Patent ID: 6961378

Claim:
In a method of encoding a digital video image stream in an encoder, comprising spatial compression of still images in the digital video image stream and temporal compression between the still images, wherein the spatial compression is carried out by converting a time domain image of a macroblock to a frequency domain image of the macroblock, taking a discrete cosine transform of the frequency domain image, transforming the discrete cosine transformed macroblock image by a quantization factor, and run length encoding the quantized discrete cosine transformed macroblock image, wherein the temporal compression is carried out by reconstructing the quantized, discrete cosine transformed image of the macroblock, searching for a best match macroblock, and constructing a motion vector therebetween, to thereby form a bitstream comprising run length encoded, quantized, discrete cosine transformed macroblocks and motion vectors, and passing the bitstream to and through an external buffer to a transmission medium, the improvement comprising feeding back to hardware logic within the encoder an external read signal from a host and incrementing an on-chip counter of the hardware logic each time that the external buffer is read and calculating therefrom the number of bits read by a host (R), and determining the number of bits encoded and written into an external buffer (E), and in the hardware logic of the encoder subtracting from a number of bits encoded (E) the number of bits read by the host (R) to continuously obtain the fullness of an external buffer (BF), and providing, from the hardware logic within the encoder to the host, in real time a dynamically updated flag comprising at least one of a BUFFER — EMPTY flag, a BUFFER — ALMOST — FULL flag and a BUFFER — FULL flag.