Resolution Aspect Ratio Zoom Nightmare

[Fredledingue]

I bought yesterday a dvd-divx player (brand: unkown) (ok, it's a Vido if you realy want to know) because it was the one that could play the best the most formats, GMC, etc

Now the problem is that almost all my movies are 640-480 and my TV in PAL and it seems that my player will always refuse to play them at a correct size and aspect ratio
.
Theoricaly I should have black stripes on bottom and top. Instead I have it full screen with not only left and right cut off, but also bottom and top! Meaning that the dvd player zooms in too much and show only the center.
Worse! My movies are already cutoffs from original PAL format (I created DivX to fill a PC monitor or a fill better a wide screen tv because PAL is very bad on wide screens). So you can imagine the loss of picture content!
Even worse! Because the movie is zoomed in, the pixelisation appears much worse than on my PC.
While when I connect my PC to the same tv, it looks better than on the monitor.

So I was telling myself "fine, I will change the settings." The instructions wrote clearly how to set it as "LetterBox" and that it should then show the full picture the way I want. Nope! It's working only with ORIGINAL dvd's, not even with self-made dvd's! And makes no change at all on the DivX display.

I also tried to play with the tv set settings, ntsc settings etc, I tried everything and the best I can have is black stripes all around the picture when I zoom out at 1/2. :(

Then I came back to the store and told them I wanted to change my player to another one which will play normaly.
We tested other devices and they all had the same debilitating problem. Even worse: a panasonic stretched the picture ugly to fill the screen and there were no way to avoid that.
I went to 3 other stores and they told me that all the devices played DivX the same way.
BTW some players, like a cheap Philips had very bad decoding quality.

So my question is why are the conceptors of dvd-divx players such morons?

We already know the problem of wide screen tv that never produce a picture with a correct PAL ratio. You know, these famous $3000 - 2500 euros flat screen tv's that can't get a correct, non-distorded picture. (Thus those overstreched tv broadcasts at the airports)

So now we can add to that the DVD-DivX ratio distortion. And don't beleive that buying a wide screen will necessarrily fix it!

As far as I remember Yamada (not Yamaha!) gives a good aspect ration "as on a PC".

So one advice if you buy a player, check this out.

[SeeMoreDigital]

Can you have a look inside the player and let us know what chip-set is inside?


Cheers

[Fredledingue]

No. I won't open it because I want to resel it for that reason. It's written D403 DivX if rings you a bell...

This player is able to play DivX-GMC-QP even at high bitrate and high resolution as well as XviD normal.

The zoom OSD logo is the same as on the Philips, so I imagine they took the same software but it decodes much better than the Phillips (less pixelisation).

There is no information at all about this made-in-China (Hong-Kong) product and there is even no website on Vido except another, non related company with a similar logo, but that doesn't seem to be producing dvd players in China... Strange...

Anyway, the zoom and/or aspect ratio problem was on every dvd players I tried at the store and in other shops, they told me that it was the same with all the players they know of.

[SeeMoreDigital]

If the player can decode Qpel, then it's most likely to be fitted with an MediaTek MT1389xx chip-set.... followed by the Zoran Vaddis 77x

Both chip-sets are able to support AR signalling detection but not all manufacturers are as pro-active at modifying firmware, as others!

[manono]

Hi-

I may be stepping into a can of worms here but:

Now the problem is that almost all my movies are 640-480 and my TV in PAL and it seems that my player will always refuse to play them at a correct size and aspect ratio

Theoricaly I should have black stripes on bottom and top.

Why do you say that? Your AVI is 1.33:1, and so is your TV set, isn't it? So the AVI gets scaled to fill your screen entirely, without any black bars being added. You are losing picture on all 4 sides because of the TV overscan, and as the people at the stores told you, it's true for all TVs, to a greater or lesser degree. In addition, some players do some cropping of their own. I don't know if this is true of your player or not.

The only way to avoid losing picture to the overscan is to encode your AVIs with black bars added all around.

And if you cropped your widescreen movies to make them full screen, as you seem to be saying, then I have no sympathy for you.

[SeeMoreDigital]

In situations such as this it's handy to know the shape of the TV the player is connected to (ie:4:3 or 16:9). And more information about how your encodes have been generated.

If most have been encoded using 640x480 pixels. Does this mean you've kept the black mattes as well, when backing up 1.77:1, 1.85:1 and 2.35:1 movies?

Unfortunately some people do some very weird cropping and/or re-sizing and finish up with encodes at all kinds of strange shapes.... So without seeing some (uncorrected) still frame captures from your encodes it can be difficult to offer good advice!


Cheers

[Fredledingue]

Manono,

No my tv-set is a PAL tv (europe) and it's 1.222/1.
As I explained above almost all my DivX's are encodes from captured tv broadcast.
In Europe, tv is braodcast in PAL format and full capture of PAL format is, with my capture card, 704x576. If I play 704x576 movies on my 1.33/1 monitor, or even worse on a wide screen that I will eventualy buy in the future, I will have black stripes on right and left and that's much worse than stripes on top and bottom IMO.

If it was a problem with tv-overscan, it should be cropped on left and right with still black stripes on top and bottom.
Here it's cropped everywhere and the player doesn't crop the movie because it shows the full picture when zoomed out.

The only way to avoid losing picture to the overscan is to encode your AVIs with black bars added all around

That's true, one movie was like that and it played indeed very fine. The only problem when doing that is that when you play it on a wide screen or on a monitor then you get framed all around: top botttom, left and right! And you then better have a good scalable zooming capability! ;)... and zooming always incure visible loss of quality. On top of that black stripes are taking a significant amount of datas and a hell of a lot longer to encode.

Yes, I cropped my movies, but it was cropped bottom and top, from a format looking more like a square than a rectangle, a format not standard with PC monitor (thought now they do "Pal" monitors as well), and because many movies were broadcast with black stripes, cropping the original capture didn't, in many cases, incure loss of pictural content of the movie. I mean in some cases, the only things I cropped were black borders!

SeeMoreDigital

Well, take any 640x480 picture and you get a caption of the movie I'm watching at.
I'm always cropping off the black stripes, sometimes I have height lower than 480, but most of the time it's 640x480 - Period.

To tell the extent of my disapointment, I used to watch DivX with my laptop connected to the tv, the movie playing full screen and I got a perfect centrage/fill on my tv-set.
I have also watched movies with a player (see the brand at the end of my first post) that played as well as my laptop tv-out, good aspect ration, no cropping etc, so why now, i'm told at the stores that all brands (Philips, LG, Panasonic etc)are doing the same debile stretching or bad resizing non-sens?

How come no one at the manufacturers have ever noticed that? 2 years after!

It was so obvious to my that prefect fit was a long solved problem, that I didn't mind checking that when I bought the player.

I only wanted is warn future DVD buyers about that.

[SeeMoreDigital]

Well, take any 640x480 picture and you get a caption of the movie I'm watching at.
I'm always cropping off the black stripes, sometimes I have height lower than 480, but most of the time it's 640x480 - Period. In light of what you say I really need to see some still images of some of your encodes before commenting further!

Most software media players offer (uncorrected) still image capture. I personally use either MediaPlayer Classic, ShowTime2 player or VLC player.... Once taken, you can use ImageShack (http://www.imageshack.us/) or TinyPic (http://tinypic.com/) to upload/make the images visible on the Doom9 Forum


Cheers

[Fredledingue]

I don't know what you will do with a normal 640x480 jpg picture but if you insist I will post one...

[SeeMoreDigital]

I don't know what you will do with a normal 640x480 jpg picture but if you insist I will post one...I need to see some examples of what your encodes look like.... And not just from one of your encodes.... From a few of them please!

[Fredledingue]

here you are...

[SeeMoreDigital]

here you are...It looks as though your images are taking some time to become approved.

Could you upload them to say ImageShack or TinyPic and create links to them here on Doom9 please?


Cheers

[Fredledingue]

Huh?
If I click on the links, they appear instantly...

[SeeMoreDigital]

Huh?
If I click on the links, they appear instantly...They will do for you.... because they're probably in your "temp internet files" folder!

Howerver, I see this: -

http://tinypic.com/f1crxl.png


Cheers

[Wolfman]

Most peoples have a digital camera (or can at least borrow one ) it would help everyone greatly if aspect ratio problems could be accompanied by a photo of the "offending video" being displayed in all its glory on the Tv. Maybe with deatails of the source, destination and processing so far
a picture is worth a thousand posts :helpful:
(compress picture to jpg of 200-400k, less than 1mb) ;) ;)
do not accidentally post THE pictures of your wife

[Fredledingue]

LOL.

But as I said, take any *.jpg picture of 640x480 pixels and you will have the same thing as I posted above in attachment (just a different subject).
But ok, when i'll have time I'll post them on imageshack...

[mimungr]

No my tv-set is a PAL tv (europe) and it's 1.222/1.
As I explained above almost all my DivX's are encodes from captured tv broadcast.
In Europe, tv is braodcast in PAL format and full capture of PAL format is, with my capture card, 704x576..
PAL pixels are not square. You can't simply divide the horizontal resolution by the vertical resolution to compute the display aspect ratio. Your PAL TV is indeed 4:3.

If I play 704x576 movies on my 1.33/1 monitor, or even worse on a wide screen that I will eventualy buy in the future, I will have black stripes on right and left and that's much worse than stripes on top and bottom IMO.
The pixels on your computer monitor are square. The black stripes are not due to PAL being narrower than 4:3; they are due to your not resizing the video properly to account for the different pixel aspect ratio.

[SeeMoreDigital]

Hi Fred,

I'm sure the images you've attached will be fine for my needs

Sadly we don't have a moderator for this section of the forum so I guess that's the reason why your images ave not been approved yet :(

But like I mentioned before you can use ImageShack or TinyPic and create direct links to your images instead.... like I did ;)

[Fredledingue]

http://img51.imageshack.us/img51/1046/cordoe02jb.th.jpg (http://img51.imageshack.us/my.php?image=cordoe02jb.jpg)

[Fredledingue]

Seemoredigital,
Can you click on the picture above?
-------

Mimungr,
There is not such a thing like "pixels" for Pal, but a number of lines created by a flux of photons in the tv picture-tube out of an analog stream.

The digital-to-analog TV output device should have a fixed and correct ratio to translate a line of pixels into a line on the tv screen AND NOT to try to fill the screen by distorting the picture or by zooming in exageratly when the height and with ratio are not that of a Pal tv.

(DivX pixels are supposed to be square unless you encoded otherwise, but practicaly nobody is doing non square pixels and I don't know how the dvd-players will interpret them.)

I have seen a panasonic player stretching the picture to fill the screen, which is a total non sens IMHO.

Other players of known brands and unkown brands as well that I tested grossly zoomed in with a too big zoom factor that cut ALL the borders also in a bet to fill the screen as if it was an obsession.
But kept a correct aspect ratio.
If you want to zoom in to fit the screen you do so as to put the top of the video at the top of the screen and the bottom of the video at the bottom of the screen. But you don't zoom more than that. They do.

I also don't understand why a 1 and half years old Yamada player, an even older laptop and my PC are all diplaying the video properly on my television set and not the new DVD-DivX players made for this specific purpose...

If the height is too small for a given width to fit the Pal format, it just had to fill with black the rest of the screen. It's not that difficult. Or is it?

[SeeMoreDigital]

Well that particular (cordoe02jb.jpg) image you uploaded is "all image"..... ie: there are no mattes.

Provided your stand-alone player is up-to the task and correctly set up (along with your TV) you really should not be having any problems playing back that encode at the correct aspect ratio, on either a 4:3 or 16:9 (wide-screen) TV.

Just for the record.... Although we like to think of pixels as being traditionally square (as found in still images), when it comes to video, a pixel can be given a shape, effectively to "any" ratio you like. This is done by allocating and embedding an AR signalling code within the MPEG-4 stream (The same goes for MPEG-2 streams in DVD VOB).

Some stand-alone players can detect such AR signalling codes and display the video accordingly ;)


Cheers

[Fredledingue]

:thanks:

[mimungr]

Mimungr,
There is not such a thing like "pixels" for Pal, but a number of lines created by a flux of photons in the tv picture-tube out of an analog stream.

I was referring to the digital representation of PAL signals as specified in ITU-R BT.601. Sorry if that wasn't clear. In any case, the pixels output by your video capture device conform to ITU-R BT.601 and are not square.