FFVideoSource(string source, int track = -1, bool cache = true, string cachefile = source + ".ffindex", int fpsnum = -1, int fpsden = 1, int threads = -1, string timecodes = "", int seekmode = 1, int rffmode = 0, int width = -1, int height = -1, string resizer = "BICUBIC", string colorspace = "", bool utf8 = false, string varprefix = "")
int width = -1, int height = -1
Sets the resolution of the output video, in pixels. Setting either dimension to less than or equal to zero means the resolution of the first decoded video frame is used for that dimension. These parameters are mostly useful because FFMS2 supports video streams that change resolution mid-stream; since Avisynth does not, these parameters are used to set single resolution for the output.
string resizer = "BICUBIC"
The resizing algorithm to use if rescaling the image is necessary. If the video uses subsampled chroma but your chosen output colorspace does not, the chosen resizer will be used to upscale the chroma planes, even if you did not request an image rescaling. The available choices are FAST_BILINEAR, BILINEAR, BICUBIC (default), X, POINT, AREA, BICUBLIN, GAUSS, SINC, LANCZOS and SPLINE. Note that SPLINE is completely different from Avisynth's builtin Spline resizers.