Livestreams - Technical Information

Index

• Context
• Native Service
• RTMPS (Third Party Broadcasting)
• Viewers
• Protocols/Ports
• Frequently Asked Questions

Context

The Workvivo Platform currently supports 2 Types of Livestreams:

• Native Livestreams where the Client broadcasts the Livestream directly within the Workvivo Product.
• RTMPS Livestreams where the Client will use a Third Party tool to Broadcast the Livestream to the Workvivo Platform, such as OBS Studio/ Zoom.
• The Attendee / Viewer Experience for both Native and RTMPS Livestreams is built upon Amazon IVS Low-Latency Streaming Service and Amazons IVs Chat Service.
• Video ingestion and distribution run over Amazon IVS’s Content Delivery Network (CDN). The CDN is specialized and highly tuned for low-latency video. This enables Amazon IVS to provide customers with end-to-end, high quality video served to a global audience with minimal delay at large scale. The video CDN has global Points-of-Presence (PoPs), allowing broadcasters and viewers to be geographically dispersed.
• Regardless of the AWS region where you chose to configure your Amazon IVS resources:
  • Streamers automatically ingest video to a PoP geographically close to their location.
  • Viewers stream video via the global video CDN.

Native Service

Workvivo's Native broadcast functionality is powered by Zooms Global Video Platform and Amazon's IVS service.

Bandwidth Requirements

The source input will define the upper bitrate and we support up to a maximum of 1080p60 at 8.5Mbps. In a Single Host configuration the Workvivo Application will broadcast in HD in 1080p.
In a Multi Host configuration each individual Host is broadcasted at 360p and combined for broadcast to IVS.
The Viewer experience implements an ABR ( Adaptive Bit Rate ) and bitrate for viewers will depend on the source input and the viewer’s network conditions. This is detailed in the FAQ below.

Host Firewall Requirements

Network and firewall Requirements are documented here under 'Firewall rules for Zoom Meetings and Webinars'. The Host Machines must implement both Host and Viewer Firewall Rules.
 

RTMPS (Third Party Broadcasting)

Workvivo's RTMPS Livestreaming functionality enables you to broadcast a live feed into Workvivo via our RTMPS server. The viewer experience is powered by Amazon's IVS service.

Host Firewall Requirements

Thirty Party Broadcasting tool will define the firewall requirements. Please review Third Party Broadcasting tool's documentation for full a breakdown of firewall requirements. The host machine must also implement the viewer requirements below. When initiating an RTMPS Livestream, the Workvivo product will provide a Streaming URL and Streaming Key to connect the Third Party product to Workvivo/Amazon IVS. More on this setup here.

Viewing a Livestream

Viewers / Attendee Firewall Requirements

All interactions for User connecting to view a Livestream utilize technologies and protocols Native to the Client Browser. Traffic is secure in transit using TLS 1.3 utilizing both the HTTPS and WSS Protocols.

Protocols/Ports

Frequently Asked Questions

When planning a livestream to >15,000 people, please let Workvivo know at least one week in advance so that we can ensure your livestream is as seamless as possible. Please include the breakdown by audience and location. You can submit a request to notify us of the above. If the audience size is smaller than 15,000 people we do not need to be notified.

• For optimal performance and reliability, Workvivo recommends streaming at 720p (HD) with the following settings:
  • Resolution: 1280x720
  • Bitrate: Up to 4.5 Mbps
  • Frame rate (FPS): 30 or 60
  • Keyframe interval: 2 seconds
  • Codec: H.264 (video), AAC (LC) (audio)
  • Bitrate control: CBR (Constant Bitrate)
• This setup offers a strong balance between video quality and bandwidth usage, and is well supported across most networks, browsers, and devices.
• NB: If bandwidth capacity on your network is not a concern, higher resolution streams are acceptable; however, Workvivo Livestreams has a maximum ingestion capacity of 8.5 Mbps

Is the Service Unicast or Multicast ?

Unicast

How does the Service support global delivery?

Video ingestion and distribution run over Amazon IVS’s Content Delivery Network (CDN). The CDN is specialized and highly tuned for low-latency video. This enables Amazon IVS to provide customers with end-to-end, high quality video served to a global audience with minimal delay at large scale. The video CDN has global Points-of-Presence (PoPs), allowing broadcasters and viewers to be geographically dispersed.

What are the bandwidth requirements?

The source input will define the upper bitrate and we support up to a maximum of 1080p60 at 8.5Mbps.

What are the viewer bandwidth requirements?

Workvivo's RTMPS Livestreaming utilizes an ABR ( Adaptive Bit Rate ) and bitrate for viewers will depend on the source input and the viewer’s network conditions. The player within the Workvivo product will automatically adjust the bitrate and Frame Resolution based on the underlying network conditions.

Resolution/Bitrate/FPS

The stream’s resolution largely determines its bitrate and frame rate (frames-per-second, or FPS). Use the following guidelines; these are our recommendations. Note the resolutions shown below are landscape orientation (horizontal x vertical), so reverse these for portrait orientation.

Bitrate, FPS, and resolution are interrelated. The optimal values depend on circumstances and can be complicated to determine. Our best guidance is to start with the values above and experiment if desired. The goal is clear and smooth motion of video components during streaming and good resolution within the available bandwidth. Increasing frame rate and/or resolution increases overall video quality, but this is necessarily limited by bandwidth.

• To estimate the bandwidth needed for viewers on a shared network (e.g. office location):

• For example, if you're streaming at 720p (up to 4.5 Mbps) and expect 100 viewers in one office:

• This means your network should be able to support at least 450 Mbps downstream to ensure a smooth viewing experience for all attendees.
• Tip: If viewers are spread across different offices or locations, calculate bandwidth per location based on expected attendance.

How is the Livestream securely delivered to the Client Browser?

The Workvivo application generates an individual One Time Use Playback Token for each User when they attempt to connect to the Livestream within Workvivo. When a User clicks to join a Livestream the application validates that the User is within the invited Audience and generates the one time use token. The AWS documentation on implementing secure access to a Private Channel within Amazon IVS is linked here; https://docs.aws.amazon.com/ivs/latest/LowLatencyUserGuide/private-channels-generate-tokens.html

Are there any Quality of Service (QoS) recommendations or best practices?

• Minimizing Latency
  • When Broadcasting using a Third Party Tool there are a number of options to improve the quality. These are documented within the Amazon IVS documentation. https://docs.aws.amazon.com/ivs/latest/LowLatencyUserGuide/streaming-config.html
  • Workvivo supports low latency (< 5 second) livestreaming that is compatible with most streaming applications with minimal configuration required. The following are the recommended settings for the lowest latency on your livestreams:
    • For the video encoding, set the “Keyframe” or “IDR” to a 2 second interval (you can also set to 1 second for even lower latency, but you may see more buffering or dropped frames for viewers due to increased resolution switching on the adaptive bitrate streaming player we use for viewing Workvivo livestreams.
    • If an option is available for “zero-latency tuning” within an x246 configuration, enable this.
    • Ensure that buffer size (VBV) does not exceed the average bitrate (kbps) of the stream.
  • We strongly recommend you don’t use stream forwarding services to broadcast to Workvivo as these will cause significantly higher latency on your streams.
  • Always stream directly to Workvivo via RTMPS for the best results.

• Encoder Settings

  We support H.264 for video and AAC (LC) for audio, ingested over RTMPS using TLS 1.2 or later. Your encoder must connect to our endpoint over the TCP port 443. We recommend always including the port number in the RTMPS URL. We do not support broadcasting over a non-encrypted RTMP port. The following are our recommendations for optimal bitrate, FPS and keyframe intervals:

  • Full HD 1080p quality (1920x1080) Up to 8500 Kbps bitrate 30 or 60 fps 2 seconds keyframe interval
  • HD 720p quality (1280x720) Up to 4500 Kbps bitrate 30 or 60 fps 2 seconds keyframe interval
  • SD 480p quality (852x480) Up to 1500 Kbps bitrate 30 fps 2 seconds keyframe interval
• For streaming video, we highly recommend 30 fps or 60 fps. If you are broadcasting a screen or motion video, we recommend 60 fps.
  For video settings, we recommend the following options where available:
  • H.264 level: Main
  • Scene change: Off (preferred)
  • Chroma subsample: YUV420P
  • CABAC: Preferred
  • ColorSpace: BT.709
• For audio settings, we support the following:
  • Codec: AAC (LC)
  • Bitrate: 96 kbps to 320 kbps
  • Sample rate: 44.1 Khz or 48 Khz
  • Channels: Maximum 2 - Stereo (1 - Mono or 2 - Stereo)
• We recommend using CBR (constant bitrate) over VBR (variable bitrate) to produce more predictable results. VBR will result in more frequent buffering and jittery playback. 
  Use progressive signal flows and avoid any interlaced video in production flow and/or encoding for best results.