A script that makes sure tdecimate doesn't screw up your perfect Yatta IVTC.

decimation-overrides.py

#!/usr/bin/env python3

import sys


def print_usage():
    print("Prints the frame numbers of cycles that don't have decimation overrides.")
    print("\nUsage:")
    print("{} file.dec.txt [frame_count]".format(sys.argv[0]))
    print("\nNote: if the frame count is not specified, the cycles after the last cycle with overrides will be disregarded.")


if len(sys.argv) < 2 or len(sys.argv) > 3:
    print_usage()
    print("\nError: invalid number of arguments.")
    sys.exit(1)


ovr_file_name = sys.argv[1]
cycle_length = 5
frame_count = 0
if len(sys.argv) == 3:
    frame_count = int(sys.argv[2])


cycles_with_overrides = [-1]
cycles_without_overrides = []

with open(ovr_file_name, "r") as f:
    i = 0
    for line in f:
        i += 1
        bits = line.split(' ')
        if len(bits) != 2:
            print("Error: bad override at line {}".format(i))
            sys.exit(1)
        cycles_with_overrides.append(int(bits[0]) // cycle_length)

if len(cycles_with_overrides) == 0:
    print("No cycles have overrides.")
    sys.exit(0)

if frame_count != 0:
    cycles_with_overrides.append(((frame_count - 1) // cycle_length) + 1)

for i in range(1, len(cycles_with_overrides)):
    diff = cycles_with_overrides[i] - cycles_with_overrides[i-1]
    if diff > 2:
        cycles_without_overrides.append([(cycles_with_overrides[i-1] + 1)*cycle_length, (cycles_with_overrides[i] - 1)*cycle_length])
    elif diff > 1:
        cycles_without_overrides.append((cycles_with_overrides[i] - 1)*cycle_length)

if len(cycles_without_overrides) > 0:
    print("The cycles starting at the following frame numbers don't have decimation overrides:")

    for cycles in cycles_without_overrides:
        print(cycles)
else:
    print("It appears all cycles have decimation overrides.")