Pixel aspect ratio in Adobe Media Encoder
by Knut Högvall
on
Jul 3, 2009 at 1:08:37 pm
The problems never end, do they?
Okay, so I've created two AE compositions - one for computer screens (square pixels) and one for TV (4:3 pixels). I render the square pixel one in Adobe Media Encoder (for reasons described in earlier posts) without a hitch.
BUT, when I render the 4:3 pixel one, the encoder doesn't pick up the pixel aspect ratio, but instead renders it with square pixels! I try playing around with the pixel aspect ratio settings in the encoder itself, but it turns out the different settings there only affect the size of the picture itself, not the imported composition. What's the use of setting a pixel aspect ratio if the content isn't affected by it?
Arrrrrrgh!
How do I get Adobe Media Encoder to render a composition with 4:3 aspect ratio pixels?
Re: Pixel aspect ratio in Adobe Media Encoder by ronaldo montalvo on Jul 3, 2009 at 6:01:12 pm
first, are you trying to get a 16x9 image letterboxed in a 4:3 screen, or an unstretched "normal" 4:3 full screen image (which in NTSC is really 640x480 square pixel). also, are you looking at the size/shape of the mpeg2 file from media encoder in quicktime? if so, maybe try to burn the 4:3 dvd in Encore with that file and ensure that it doesn't work properly. quicktime can apparently see/display the size of mpeg2 files incorrectly. also, did you make sure the small button under the summary in media encoder is set to 4:3 and not 16:9? it can be a gotcha'.
Re: Pixel aspect ratio in Adobe Media Encoder by Knut Högvall on Jul 6, 2009 at 8:04:24 am
No, letterboxing or not is not what I mean. Let me try to expound:
What I do is I create demo movies of our company software. These can then be shown to prospective customers by sales staff on either computer monitors or TV monitors. Since computer monitors have square pixels and TVs have 4:3 ratio pixels, I have to render two different versions of each movie - one for computers and one for TVs (to make a circle look like a circle on both types of monitor).
This works just fine if I do it in AE - changing the pixel aspect ratio changes the aspect ratio of the content, just as it is meant to. So in AE I have created two compositions with the same content - one for square pixels (which the source material also is in), and one for 4:3 pixels (which looks squeezed together on the computer, but then gets displayed correctly on a TV).
BUT, if I render the AE compositions in Adobe Media Encoder (which I must to make the WMVs viewable on a Mac), the square pixel comp renders without a problem, but when I import the 4:3 pixel comp into Adobe Media Encoder, the content does not get squeezed together as it should. Instead, Media Encoder only changes the proportions of the picture frame itself, and then proportionally fits the content into that picture frame.
I.e. instead of a squeezed 4:3 pixel ratio movie, I get a proportionally shrunk square pixel movie running in a frame with black borders.
Media Encoder seems not to pick up the pixel aspect ratio setting from AE, but instead uses the original source directly. And then playing around with the pixel aspect ratio setting in Media Encoder has no effect on the content, only the picture frame.
So my question is - How do I get Adobe Media Encoder to produce a squeezed 4:3 pixel aspect ratio movie which will look good on a TV monitor?
(BTW, I can't find the "small button" you are talking of.)
Re: Pixel aspect ratio in Adobe Media Encoder by ronaldo montalvo on Jul 6, 2009 at 7:26:58 pm
small buttons in the basic video settings pane of media encoder, bottom line, just above bitrate settings, two buttons for pixel aspect ratio, one standard 4:3, one for widescreen 16x9.
so you're not burning DVD's but making WMW's? maybe just make the TV version a square pixel size. a TV doesn't actually "have 4:3 ratio pixels", it's just the ratio of the screen right? ultimately NTSC is 640x480. you could make your WMV version for TV 640x480. build your TV version projects in square pix 640x480 afx comps and avoid the pixel aspect problem you're having altogether.
not sure why you would make "WMV's viewable for the mac". seems like quicktime might be better.
Re: Pixel aspect ratio in Adobe Media Encoder by Dave LaRonde on Jul 6, 2009 at 9:19:21 pm
Why don't you try this:
Create TWO AE comps, one in 720x576 (4x3 for PAL TV sets) and one in the 4x3 square-pixel aspect ratio of your choice for Windows Media, like 720x540, then do all the AE work in the 720x576 comp.
It's an easy matter to nest the 720x576 comp in the 720x540 comp, and scale the nested layer to fit the comp size. Render each in the codec of your choice.
OR: Render only the 720x576 comp, reinport the file into AE, and nest the file in a 720x540 square-pixel comp, scaling the layer as before.
Dave LaRonde
Sr. Promotion Producer
KCRG-TV (ABC) Cedar Rapids, IA
Re: Pixel aspect ratio in Adobe Media Encoder by ronaldo montalvo on Jul 6, 2009 at 9:34:41 pm
sorry, maybe i'm misunderstanding what you are trying to do. do you want a 4:3 aspect ratio image for 4:3 TV or are you trying to get a widescreen 16x9 image for a 16x9 widescreen TV (which displays round circles correctly)?
the reason the circle looks oval on your tv screen is because you're rendering with an anamorphic rectangular PAR and funky media encoder is not taking that into account, not because a TV has rectangular pixels. if what you want is a 4:3 image with round circs and assuming your square pixel comps work OK for media encoder and WMV's, if you render square pixel 640x480 from square pixel 640x480 AFX comps i don't think you would have your problem.
Re: Pixel aspect ratio in Adobe Media Encoder by Knut Högvall on Jul 7, 2009 at 7:05:57 am
Ronaldo:
No, that is still not what I mean. It is not a matter of filling an entire 4:3 or 16:9 screen that is the problem. The frame (screen) proportions is not the problem. It is the differing physical size of the pixels between a computer monitor and a TV monitor that is the problem.
If I render a movie that is 10x10 pixels in size, it will look like a square on a computer monitor, but as a rectangle on a TV, because the pixels are not square on a TV.
A movie that is 1" x 1" on a computer monitor will be 1" x 1.3" on a TV. Therefore, I need to reduce the movie from (for example) 100x100 pixels to 100x75 to make it look square on a TV.
Media Encoder doesn't do this. If I ask it to change the pixel aspect ratio, it only changes the frame size, not the content proportions. (Media Encoder reduces the size of the content proportionally to fit in the new frame, so that a circle still looks like a circle on the computer monitor. I need it to look like a standing oval on the computer monitor to have it look like a circle when I show the same movie on a TV. I need Media Encoder to change the size of the content unproportionally.)
Re: Pixel aspect ratio in Adobe Media Encoder by Knut Högvall on Jul 7, 2009 at 8:03:26 am
Dave:
No, it didn't work. If I try nesting a 4:3 comp back into a square pixel comp the pixels get square again. (Which, after all, would be expected since that is how I got the pixels to be 4:3 in the first place. If if works that way one way, it's natural it would work the same the other way round.)
Re: Pixel aspect ratio in Adobe Media Encoder by Dave LaRonde on Jul 10, 2009 at 3:35:18 pm
Y'know, 720x576 video isn't intended to be played in a media player on a computer monitor. It's intended to be played on a DVD or through an editing system. If you play it any other way, things will look strange.
Dave LaRonde
Sr. Promotion Producer
KCRG-TV (ABC) Cedar Rapids, IA
Re: Pixel aspect ratio in Adobe Media Encoder by Knut Högvall on Jul 10, 2009 at 10:17:52 pm
Maybe, but then I never said anything about 720x526 or any specific size at all. I'm talking about any video, in any size. (And in my second post I explained that I am talking about the WMV file format, which is meant to be viewed in Windows Media Player.)
And I am also talking about the simple fact that different monitors do have different pixel proportions. Which fact AE addresses by offering a way to produce video for different pixel aspect ratios.
What I am wondering is why the Adobe Media Encoder doesn't offer it. And why the setting they call "Pixel Aspect Ratio" is actually a frame aspect ratio. Is all output from Media Encoder supposed to be viewed on square pixel monitors only?
Anyway, I have mailed Adobe support about the problem. Let's see if they can give an answer.
