Mit Immaavs müsste das jedenfalls gehen:
ImmaRead (string filename, int start, int end, int size_x, int size_y, bool animation, bool gapless, bool info, string magick_home)
filename is the image or image sequence (multiple images) which should be read. For an image sequence, the frame number substitution should be specified using "sprintf syntax", or using wildcards (sorted by filename, subfolders are not included). For example, the files written by ImmaWriter's default parameters can be referenced with "c:\%06d.jpg" (meaning filenames with 6 digits, thus C:\000000.jpg, C:\000001.jpg, etc ...). The start and end of the image sequence should be specified with the start and end parameters. When (size_x, size_y) is not specified, the images in the sequence should have the same width and height, otherwise a black frame is returned with an error message. When (size_x, size_y) is specified, the images in the sequence are scaled to their maximum and black borders are added when necessary. Also if an image (within the sequence) doesn't exist, a black frame is returned with an error message.
Bei FFmpegSource2 bin ich mir allerdings nicht sicher, ob man dort mehrere Bilder auf einmal einlesen kann.
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.