What are some advanced encoding methods ?
Quantizer feedback [Thomson patent] Horizontal variance Motion vector cost: this is true for any syntax elements, really. Signalling a macroblock quantization factor or a large motion vector differential can cost more than making up the difference with extra quantized DFD (prediction error) bits. The optimum can be found with, for example, a Lagrangian process. In summary, any compression system with side information, there is a optimum point between signalling overhead (e.g. prediction) and prediction error. Liberal Interpretations of the Forward DCT Borrowing from the concept that the DCT is simply a filter bank, a technique that seems to be gaining popularity is basis vector shaping. Usually this is combined with the quantization stage since the two are tied closely together in a rate-distortion sense. The idea is to use the basis vector shaping as a cheap alternative to pre-filtering by combining the more desiderable data adaptive properties of pre-filtering/ pre-processing into th
Quantizer feedback: determine the dependent quantization stepsize by modeling quantization error propagating over multiple pictures. [Uz/et al ICASSP 93, Ortega/Vetterli/et al ICASSP 93] Smoothness constraint placed on local activity measures. immediate blocks outside target macroblock are considered when selecting macroblock quantization stepsize .[Thomson/Savitier patent] Horizontal variance: measure variance between columns of pixels in addition to the traditional measure of variance along rows (lines) when making field/frame macroblock prediction decision. DFD energy: examine DFD energy/variance when making Intra/Non-intra macroblock decision. Activity measures: use total bits from a first-pass encoding of a picture or macroblock as a measure of the activity. Coded bits is a more accurate reflection of local complexity than variance. [Thomson/Savitier patent] motion vector cost: this is true for any syntax elements, really. Signaling a macroblock quantization factor or a large moti
