HELP WANTED to debug avisynth function used with avidemux (avsproxy)

[Khyinn]

Hi,

First, sorry for my bad english.

I'm trying to do an avisynth function and i have a crash when i use it (no error log ).

Here is the code :

function Incruster(clip film, string "image", int "abs", int "ord", int "start", int "end", float "fade")
{

fps=film.FrameRate
fade=Default(fade, 0)
fade=Round(fps*fade)

incrust=ImageSource(image, pixel_type="RGB32")
film1=film.Trim(0, start-1)
film2=film.Trim(start, end)
film3=film.Trim(end+1, film.FrameCount-1)

film2b=Overlay(film2,incrust,mask=incrust.ShowAlpha().Trim(start,end).FadeIO0(fade),x=abs,y=ord)

v=film1++film2b++film3

return(v)
}

This function should make an overlay on a video with a transparent PNG file and make this overlay appears only after "start" and before "end" with fading in and out.


And this is the script i use for avsproxy :

film=AVISource("C:\01.avi")
film=film.Incruster(image="C:\01.png", abs=0, ord=0, start=1000, end=3000, fade=1.5)

Can anyone tell me what's wrong ?

[jagabo]

Does it work if you open it in a media player or VirtualDub?

Add "return(film)". Otherwise AviSynth will attempt to return last (the default video name).

film=AVISource("C:\01.avi")
film=film.Incruster(image="C:\01.png", abs=0, ord=0, start=1000, end=3000, fade=1.5)
return(film)

Can AviDemux open AVS scripts? Not all programs can.

[Khyinn]

AVIDemux use a small program called AVSProxy to read AVS scripts.

Oh, adding return(film) to the AVS script solved this issue, thanks !

Now, just something to change in this function and it'll be ok

[Khyinn]

Hum, now there is still one problem. Here it is :

I want to display an overlay from frame 1000 to frame 3000 so here is my AVS script :

film=AVISource("C:\01.avi")
film=film.Incruster(image="C:\01.png", abs=0, ord=0, start=1000, end=3000, fade=1.5, verbose=true)
return(film)

And here is my function :

function Incruster(clip film, string "image", int "abs", int "ord", int "start", int "end", float "fade", bool "verbose")
{

fps=film.FrameRate
fade=Default(fade, 0)
fade=Round(fps*fade)

incrust=ImageSource(image, pixel_type="RGB32")
film1=film.Trim(0, start-1)
film2=film.Trim(start, end)
film3=film.Trim(end+1, film.FrameCount-1)

film2b=Overlay(film2,incrust,mask=incrust.ShowAlpha().FadeIO0(fade),x=abs,y=ord)

v=film1++film2b++film3

verbose = Default(verbose, false)
v = verbose ? v.Show(start, end, abs, ord, fade) : v

return(v)
}

function Show (clip v, int "start", int "end", int "abs", int "ord", int "fade")
{
i = 10
v= v.subtitle("Overlay from "+start.string +" to "+end.string, 10,i)
i = i+20
v = v.subtitle("Display (x,y) = ("+abs.string +","+ord.string+")", 10,i)
i = i+20
v = v.subtitle("Fading = "+fade.string+" frame(s)", 10,i)

return(v)
}

Verbose mode returns :

Overlay from 1000 to 3000
Display (x,y) = (0,0)
Fading = 36 frame(s)

36 frames because my movie is 23.976fps.

Now, in fact, overlay really appears from frames 1000 to 2000 and i don't know why...

[Gavino]

Hum, now there is still one problem.
overlay really appears from frames 1000 to 2000 and i don't know why...

That's because ImageSource by default gives you a clip of 1001 frames.
Change the definition of incrust to:
incrust=ImageSource(image, pixel_type="RGB32", start=start, end=end)

Incidentally, your function suffers from a common problem when using Trim with variable arguments - it will not work if called with start=1 (can you see why?).
Replace
film1=film.Trim(0, start-1)
by
film1=film.Trim(0, -start)

Actually, it won't work for start=0 either, or ending at the last frame.
If those cases may be required, you need to add extra logic to handle them.

Add "return(film)". Otherwise AviSynth will attempt to return last (the default video name).

The solution is correct, but the explanation is not.
It's a common myth that 'last' is returned by default. If the last statement is an assignment, a void value (equivalent to a defaulted parameter) is returned, even if 'last' was previously set.

[Khyinn]

Thank you so much Gavino for all your explanations, now it works as intended.

Don't need to start at 0 or ending on the last frame but if you have time to modify this function for those who need this, please do it.

Here is my final function :

function Incruster(clip film, string "image", int "abs", int "ord", int "start", int "end", float "fade", bool "verbose")
{

fps=film.FrameRate
fade=Default(fade, 0)
fade=Round(fps*fade)

incrust=ImageSource(image, pixel_type="RGB32", start=start, end=end)
film1=film.Trim(0, -start)
film2=film.Trim(start, end)
film3=film.Trim(end+1, 0)

film2b=Overlay(film2,incrust,mask=incrust.ShowAlpha().FadeIO0(fade),x=abs,y=ord)

v=film1++film2b++film3

verbose = Default(verbose, false)
v = verbose ? v.Show(start, end, abs, ord, fade) : v

return(v)
}

function Show (clip v, int "start", int "end", int "abs", int "ord", int "fade")
{
i = 10
v= v.subtitle("Overlay from "+start.string +" to "+end.string, 10,i)
i = i+20
v = v.subtitle("Display (x,y) = ("+abs.string +","+ord.string+")", 10,i)
i = i+20
v = v.subtitle("Fading = "+fade.string+" frame(s)", 10,i)

return(v)
}

[Gavino]

Don't need to start at 0 or ending on the last frame but if you have time to modify this function for those who need this, please do it.

The simplest way to do it is to replace the line
v=film1++film2b++film3
by
v = start > 0 ? film1++film2b : film2b
v = end+1 < film.Framecount ? v++film3 : v

[Khyinn]

Thanks, so the really really final function :

function Incruster(clip film, string "image", int "abs", int "ord", int "start", int "end", float "fade", bool "verbose")
{
fps=film.FrameRate
fade=Default(fade, 0)
fade=Round(fps*fade)

incrust=ImageSource(image, pixel_type="RGB32", start=start, end=end)
film1=film.Trim(0, -start)
film2=film.Trim(start, end)
film3=film.Trim(end+1, 0)

film2b=Overlay(film2,incrust,mask=incrust.ShowAlpha().FadeIO0(fade),x=abs,y=ord)

v = start > 0 ? film1++film2b : film2b
v = end+1 < film.Framecount ? v++film3 : v

verbose = Default(verbose, false)
v = verbose ? v.Show(start, end, abs, ord, fade) : v

return(v)
}

function Show (clip v, int "start", int "end", int "abs", int "ord", int "fade")
{
i = 10
v = v.subtitle("Overlay from "+start.string +" to "+end.string, 10,i)
i = i+20
v = v.subtitle("Display (x,y) = ("+abs.string +","+ord.string+")", 10,i)
i = i+20
v = v.subtitle("Fading = "+fade.string+" frame(s)", 10,i)

return(v)
}

[jagabo]

Add "return(film)". Otherwise AviSynth will attempt to return last (the default video name).

The solution is correct, but the explanation is not.
It's a common myth that 'last' is returned by default. If the last statement is an assignment, a void value (equivalent to a defaulted parameter) is returned, even if 'last' was previously set.

Thanks for that clarification. That explains something I saw the other day when debugging a script.