[Kdenlive-devel] Title Widget / Monitor scene speed

[Dan Dennedy]

On Sat, Aug 21, 2010 at 1:01 PM, Dan Dennedy <dan at dennedy.org> wrote:
> On Sat, Aug 21, 2010 at 7:30 AM, Till Theato <root at ttill.de> wrote:
>> -----BEGIN PGP SIGNED MESSAGE-----
>> Hash: SHA1
>>
>> Starting in January 2011 I have the opportunity to write a research
>> paper (correct term?) for school. I have been thinking about writing a
>
> yes, correct term.
>
>> MLT filter for masking using bezier curves (like masking using a
>> polygon) & and a Kdenlive GUI for it. Combined with your idea this would
>> be very useful.
>
> My concept would make "Set mask" be somewhat generic and take any
> producer. So, for example, the editor would be a QGraphicsScene, and
> Qt can generate SVG Tiny from the drawn shapes via QSvgGenerator paint
> device. That SVG would be fed into the MLT qimage producer that is
> used by the mask-setter. One could also use a file made in another
> tool - even a video. (Final Cut lets one drag a file from the clip bin
> onto the filter's file widget.)
>
> Other properties on the mask-setter could use image attributes instead
> of a producer - for example, all pixels that fall within a hue range.
> Yes, it might be nice if this selection mechanism were extensible
> entirely through the other filters, but I think that crosses the line
> into the territory of node-editing and my head starts hurting because
> I still have to figure out how to integrate the mask with the motion
> tracking stuff.

Hmm, just playing around with the new Alpha selection effects, and I
should add the option to use the alpha channel. Possibly, I could have
a mask-define, which will snapshot the alpha and optionally clear it,
then allow filters to operate on alpha until a mask-set, then allow
filters that apply to primary image channels until mask-apply, which
will finally composite the filtered image using the alpha channel over
the snapshotted image (in mask-set), and restore the snapshotted
alpha, and clear the mask. For example:

Levels
Mask define
    Alpha shapes
Mask set (from self or file, using alpha or luma)
    3 point balance
Mask apply
Contrast

>>>
>>> Just some thoughts.
>>>
>>>> I guess what you mean is that e.g. moving objects has a delay of around 0.2 s?
>>>>
>>
>> For me the delay is much longer 0.2 s. Maybe around 1s.
>
> I seem to recall some interesting blog posts on the Nokia Qt site
> about QGraphicsScene performance.
>
>> -----BEGIN PGP SIGNATURE-----
>> Version: GnuPG v1.4.10 (GNU/Linux)
>> Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/
>>
>> iEYEARECAAYFAkxv4u0ACgkQzwEyz7QP6nRlZACgwuMIDLSRh4f5s1f389Sh6/v7
>> qeQAnjtejgijjgbE4X7fW6UfT+0vwFko
>> =TI72
>> -----END PGP SIGNATURE-----
>>
> --
> +-DRD-+
>



-- 
+-DRD-+