Converting Q3 demos to AVI using AVIedit
You're reading this article, so we assume you are familiar with Quake :)
Probably you have seen the movies over the net and now you're
ready to start with your own one.
As you already know, Q3 allows you to track down your mission in a form
of series of picture files, or just screenshots. This can be done in
console mode by typing cl_avidemo NN where NN stands for
the number of frames per second. For example, cl_avidemo 25 will
write 25 screenshots per second, and cl_avidemo 0 will stop tracking.
You may wish to /bind some keys to these commands to avoid too
much typing later.
So, after you launch Quake and load the demo, enter the first command,
then play the demo, then enter the second command. You will finish with
a lot of .TGA files in your /screenshots directory.
You are ready to get the pictures in a movie.
Start AVIedit. Go to File/Import/Bitmap images menu item. You
will see an AVI options dialog box. Set color depth to TrueColor,
speed, fps to the same value you used in cl_avidemo command,
and frames per .bmp to 1. Click Ok.
In a standard Select Image dialog box click on the last image that
you would like to import, then scroll the list and click with SHIFT pressed
the first image. This ensures you will get right pictures order instead
of getting "last on the top". Click Save button.
Now you will see Video Compression dialog box. Scroll down the list
to get DivX codec selected (either Fast or Low motion). Click Configure
button. Set the keyframes interval to 1 second, crispness to 100, data rate
to 600 kbps. Click Ok here and in the Video Compression window click Ok too.
You will see just running digits like IMG->AVI step NNN and nothing
more. Try to relax :)
After all, AVIedit will load the AVI file just created. It defaults the name
to OutputBM.avi when importing pictures. The file will be created in the same
directory where you do import.
To fix the file header (on imported movies there is an empty handler
field), close the OutputBM.avi then select File/AVI header menu item,
load the file again and fill in the handler field with same 4 characters
you see at right (DIV3 for Low motion DivX codec, or DIV4 for Fast). Click Ok.
That's all! (Should I suggest you click a file created ? :)
Q. What is .TGA file ?
A. It is an image file saved in TARGA format. It is less popular than Windows
Bitmap (.BMP) format but offers nearly the same file sizes and picture quality.
You can edit these files using Adobe Photoshop, JASC Paint Shop Pro, convert
and view them using IrfanView, ACDSee and many other software including AVIedit.
Q. How much HDD space I need ?
A. To calculate the size of a single .TGA file, just multiply your
screen width in pixels by screen height, then take the result three times.
Say, for 640x480 resolution you will get 640*480*3/1024 = approx. 900 KB
To determine how much space will eat the entire demo multiply this value
by cl_avidemo parameter and by time duration in seconds. For example,
the 20 seconds of a 25 FPS demo will occupy 900*20*25/1024 = approx. 440 MB on
your storage device. After you import the frames and compress to avi file,
you can delete them.
Q. What about video settings ?
A. Your problem starts when you choose a framerate to cl_avidemo :)
The higher is
NN value you used, the smoother is the movement in a demo. Setting a 20
frames per second or less you can get jerky video. On the other hand, your
PC should support fine such a huge data stream: for 640x480 @ 25 fps you will
get 640*480*3*25/1024 = approx. 22500 KB/sec. Due to system overload you may
drop down to 10 fps or even less :(
Next topic to discuss - the DivX settings. The main idea - the higher the
data rate, the better final movie quality. But the file size will grow too. To
share your movies on a CD-R media you can choose the data rates from 900 kbps
to 2000 kbps, while the internet surfers probably will expect 1/4 size movies
at less data rate, from 128 kbps to 420 kbps. Anyway, you will need to
experiment a bit.
Q. Does trial AVIedit accept large series of screenshots ?
A. Sorry, no free cheese... But you still can join few short imported avi
files together in AVIedit to get a large one, if the registration fee is
too much for you. On the other hand, Q3 creates only 10K frames at a time.
Q. How do I add the soundtrack to the demo ?
A. Load demo avi file in AVIedit, then drag a .WAV file on its window.
Next, save the result to a new avi file.
Copyright 2000, 2009 AM Software