0000565: scale and crop effects

Notes
(0002428) ddennedy (developer) 2009-02-15 04:54	in MLT SVN r1357 and Kdenlive SVN r3048

(0002431) reinhard (reporter) 2009-02-15 22:55 edited on: 2009-02-15 23:21	Thanks for adding the crop effect, but it works not as I've expected...but maybe I'm wrong... Actually it works a little bit dynamically ;) Because when I move one of the sliders the opposite side will be affected too. For example - I move the 'Top' slider to remove some lines of pixels from the top, but the buttom of the movie moves up in addition?!? Is this the correct behaviour? Also sometimes it works more like a 'crop & zoom'... For example - move the 'Top' slider and afterwards move the 'Left' slider which zooms into the movie... I'll upload a video to illustrate the issue...

(0002433) ddennedy (developer) 2009-02-16 09:45	I understand, this reaction was somewhat exepected, but this is intended behavior to preserve the aspect ratio. It is not correct to distort the aspect ratio. So, yes, you have to remove some from neighboring edges to compensate. Alternatively, you could just use the new Pan and Zoom I have added to scale up the image slightly. I suppose one could justify slightly distorting the aspect ratio to trim tiny amounts from the edges; however, you can also easily do the more proper thing to keep aspect ratio by adjusting the neighboring edges.

(0002434) ddennedy (developer) 2009-02-16 10:29	A helpful clarification - it is preserves the pixel aspect ratio, not the display aspect ratio of the active image area. Then, it must pad the image to meet the project settings resolution and apsect ratio. Think about it like this: if you remove 50 pixels from the left edge of a 4:3 image and you want to keep the same output 4:3 image and size, then you either need to stretch the video and thereby distort it, or you can center it and pad each side, or you can scale it to fill the width, which effectively is removing equal amounts from the top and bottom. Right now, I am just not giving you the option to distort it, but if you really want to distort, then you can use the Composite transition with a color clip, which features the very obvious and scary "Distort" checkbox.

(0002436) reinhard (reporter) 2009-02-17 23:20	Ok, I think I understand your point and I also want to keep the pixel aspect ratio! At least most of time ;) But originally I thought the removed pixels would be just transparent, since I mostly need it when doing PIP compositions to remove unused pixels. So what about adding this as a option? BTW - Would also be nice to have this for 'pan and zoom', or is this a ugly/bad solution? But on the other hand - maybe I just don't understand the benefit of the actual behaviour...

(0002437) ddennedy (developer) 2009-02-17 23:27	Yes, I will look into adding an alpha mask for these.

(0002438) reinhard (reporter) 2009-02-17 23:34	GREAT, THANKS!!!

(0002542) ddennedy (developer) 2009-03-13 07:37	Fixed in kdenlive SVN r3146. This works now via the Composite transition when Align is enabled (default). Align causes the automatic padding to set the alpha channel to make padded areas be transparent. This works with anything that does padding including compositing slideshows, image clips, cropped video clips, etc. When Distort is disabled the composite rectangle acts as a bounding box, and with Align enabled it ignores the padding for positioning the overlay within the bounding box.

Issue History
Date Modified	Username	Field	Change
2009-01-04 13:21	reinhard	New Issue
2009-01-04 13:21	reinhard	Build/Install Method	=> Not Applicable
2009-02-09 09:43	ddennedy	Status	new => assigned
2009-02-09 09:43	ddennedy	Assigned To	=> ddennedy
2009-02-09 09:45	ddennedy	Relationship added	has duplicate 0000509
2009-02-09 09:45	ddennedy	Relationship added	has duplicate 0000632
2009-02-15 04:54	ddennedy	Note Added: 0002428
2009-02-15 04:54	ddennedy	Status	assigned => resolved
2009-02-15 04:54	ddennedy	Resolution	open => fixed
2009-02-15 22:55	reinhard	Note Added: 0002431
2009-02-15 22:55	reinhard	Status	resolved => feedback
2009-02-15 22:55	reinhard	Resolution	fixed => reopened
2009-02-15 23:21	reinhard	Note Edited: 0002431
2009-02-15 23:22	reinhard	File Added: crop behaviour.ogv
2009-02-16 09:45	ddennedy	Note Added: 0002433
2009-02-16 10:29	ddennedy	Note Added: 0002434
2009-02-17 23:20	reinhard	Note Added: 0002436
2009-02-17 23:27	ddennedy	Note Added: 0002437
2009-02-17 23:34	reinhard	Note Added: 0002438
2009-03-13 07:37	ddennedy	Note Added: 0002542
2009-03-13 07:37	ddennedy	Status	feedback => resolved
2009-03-13 07:37	ddennedy	Fixed in Version	=> Recent git
2009-03-13 07:37	ddennedy	Resolution	reopened => fixed
2009-04-15 13:07	madsdyd	Fixed in Version	Recent git => 0.7.3
2009-06-18 01:51	xzhayon	Status	resolved => closed