IP is almost omnipresent in the media universe, owing to its ability to provide a sturdy connection in the most remote locations, with little or no lag
By Anisha Gakhar
As our lives become ever more mobile, an increasing amount of live video content needs to be captured on the ﬂy – and out in the real world. Regardless of how the content is captured – from a drone, a body camera, on the move, or in the air – one can never anticipate where and how a need may arise, to capture video in locations where there is fluctuating network without a reliable bandwidth. As widely as Wi-Fi and cellular networks are used, these media are seemingly brittle, and may cause loss in data. Enter – technology! Advancements such as connection bonding, adaptive bit-rate encoding, and dynamic forward error correction, evoke peace of mind for the media organisation.
In order to ensure that the outputted content is high quality, with as little delay as possible, one needs to solve the problem of getting the video into the cloud over IP-based technologies.
FERRYING YOUR LIVE STREAM
The two methods mostly applied for transmitting data as packets over IP networks, are TCP (Transmission Control Protocol) and UDP (User Datagram Protocol). TCP is ideal for consolidated data (like in the case of web pages and emails), but might come with its own cons like latency and additional overhead, to accomplish that which is eliminated in the case of UDP. UDP does not ensure arrival of all data, yet it can prove useful in audio and video, given the large amounts of data involved. Although not preferred, the loss of a few bytes is often inconsequential to actually seeing images and hearing sound. But what happens when the data loss surpasses the acceptable limit? It leads to everything a streamer and the viewer might despise– broken images, poor audio, buffering and ultimately dropped views.
A perfect solution scenario would be something that incorporates all of these techniques into a single, integrated protocol: TCP feedback, UDP speed, and RTP reliability – all without the delay. One needs a reliable transport over the most unreliable of networks, and tight integration with the encoder,” added Bhatti.
The LiveU Reliable Transport (LRT™) brings together techniques into one integrated protocol that works with the encoder, so one does not have to do much. This is achieved by:
LRT uses numbered packets so that they can be re-ordered when they arrive out of order. This is an absolute requirement with connection bonding, where data will almost always arrive in a diﬀerent orders than intended.
DYNAMIC FORWARD ERROR CORRECTION
Forward Error Correction adds overhead to the stream, with the idea that the small amount of additional overhead can be used to recover lost data faster than a resend. Groups of lost packets can be recovered without requesting for a resend. LRT uses a dynamic version of FEC. It automatically varies how much FEC to use, based on monitored network conditions.
ACKNOWLEDGE AND RESEND
LRT uses a form of acknowledge and resend for large groups of packets. If some fail to arrive, it can inform the streaming engine to resend needed data. By acknowledging large groups of packets at a time, the overhead and latency of TCP is not re-introduced. The packet numbers are used to let the system know what was delivered (or not).
Tight Encoder Integration or Adaptive Bit Rate Encoding
The most important piece of the LRT protocol is its tight integration with the encoder. As the bandwidth condition changes, LRT automatically recognises itand informs the video encoder to allow it to adapt the bit rate of video it is delivering and keep the best possible stream within the available bandwidth at any given moment, thus avoiding crowding.
LIVING IT ‘IP’
Producing engaging content live, requires freedom to do what one pleases to, reliably. Erratic networks and a quivering Internet bandwidth is now a hitch of the past, with the advent of IP technology. It enhances available bandwidth in the field and reliable transport protocols enhance bonding and quality almost in any outdoor location, thus enabling the focus of energy on getting great content.