changes_v65.txt

Mobile IP VCEG的信道模拟程序

Changes from version 6.4 to 6.5


Fast Integer Pixel Motion Estimation
	- precalculation of SAD for all 4x4 blocks and all vector positions
	- SAD calculation of nxm blocks is based on 4x4 SAD's
	- search range center is the predictor of 16x16 block for all block sizes

Extended Search range
	- search range can be 39x39 at maximum
	- search range reductions for older reference frames or older reference frames
	  and smaller blocks can be enabled in the configuration file

Unrestricted Motion Vectors
	- Unrestricted motion vectors for P- and B-frames
	- no range checking in Direct mode

Adaption of P-Interval and Single Quantizer Change (primarily for MPEG-test)
	- the interval P-P can be adapted at the very end of a sequence to hit the last
	  frame which then have to be specified in the configuration file
	- the quantization parameters can be changed once per sequence (config file)

Rate-Distortion Optimization
	- a rd-optimized mode can be enabled in the configuration file
	- in rd-opt. mode:
		- slightly modified rate-constrained motion estimation
		- rate-constrained macroblock mode decision
		- rate-constrained mode decision for 4x4 intra modes
	- the rd-opt. mode decision need to code (DCT, Q, Q^-1, IDCT, entopy coding)
	  each block/macroblock several times

Increased Frame Buffer
	- the frame buffer for long term memory prediction is no longer restricted to
	  five reference frames
	- the buffer size in the encoder will be adapted according to the number of reference
	  frames given (config file) and the config file parameter "AdditionalReferenceFrame"
	- the buffer size in the decoder has to be specified in the config file
	- the parameter "AdditionalReferenceFrame" specifies a reference frame index which is
	  considered during motion estimation
	- E.g:	NumberReferenceFrames=5, AdditionalReferenceFrame=19
		-> 20 reference frames are stored at encoder side
		-> the frames with indizes 0,1,2,3,4, and 19 are searched during motion estimation

NAL/Slices
	- support of slices in both symbol modes
	- at the decoder UVLC symbols are decoded by the time they are needed, not for the whole 
	  slice at one time (to be in line with the encoder)
	- data partitioning support has been (temporally) removed

General
	- Some clean-ups of data structures
	- removal of superfluous source and include files in the decoder

--

Heiko Schwarz	<[e-mail]>
Tobias Oelbaum	<[e-mail]>
Detlev Marpe	<[e-mail]>