     HOW TO CREATE MPEG-VIDEOS FROM YOUR FAVOURITE PARTS OF   D O O M  !

This text is donated to the public domain.

What you need:
  - DOOM   (I've only the shareware-version, but it should work with the
    registered version and "Hell on Earth" as well.)
  - a graphics-converter, that supports PCX and PPM, e.g. IMAGE ALCHEMY
  - the PV-MPEG-package, containing PVRGMPEG.EXE and PPM2CYUV.EXE
    (I found it on  ftp.tu-clausthal.de , but it's probabely available from
    other sites as well.  There are also several MPEG-Players available from
    ftp.tu-clausthal.de )
  - a large hard-disk :-)


What to do (overview):
  1. Record a demo.
  2. Make many screen-shots while playing the demo.
     (It's rather difficult to make the screen-shots, while actually playing
     the game.  Therefore I prefer recording a demo first.)
  3. Resize, gamma-correct and convert the screen-shots to the PPM-format.
     (Image Alchemy is extremely good for this job.)
  4. Split the PPM-files into three components using PPM2CYUV.EXE.
  5. Create the MPEG-Video using PVRGMPEG.EXE


More detailed description:

1. Recording a demo

  Call DOOM with the following command-line:

  DOOM -devparm -warp 1 2 -skill 3 -record NAME

  Substitute "2" with the desired level and "3" with the desired skill.
  "NAME" can be any legal file-name without extension.
  If you use the registered version, substitute "1" with the desired episode.
  I don't know what changes are required for "Hell on Earth", but I've been
  told, that it doesn't feature several episodes, so you might have to ommit
  this "1".

  Don't use any cheats while recording.  At least my shareware-version
  won't record any cheats.


2. Playing the demo and creating a series of screen-shots

  Call DOOM with the following command-line:

  DOOM -devparm -playdemo NAME

  You can save up to 100 screen-shots by pressing F1.
  Try to save the frames as closely after one another as possible to
  create a smooth video.
  If 100 frames aren't enough, copy the first 100 screen-shots to another
  directory, play the demo again and save the next 100 frames from where
  you left off.  Rename the second 100 files from DOOM??.PCX to DOOM1??.PCX
  and move them to the same directory, as the first 100.
  Procede with the next 100 etc.

  Rename the first 10 screen-shots from DOOM0?.PCX to DOOM?.PCX, because
  PVRGMPEG expects the individual frames to be numbered in this manner.


3. Resizing, gamma-correction and convertion to PPM

  Image Alchemy (available as shareware from many sites) can do all of that
  with just one command.
  The gamma-correction, set with F11 in DOOM, is not preserved in the
  screen-shots, therefore you have to use the parameters  -Gi1  and  -Go2
  of Image Alchemy to do this correction now.
  Gamma-correction and conversion to PPM can be done with this command:

  ALCHEMY -k -Gi1 -Go2 *.PCX

  If you aren't satisfied with this gamma-correction you can substitute
  "2" with a lower number (e.g "1.5") to get a darker picture or a higher
  number to get a brighter picture.

  You can also resize the frames to a smaller size, if you feel, that Videos
  with the full size of 320x200 pixels run to jerkey on slow machines or
  you just want to save disk-space.
  The following command-line also reduces the frame-size to 160x100:

  ALCHEMY -k -Gi1 -Go2 -X160 -Y100 *.PCX

  Image Alchemy is case-sensitive!
  Image Alchemy uses the extention PNM for the PPM-Images.


4. Splitting the PPM-files using PPM2CYUV.EXE

  You have to call PPM2CYUV.EXE for each frame individually:

  PPM2CYUV DOOM0.PNM DOOM0 -CCIR601
  PPM2CYUV DOOM1.PNM DOOM1 -CCIR601
  PPM2CYUV DOOM2.PNM DOOM2 -CCIR601
               etc.
               etc.

  I used the following two lines as a batch-file to make this procedure
  easyer:

  PPM2CYUV DOOM%1.PNM DOOM%1 -CCIR601
  DEL DOOM%1.PNM

  So I didn't have to type this command-line hundreds of times, but only
  the name of the batch-file (for which I've chosen a one-letter name)
  with all the numbers as parameter.
  After this, there should be three different files with the extensions
  .Y, .U and .V for each frame.


5. Creating the MPEG-Video using PVRGMPEG.EXE

  The MPEG-file can be created with this command-line:

  PVRGMPEG -XING -a 0 -b 99 -h 320 -v 200 DOOM -s NAME.MPG

  You have to substitute "99" with the actual number of the last frame.
  If you resized the frames, you have to substitute "320" and "200"
  with the new size.
  Of course you can substitute "NAME" with any legal file-name.
  You can use the additional parameter  -r  or  -x  to adjust the file-size
  of the MPEG-file and the quality.  The smaller the MPEG, the smaller the
  quality.
  To get an explanation of these and all other parameters type:

  PVRGMPEG | MORE


Have fun creating your own DOOM-Videos!
I'm already looking forward to seeing not just screen-shots but lots of
Videos of "Hell on Earth" poping up all over the place!
Don't disappoint me!
