Why smoother video streaming needs more than just faster internet

From video codecs such as AV2 to browser engines and hardware decoding, streaming videos smoothly involves more than faster internet. Here is how the technology behind web video works

YouTube plans to begin streaming videos using AV2, a next-generation video codec, on its web platform as early as 2027. Developed by the Alliance for Open Media (AOMedia), AV2 promises around 30 per cent greater compression efficiency than its predecessor, AV1, potentially allowing streaming platforms to deliver better picture quality without increasing bandwidth requirements.

 

The announcement marks an important step towards the adoption of a new video compression standard. Netflix and Amazon Prime Video are also exploring AV2, while Google has demonstrated playback support for the format in Chrome. The development could eventually affect how video is delivered across websites, streaming services and other internet-based applications. 

However, a more efficient codec does not automatically translate into lower data consumption or smoother playback. Before viewers can benefit from AV2, browsers must be able to process it, streaming platforms must encode and deliver compatible video, and consumer devices must decode it without excessive demands on their processors and batteries.

What is a video codec, and why does it matter?

A video codec, short for coder-decoder, reduces the amount of data needed to represent a video and reconstructs the images during playback. Without compression, transmitting high-resolution video over the internet would require considerably more bandwidth.

 

Compression algorithms identify redundancies within individual frames and across successive frames. Instead of transmitting every pixel independently, a codec can represent changes between frames and use other techniques to reduce the information that needs to be sent.

 

A more efficient codec can deliver comparable picture quality using less data, or improve picture quality without increasing the bitrate. For streaming platforms, this can reduce bandwidth requirements and distribution costs. For viewers, it can help maintain playback quality when internet connections are slow or unstable.

 

H.264, also known as Advanced Video Coding (AVC), became widely adopted for online video because it offered a balance between compression, playback performance and device compatibility. High Efficiency Video Coding (HEVC), or H.265, improved compression and became important for high-resolution video, including 4K content. However, patent licensing arrangements have been among the factors influencing companies' decisions about adopting alternative formats.

 

AOMedia subsequently developed AV1 as a royalty-free alternative. Backed by technology companies including Google, Amazon and Netflix, AV1 improved compression efficiency over earlier formats and has been adopted by major streaming services.

 

AV2 builds on that foundation, aiming to deliver further efficiency gains while supporting applications ranging from conventional streaming to multi-view video and immersive media.

What could AV2 improve beyond picture quality?

According to the Alliance for Open Media (AOMedia), AV2 can deliver comparable visual quality with approximately 30 per cent better compression efficiency than AV1 across a range of content types and resolutions. Streaming services could use these gains to improve picture quality at existing bitrates or reduce the amount of data required to maintain comparable quality.

 

For viewers, the potential benefits include clearer video, less buffering under difficult network conditions and lower bandwidth requirements for high-resolution playback. At scale, even modest reductions in the data required for individual streams could help streaming companies manage network capacity and distribution costs.

 

However, the 30 per cent improvement should not be interpreted as a guaranteed reduction in internet data consumption. Compression efficiency depends on factors such as the content being encoded, resolution, bitrate and quality settings. A static scene may be easier to compress than a fast-moving sports broadcast, while different encoding settings can produce different results.

Streaming services may also choose to use the efficiency gains to improve picture quality, support higher frame rates or deliver more detailed video instead of reducing the bitrate. Actual data consumption will continue to depend on the resolution selected, adaptive streaming decisions and the service's encoding policies. A viewer watching higher-quality video after AV2 becomes available could use as much data as before, or more, even if the codec itself is more efficient.

 

The potential benefits extend beyond conventional streaming. AV2 is being developed to support applications such as multi-view video, screen content and immersive media. More efficient compression could make experiences involving several simultaneous video feeds less demanding on network bandwidth, although the actual gains would depend on how the feeds are encoded and delivered.

 

Video conferencing is another potential application. Calls involving multiple participants, high-resolution feeds or screen sharing can place considerable demands on networks and computing hardware. Better compression could improve picture quality at a given bitrate or reduce the bandwidth required to maintain an acceptable experience.

 

However, compression is only one part of the equation. Real-time applications also depend on encoding speed, network latency, error recovery and the ability to decode incoming video without delays. A codec optimised for recorded video may not deliver the same practical benefits in a live interaction.

 

Ultimately, AV2's efficiency gains could help streaming services deliver better-quality video, reduce distribution costs and support more complex video experiences. How much viewers benefit will depend on how platforms use the technology and whether browsers and consumer devices can support it efficiently.

Why the browser is becoming part of the video equation

A codec specification does not, by itself, make a format usable across the web. Browsers need compatible decoding implementations, while operating systems and devices must provide the necessary capabilities. Streaming services must also encode and deliver content in the format.

 

Browser engines, including Chromium's Blink, Apple's WebKit and Firefox's Gecko, handle the underlying technologies that make websites work. Their codec implementations, operating system integrations and access to hardware decoding can influence whether a video format works on a particular device.

 

Support on one platform does not guarantee compatibility with another, even when the devices have similar specifications.

 

Web technologies help applications assess and use the capabilities available to them. The Media Capabilities API, for instance, allows websites to check whether a particular media configuration is supported and whether playback is likely to be smooth and power-efficient. The assessment can take into account parameters such as codec, resolution, bitrate and frame rate.

 

This can help a streaming service select a suitable version of a video instead of assuming that every viewer can play the same file.

 

The WebCodecs API provides another part of the infrastructure. It gives web applications access to low-level video and audio encoding and decoding capabilities, including frame-by-frame processing. This can be useful for browser-based video editors, live-streaming tools and video conferencing applications.

 

WebCodecs is not a universal switch that makes every codec available in every browser. Its functionality depends on the codecs and configurations supported by the underlying platform. It also does not eliminate the need for streaming services to encode and deliver compatible content.

Why hardware decoding matters

Modern processors, graphics processors and system-on-chips often include dedicated video decoding hardware. These components are designed to handle supported formats more efficiently than a general-purpose processor running the same task in software.

 

Hardware decoding can reduce processor utilisation, heat generation and battery consumption. This is particularly important for laptops and smartphones, where demanding video workloads can affect performance and battery life.

 

Software decoding, by comparison, relies on the device's general-purpose processor to reconstruct video frames. It can bring support for a new format to devices that lack dedicated decoding hardware, provided their processors can handle the workload. However, it may increase power consumption and make high-resolution or high-frame-rate playback more demanding.

 

YouTube's planned AV2 rollout is significant partly because it is expected to begin before dedicated hardware support becomes widespread. Initial playback could rely on software decoding, allowing the format to reach compatible desktop browsers before AV2-capable processors become common.

 

That does not mean every existing computer will be able to play AV2 smoothly at every resolution. A desktop processor may handle software decoding more comfortably than an entry-level smartphone or a thin laptop, while the demands increase with resolution, frame rate and video complexity.

 

Dedicated hardware support will therefore remain important for widespread adoption, particularly on mobile devices and televisions. Chipmakers must incorporate suitable decoding capabilities into their processors, while operating systems and browsers need to expose those capabilities to applications.

Why new codecs take time to gain adoption

The history of video compression shows that technical improvements alone do not determine which formats become widely adopted.

 

H.264 remains important because of its extensive support across browsers, operating systems, cameras, televisions and other consumer devices. HEVC has a significant role in high-resolution video, while AV1 has gained traction as streaming services and device manufacturers have invested in support for it.

 

Replacing a codec involves more than updating a specification. Streaming platforms must encode content in the new format, maintain delivery infrastructure, test playback across devices and manage the complexity of supporting multiple versions of the same video.

 

Encoding can itself be computationally demanding. A streaming platform may need to process a large catalogue in several resolutions and formats, with different versions available for different devices and network conditions. The costs of generating and storing those versions must be weighed against potential savings in bandwidth and distribution.

 

Licensing arrangements also influence adoption. AOMedia's AV1 and AV2 specifications follow a royalty-free patent policy, intended to make the formats easier to adopt without conventional codec licensing fees. Royalty-free does not necessarily mean every implementation is free of all legal or commercial obligations, but it can influence the economics of adoption.

 

The experience with AV1 offers a useful comparison. YouTube has invested in encoding infrastructure and compatibility to make the format available across a substantial portion of its catalogue. AV2 will require similar coordination between streaming platforms, browser developers, chipmakers and device manufacturers.

 

Its availability on YouTube's website will not automatically mean that the format is supported in the smartphone app, on a smart television or by another streaming service. Each platform has its own software stack, hardware constraints and deployment requirements.