===========================================================
Video Edit Code issue
(All based on AVS-M1956 by Grandview Semi. 2006/12/12)
===========================================================
Encoder:
1. picture_header() in image.c
   * row 159, 183
      write the VEC_EXT byte to bitstream
   * row 170, 194
      force to write the value 3 to bitstream 
      because of the first I picture

2. PartitionMotionSearch()     in mv-search.c
   PartitionMotionSearch_bid() in mv-search.c
   * row 1982, 2087
      force the cost to maximum when forward precition

3. encode_one_macroblock() in rdopt.c
   * row 1903
      skip the Direct_B8x8  prediction
   * row 2403
      skip the Direct_16x16 prediction
   * row 2406~2409, 2461~2462
      skip the situation wehn vec_ext = 3

4. image.c
   misc modification only for displaying more information
   about VEC status.

===========================================================
Decoder:
1. Header() in image.c
   * row 720~728
      if finds the vec_flag and vec_ext is 1,
         the current B picture should be discarded,
         and find the next start code,
      otherwise,
         begin decoding for current picture.
   * row 734~740
      discard the middle slice_header start codes.

2. decode_one_frame() in image.c
   * row 235~256
   pls focus on 'vec_pr_flag'.
   misc modification only for displaying more information
   about VEC status.