Statistical multiplexing system which encodes a sequence of video images using a plurality of video encoders

In a statistical multiplexing system comprising a plurality of video encoders and a central controller in communication with the encoders, a method for allocating the bandwidth of a shared channel among said encoders comprising the steps of

• (a) at each encoder determining upper and lower rate limits for the encoder depending on the fullness of an output buffer of the encoder,
• (b) computing at said central controller, a desired rate allocation for each of said encoders independent of the limits determined in step (a),
• (c) for each encoder, clamp the desired rate allocation determined in step (b) to be within the limits determined in step (a)
• (d) rescale the bit rates allocated in step (b) so that a bundle rate of the channel is not exceeded while excluding from the rescale one or more of the clamped encoders, and
• (e) encoding a sequence of video images at said encoders in accordance with the rates determined in step (d).