Mathieu Chamagne

When I use my PAL DV cam with jit.dx.grab @dim > 320 240 (for ex : 640x480 or 720x576) I get an interleaved video.

http://mathieu.chamagne.free.fr/max/dx.grab_720-576-interlea

If I use jit.demultiplex, I get 2 matrixs of 720x288...

of course, I searched in the mail archive, but found nothing about "deinterleave, demultiplex, deinterlace..."

(what's the difference between interleave, interlace, multiplex?...)

So, my question is : how can I get a "normal" image in PAL DV with my camera & jit.dx.grab ?

(MaxMSP 4.5.6 Jitter 1.5.2 for windows / P4 3Ghz / Sony HDR-HC1E PAL camera)

When I use my PAL DV cam with jit.dx.grab @dim > 320 240 (for ex : 640x480 or 720x576) I get an interleaved video.
(example :  http://mathieu.chamagne.free.fr/max/dx.grab_720-576-interlea ved.jpg )

If I use jit.demultiplex, I get 2 matrixs of 720x288...
of course, I searched in the mail archive, but found nothing about "deinterleave, demultiplex, deinterlace..."
(what's the difference between interleave, interlace, multiplex?...)

jit-dx-grab-how-to-deinterleave-dv-input

On Feb 7, 2006, at 2:23 AM, Mathieu Chamagne wrote:

> (what's the difference between interleave, interlace, multiplex?...)

Nothing. Just different words for the same thing. Multiplex is a more 

generally used term, which since Jitter is not video specific, the 

> So, my question is : how can I get a "normal" image in PAL DV with 

Typically for deinterlacing you either throw away every other scan 

line and upsample, or use computer vision techniques (which can be 

slow for realtime operation). We don't support the latter in the 

JItter standard distribution, but you might be able to use the cv.jit 

objects to accomplish this, though it might be cumbersome. There is 

also at least one freeframe deinterlace object which might do 

something more than just lose every other scanline and upsample with 

interpolation, but I haven't checked it out.

You can accomplish this with [jit.dx.grab 720 576]->[jit.matrix 4 

char 720 288]->[jit.matrix 4 char 720 576 @interp 1] for CPU based 

interpolation, or replace the final jit.matrix with jit.gl.videoplane 

or jit.gl.texture to use HW accelerated interpolation. You can also 

make use of colormode uyvy for added speed benefits, and the 

interpolation will work fine (poses problems with the chromatic 

downsampling if resizing about the downsampled horizontal axis).

Of course the *best* way to avoid this problem is to use a 

progressive scan camera in progressive scan mode.

Nothing. Just different words for the same thing. Multiplex is a more  
generally used term, which since Jitter is not video specific, the  
reason it was chosen.

> So, my question is : how can I get a "normal" image in PAL DV with  
> my camera & jit.dx.grab ?

Typically for deinterlacing you either throw away every other scan  
line and upsample, or use computer vision techniques (which can be  
slow for realtime operation). We don't support the latter in the  
JItter standard distribution, but you might be able to use the cv.jit  
objects to accomplish this, though it might be cumbersome. There is  
also at least one freeframe deinterlace object which might do  
something more than just lose every other scanline and upsample with  
interpolation, but I haven't checked it out.

You can accomplish this with [jit.dx.grab 720 576]->[jit.matrix 4  
char 720 288]->[jit.matrix 4 char 720 576 @interp 1] for CPU based  
interpolation, or replace the final jit.matrix with jit.gl.videoplane  
or jit.gl.texture to use HW accelerated interpolation. You can also  
make use of colormode uyvy for added speed benefits, and the  
interpolation will work fine (poses problems with the chromatic  
downsampling if resizing about the downsampled horizontal axis).

Of course the *best* way to avoid this problem is to use a  
progressive scan camera in progressive scan mode.

I tried the "deinterlace" Freeframe plugin (PetesPlugins_FreeFrame1.15 pack) wich works great with others freeframe hosts (foe ex vvvv Toolkit), but with jit.freeframe, i get very strange results : white parts of image becomes yellow !

http://mathieu.chamagne.free.fr/max/freeframe_deinterlace_ar

http://mathieu.chamagne.free.fr/max/freeframe_deinterlace_uy

too bad, it seems to be the cheaper and easier solution to really deinterlace (not just interpolate 720*288 -> 720*576).

Would it be possible to make a .jxs for jit.gl.slab to make this job in the GPU ?

It's the first time I'm trying to work with a DV cam in full resolution with Jitter, and I would find it very anoying to use half of my CPU power just to get a "clean" deinterlaced video input...

I'm sure that I'm not the only one to use a non-progressive scan camera with jitter ; I would be very curious to know how people usualy deal with this problem...

I tried the "deinterlace" Freeframe plugin (PetesPlugins_FreeFrame1.15 pack) wich works great with others freeframe hosts (foe ex vvvv Toolkit), but with jit.freeframe, i get very strange results : white parts of image becomes yellow !
 http://mathieu.chamagne.free.fr/max/freeframe_deinterlace_ar gb.jpg
 http://mathieu.chamagne.free.fr/max/freeframe_deinterlace_uy vy.jpg

It's the first time I'm trying to work with a DV cam in full resolution with Jitter, and I would find it very anoying to use half of my CPU power just to get a "clean" deinterlaced video input...
I'm sure that I'm not the only one to use a non-progressive scan camera with jitter ; I would be very curious to know how people usualy deal with this problem...

For jit.qt.grab, we were able to implement an internal "singlefield" 

filter. I will need to do a little research to see if this would also 

be possible for jit.dx.grab. It would probably be the cheapest 

Thanks for the freeframe report. I will check it out.

For jit.qt.grab, we were able to implement an internal "singlefield"  
filter. I will need to do a little research to see if this would also  
be possible for jit.dx.grab. It would probably be the cheapest  
option, CPU-wise.

an internal filter in jit.dx.grab would be very useful, I think...

and what about doing it in the GPU (jit.gl.slab) ?

On Feb 9, 2006, at 3:00 AM, Mathieu Chamagne wrote:

> an internal filter in jit.dx.grab would be very useful, I think...

> and what about doing it in the GPU (jit.gl.slab) ?

Just drop every scanline before sending to GPU as a texture. It will 

interpolatedly upsample, which is all the singe scanline filter 

> an internal filter in jit.dx.grab would be very useful, I think...
> and what about doing it in the GPU (jit.gl.slab) ?

Just drop every scanline before sending to GPU as a texture. It will  
interpolatedly upsample, which is all the singe scanline filter  
inside jit.qt.grab does.

I'm trying jit.qt.grab.help at 720x576 with a DFG/1394 1e but the singlefield attribute doesn't visually change the output; it still looks interlaced with the attribute set to 1.

Joshua's solution with two jit.matrix's works well but is slow, the solution with one jit.matrix and jit.gl.videoplane works well and is not slow.

Btw I assume that nobody happened to make a 'proper' deinterlacing shader in the mean time?

Mac OS X.4.11, Max 4.6.3, Jitter 1.6.3, Sony DCR-VX2000E

Quote: Jeremy Bernstein wrote on Thu, 09 February 2006 11:20

----------------------------------------------------

> For jit.qt.grab, we were able to implement an internal "singlefield" 

> filter. I will need to do a little research to see if this would also 

> be possible for jit.dx.grab. It would probably be the cheapest 

> Thanks for the freeframe report. I will check it out.

Quote: Jeremy Bernstein wrote on Thu, 09 February 2006 11:20
----------------------------------------------------
> For jit.qt.grab, we were able to implement an internal "singlefield"  
> filter. I will need to do a little research to see if this would also  
> be possible for jit.dx.grab. It would probably be the cheapest  
> option, CPU-wise.
>
> Thanks for the freeframe report. I will check it out.
>
> jb
>
----------------------------------------------------


Update (for the archives): I found out that the DFG/1394 1e has a built-in setting to leave out odd or even frames.

No need for any additional matrix or shader operations there (although simply leaving out half of the data is still a relatively crude way to de-interlace).

Quote: Mattijs wrote on Mon, 14 April 2008 12:28

> I'm trying jit.qt.grab.help at 720x576 with a DFG/1394 1e but the singlefield attribute doesn't visually change the output; it still looks interlaced with the attribute set to 1.

> Joshua's solution with two jit.matrix's works well but is slow, the solution with one jit.matrix and jit.gl.videoplane works well and is not slow.

> Btw I assume that nobody happened to make a 'proper' deinterlacing shader in the mean time?

Update (for the archives): I found out that the DFG/1394 1e has a built-in setting to leave out odd or even frames. 

Quote: Mattijs wrote on Mon, 14 April 2008 12:28
----------------------------------------------------
> Hi Jeremy,
>
> I'm trying jit.qt.grab.help at 720x576 with a DFG/1394 1e but the singlefield attribute doesn't visually change the output; it still looks interlaced with the attribute set to 1.
>
> Joshua's solution with two jit.matrix's works well but is slow, the solution with one jit.matrix and jit.gl.videoplane works well and is not slow.
>
> Btw I assume that nobody happened to make a 'proper' deinterlacing shader in the mean time?
>
> Mattijs
>


jit.dx.grab : how to deinterleave DV input ?