Test the reliability of your favourite source filter

seek-test.py

# Usage:
# python3 seek-test.py file.mkv [start_frame end_frame]
#
# Change the source filter as needed.

# Note: this script is slow because making the source filter decode frames randomly is slow.


import vapoursynth as vs

import sys, hashlib, random

c = vs.get_core(add_cache=False)

clip = c.d2v.Source(sys.argv[1], rff=False)
#clip = c.ffms2.Source(sys.argv[1])
#clip = c.lsmas.LWLibavSource(sys.argv[1])

start = 0
end = clip.num_frames - 1
if len(sys.argv) == 4:
    start = int(sys.argv[2])
    end = int(sys.argv[3])

clip = c.std.Trim(clip, start, end)

print("Clip has {} frames.".format(clip.num_frames))

def hash_frame(frame):
    md5 = hashlib.md5()
    for plane in range(frame.format.num_planes):
        for line in frame.get_read_array(plane):
            md5.update(line)
    return md5.hexdigest()


reference = []
for i in range(clip.num_frames):
    reference.append(hash_frame(clip.get_frame(i)))

    if i % 100 == 0:
        print("Hashing: {}%".format(i * 100 // (clip.num_frames - 1)), end='\r')

print("\nClip hashed.\n")

test = list(range(clip.num_frames))
random.shuffle(test)


for i in test:
    try:
        result = hash_frame(clip.get_frame(i))
        if (result != reference[i]):
            print("Requested frame {}, ".format(i), end='')
            try:
                print("got frame {}.".format(reference.index(result)))
            except ValueError:
                print("got new frame with hash {}.".format(result))
            print("    Previous requests:", end='')
            start = test.index(i) - 10
            if (start < 0):
                start = 0
            for j in range(start, test.index(i) + 1):
                print(" {}".format(test[j]), end='')
            print("")

        if test.index(i) % 100 == 0:
            print("Seeking: {}%".format(test.index(i) * 100 // (clip.num_frames - 1)), end='\r')

    except vs.Error as e:
        print("requesting frame {} broke d2vsource. total: {}".format(i, len(test)))
        raise e

print("Test complete.")