[CinCV TNG] Setting up a Project

igor_ubuntu sitelve at gmail.com
Mon Dec 19 22:53:31 CET 2016


> 2016-12-19 21:26 GMT+02:00 Terje J. Hanssen <terje at nordland-teknikk.no>:
>>
>  >> I have also been thinking about if the pixel aspect ratio could be set
> in SF,  it could possibly be an idea to test W.Ratio=1.33
> >> But I haven't tried this yet, as I didn't know if W. Ration had this
> meaning
> >
> >  Noop.  W.Ratio=1.3333 caused an error message that the project was
> wrong and not multiples of 4 which could not be used with OpenGL.
>


Yes, of course.  It's to be expected.  Read below.



> *Terje J. H*

       Also of interest to retriev that I asked about just these Project
settings, in HDV's childhood 9 years ago on the previous Cinelerra mailing
list.

> *   And the replies here show this was a confusing topic for more than me
> ............*
> *
> http://cinelerra.skolelinux.narkive.com/bJkYc6Og/cincvs-beginner-configuration-and-project-setting
> <http://cinelerra.skolelinux.narkive.com/bJkYc6Og/cincvs-beginner-configuration-and-project-setting>*
>


 I know this link and discussion...
Cinelerra is not only a video editing software   but and a **compositing**
software.
That is a key to many  puzzles of compositing pipeline of Cinelerra.

The function `W Ratio H Ratio` is pretty simple, actually.
*W Ratio/H Ratio means: Ratio of new canvas size (W H) to the old canvas
size (W H).*
If a user loads video to the program and adjusts  SF settings accordingly
to the input file (for example 1280x720), Cin sees these 1280x720 as 1:1
If the user changes W Ratio H Ratio as 2 : 2 , Cin changes `Canvas Size`
from 1280x720 to 2560x1440  The user can see the changes in Compositor

So the second assumption of Herman Robak was true:

*Quote:*
*they look like convenience inputs that you can use to change the current
width and height by a certain factor.*
*Usecase: The current resolution is 640x480, and for some reason you want
it to be 1.33 times wider. You don't have to calculate*
*what 640x1.33 is; you type 1.33 into the "W" input instead, and Cinelerra
calculates it for you.*

And your observation was correct:

    Quote:
...
*Third, I notice the changed values W.Ratio=2.6667 and H.Ratio=1.8750
Again, what are and what do these W and H ratios .......?*
*Playing with number ratios, look at this:*
*Width of 1080_HD_video/DV=1920/720 =2.6667=W_Ratio_for_1080_HD_video*
*Height of 1080_HD_video/DV=1080/576=1.8750=H_Ratio_for_1080_HD_video*
*Mere chanches or some reasonable explanation for these coincidences?*
-------

 In what cases we can use this *useful* function ?

For example
http://www.calcmaster.net/cinelerra/forgotten-guide/effects-transitions/motion-stabilization/

Quote:
... ....




*Right-click on the track and choose Resize track. In the Scale boxes enter
1.2 and 1.2. Under the Settings menu, choose Format and enter 1.2 for W
Ratio and 1.2 for H Ratio. Under the Settings menu choose Preferences and
go to the Playback tab...We added 20% to the width and height of the track
by scaling to 1.2 and 1.2, respectively.Since the track would then be
larger than the project, we scaled the project by the same amount.By
scaling up the track, we give the Motion effect the room to move the video
around to stabilize it.*
..


> Den 19. des. 2016 01:12, skrev Terje J. Hanssen:
>
>> ...Cin-GG continued:
>> I loaded my own hdv.m2t files again.
>> SF aspect ratio looks to change automatic to 4:3 during file load.
>>
>
Yes.  As I already said, insertion strategy `Replace ..`  in CGG  does not
work  in accordance with manual
If a user loads video (not XML), CGG changes project attributes (settings
in SF) including output size (canvas size)
Is it a bug ? A feature ?


>
>> *Igor*:
>>
>>> Did you set /Track Size/ = /as Output Size/ ?
>>>
>> *Terje J. H*
>>   No. I read the manual section but could not find the program tool to do
>> it (?)
>>
>
*Right-click on the track and choose Resize track. *

`Track Size` is an extremely important thing.
If we very simplify and generalize some things, we can say that *temporary
size, viewport of camera, track size are all the same (**from a user
perspective).*

It is absolutely necessary to carefully read this chapter 8.2 Compositing

Quotes:












*Cinelerra’s compositing routines use a "temporary", a frame of video in
memory where all graphics processing is performed.Inside Cinelerra’s
compositing pipeline, the camera determines where in the source video the
"temporary" is copied from. The projector determines where in the output
the "temporary" is copied to. ...Each track has a different "temporary"
which is defined by the track size. By resizing the tracks you can create
split screens, pans, and zooms. .. The viewport is a window on the camera
that frames the area of source video to be scanned. The size of the
viewport is defined by the size of the current track...The size of the
temporary and the size of the output in our compositing pipeline are
independent and variable....The temporary size is defined as the track
size. Each track has a different size. Right click on a track to bring up
the track’s menu. Select Resize Track to resize the track to any arbitrary
size. Alternatively you can select Match output size to make the track the
same size as the output. *
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