Patent ID: 7839932

Claim:
Method for encoding a first and a second digital video signal using compression, samples of each signal having a pre-selected original word length, into a combined video signal having code words of which have a pre-selected main word length that is smaller than two times said original word length, said method including the steps: from lines of said first and second video signals, successively forming sample blocks for a luminance component and for two different chrominance components of each one of said first and second video signals; determining the minimum and the maximum amplitude values in a current sample block; in said current sample block, subtracting said minimum amplitude value from every sample in said current sample block and quantizing the resulting difference values such that the word length of the quantized difference values gets a pre-selected first word length for the quantized difference values of said first video signal and gets a pre-selected second word length for the quantized difference values of said second video signal, wherein said first and second word lengths can be different, and whereby said quantizing is controlled by a dynamic range value in said current sample block, said dynamic range value representing the difference between said maximum amplitude value and said minimum amplitude value in said current sample block; assembling, for a current data block of said combined video signal, each quantized difference value of said first and second video signals such that the bits of a quantized difference value of said first video signal form lower bit positions of a data word of said combined video signal and the bits of a corresponding quantized difference value of said second video signal form upper bit positions of a data word of said combined video signal, said upper bit positions being arranged adjacent to said lower bit positions, whereby the bits of the data words for said minimum amplitude value and said dynamic range value of said current data block, or for said minimum amplitude value and said maximum amplitude value of said current data block, each form one bit per data word of said quantized difference values of said first and second video signals; successively outputting data words assembled in such way as said combined video signal.