초록 ▼

In a differential pulse code modulator for image-representative signals, a coder codes difference signals to produce coded signals which have a highly variable rate, which depends upon motion in the image being represented. A rate buffer receives the coded signals and generates a control signal repr

In a differential pulse code modulator for image-representative signals, a coder codes difference signals to produce coded signals which have a highly variable rate, which depends upon motion in the image being represented. A rate buffer receives the coded signals and generates a control signal representative, at least in part, of the rate of fill of the rate buffer. Various filters, decimators and/or coarse quantizers associated with the modulator have characteristics controlled by the control signal in order to tend to control the rate of fill of the rate buffer. This aids in preventing loss of information at the receiver.

대표청구항 ▼

A method for communication by differential pulse code modulation, comprising the steps of: subtracting delayed predicted signals from input signals to produce difference signals; adding said difference signals to said delayed predicted signals to produce current predicted signals; at least delaying

A method for communication by differential pulse code modulation, comprising the steps of: subtracting delayed predicted signals from input signals to produce difference signals; adding said difference signals to said delayed predicted signals to produce current predicted signals; at least delaying said current predicted signals to produce said delayed predicted signals; coding said difference signals to form codewords of variable length having a variable data rate; applying said codewords to a rate buffer at least part of the time for temporarily storing said codewords; reading said codewords from said rate buffer; generating a control signal representing the rate of fill of said rate buffer; and controlling the rate of fill of said rate buffer by means including said control signal.