What is the reasoning behind MPEG syntax symbols ?
A. Here are some of the Whys and Wherefores of MPEG symbols: Start codes These 32-bit byte-aligned codes provide a mechanism for cheaply searching coded bitstreams for commencement of various layers of video without having to actually parse variable-length codes or perform any decoder arithmetic. Start codes also provide a mechanism for resynchronization in the presence of bit errors. Coded block pattern (CBP –not to be confused with Constrained Parameters!) When the frame prediction is particularly good, the displaced frame difference (DFD, or prediction error) tends to be small, often with entire block energy being reduced to zero after quantization. This usually happens only at low bit rates. Coded block patterns prevent the need for transmitting EOB symbols in those zero coded blocks. DCT_coefficient_first Each intra coded block has a DC coefficient. With coded block patterns signaling all possible combinations of all-zero valued blocks, the dct_coef_first mechanism assigns a diff
Here are some of the Whys and Wherefores of MPEG symbols: Start codes These 32-bit byte-aligned codes provide a mechanism for cheaply searching coded bitstreams for commencement of various layers of video without having to actually parse or decode. Start codes also provide a mechanism for resynchronization in the presence of bit errors. Coded block pattern (CBP –not to be confused with Constrained Parameters!) When the frame prediction is particularly good, the displaced frame difference (DFD, or prediction error) tends to be small, often with entire block energy being reduced to zero after quantization. This usually happens only at low bit rates. Coded block patterns prevent the need for transmitting EOB symbols in those zero coded blocks. DCT_coefficient_first Each intra coded block has a DC coefficient. Inter coded blocks (prediction error or DFD) naturally do not since the prediction error is the first derivative of the video signal. With coded block patterns signalling all possib
