Comp test sampling?

[Kent Wang]

How exactly does comp test sample the file? It seems like testing the first 5% of a movie would be really inaccurate because it's the opening sequence. Anyway, I'm just curious since jonny has already shown that it is indeed a reliable method.

[N_F]

It works something like this (perhaps jonny will be a bit more specific):

1. Divide the whole movie into intervalls (I believe default is 280 frames).

2. Encode a certain amount of frames of each intervall depending on how high you set your percentage.

So if you use 5% it will encode 14 frames out of each 280 interval. It's not quite as easy as this, but hopefully you get the general idea.

[jonny]

Yes, what N_F says is perfect.

I add only one thing:

14 is the "snip size". This value is fixed.
Selecting 5% you have the first 14 frames encoded every 280 (14/280=5%)
Selecting 10% you have the first 14 frames encoded every 140 (14/140=10%)
Selecting 1% you have the first 14 frames encoded every 1400 (14/1400=1%)

And so on ...

As you can see the sample cover all the movie.