Is it insane to encode in Xvid anamorphic ?

[mrbruno]

Hi,
I have some DVDs which I'd like to back up.
The vobs are originally 720x576 16/9 anamorphic.
(distorted picture).
Is it totally wrong to encode them just as they are
directly to Xvid ?
With such encoded files, playing is OK with BSplayer
(provided I set the aspect ration to 16/9 on the menu).
Will it be OK to play them in standolane player with
correct aspect ratio?

Thanks !

[Koepi]

The search function is your friend, this has been answered more than once.

Regards
Koepi

[begu]

Well the result looks really good, if You use high bitrate. I have a LCD projector, which uses 16:9 LCD chip.

I have a xcard too from sigma designs, and I can use it to hardware decode my encodings. Now, I just encode the full image, with no resize (of course You can crop the blacks out, and when encoding cinemascope anamorphic, it is recommended to crop the black borders in up and bottom off too) and then I set the xcard to output to standad 4:3 TV.

And here is the trick. Because the TV is set to 4:3 in xcard settings, but the projecotr is 16:9, the image gets stretched into correct 16:9 in the projector. So it is not stretched in the vertical direction, only at the horizonal.

Note: if You encode with resize, You will have to stretch the image in vertical direction too, which causes lesser resolution and quality.

I must say, that anamorphic encoding (no resize, just crop) using xvid and high bitrate (over 2000 kbps) will result very good quality even on big screen (80") out of the projector. For example LOTR using average bitrate of 2700 kbps looks almost DVD :)

[Koepi]

Cool observation :)

But I fear that you own a fairly unique setup there, I know noone with a XCard or a projector :)

Enjoy the nice results!

regards
Koepi

[Doom9]

My DivX (and XviD) capable standalone displays all MPEG-4 content in 4:3 even though the player is set to 16:9 mode. Thus, if I encode a movie at D1 resolution (better minus the black bars), play it and set the TV to 16:9 mode, it works as it should (though so far I have only stretched 1:1 DAR encoded files (which are displayed like letterboxed 4:3 content) to full screen).

Without DAR support in playback filters or containers, you have to resort to a player that can handle DAR correction upon playback. In software, the whole DAR thing is really still in the "first steps" phase.

[chilledoutuk]

one alternative is to keep the y axis as is and stretch the x axis to 1024 for example on matrix i cropped 80 off the top and bottom and then resized it to 1024x416 with lanzos and at a bitrate of about 2000 it looks great on high res displays.

p.s the xbox plays back 1024 pixel wide content fine

[symonjfox]

Just a simple question to standalone owners (and knowledged people).

Can we use a custom AR (16:8 for example) or is it better to stay with standard settings (eg. 4:3, 16:9)?

For example this way should be useful when cropping black bars from some sources, but sometimes, after cropping, both the 4:3 and 16:9 were wrong. Something between them would be needed.

I assume that in PC world it works, but on standalone? on standard TV?

[Zhnujm]

It should works like this: (it does with the Sigma players i had and the elta 8883)

The player assumes a pixel aspect ratio of 1:1 and a display aspect ratio of 4:3.
So for non-anamorphic you can just crop+resize as you would do for pc playback, and for anamorphic you have to crop and resize to adjust the pixel aspect ratio to 1:1, if you only crop the picture would be to high.
All aspect ratio settings in avi files/mpeg-4 stream are ignored by the players.

But thats not true for all players, especially some ess based have completely screwed up aspect ratios.

[ChristianHJW]

Originally posted by Zhnujm ... and for anamorphic you have to crop and resize to adjust the pixel aspect ratio to 1:1, if you only crop the picture would be to high. .. using a resizing filter for an anamorphic encoding, and in any direction ( up or down ) will completely defeat the purpose IMO ...

[patja]

I'm curious about the remark that Koepi doesn't know anyone with a projector and an xcard...I have this same setup, plus an HDTV PCI card and Immersive Holo3dgraph, and I kind of took for granted that this kind of setup would be fairly common for folks interested in encoding (good HTPC and serious home theater). This is a common setup on other forums I frequent such as avsforum. What is the more common setup that you folks use? do you watch encoded material on a PC monitor?

[mikeX]

i use a TV-out and watch on a 4:3 29" sony trinitron TV set :( (still beats pc monitors though...)

[Mug Funky]

HA! i'm interested in encoding and don't even have a 5.1 amp.

i have a TV output, but my computer isn't sufficiently close to my TV :)

then there's the problem of noisy-as-hell soundcard output (soundchip-on-motherboard)...

if i want to watch on TV, i'm afraid it's SVCD for me. hehe.

[NoLogo]

It really depends on the movie: I just encoded Dead Man (B&W, slow-motion movie) in one CD, two languages (about 80 Mo each, so the movie size is 540 Mo) in anamorphic size, and the result is just great. Other movies could be not so compressible. You have to try to know.

[Zhnujm]

Originally posted by ChristianHJW
.. using a resizing filter for an anamorphic encoding, and in any direction ( up or down ) will completely defeat the purpose IMO ...

Better a resize from 416->384 than from 416->288, i would think.

[Selur]

just wanted to mention that anamorphic encodes work fine if you mux them into a .mp4 shell ;)

Cu Selur

Ps.: got no mpeg4-SAP but a beamer ;)

[ChristianHJW]

Originally posted by Zhnujm Better a resize from 416->384 than from 416->288, i would think.

Take any anamorphic 16/9 PAL DVD, and make a fixed quantizer ( q = 5 or 6 ) encoding of

720 x 432 ( just cropped, no resizing )
720 x 384 ( cropped and resized )
720 x 288 ( cropped and resized )

I bet the 720 x 384 will need the biggest file size, by giving less vertical resolution than the full res without resize ....

[Zhnujm]

-sorry double post

[Zhnujm]

I dont doubt that, but its not a matter of what i want to do, its what i have to do to get a correct aspect ratio with current hardware players.
(720x400 in your example)