Software-based encoder for a software-implemented end-to-end scalable video delivery system

A method, for use in a video delivery system server having a source of video images, of encoding an embedded bit stream containing information including image data at at least two spatial resolutions, said embedded bit stream being sent over at least one network to at least one decoder, the method including the following steps:

• (a) providing a central processor unit coupled to a memory unit;
• and
• (b) providing encoding means, digitally stored in said memory unit and coupled to said source of video images and receiving a first image at first spatial resolution, for decimating said first image to form an first intermediate image at half said highest resolution, for decimating said first intermediate image to form a second intermediate image, for compressing said second intermediate image to form a base layer image whose resolution is less than said first image;
• said encoding means further decompressing said base layer image to form a third intermediate image, and interpolating said third intermediate image to form a fourth intermediate image, and for subtracting said fourth intermediate image from said first intermediate image to form a fifth intermediate image, and for compressing said fifth intermediate image to form a first enhancement layer image whose resolution is less than said first image but greater than said base layer image;
• said embedded bit stream having data packets of fixed length code words and containing at least said base layer image and said first enhancement layer image.