1:1 becomes stretched on 'Philips DVD737'

[AndiDog]

Hi

I created an AVI file for test purposes: 720x576, XviD, 1:1.
It contains a square (400x400 pixels). The pixel aspect ratio is 1:1, so I thought it must show on displays in exactly the aspect of 720/576. As a matter of fact, thats what all of my software players did (WinAMP, vlc, MediaPlayerClassic...)

Well, my standalone player 'Philips DVD737' stretches the video onto the TV screen - I measured it with a ruler. It seems like it's resized to 768x576, but damn it's not a 4:3 PAL DVD!

Now finally my questions:
1) Am I right if I say my standalone player is doing it wrong?
2) If yes, do other players display it correctly with the aspect 720:576 = 5:4 (alias PAR 1:1) ?

[SeeMoreDigital]

First....

I think you need to do some lurking around and read up about "anamorphic" images... and what they really look like, before and after aspect ratio signalling has been applied ;)

[AndiDog]

I think I already did a lot research with some ambiguous stuff about anamorphic videos.

For example, if I have a 16:9 PAL DVD with 720x576, I learned that it must be resized to 1047x576 (stretch by the PAR 16/11 defined in the ITU *whatever* standard) -> this is the display resolution, i.e. on the screen it must have an aspect of 1047:576.

In my video, I want the square to be displayed as a square (not a stretched rectangle!) -> ergo 1:1.

Thus, my hardware player is doing it wrong by showing it as a rectangle...right?

[SeeMoreDigital]

Well... not all MPEG-4/DVD players offer support for playing back MPEG-4 encodes with aspect ratio signalling!

Try these samples (http://www.one.seemoredigital.net/MPEG-4_Player_Test_Files/MPEG-4_AR_Signalling_Test_Cards_Videos.7z) and report your findings?

But as the Philips DVD737 is fitted with an ESS Vibratto S chip-set, it's too old to support aspect ratio signalling detection!


Cheers

[AndiDog]

The player didn't play them at first, so I reencoded with the XviD PAR's 4:3pal and 16:9pal.

Then it worked, and like I guessed the player doesn't use the files' PAR at all:
- the 720(768) movie is displayed with perfectly round circles
- but the 720(1024) movie is displayed like VirtualDub would show it: unprocessed!

So, my result is: The Philips DVD737 does assume PAR 4:3, no matter which info is in the mpeg-4 stream :(

[SeeMoreDigital]

So, my result is: The Philips DVD737 does assume PAR 4:3, no matter which info is in the mpeg-4 stream :(Indeed... your player is performing as I had expected ;)

The fact is the ESS chip-set completely borks when it's fed with MPEG-4 streams containing aspect ratio signalling conforming to DAR values and plays all other types of MPEG-4 streams with aspect ratio signalling conforming to PAR values at 1:1 :eek:


Cheers