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Lossless compression of digitized data such as video, digitized film, and audio preserves all the information, but it does not generally achieve compression ratio much better than 2:1 because of the intrinsic entropy of the data. Compression algorithms which provide higher ratios either incur very large overheads or work only for specific data ...
The quality the codec can achieve is heavily based on the compression format the codec uses. A codec is not a format, and there may be multiple codecs that implement the same compression specification – for example, MPEG-1 codecs typically do not achieve quality/size ratio comparable to codecs that implement the more modern H.264 specification.
Video compression schemes for Web and DVD make use of a 4:2:1 color sampling pattern, and the DV standard uses 4:1:1 sampling ratios. Professional video codecs designed to function at much higher bitrates and to record a greater amount of color information for post-production manipulation sample in 4:2:2 and 4:4:4 ratios.
Although lossless video compression codecs perform at a compression factor of 5 to 12, a typical H.264 lossy compression video has a compression factor between 20 and 200. [69] The two key video compression techniques used in video coding standards are the DCT and motion compensation (MC).
A video coding format [a] (or sometimes video compression format) is a content representation format of digital video content, such as in a data file or bitstream. It typically uses a standardized video compression algorithm, most commonly based on discrete cosine transform (DCT) coding and motion compensation .
The HEVC standard defines thirteen levels. [1] [2] A level is a set of constraints for a bitstream.[1] [2] For levels below level 4 only the Main tier is allowed.[1] [2] A decoder that conforms to a given tier/level is required to be capable of decoding all bitstreams that are encoded for that tier/level and for all lower tiers/levels.
Video compression is used to greatly reduce the bit rate while having little effect on quality. [35] Bits per pixel (BPP) is a measure of the efficiency of compression. A true-color video with no compression at all may have a BPP of 24 bits/pixel. Chroma subsampling can reduce the BPP to 16 or 12 bits/pixel.
Video compression formats. Non-compression. RGB 4:4:4 (only linear, transfer-converted and bit-reduced also sort of compression up to about 3:1 for HDR) ...