What is a Codec?
A codec is software or hardware that compresses and decompresses video files. The term combines "coder" and "decoder." Codecs reduce file sizes dramatically while maintaining visual quality, making video practical for distribution across networks, broadcast systems, and storage media.
H.264 (AVC)
H.264, also called MPEG-4 Part 10 or AVC (Advanced Video Coding), is the industry workhorse. Released in 2003, it became the standard for broadcast television, streaming platforms, and digital cinema across the UK and globally.
Why it matters: H.264 balances file size and quality exceptionally well. A typical HD broadcast uses H.264 encoding. YouTube, BBC iPlayer, and most UK streaming services default to H.264 for compatibility and reliability.
When to use it: H.264 suits broadcast delivery, web streaming, and archive storage where compatibility across devices matters. If your campaign targets multiple platforms or older viewers, H.264 ensures universal playback.
H.265 (HEVC)
H.265, or HEVC (High Efficiency Video Coding), launched in 2013 as H.264's successor. It achieves roughly twice the compression efficiency – meaning smaller files at identical quality, or better quality at equivalent file sizes.
Why it matters: H.265 reduces bandwidth costs significantly, crucial for mobile streaming and 4K/8K content. As UK broadcasters transition to 4K services, H.265 becomes increasingly relevant for premium campaigns.
When to use it: H.265 excels for high-resolution content, 4K streaming, and bandwidth-constrained environments. However, older devices may not support it, limiting reach. Use H.265 when your audience has modern smartphones or smart TVs.
Apple ProRes
ProRes isn't a delivery codec – it's a professional editing codec. Apple's ProRes format prioritises editing performance over file size, offering several quality tiers (Proxy, LT, Standard, HQ, Max).
Why it matters: Editors and colourists in UK post-production facilities rely on ProRes for smooth, real-time editing without rendering delays. It preserves detail during grade and effects work.
When to use it: Use ProRes during production and post-production workflows, not final delivery. Export your finished content to H.264 or H.265 for distribution.
Choosing the Right Codec
For UK agencies: specify H.264 for safe, universal broadcast and online delivery. Use H.265 for premium 4K campaigns targeting modern platforms. Reserve ProRes for internal production workflows. Always discuss codec requirements with your production partner early – encoding choices affect timeline, budget, and compatibility.