Hello Gary, thanks for your long reply. I'm not sure to understant all the technical aspects because of my poor knowledge of those things.
gary wrote:
Well I don't understand the width distortion because because 32x48 and 64x96 have the same aspect ratio, but yes, if you want to exceed the NBTVA bandwidth specification (9.6kHz) then the optimal video size would be 80x120 (for 48kHz).
Why is it 80 ? I took 64 because is it twice 32 and it was easy for me to make tescards and things.
gary wrote: Note that if you use the Brown/Robers colour format (i.e. the current RELEASE version of video2NBTV) then the overall resolution WILL be constrained by the 10kHz smoothing filter (effectively 32x48) because it produces an NBTVA standard format.
I don't know this color format
is 10㎑ enough for color ?
gary wrote: Not also though, that ideal size of the video would be 294x441 as the image will be resized to that anyway during conversion.
The picture is getting bigger, and closer to CRT television. It would make big files. I think i need to try all those different sizes an see what makes the best picture.
gary wrote:Well, that will only work (for B/R colour format) IF the resizing algorithm used by Premiere is BETTER than that used by Video2NBTV (possible but unlikely) AND, and this is a big AND, the size of the image you produce is 294x441 because, whatever you put into it WILL be converted to that size prior to conversion. If it isn't then Video2NBTV's resizing algorithm will be used anyway, therefore removing any benefit gained by resizing with Premiere.
The pictures are quite good, for movies, and everything natural. But if make testcards or abstract drawings with straght lines and squares, it gets a little blurry on the edges.
gary wrote:If you are using one of the Alpha release versions then the ideal size will be 80x120 because in that case no resizing will need to be done at all in the vertical direction (the image will converted to 32 x 120) and so the pixels in the vertical direction will be passed one for one to the NBTV video.
I'm not sure to understand. 32×120 makes a very long picture ( and distorted i guess ) So that means there are more pixels than 48, so the pixels along the lines don't have the same size as the lines ( = non square pixels )
That is the "defect" that i was trying to use in order to increase the quality ( according or not to the NBTVA format, if the thing is working fine, well it is good for me )
But non-square pixels can make some odd effect.
In a movie, if there is a zoom, or travelling on rails, as the pixels aren't square, it seems that it zooms faster in one direction than the other one.
Quite amusing though.
gary wrote:It is *probably* a good idea to do that. Video2NBTV asks DirectShow to do the conversion from the videos native frame rate to 12.5 - I suspect that DirectShow doesn't do a particularly good job of that. If the frame rate presented to the NBTV conversion algorithm is NOT 12.5 then it will use a simple drop frame or duplicate frame algorithm to compensate.
I don't know, i've never see any problem with the frame rate.
The only problem i could see is if i want to take the AVI and convert it to another standard that use more fps. It could work, but won't be the best thing ( like super 8 to VHS from 18 to 25 fps, it makes weird things while looking frame by frame )
gary wrote:Well it *should* be given the constraints given above.
mmm ok i will experiment further
gary wrote:Well, as you can see, 31 out of 32 are fine so it is NOT a resolution problem,
If you wan i can make ALL the lines like this one !
I even done new testcards to see if i could go further !
And i open this thread because i couldn't !
I thought the problem was the 48㎑. So i wanted to increase everything.
gary wrote:now this *could* be a genuine bug,
Ah yes
And i wonder how many videos were made like this before we noticed
gary wrote: but without someway of reproducing it (i.e. the original video input, version of Video2NBTV, format used) I can't be sure of the cause, nor can I fix it if it is a Video2NBTV bug.
V2 alpha, NBTVA format.
If you fix it i would keep the version with bug because i found it good. But i understand that you must be as close as possible to the club standard.
gary wrote:So if you can send me that information I can have a look at it. However, it is probably a boundary condition associated with the resizing algorithm, something I don't actually have control over, but it should be corrected by applying the resizing rules indicated above. None-the-less I would like to investigate it so if you can please send me the original video or let me know the procedure used to create it.
File was an AVI in 64×96 12.5p square pixels, color.
It was a big size file but i could post pictures. or maybe make a short file.
I just put the fil in the software and click. It makes a WAV file. Everything went fine.
Here are some pictures at the size 64×96