Performance tuning – Quick export of png images from a large avi file

In version 11.1.1 I used the Simon Woods MathMF form to extract png images from large avi files (up to 100 GB in size). Your package was MUCH faster than using something like this:

nImages = Length @ Import["D:\movie.avi", "Frames"];

  image = Import["D:\movie.avi", {"Frames", i}];

strCounter = ToString @ PaddedForm[i, 4, NumberPadding -> {"0", ""}];

To export[StringJoin[outputPath, "image_", strCounter, ".png"]image
"png"], {i, 1, nImages}

Here, just reading the number of images taken by a large 6 GB avi file (containing 640 * 480 pixels) takes a long time (45 s).

Reading a a single image in a certain position i = 1 It also takes about 45 sec.

Why is this so slow? (I have 32 GB of RAM, processor: i7-4940MX 3.1 GHz)

Watch this:

image = Import["D:\movie.avi", {"Frames", 1}]; // AbsoluteTiming
{44.1149, null}

In versions 11.3. MathMF It does not work anymore (see this question and Simon's comment).

Simon mentioned the following:

Looking at the MediaTools package it looks like it could do everything
that MathMF can do anyway. If you do Needs["MediaTools["MediaTools[“MediaTools[“MediaTools"]and so
? MediaTools
Private` $ MF * seems to have functions for
Reading and writing frame by frame.

If I execute ? MediaToolsPrivate$ MF * I get a list of fuctions
enter the description of the image here

How can I replace my higher code with these functions to increase performance?