Aspect Ration and frame extraction
Up one level
Aspect Ration and frame extraction
for several versions now, ELAN has imposed an arbitrary aspect ratio on my .dv files.
To avoid this problem, I would convert them to .mov files, but now ELAN 3.8.0 does the same thing to .mov files.
This is not so serious because I can convert any measurements extracted from images using a simple transform.
Unfortunately, now frame extraction quality depends not on the source information, but on how much I have zoomed in or out the videos (MAC, coco viewer). The result is that frame extraction is only practical on a 24 inch screen :(.
It would be really good if users could set their own aspect ratios and stipulate that frame extraction is based on the quality of the source material, not the view screen.
Thanks!
DD
P.S. - I can prove both these claims via screen-shots, etc... if that will help.
Re: Aspect Ration and frame extraction
In almost all cases the aspect ratio used is the one reported by the media framework that plays the file. With the exception of mpeg-1 files on Mac, which QuickTime seems to like to display as 320x240; here we try to read image size information from the mpeg header and use that for the aspect ratio. ELAN does not interfere with DV files, it is completely up to the player framework.
The same for image extraction, the framework is just asked: give me the image for frame n. But here it seems not possible to override QT behaviour and it might be that the image is a bit smaller than expected.
But there will probably be an option to force a certain aspect ratio in a future version of ELAN; several reports have been issued on distorted video's, so it makes sense to make it possible for the user to change this.
-Han
Release of ELAN 4.3.0
