Transcoders

Transcoders are devices or software that convert media data from one encoding format to another. They work by decoding the input stream or file into an intermediate representation, then encoding it into a different codec, container, or configuration. Transcoding is used to make content accessible across devices, networks, and services, for example delivering the same video to desktop, mobile, and smart TVs, or producing multiple bitrate profiles for adaptive streaming.

There are two main types: hardware transcoders and software transcoders. Hardware transcoders are specialized devices designed for real-time operation and energy efficiency, often used in broadcast headends, OTT servers, or video surveillance. Software transcoders run on general-purpose CPUs or GPUs, and can be deployed on-premises or in the cloud, providing flexibility and scalability.

The typical workflow involves decoding the input into raw video frames and audio samples, optional processing (scaling, de-interlacing, noise reduction), and re-encoding with a chosen codec and parameters. Common video codecs include H.264/AVC, H.265/HEVC, and AV1; audio codecs include AAC, MP3, and Opus. Containers such as MP4, MKV, and MPEG-TS encapsulate the streams. Transcoding settings trade off quality, latency, and bitrate; lower latency is critical for live streaming.

Common use cases include live broadcast contribution and distribution, video on demand preparation, and cloud-based ABR workflows. FFmpeg and commercial solutions provide widely used transcoding capabilities, supporting a range of codecs, formats, and streaming protocols.