Using square pixel images in widescreen comp question!

B

benandaim

Well-known member
Hi Guys,

I'm doing some TVC's for a client that require images & graphics which are of course square pixels.

For the life of me I cannot get the final output ( PAL 16:9 720 x 576 1.42 ) to have beautiful crisp edges. If you set the comp to Widescreen Sqaure Pixels everything looks great but then your stuck with an output file of 1024 x 768 & that get's messed up again when you compress back to MPEG2 720 x 576 for TV delivery.

I've tried all the obvious things like interpreting the footage & putting the graphics into a PAL 16:9 template in photoshop first ( which also looks wrong )

Is it even possible to have the sqaure pixel images look perfect if your final result will be PAL 720 x 576 Widescreen???



Regards,

Ben
 
benandaim said:
If you set the comp to Widescreen Sqaure Pixels everything looks great but then your stuck with an output file of 1024 x 768
Click to expand...
When I create a new comp in AE using the PAL D1/DV Widescreen Square Pixel preset the dimensions are 1024 x 576. I think 1024 x 728 is PAL widescreen with non-square pixels. Perhaps that's part of the problem.

I would let AE deal with the math. Set up a comp using the PAL D1/DV widescreen preset (720 x 576). Just make sure the still images are interpreted properly as square pixel (1.00). You should be good to go.

I would guess the biggest reason your images don't have 'beautiful crisp edges' is because of the MPEG-2 compression. Is your client requesting that the files be delivered this way?
 
Last edited:
Hi milksac,

I have the comp set as 720 x 576 wide (PAR 1.42) & the images are all interpreted as square pixels. There's 2 things that I don't get. If I take the above situation and render an MPEG2 copy and play it on the PS3 the edges are a bit aliased. But if I burn the same MPEG2 to DVD and play it in the PS3 the edges are smooth! AGGHHH. Also if I take that 720 x 576 wide (PAR 1.42) comp and change it's settings to 1024 x 576 wide sqaure pixels the images in the comp look perfect and the edges are awesome! Trouble is the frame size is unusable as an MPEG2.
 
benandaim said:
Also if I take that 720 x 576 wide (PAR 1.42) comp and change it's settings to 1024 x 576 wide sqaure pixels the images in the comp look perfect and the edges are awesome!
Click to expand...
This is because the comp is square pixels (the native pixel aspect of your display). With a non-square comp AE does the par correction to simulate the final image. This causes the image in the comp window to be slightly soft. It does not affect the final render, it's a display issue. If your stills are large enough you can certainly work with a 1024 x 576 square pixel comp and then drop that comp into a 720 x 576 comp for rendering.

Regarding the problems with MPEG-2, there's plenty that can go wrong with long GOP compression. Frame rate, field order, data rate, etc. You might have a look at the output and compression forum to see if they can help. I usually output a file, such as Quicktime uncompressed, that I import into Avid for finalizing the spot and laying off to tape.
 
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