a toy codec fork from x264 for studying h264
1. ./configure "--enable-debug" "--disable-opencl" "--disable-asm" "--enable-gprof" "--disable-avs" "--disable-swscale" "--disable-lavf" "--disable-ffms" "--disable-gpac" "--bit-depth=8" "--chroma-format=420" "--disable-thread" "--disable-interlaced"
2. then del some code do not need