[dev] Need some advice for Wide screen problem

Hi there ...

I need some help, explanation concerning the handling of graphics for wide screen.

I explain the problem, when graphics are drawn on common widescreen TV they will look horizontally stretch. Look at the "disc" icon in OPL, they are not round ...

I would like to know what solution there are ?

I see one unsatisfying workaround (but I fear it is the only one available in fact ...): scaling down horizontally the graphics that have to be drew on widescreen. That will work but you loose pixel definition and image may get blurry.

Thanks

PS: it is a "DEV" concern, not a user one ;)

This isn't even really an OPL issue but more of a GSM.

Certainly. Besides, I did not stated it was only related to OPL ;)

I know every graphic app will encounter this situation, and that's why I created a new thread, so any dev from any project could share how he suggest to process this issue :)

I think about another question, is there a way to detect the screen (TV) resolution, either 4:3 or 16:9 ? I guess not, as even commercial game may have an option for "wide screen".

1 Attachment(s)

Most games that support 16:9 won't have the option on their settings screen though, as it can be read from the Mechacon EEPROM ("Screen Size" at "System Settings") and I believe that may affect how the game behave when GSMode is being used. I'm not sure about this as I'm not a GSM user myself.

But then, I only have 4:3 displays here. :crazy:

Quote:

Originally Posted by l_oliveira

Most games that support 16:9 won't have the option on their settings screen though, as it can be read from the Mechacon EEPROM ("Screen Size" at "System Settings") and I believe that may affect how the game behave when GSMode is being used. I'm not sure about this as I'm not a GSM user myself.

But then, I only have 4:3 displays here. :crazy:

Ooh I did forget this settings in the PS2 Browser !

1. But if this general setting exist, why does some games (I have in mind God Of War, but I can remember there are a lot more) ask the user to set his screen resolution ... ?

2. Let assume I want to use this info, do you know which API I must call to get it ... I will search in the gsKit first

3. To be sure what I understood. In 4:3 or 16:9, the screen resolution is the same, it is just that in 16:9 the horizontal display is stretched ? Am I right ?

4. What are the screen resolution in PAL and NTSC, I am a little bit confused as OPL use background image of 640x480 for both ...

EDIT: I got the screen resolution for PAL and NTSC (along with other modes ... GS_MODE_DTV_480P, GS_MODE_DTV_1080I, ...) in the file gsKit/examples/basic/basic.c

GS_MODE_NTSC
Width = 640
Height = 448

GS_MODE_PAL
Width = 640
Height = 512

EDIT2: Problem "solved". I used the workaround (in my first post), which finally looks good enough.

Quote:

Originally Posted by Gilgamesh88

Ooh I did forget this settings in the PS2 Browser !

1. But if this general setting exist, why does some games (I have in mind God Of War, but I can remember there are a lot more) ask the user to set his screen resolution ... ?

One reason is that they obviously don't expect everyone to have their console configured properly for their hardware. It's quite natural really, as a large portion of the game product target demographic are kids.

Quote:

2. Let assume I want to use this info, do you know which API I must call to get it ... I will search in the gsKit first

I'm not really sure, as I never bothered to read that info in any application I worked on.

Quote:

3. To be sure what I understood. In 4:3 or 16:9, the screen resolution is the same, it is just that in 16:9 the horizontal display is stretched ? Am I right ?

No of course not. But if you have a normal old-fashioned 4:3 signal and tell your widescreen TV that this signal is to be treated as 16:9, then of course it will be magnified horizontally.

The thing is that for any normal TV signal standard the given signal timing interval of a video line is always the same length, regardless of how many visible pixels it represents (63.5 microsec for NTSC, 64 microsec for PAL). So for proper 16:9 usage the same amount of time should have more pixels crammed into it than would be the case for 4:3 usage of the same time period.

So for a game that uses 16:9 properly, a change to that setting will cause the game to maintain the same screen height in pixels as before, while adding 33% additional graphics distributed at both the right and the left edge of the screen, and timing-wise this requires compressing all the pixels per horizontal line, so as to make room for the new pixels at the start and end of the scanline period. In other words, the pixel rate will be higher.

Very few games do this, but FF12 is one of those that does do it correctly, and SMS is one of the few homebrews with support both for widescreen use and HDTV modes as well. (Assuming you configure and use it correctly)

Quote:

4. What are the screen resolution in PAL and NTSC, I am a little bit confused as OPL use background image of 640x480 for both ...

The standard PS2 resolution for PAL is 640x512 and for NTSC it is 640x448.

Note that there is no PS2 SDTV standard for 640x480, as no standard NTSC screen is capable of displaying 480 lines (before HDTV innovations). The original 480 line value of NTSC specs relates to the 'overscan' area of the NTSC standard, which defines the recommended screen area that should contain real picture modulated signal for all commercial TV use, so that the picture displayed on all healthy NTSC TV sets shall never include any 'blank' signal portion, even on slightly misaligned sets. So between the PS2-used screen height and the overscan height there is a 32 scanline difference, evenly distributed as a top and bottom 'safety margin' of appx 16 scanlines each. The 448 pixels height used by a PS2 for NTSC should match (within a pixel or two) the total screen height that a normal well aligned and trimmed pre-HDTV NTSC TV set can really display.

The corresponding PAL overscan area height is of course 576 lines, which allows for a line-count safety margin of 32 scanlines at top and bottom, which is a bit exaggerated. But basically the usage is the same, with the 512 scanlines used by PAL games for the PS2 being centered on the screen.

I assume you are already familiar with the fact that the total scanline count of NTSC and PAL SDTV sets are 525 and 625 respectively (including VSync and blanking periods), but with only half that amount of scanlines available per video half-frame (the total amount available only through interlacing.

Now with the innovations of modern electronics and HDTV sets, a lot of the old standards needed to be changed. For one thing modern TV sets can auto-align their screen displays digitally, eliminating all need for the huge overscan margins which were only motivated by the imprecision of the analog units of old. But it still made sense to keep some of the relationship to the older standards.

IMO that is why the primary HDTV modes of 480p and 576p were defined.

Essentially they allow exactly the same circuitry and methods to be used in parts of the video processing as for an old overscanned TV signal, with the difference that it is then sent to the TV set not as an interlaced sequence of half-frames, but as a progressive sequence of full-frames.

For both PAL and NTSC the screen width of a PS2 is normally defined as 640 pixels, or half that for a low rez program (most PS1 games used 320x224). NTSC games are often simply ported to a PAL mode, without adding extended graphics, instead just adding wide black borders at top and bottom, so that the screen section used for the graphics remains as used in the NTSC game. This is the simplest possible port method, but is flawed in that the higher density of scanlines in PAL resolutions will make everyone and everything look 'fatter'. This is because the 640 pixel width used in both game versions does occupy the full screen width of both, whereas the 480 pixel height which fills the NTSC screen leaves large unused spaces on the PAL screen, the effective height being compressed to appx 93% of the full screen height.

A proper port to PAL requires reworking all graphics throughout the game in order to compensate for the higher line density, but very few game companies bother to even try doing this right. So PAL users are quite used to disproportionate graphics of various kinds.(Circles and spheres that are not round etc.)

Now for the complexities of widescreen modes:

While few companies bother to compensate for PAL proportions, it is not surprising that even fewer companies have bothered with proper widescreen implementation. Most simply ignore the problem and continue to generate 4:3 graphic screens, and proper viewing of these naturally require that you use a TV set in 4:3 mode, even though that does leave some parts of the screen unused. If the programmers didn't supply any extra graphics for those areas, then there is no way such graphics can automatically be generated.

This is also quite understandable, as it would mean having to predefine 33% more graphics, which will never even be used when using 4:3 mode. Those 33% not only increase the development work, but also increase the storage space needed, possibly forcing a game that could be stored on DVD5 media as 4:3 to use DVD9 media to make room for the 16:9 graphics. For such cases it is a frequent choice to stick with 4:3 graphics, to keep down the production costs.

And when displayed on a 16:9 screen in 16:9 mode such 4:3 graphics will of course look awful, just as it will look awful if you tune the TV to a channel showing an old show in 4:3 proportions and you then switch the set to 16:9 mode.

The responsibility for that awfulness rests as much with the user and TV set design, as the proper thing to do when seeing that a picture needs 4:3 display is to simply switch the TV set to 4:3 mode. (ALL proper widescreen sets should have such a 4:3/16:9 choice in some menu) So this is what you should do for any material shown with the wrong proportions, regardless of whether it is a TV show, a PS2 game, or the display of some homebrew like OPL.

Now you may wonder why such manual choices are needed, when the TV set always manages to switch automagically between 4:3 and 16:9 when connected to a DVD player with HDMI connectors. But here the answer is found in the question (as is often the case), as an HDMI connection is a digital connection, which always conveys the screen size info.

But when using a 'component' or SCART signal from a PS2, no such size information is available to the TV set as all the signals are purely analog, just as when the same TV set receives a transmission from a purely analog TV channel (yes, they still exist). For all such cases the TV only knows the timing intervals of the incoming signal, and that is identical for 4:3 and 16:9 material. This makes it impossible for the TV set to know the difference, which makes it the responsibility of the user to set the correct mode.

Now, the intended solution for such problems with a PS2, is to have the programs read the configured screen size setting (the one chosen in OSDSYS menu), and adapt their screen output accordingly, always by adding new graphic material. But as discussed above nearly all game designers (and homebrew designers) just ignore this setting, even in the very few programs that have 16:9 properly designed, thus moving the responsibility for choosing proper modes both for the game software and the HDTV hardware fully and permanently onto the user.

Now as for adding widescreen support to a pure game launch menu like that of OPL, I really don't see any point to it, though I suppose the eye-candy fanatics disagree. It would certainly make a mess of things for the theme designers, as a demand for non-stretched 16:9 backgrounds would require replacement of all existing theme designs. Possibly with duplicate background images for 4:3 and 16:9 versions of the background.

Themes are bad enough as-is when it comes to consuming MC space, but with widescreen complexities added I don't see anyone using themes for MC-only setups. It might be OK for USB-based setups, but never for MC...

Best regards: dlanor