Video Codec

General definition

A video codec (coder-decoder) reduces the bandwidth needed to transmit video by exploiting spatial redundancy within frames and temporal redundancy between frames. The encoder compresses video at the sender; the decoder reconstructs it at the receiver. Different codecs achieve different balances between compression efficiency, encoding speed, and hardware support.

• H.264 (AVC): the most widely supported codec; mandatory in WebRTC and hardware-accelerated on nearly all devices
• VP8: Google’s royalty-free codec; mandatory in WebRTC browsers alongside H.264
• VP9: significantly better compression than VP8 at the same quality; widely supported in Chrome and Firefox
• H.265 (HEVC): 40-50% more efficient than H.264 but with licensing complexity and limited browser support
• AV1: royalty-free, highly efficient, increasingly hardware-accelerated; the emerging standard for next-generation video

In WebRTC, codec negotiation happens during session setup via SDP. H.264 and VP8 are the universally safe choices; VP9 and AV1 are preferred when both endpoints support them because they deliver equal quality at lower bitrate.

In the Ethora ecosystem

Ethora’s voice and video calling relies on WebRTC’s native codec negotiation, which means H.264 and VP8 are available everywhere and VP9 or AV1 engage automatically when both participants’ devices support them. This produces the best possible quality at the lowest bandwidth without manual configuration.

Teams deploying Ethora on their own infrastructure can configure codec preferences and hardware acceleration flags in the media server to optimise for their specific device fleet, which matters when a healthcare or financial services organisation has a mix of managed devices with varying hardware codec support.