, this made the stream unwatchable, see Figure 5.
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| Figure 5 - Wirecast software encoder |
Because of this the hardware encoder was used instead. As you can see from Figure 6 the CPU usage was below 20% and there was only 1 frame drop. The stream also played smoothly.
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| Figure 6 - Wirecast Hardware encoder |
Uplink
As mentioned earlier, see Figure 1, the location had a very good mobile network coverage on Virgin Mobile, the network provider on the network devices used for uplink. The upload speed was stable and steady throughout the stream. The bitrate used for the stream was 2500 kbits/sec
The available bandwidth on the network device was more sufficient (over 150GB) for the duration of the event and stream. There were also 2 backup mobile devices in the event of a network failure on the main device.
Streaming server configuration
Wowza streaming engine was configured and setup for this event. The Wowza developer licence used for the server has a limitation of 10 concurrent connections at any given time, so because of this limitation YouTube Live was also configured to accommodate the number of expected viewers.
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| Figure 7 - Wowza streaming engine installation |
The YouTube stream also provide additional advantages on the fly such as adaptive bitrate streaming serving multiple bitrate of the original stream sent from the encoder, multiple platform and device ready.
Broadcast
From the wowza streaming engine hosted on a private cloud server the ingest RTMP stream was transcoded and distributed as HLS and DASH streams.
The same was also the case for the YouTube stream. Utilizing the YouTube streaming service offered many benefits including the use of it wide content distribution network to send high quality video to viewer around the world with minimal latency. Figure 8 shows the YouTube page
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| Figure 8 - YouTube page showing the LIVE stream |
Playback
For the streaming coming from the wowza streaming engine, a html5 video player Radiant Media Player was configured and embed on the Karis website. Figure 8 & 9 shows a screenshot of the player on the Karis website and the player setup script.
Radiant Media Player is unique as it supports both HLS and DASH stream in the same player configurations and works on a wide range of devices and platforms.
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| Figure 9 - Radiant Media Player Embedded on the Karis Website |
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| Figure 10 - Radiant Media Player setup script |
Test Stream
Shortly after setting up and configuring the streaming a test stream was started at about 11:30am and continued until after the main match was completed and winning medals presented. According to the YouTube Live playback the stream lasted for a total of 3hrs40mins.
Conclusion
The Live stream was very successful, a has been learnt throughout the planning and implement of this live stream and the streaming media module in general has been a truly enjoyable module.
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