Compare two frames

I have installed Chr.dll and I've been able to create a text file. The script now looks like this: Code:

What would be the fastest way to use YDifferenceFromPrevious()? I mean something like this: If YDifferenceFromPrevious()<0.1 then dropped=dropped+1

This is faster. No text on screen (Subtitle) but only in the text file. I've replaced Subtitle with ConvertToYV12 for speed reasons, because I assume ConvertToYV12 doesn't really do anything in this case. If there's a more elegant way of doing nothing let me know. The first two faulty lines in the text file are no longer written now. Code:

Nop() effectively does nothing at all. :D

Tried Nop() but I get an error message. I need a command that accepts a clip as input. eq=Nop(org) doesn't seem to be allowed. Avisynth open failure: Script error: Invalid arguments to function "Nop"

Hmmm, I just noticed something strange. I captured directly to MPEG-2 with ATI MMC and ran Internet Explorer. That caused 4 dropped frames according to ATI MMC. The Avisynth script only found one so I used VirtualDub to step through the MPEG-2 file frame by frame. The one dropped frame the script had found was indeed an exact copy of the previous one. I had captured a channel with a stock ticker at the bottom of the screen. Obviously scrolling text looks interlaced. However, where some dropped frames had been reported there was still some motion (so no exact copy of the previous frame) but this time the frame looked non-interlaced. It was as if only one field had been dropped and the one captured field had been resized to full screen. I don't know if that is what the MPEG-2 encoder does or if it is even possible, but obviously the Avisynth script can't detect those frames as dropped. One thing I know now: the ATI MMC MPEG-2 encoder doesn't always insert an exact copy of the previous frame when a frame is dropped. It sometimes does some other sh*t too.

Try this instead then: function NullFilter(clip c, string "args") { args = Default(args, "") return c } You can then use NullFilter() anywhere you like. That should work.

Yes, a Nullfilter function works.

That's a normal behavior, and indicates that the encoder is actually pretty smart about repeating dropped fields. (Also, maybe MMC reported 4 dropped fields, and no 4 dropped frames). If you're encoding interlaced, let's say you have frame 1 consisting of field A and field B, then frame 2 consisting of field C and field D. Assuming field C and D were dropped: If the encoder repeats frame 1, you'll get AB.AB, which will produce shakyness (the scrolling text will move backwards for 1 field, since field A is supposed to be displayed before field B). Instead, it looks like the encoder did the following: AB.B'B. where B' is probably B deinterlaced.