Process of reducing video file size through mathematical algorithms while maintaining acceptable quality.
Definition
Video compression reduces data amounts by removing redundant or perceptually less relevant information. A distinction is made between lossless and lossy compression.
Practical Application
Raw footage from cinema cameras (50-300 Mbps) is compressed for delivery to streaming levels (5-25 Mbps). For archiving, mezzanine formats like ProRes or DNxHR are used. Modern codecs like H.265 and AV1 achieve 30-50% smaller files than H.264 at the same quality.
Technical Details
Intra-frame compression utilizes spatial redundancy (similar pixels next to each other). Inter-frame compression utilizes temporal redundancy (similar frames one after another). Bitrate (constant/variable), GOP structure, and quantization determine the quality/size ratio.