import vapoursynth as vs
core = vs.get_core()


# skip motion interpolation completely for content exceeding the limits below
max_width  = 1920
max_height = 1200
max_fps    = 60
# use BlockFPS instead of FlowFPS for content exceeding the limits below
max_flow_width  = 1280
max_flow_height = 720
# a block is considered as changed when 8*8*x > th_block|flow_diff with 8*8
# being the size of a block (scaled internally) and x the difference of each
# pixel within this block, default 400
th_block_diff = 8*8*7
th_flow_diff  = 8*8*7
# (threshold/255)% blocks have to change to consider this a scene change
# (= no motion compensation), default 130
th_block_changed = 14
th_flow_changed  = 14
# size of blocks the analyse step is performed on
blocksize  = 2**4



# assume display_fps to be bogus when not in a certain range
target_num = 60 if display_fps < 23.9 or display_fps > 300 else display_fps
while (target_num > max_fps):
    target_num /= 2
target_num = int(target_num * 1e6)
target_den = int(1e6)
source_num = int(container_fps * 1e6)
source_den = int(1e6)

clip = video_in

if not (clip.width > max_width or clip.height > max_height or container_fps > max_fps):
    clip = core.std.AssumeFPS(clip, fpsnum=source_num, fpsden=source_den)
    sup  = core.mv.Super(clip, pel=2, hpad=blocksize, vpad=blocksize)
    bv   = core.mv.Analyse(sup, blksize=blocksize, isb=True , chroma=True, search=3, searchparam=2)
    fv   = core.mv.Analyse(sup, blksize=blocksize, isb=False, chroma=True, search=3, searchparam=2)

    use_block = clip.width > max_flow_width or clip.height > max_flow_height
    if use_block:
        clip = core.mv.BlockFPS(clip, sup, bv, fv, num=target_num, den=target_den,
                                mode=3, thscd1=th_block_diff, thscd2=th_block_changed)
    else:
        clip = core.mv.FlowFPS(clip, sup, bv, fv, num=target_num, den=target_den,
                               mask=0, thscd1=th_flow_diff, thscd2=th_flow_changed)
    print('motion-interpolation: {0} -> {1} FPS | {3} | {2} Hz'
          .format(source_num / source_den, target_num / target_den,
                  display_fps, use_block and "block" or "flow"))
else:
    print('motion-interpolation: skipping {0}x{1} {2} FPS video'
          .format(clip.width, clip.height, container_fps))

clip.set_output()