Broadcast Contribution over IP: Network Adaptive Encoding vs Adaptive Bitrate Streaming
Dropped frames are the bane of every network and broadcast engineer, especially when relying on unmanaged IP networks for live video broadcast contribution and remote production or REMI. The internet, the network of networks, has so many different elements that can change at any given moment. Add distance to the mix, and the chance of losing frames increases exponentially. So, what can you do to ensure the delivery of high quality content for your live production workflow? Well, you’re going to have to adapt to ever-changing network conditions.
Does Adaptive Bitrate Streaming have anything to contribute?
Since it’s so hard, if not impossible, to predict precise bandwidth availability or account for sudden bottlenecks or spikes when using an unmanaged IP network, broadcast engineers need to adapt a flexible approach to dealing with fluctuating bandwidth availability and jitter.
One approach is ABR or Adaptive bitrate streaming (sometimes shortened to ABS) which relies on a transcoder to take a single high quality video source and re-encode it as multiple profiles each with different resolutions and levels of compression. The encoded video streams are then packaged and chunked into segments using an ABR protocol such as HLS or MPEG-DASH. A video player will then assign an encode to each chunk to best match the bandwidth available at a given time. Though ABR is the preferred and most flexible approach for viewing OTT content, it is not ideal for broadcast contribution as it introduces too much latency because of the buffering needed for larger chunks sizes, typically around 10 seconds long.
Deliver high quality content over IP with Network Adaptive Encoding and SRT
In an ideal world, video contribution would not have to face any bandwidth restrictions. Video could be delivered uncompressed or very lightly compressed over a dedicated fiber optic network or over a satellite link from point A to point B. Unfortunately, in the modern broadcast world, bandwidth restrictions still exist.
In most cases, especially for second tier sports, outdoor events, and breaking news coverage, broadcasters need to contend with bandwidth restrictions for their live contribution feeds. For this reason Haivision introduced Network Adaptive Encoding (NAE) on its Makito series of H.264 and HEVC video encoders.
NAE differs from ABR in that it only needs 1 encoded stream instead of a cascade of profiles with the ABR approach. In the case of the Makito X video encoder, an NAE stream will rely on SRT protocol statistics to determine bandwidth availability and reliability and adjust the compression level of the encoded stream in real-time. Combining NAE with SRT’s built-in ARQ (Automatic Repeat reQuest) error detection and correction, ensures that the highest possible picture quality is being streamed at a given time over unpredictable networks, especially the internet.
Adapt in real-time for live video
Want to learn more about Network Adaptive Encoding? Discover how you can ensure your video streams are always at their best quality, even over unpredictable networks, and find the answers to frequently asked questions. Download our free white paper, Network Adaptive Encoding, today.