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----------------------------------------------------------------------------- Q P E G 3 8 6 F A Q ~~~~~~~~~~~~~~~~~~~~~~~ Frequently Asked Questions about QPEG386 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ----------------------------------------------------------------------------- Table of Contents ~~~~~~~~~~~~~~~~~ 1. I can't get QPEG386 to work with my graphics card. What can I do? 2. QPEG386 displays images greyscaled only. How do I get color? 3. I'm using the VESA configuration. 16 and 256 color modes work, but I can't get hicolor or truecolor. What's wrong? 4. Is it possible to switch off that annoying beep? 5. When zooming or panning across large images, the bottom part is distorted. Why? 6. When I try to zoom or pan, the screen turns black. What happened? 7. Will there be a Windows version? 8. Why is the menu screen only black and white? 9. Why do I get only greyscaled images in 16 color modes? 10. Color dithering in 256 color modes looks bad. Why? 11. It takes so long to read a directory from a CD-ROM. What can I do? 12. Which configuration file should I use? 13. VESA - what's that? 14. Zooming ('+' and '-' keys) doesn't work. What's wrong? ----------------------------------------------------------------------------- Question 1: ~~~~~~~~~~~ > I can't get QPEG386 to work with my graphics card. What can I do? First of all, perhaps QPEG386 can work with your graphics card, but you are not using the right configuration file. For more information about choosing the right configuration file please refer to the answer of question 12. Sometimes none of the existing configuration files works with a certain graphics card. In this case there are several ways: 1. Use the VESA configuration if possible. Please refer to question 13 and its answer for more information about VESA. 2. Use the standard VGA configuration (STDVGA.CFG). However, this provides only a very small number of video modes. 3. If you are an experienced programmer, you can create a video driver yourself. Of course you must have some information about your graphics hardware. Read the file DRV.DOC for more information about how to create a QPEG386 video driver. ------------------ Question 2: ~~~~~~~~~~~ > QPEG386 displays images greyscaled only. How do I get color? By default, QPEG386 uses the video mode 640x480x16 which only offers greyscaled display. To change the mode, use the '+' and '-' keys while in the directory screen (not while viewing an image!). Watch the status line in the upper window: it tells you the currently selected resolution and number of colors. Hit the '+' key until it says at least '256 colors'. Be sure not to be in greyscaled mode (if the status line says '<grey>', use the '$' key). Now QPEG386 will display images in color. You can change the default video mode by editing the initialization file QPEG386.INI. For that purpose you can use any standard ASCII text editor (e.g. EDIT which is supplied with MS-DOS 5/6). Please read the comments in QPEG386.INI, and you will be able to change QPEG386's defaults. (If you run QPEG386 from a non-writeable media, e.g. froma CD-ROM, then copy QPEG386.INI to the directory C:\QPEG386 first, otherwise you won't be able to modify it.) ------------------ Question 3: ~~~~~~~~~~~ > I'm using the VESA configuration. 16 and 256 color modes work, but I can't get hicolor or truecolor. What's wrong? In order to be able to use hicolor and truecolor modes with the VESA driver, your VESA BIOS (or VESA VBE/TSR) must be at least version 1.2. Versions prior 1.2 of the VESA standard did not define hicolor and truecolor modes. (Use the VESATEST program to get the version of your VESA VBE/TSR). Try to get UNIVBE or UNIVESA. These are TSRs (i.e. programs that stay resident in memory) which make your BIOS VESA 1.2 compatible. They are available from most major PD/Shareware sources. ------------------ Question 4: ~~~~~~~~~~~ > Is it possible to switch off that annoying beep? Yes, you can do that by editing the initialization file QPEG386.INI. For that purpose you can use any standard ASCII text editor (e.g. EDIT which is supplied with MS-DOS 5/6). Please read the comments in QPEG386.INI, and you will be able to change QPEG386's defaults. (If you run QPEG386 from a non-writeable media, e.g. froma CD-ROM, then copy QPEG386.INI to the directory C:\QPEG386 first, otherwise you won't be able to modify it.) ------------------ Questions 5 and 6: ~~~~~~~~~~~~~~~~~~ > When zooming or panning across large images, the bottom part is distorted. Why? > When I try to zoom or pan, the screen turns black. What happened? Two questions, one answer: there's not enough XMS/EMS memory. QPEG386 stores the decoded image in XMS/EMS memory (if such memory is present at all). When zooming or panning, QPEG386 copies the visible part of the image back from XMS/EMS to video memory. If you don't have any XMS/EMS memory at all, the screen will turn black. If you have XMS/EMS memory, but it's not enough for the image, the bottom part will look distorted. Remember that in truecolor modes each pixel takes three bytes (so a 640x480 image needs 900 Kb), in hicolor modes each pixel takes two bytes, in 256 and 16 color modes each pixel takes one byte. How to solve the problem? Well, there are several ways: - Don't use panning/zooming. - Use a video mode with less colors. For example, in 256 color modes an image takes half the memory as compared to hicolor modes. - Free some XMS/EMS memory. For example, if you have installed a RAM disk or disk cache program, removing it may give you some more memory. - Buy more memory. ------------------ Question 7: ~~~~~~~~~~~ > Will there be a Windows version? The current version of QPEG386 runs in fullscreen mode under Windows 3.1 and OS/2 2.1. Under certain circumstances the display doesn't work correctly under Windows (that's probably the fault of Windows). There's usually less XMS/EMS memory available when started under Windows or OS/2, so you may not be able to pan across larger images. By the way, there are plans to develop an OS/2 PM version. ------------------ Question 8: ~~~~~~~~~~~ > Why is the directory screen only black and white? I'm using the 640x480 video mode with 16 colors for the directory/menu screen, because it's a standard VGA mode common to all VGA cards. See the next question. However, it is possible to use a 256 color mode for the directory sceen by changing an entry in the QPEG386.INI file, but you must be absolutely sure that the mode 640x480 with 256 colors works fine with your graphics card. (The entry to be changed is "Interface_256_Colors".) ------------------ Question 9: ~~~~~~~~~~~ > Why do I get only greyscaled images in 16 color modes? 16 colors are way too few to display truecolor images. That's why QPEG386 displays images greyscaled when in a 16 color mode. ------------------ Question 10: ~~~~~~~~~~~~ > Color dithering in 256 color modes looks bad. Why? QPEG386 was written for speed. A 2-pass color quantization would yield better quality in 256 color modes, but at the cost of speed. To have both high speed and high image quality, use hicolor or truecolor modes. If you don't have a graphics card capable of hicolor/truecolor, buy one. They're not that expensive anymore. (To be honest, at first I didn't even plan to support 256 color modes at all, but later it became obvious that there are still many 256 color people...) ------------------ Question 11: ~~~~~~~~~~~~ > It takes so long to read a directory from a CD-ROM. What can I do? Switch 'File info' off using the '*' key before changing to the CD-ROM's directory. Now QPEG386 won't examine each file anymore to get its width and height. If you view images from CD-ROMs very frequently, you should change QPEG386's default setting for 'File info' to off, just edit the respective line in the QPEG386.INI file. ------------------ Question 12: ~~~~~~~~~~~~ > Which configuration file should I use? Most "experts" know which chipset is used by their graphics card, and therefore they know which configuration file (*.CFG) to use (or which configuration to select if you use the SETUP utility). If you don't know that, there are several ways to find it out, one of them is usually successful: 1. Have a look at the manual of your graphics card, it should mention the name of the chipset being used by the card. Often the name of the card ist identical to the name of the chipset, or the chipset's name is part of the card's name. 2. When the computer is startet (after power up or reset, before the DOS operating system is loaded) the chipset's name should be displayed on the screen. 3. Some graphics related programs and hardware test utilities are able to detect and display the name of the graphics card's chipset. 4. At the DOS prompt, enter "DEBUG". Then (at the DEBUG prompt "-") enter "dc000:0" to display the beginning of the video BIOS memory area. It usually contains the name of the graphics chipset. You can type "d" to view more of the video BIOS. (Some graphics cards which are fixed part of the main board use a different location for the BIOS, in this case try "de000:0" instead.) As soon as you know the name of the chipset, select the appropriate entry from the list of the SETUP utility. Alternatively, you can configure QPEG386 manually: delete the old configuration file (QPEG386.CFG) and copy the new one to QPEG386.CFG; then you're finished. If you can't find a suitable configuration file, please read question 1 and its answer. ------------------ Question 13: ~~~~~~~~~~~~ > VESA - what's that? First of all, the VESA we are talking about has nothing to do with the VESA local bus (VLB). You don't need a VLB equipped machine to be able to use QPEG386's VESA configurations. VESA (Video Electronics Standards Association) is a standardized method to put graphics on the screen. The advantage is that it's independent from the VGA graphics card and its chipset, i.e. QPEG386's VESA driver works with all VGA cards which are 100% VESA compatible. You may be asking if your graphics card is VESA compatible. Unfortunately not all of them are, otherwise QPEG386 wouldn't need all those drivers and configuration files, and the users wouldn't need to worry about configuring QPEG386. Have a look at your graphics card's manual, it should mention if your card is VESA compatible. Many modern cards have VESA compatibility built into their BIOS ROM, such cards work with one of QPEG386's VESA configurations. You can use the VESATEST program (distributed with QPEG386) to check if there is any VESA support. Most cards which don't have built in VESA are shipped with a driver disk, containing a so-called VESA TSR (often referred to as VBE, i.e. VESA BIOS Extension). Simply run that program before starting QPEG386 to make your graphics card VESA compatible. Again, use the VESATEST utility to check for correct VESA support. If you don't have such a VESA TSR either, you can try to get one. For example, there are UNIVBE and UNIVESA. They're freeware or shareware programs, available at most major PD/Shareware sources. They're on many graphics related CD ROMs, too. There's one small problem: There are two VESA standards, an old one (1.0 and 1.1) and a new one (1.2). The old one supports only graphics modes using 16 and 256 colors, the new one additionally supports hicolor (32000 and 65000 colors) and truecolor (16 million colors). So if you have a graphics card capable of hicolor and/or truecolor and you wish to use that capabilities, you need to have VESA version 1.2. (The VESATEST utility displays the VESA version.) Many users think that the VESA configuration is a makeshift, and that it's slow and has other disadvantages. That is not true. It supports everything that the other configurations support, and it's not noticeable slower. I'm using VESATRUE.CFG myself, although my ET4000/W32 card has a dedicated configuration (ET400032.CFG), because my VESA BIOS offers more video modes. ------------------ Question 14: ~~~~~~~~~~~~ > Zooming ('+' and '-' keys) doesn't work. What's wrong? First, be aware that those two keys just increase and decrease (respectively) the graphic resolution. For example, in 800x600 mode, pressing the '-' key changes to the next smaller resolution (usually 640x480), effectively zooming into the image (because the image appears bigger because of the lower resolution). Note that the number of colors does not change, i.e. QPEG386 won't switch from hicolor to a 256 color mode this way, for example. (This can be done from the directory screen only.) This leads to the following problem: Many commonly used graphics cards only support one truecolor resolution, namely 640x480. Thus, if an image is displayed in that mode, the '+' and '-' keys don't have any effect, because there are no truecolor modes with lower or higher resolution. The problem can be solved by not using the truecolor mode, but using hicolor modes instead. Then there are more resolutions available (usually 320x200, 640x480 and 800x600), therefore you can use the '+' and '-' keys. Don't worry about the image quality: You will hardly notice any difference because of QPEG386's advanced dithering algorithm which is applied in hicolor modes -- resulting in truecolor-like quality. -----------------------------------------------------------------------------