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Unformatted text preview: accurate and hence the coding efficiency will be lower. But
this approach does not cause any mismatch error in the receiver if it only receives the base layer.
There are multiple reasons to cause error propagation, including temporal prediction, spatial prediction and
variable length coding. Some encoding tools that can suppress error propagation includes 1) periodic
insertion of intra-blocks (or intra-frames), 2) insertion of synchronization markers; 3) multiple description
coding. d) (20 pt) Write a Matlab code that implements coding of a P-frame in a block-based hybrid video coder. For
simplicity, use 8x8 blocks for both prediction and DCT coding, and consider the coding of Y-pixels only.
For each block, you may decide to code it in either I-Mode (predict this block from previously coded
samples in this frame using one of a few intra-prediction modes) or P-Mode (predict from a best matching
block in the previous frame). For either mode, you perform DCT on the prediction error block, quantize the
DCT coefficients using a preset QP and quantization matrix QMatrix, code the mode and the quantized
DCT coefficients using an entropy coding method.
Denote the frame to be coded by CurrentFrame, the previous frame used for temporal prediction by PrevFrame.
Your program should write the resulting bits for successive blocks into a file outfile. Your program should also
compute and save the reconstructed frame in QuantizedFrame. Also use Width and Height to denote the width
and height of a frame and assume both the width and height are dividable by 8. Furthermore, assume the following
functions are available (i.e. can be called by your matlab code). Your program can call these functions as well as
other MATLAB functions and functions defined by yourself.
function [mvh, mvv,PredictedMBlock]=MotionEstimation(bx, by, MBlock,PrevFrame):
finds the best matching block for a...
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This document was uploaded on 03/12/2014 for the course EL 6123 at NYU Poly.
- Spring '14