It may also be a custom application or a video player supplied by the operating system (OS). In the simplest form, a streaming client can be JavaScript run by a web browser. To play the video content, user devices use special software, called a streaming client. The subsequent delivery of the encoded content to user devices is done over HTTP and by using a Content Delivery Network (CDN), ensuring the reliability and scalability of the delivery system. Such manifests are typically presented in HLS or MPEG DASH formats. Along with the set of renditions, the origin server also receives a special manifest file, describing the properties of the encoded streams. Once all renditions are generated, they are placed on the origin server. Such renditions typically have different bitrates, resolutions, and other codecs- and presentation-level parameters.

When a video asset is prepared for ABR streaming, it is typically transcoded into several renditions (or variant streams). For simplicity, we will focus on the VOD delivery case. We show a conceptual diagram of such a system in the figure below. In this blog post, we will try to answer this question by introducing the concept of multi-codec streaming and explaining key elements and technologies that we have engineered to support the Brightcove Video Cloud platform.īefore we start talking about multi-codec streaming, let's briefly review the main principles of the operations of modern-era Adaptive Bit-Rate (ABR) streaming systems. This situation begs the question: Given such a fragmented support of new codecs across different devices, how do you design a streaming system to reach all devices and with the highest possible efficiency? The AV1’s support among web browsers is higher, but notably, it is not supported by Apple devices and most existing set-top box platforms. HEVC for example reportedly only has a reach of 18.73%, pointing mostly to Apple devices, and devices with hardware HEVC support. However, in practice, these new codecs can only reach particular subsets of the existing devices or web browsers. In theory, such gains should lead to a significant reduction in the costs of streaming. Both claim at least a 50% gain in compression efficiency over the H.264/AVC. In recent years – two new codecs have been introduced: HEVC from the ITU-T and MPEG standards groups, and AV1 from Alliance for Open Media. However, as far as technology is concerned, this codec is pretty old. Developed in the early 2000s, this codec has become broadly supported on a variety of devices and computing platforms with a remarkable 97.93% reach.

During the last decade, the majority of video streams sent over the Internet were encoded using the ITU-T H.264 / MPEG-4 AVC video codec.

Video codec meaning