How to display variable values 4 debuggin in Avisynth

[lindylex]

I want to display a variable value in Avisynth for debuggin purpose but this does not work.

varfirsquarter=top_banner.FrameCount*.25

return combined.Subtitle(varfirsquarter , text_color=$000000, x=25, y=11, font ="Arial", size=60, first_frame =0, last_frame = 200, lsp=30, align=7, spc =62, halo_color=$ffffff)

How does one display variable values for debugging?

[AlanHK]

I want to display a variable value in Avisynth for debuggin purpose but this does not work.

What do you mean "does not work?
Is there an error message?
If so, what?

And please post the entire script, the fragment you posted refers to undefined things. I can't tell if your variables refer to numbers, functions, clips or what.

Also for esoteric Avisynth questions the best place to ask is the
Doom 9 forum.

[lindylex]

This is one possible solution. I am interested in how others output variables for debugging?

AlanHK, sorry you do not understand.

I have a variable named "varfirsquarter" I want to store the first quarter in length of the movie "top_banner" in that variable. To do that I do this.

varfirsquarter=top_banner.FrameCount*.25

I wanted to see what the variable value was. So I decided to use the "Subtitle" method but it only takes strings. So I had to convert the number in my variable to a string by doing this "string (varfirsquarter)".

This is a solution.

return combined.Subtitle(string (varfirsquarter), text_color=$000000, x=25, y=11, font ="Arial", size=60, first_frame =0, last_frame = 200, lsp=30, align=7, spc =62, halo_color=$ffffff)

Does anyone have a different, better way of checking variable values for debgging?

Thanks Lindylex

[AlanHK]

Does anyone have a different, better way of checking variable values for debugging?

I think "Subtitle" is the only way in general.

But if you're just debugging, you don't need to bother with all the parameters of subtitle.

Just:

BlankClip(500)
top_banner=last
varfirsquarter=top_banner.FrameCount*.25 
Subtitle(string (varfirsquarter))

Or define your own function if you want to set different subtitle defaults.

[lindylex]

AlanHK, thanks I was just using one of my previous used subtitle method calls. It definitely did not need so many parameter to display my variable value.

Thanks

[lindylex]

It looks like you can use the following to help debug also.

filename = "c:\myprojects\output.txt"
# create a test video to get frames
Version()

# the expression here is only a variable, which is evaluated and put in the file
# you will get a file with the framenumber in each line


WriteFile(filename, "current_frame")

# this line is written when the script is opened
WriteFileStart(filename, """ "This is the header" """)

# and this when the script is closed
WriteFileEnd(filename, """ "Now the script was closed" """)

////// AND ScriptClip method //////

.ScriptClip(" Subtitle(String(current_frame)) ")

[AlanHK]

Yes, I forgot those.

And if you aren't already using AvsP, get it immediately.
It has many useful features for editing Avisynth scripts.

[lindylex]

I currently use it or maybe even under use it. I'm sure there are good primer out there? What do you recommend?

[AlanHK]

I currently use it or maybe even under use it. I'm sure there are good primer out there? What do you recommend?

The author's documentation is quite good.

Otherwise browse the topic in Doom 9.
http://forum.doom9.org/showthread.php?t=129385

Unfortunately, after an initial period of rapid development, the author appears to have stopped work on it.
But its extensibility, allowing you to add your own functions and macros, makes it very flexible.

[Gavino]

ScriptClip(" Subtitle(String(current_frame)) ")

I know this is probably just an example, but if all you want to do is show the current frame number, you can just use ShowFrameNumber().

[jagabo]

Gavino, do you know how to get the current frame number as a variable? For example, I want to do something like:

Crop(FrameNumber,0,720,480)

to pan across a large frame.

[Gavino]

The variable current_frame is available inside run-time filters like ScriptClip.

But something like panning is best done by using Animate, applied either to Crop or to a resizer with the extra cropping parameters (smoother because of sub-pixel movement).

[jagabo]

The variable current_frame is available inside run-time filters like ScriptClip.

I must be missing something. Whenever I try to use current_frame I get an error message: "I don't know what current_frame means".

AviSource("uncompressed rgb.avi")
Crop(current_frame,0,320,240)

Ah, nevermind. I see you have to use ScriptClip() (or one of the other special runtime functions):

AviSource("uncompressed rgb.avi")
ScriptClip("Crop(current_frame,0,320,240)")

And it doesn't like it if the returned clip dimensions are different. Guess I have some more reading to do...

[Gavino]

Yes, outside the 'run-time environment', the concept of the 'current' frame makes no sense, because it's dealing with entire clips.

Your example could be written as
Animate(0, frameCount-1, "Crop", 0, 0, 320, 240, frameCount-1, 0, 320, 240)
which varies the first parameter from 0 to frameCount-1 over the length of the video.

[jagabo]

Your example could be written as
Animate(0, frameCount-1, "Crop", 0, 0, 320, 240, frameCount-1, 0, 320, 240)
which varies the first parameter from 0 to frameCount-1 over the length of the video.

Yes, but I was just using Crop() as a simple example of where one could use the current frame number. I've had other reasons for wanting conditional processing based on frame number in the past.

Thanks for steering me in the right direction...

[Gavino]

You're more than welcome - glad to be able to help.

If you get into serious use of ScriptClip and friends, you might be interested in my GRunT plugin, which addresses some of their usability problems, particularly inside script functions.