Transcoder

Common mobile devices such as smartphones, tablets or PC connect through different networks (NAT networks, Wi-Fi access points, 3G and LTE networks, etc. ), which seldom support network protocols without status control features, like UDP or RTP. For this reason, and also to ensure an appropriate service, the use of TCP-based transmissions is usually a mandatory requirement.

Moreover, this type of networks do not usually provide a guaranteed bandwidth, which produces instability and video streaming (or buffering) cut-outs. By using adaptive streaming, the video stream will dynamically adapt to the network resources available at any given time, thus delivering the highest possible quality.
Another significant advantage of adaptive streaming is the fact that it ensures video playback on any device, since the device itself - based on its resources and limitations - will be requesting the appropriate video stream.

In order to offer this set of services, the use of a Transcoding process is required; it aims at transforming video, audio or any data track streams. This transformation allows for the use of different coding standards, each compliant with different requirements or limitations.
The video transcoding process consists in the intake of video streams, their decoding, their further processing or transformation (resolution, aspect ratio, sampling rate, etc.), and finally their new coding. The audio transcoding process is very similar to the video transcoding process, the difference being that the main transformation processes consist in the re-sampling and the channel mixing.

Two functions on a single equipment: Transcoding and Streaming.
The equipment can either behave as a transcoder (to adapt channels to the output requirements), a streamer (to deliver the HLS-transcoded contents), or both.