Adaptive Bitrate (ABR) Video Streaming for HD Broadcasts

Definition: Adaptive Bitrate (ABR) video streaming: where the streaming video display adapts itself automatically to the viewing capabilities of the end-user in order to maximize an audiences’ viewing experience regardless of their connection speed or which device they use to playback streaming content.

ABR technology allows your viewing audience to watch the Webcast in the definition of their choice – from High Def to Standard Def and all the way down to Mobile devices, depending on the speed of their Internet connection. Call us to find out how we can harness this powerful technology to improve your audience’s Live Stream Experience…

ABR Streaming

These devices & connections range from the more traditional Web browser interface of a desktop or laptop PC, to tablets, mobile phones and even Internet-connected TV sets. Each device & type of Internet connection has different capabilities in terms of their efficiency in displaying streaming video without hiccups or interruptions.

For example, a desktop PC with a high end graphics card with its own dedicated on-board memory and a gigabit ethernet connection running on a high-speed broadband Internet connection would be able to playback high-definition (HD) video at high resolutions and bitrates, whereas older mobile phones or older laptops running on a slow WiFi or satellite connection in the boonies would just freeze up at those speeds.

So what is Bitrate?

The digital terminology for data is bits, and the amount of data that can be delivered in a set period of time is the bitrate. (8 bits make a byte, 1000 bytes make a kilobyte, 1000 kilobytes make a megabyte – and so on…)

So Bitrate is simply the number of ‘bits’ of data that stream through per second. The higher the bitrate the better the quality of the video – but it also consumes more resources and needs a much faster connection to allow it to stream without any interruption or disruption.

Bitrate is also connected to video resolution – high definition video contains more ‘bits’ packed into a single second and therefore requires a higher bitrate to display well. Lower resolution video contains less bits and is therefore lower in quality but can stream smoothly through a slower internet connection.

Given a specific format (codec) of video content, which we won’t go into here, the more data that can be delivered over a specific time period, the higher the resolution and quality that can be displayed in a given stream. This is true in traditional broadcasting and also applies in the case of digital delivery.

So how does ABR work?

To put it very simplistically, the technology at the publishing end detects the speed of the individual consumer and decides how strong the bitrate/resolution should be to afford that viewer an ideal, non-interrupted stream. This can not only be handled by the publishing technology but in many instances can also be a function of the media player.

The ideal experience is one where the video playback is smooth and makes full use of all available bandwidth, computing resources, and display resolution in a process transparent to the consumer.

There are various ways in which media players make decisions about the most appropriate rendition at any given moment. Some simply look at the length of time it takes to download bits of the video; this only takes connection speed into account, without computing resources or screen resolution. Others periodically try higher bitrate renditions and prepare to react quickly to playback issues (buffering, pixellation, etc.) of any kind by switching to lower bitrates.

This takes all resources into account, but necessarily leads to some issues as the player tests the waters, so to speak, using higher-bitrate renditions. Finally, more sophisticated media player systems perform complex functions, such as server-based network monitoring and trend analysis based on an audience member’s geographic location and Internet Service Provider, rendition pre-fetching, switching between physical sources for renditions, etc. In any case, the ability of the media player to appropriately select renditions to display is critical to a good audience experience.

There are four main implementations of ABR:

  • Adobe Dynamic Streaming (Flash)
  • Apple HTTP Adaptive Streaming (also known as HTTP Live Streaming or HLS)
  • Microsoft Smooth Streaming
  • Dynamic Adaptive Streaming over HTTP (DASH or MPEG-DASH).

Without going into too many technical details, the main differences between these implementations are the technology required to create (encode) them and the playback interfaces that support them.

So how does one offer ABR to one’s viewers?

Creating single-bitrate content is a relatively straightforward process. A broadcast video signal (usually for the lowest common denominator) is used as source material, fed into an
encoder (or transcoder) and the resulting stream is delivered. ABR however, requires the creation of multiple renditions of the same video which makes things more complicated. This is partly due to the amount of content being created – usually three or more files, instead of just one, but also because the renditions must be well synchronized with each other; otherwise, switching between them will not work well.

For this reason, all the versions must be created simultaneously and, if there are any issues with any of them (e.g., a file is corrupted for some reason), they all need to be recreated from scratch.

This takes enterprise-class encoding software/hardware and it also means that the production process takes longer and is that much more expensive than the single-bitrate type. Ensuring quality of ABR content is also more difficult, as three to ten streams (plus the manifest file) must be checked prior to final publishing, as opposed to just one.

THE BUSINESS CASE FOR ABR: Cost vs. Revenue

COST:

Storage costs are three to ten times greater than for single-bitrates. In addition, unlike conventional broadcasting, the cost of delivering content to digital audiences scales linearly with consumption. A content producer literally pays for each bit of data delivered to their audience.

Typically, ABR audiences consume bitrates two or three times higher than producers make available for single-bitrate consumption. This means that, when dealing with consumption of the same content, ABR delivery costs can be two or three times higher because it consumes 3-10 times more bandwidth for the upload and download streams. As such, a producer can expect the delivery costs to be closer to four or five times greater than single-bitrate.

REVENUE:

The difference between ABR and single-bitrate streaming in terms of revenue potential is that ABR audiences tend to be more engaged and thus advertising, subscriptions and pay-per-view rates can be set higher.

The revenue benefits of each broadcast must be evaluated on a case by case basis as they are partially offset by the increased cost of production.

Have a look at our packages and pricing page to see how ABR Streaming will impact on your cost of production or give us a call if you would like to discuss its pros and cons with regard to your events.