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- Q P E G F A Q
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- Frequently Asked Questions about QPEG
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- Table of Contents
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- 1. I can't get QPEG to work with my graphics card. What can I do?
- 2. QPEG displays images greyscaled only. How do I get color?
- 3. I'm using the VESA driver. 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?
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- > I can't get QPEG to work with my graphics card. What can I do?
-
- There are several ways:
- 1. Use the VESA configuration. If your BIOS doesn't support native VESA
- compatibility, try to get UNIVBE or UNIVESA. These are TSRs (i.e.
- programs that stay resident in memory) which make your BIOS VESA
- compatible. They are available from most major PD/Shareware sources.
- 2. Use the standard VGA configuration (STDVGA.CFG and STDVGA.DRV).
- 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 QPEG video driver.
-
- ------------------
-
- > QPEG displays images greyscaled only. How do I get color?
-
- By default, QPEG 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 QPEG will display images in color.
- You can change the default video mode by editing the initialization file
- QPEG.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 QPEG.INI, and you will be able to change QPEG's defaults.
-
- ------------------
-
- > I'm using the VESA driver. 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.
- 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.
-
- ------------------
-
- > Is it possible to switch off that annoying beep?
-
- Yes, you can do that by editing the initialization file QPEG.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 QPEG.INI,
- and you will be able to change QPEG's defaults.
-
- ------------------
-
- > 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.
- QPEG stores the decoded image in XMS/EMS memory (if such memory is present
- at all). When zooming or panning, QPEG 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.
-
- ------------------
-
- > Will there be a Windows version?
-
- No, not in the near future. QPEG 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.
-
- ------------------
-
- > 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.
-
- ------------------
-
- > Why do I get only greyscaled images in 16 color modes?
-
- 16 colors are way too few to display truecolor images. That's why QPEG
- displays images greyscaled when in a 16 color mode.
-
- ------------------
-
- > Color dithering in 256 color modes looks bad. Why?
-
- QPEG 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...)
-
- ------------------
-
- > 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 QPEG won't examine each file anymore to get its width and
- height. If you view images from CD-ROMs very frequently, you should change
- QPEG's default setting for 'File info' to off, just edit the respective
- line in the QPEG.INI file.
-
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