Video codec
A video codec is a method for compressing moving pictures into far fewer bits and then rebuilding them on the viewer's screen. Raw video is enormous, so a codec removes detail the eye barely notices and repeats between frames. H.264, HEVC, VP9 and AV1 are widely used video codecs. Each one trades file size, image quality, encoding speed and device support differently.
Why it matters
A video codec sets the cost of every minute you store and stream, and the quality viewers see. Picking a newer codec can lower bandwidth bills, but only for viewers whose devices can decode it, so most platforms run more than one.
How it works
- The encoder splits each frame into blocks of pixels.
- It predicts each block from nearby pixels or from earlier frames, and keeps only the difference.
- That difference is simplified by rounding away fine detail, which is where most size savings come from.
- The remaining data is packed tightly into a bitstream that a matching decoder can turn back into frames.
What is the best video codec?
There is no single best video codec; it depends on your audience and budget. H.264 plays almost everywhere. HEVC and AV1 produce smaller files at the same quality but need newer devices, and AV1 takes more computing time to encode. Many services encode popular titles in AV1 or HEVC and keep H.264 as the fallback.
Is AV1 better than HEVC?
AV1 usually compresses slightly better than HEVC and is royalty-free, but HEVC has wider hardware support on TVs and Apple devices. For example, a 2020 University of Waterloo study of 4K video measured AV1 saving about 9.5% bitrate compared with HEVC. Choose AV1 for browsers and newer Android devices, and HEVC where Apple and TV playback matter.
Why do video codecs matter for streaming costs?
Video codecs matter because delivery costs scale with the number of bits you send. A codec that keeps the same quality in fewer bits lowers CDN (content delivery network) bills and storage. It also helps viewers on slow networks get a sharper picture with less buffering. Codec savings land differently on FastPix, where streaming is billed per minute watched at each resolution rather than by data sent, so the codec choice is about picture quality and device reach more than the delivery bill.
Where it's used
Every video platform picks a video codec for each file. OTT services use newer codecs for 4K titles, while short video apps favor codecs with universal playback.
Where it usually goes wrong, and how FastPix handles it
Teams pick a codec and bitrate settings but rarely see how those choices play out on real devices, networks and browsers once viewers start watching.
Per-view metrics in FastPix Video Data include average bitrate, dropped frames and upscale or downscale percentage. Each breaks down by device model, OS, browser, CDN and ISP through the dashboard or the Data API. That shows your team which devices and networks get a soft or choppy picture, so you can act before complaints pile up.
By the numbers
- In a 2020 University of Waterloo study of 2160p video, AV1 saved 9.5% bitrate compared with HEVC and 16.4% compared with VP9. (Wikipedia: AV1)
