Mapping on Fully Dedicated Architecture - Digital Design of Signal Processing Systems: A Practical Approach - page 142

reference block is computed. This difference block is then quantized and Huffman-coded for
transmission. The motion vector refereeing the block in the reference frame is also transmitted.
At the receiver the difference macro-block is decoded and then added in the reference block for
recreation of the target block.

I P P P I P P P

(a)

C r

Y

C b

DCT Quant

For each
8x8 block

Zig - zag

RLE

Huffman

01101…..

(b)

Figure 4.9 Steps in video compression. (a) Video is coded as a mixture of Intra-Frames (I-Frames) and
Inter- or Predicted Frames (P-Frames). (b) I-Frame is coded as JPEG frame. (c) The I-Frame and all other
frames are also decoded for coding of P-Frame, KPN implementation with FIFO's is given. (d) For P-
Frame coding, the frame is divided into sub-blocks and each block is searched in the previously self-
decoded frame. The target block is searched in the previous block for best match. This block in called the
reference block. (e) The difference of target and reference block is coded as a JPEG block and the motion
vector is also coded and transmitted with the coded block