avs4x26x - Modified avs4x264

The code is based on on AVS-input
from x264 (http://www.videolan.org/developers/x264.html).

You can use this software to encode videos using the 32-bit version
of Avisynth with the 64-bit version of x264 or x265 under Windows.
The x26x executable needs to be named x264_64.exe or x265 and placed
in the same folder as this program. Otherwise you need --x26x-binary
"x26x_path" or -L "x26x_path" to define the pach of x26x binary.
Example:
avs4x26x.exe --x26x-binary "C:\x264-abc.exe" -o out.264 in.avs

avs4x26x v0.10:
Modified by 06_taro ( astrataro@gmail.com ).
Modifications: 
-- When x26x's parameter "input-depth" is set and is not equal to 8,
   divide "width" by 2. This makes faked 16-bit avs output, i.e.,
   MSB and LSB field interleaved clip, be treated correctly by x26x.
   If "input-depth" is not defined or equals to 8, avs4x26x acts
   in the same way as original avs4x264.
-- Print full command-line piped to x26x.exe to screen, prefixed
   by "avs4x26x [info]:".
-- Make x264_64.exe path changeable. The path of x26x binary can be
   set by --x26x-binary "x26x_path" or -L "x26x_path". If custom path
   is not set, default path "x264_64.exe" will be used in normal case,
   while if output file extension is *.265/.h265/.hevc, "x265" will be
   launched.
-- Directly output i422/i444 with AviSynth 2.6 csp YV16/YV24.
-- Show help info when running with no options.
-- Improve capability with more styles of parameters in x26x.
   E.g., --tcfile-in="timecode.txt", --input-depth=16,
         --x26x-binary="x264", -L=x264 and -Lx265.
-- Do not add --input-res/--fps/--frames/--input-csp if already defined.
-- Correct number of frames to be handled when --frames is defined.
-- Add "--seek-mode" to decide use "fast" seek mode or "safe" seek
   mode when has "--seek". Default is "fast".
   -- "fast" mode is similar to x26x's internal method of avs demuxer:
      skip frames until the frame --seek indicates. However, when used
      with --qpfile/--tcfile-in, it won't skip but add a "FreezeFrame(0,
      seek, seek)" to avs script to actually skip the process of those
      frames. I have to play this trick because x26x regards qpfile or
      tcfile-in as qpfiles or timecodes of input files, not output files,
      so the frame numbers of input piped raw ( can be linearly seeked
      only in x26x ) has to be left untouched.
   -- "safe" mode uses a safer but slower method: delivering every
      untouched frame to x26x. When the process of frames before "--seek"
      frame is heavy, the "useless" running time of processing those
      frames will be much longer than "fast" mode, but the result is
      safer for scripts like TDecimate(mode=3), which can only be seeked
      in a linear way.
-- Add "--timebase" when using "--tcfile-in".
-- Correct framerate to proper NTSC fraction if applicable.
-- Support direct .d2v/.dga/.dgi input, plus .vpy input with either
   VapourSource(VSImport) or vfw interface(AVISource/HBVFWSource), and
   some media file input such as .avi/.mkv/.mp4/.m2ts/etc.
-- Support AviSynth+.
-- Support x262/x265.
   However, the x265 style "x265 <infile> <outfile>" is not supported
   and probably never will. You need to use -o or --output before outfile.

Compiling:
with gcc 4.6.0+:
gcc avs4x26x.c -s -Ofast -oavs4x26x -Wl,--large-address-aware
with old versions:
gcc avs4x26x.c -s -O3 -ffast-math -oavs4x26x -Wl,--large-address-aware