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What Is a Video Codec
A video codec compresses footage into a compact stream and decodes it for playback. Learn how encoders and decoders work and why so many codecs exist.
Streaming Technology
Codecs and Compression
How video is squeezed into manageable files.
AV1 and the Push for Open Video Codecs
Why royalty-free video codecs matter, how the Alliance for Open Media created AV1, and how AV1 compares with H.264, HEVC and VP9 on efficiency and support.
Bitrate Explained
Bitrate is the amount of data used per second of video. Learn how it affects quality and file size, how to estimate size, and why more bits don't always help.
Constant vs Variable Bitrate
Compare constant, variable and constrained bitrate rate control: how each works, what it does to quality and file size, and which suits streaming or archiving.
H.264 Explained
H.264 (AVC) became the default video codec thanks to broad device support and solid efficiency. Learn how it works, why it lasted and where it falls short.
Hardware Encoding vs Software Encoding
Compare GPU and dedicated hardware encoders with CPU software encoders: speed, quality, power use and when each makes sense for streaming, editing and archiving.
HEVC and H.265 Explained
HEVC (H.265) can deliver similar quality to H.264 at a lower bitrate, but patent licensing complexity slowed its spread. See how it works and where it is used.
How Video Compression Works
Video compression removes redundancy within frames and between frames, then discards detail the eye barely notices. See what is kept, what is lost and why.
VP9 and Its Role on the Web
VP9 is Google's royalty-free video codec, released in 2013. Learn how it developed from VP8 and On2, where browsers and platforms use it, and how AV1 followed.
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