RGB Movie Widget Help
This widget saves images created by DAVE by writing them
them out to a file (or two files if in stereo on an SGI).
This is useful if you want to see a high
resolution stereo movie for instance. Note: the movie stuff here
is totally different from Create Movies on the Goodies menu (that
only saves viewing parameters, the images themselves must still be
generated at playback time).
Typically you would turn "Single Buffer-moving" on (from the Goodies
menu). Then find the starting view you want. In low res mode,
take DAVE off Pause and see what the next 10 (say) images look like.
If you want the sequence in stereo you should then go into stereo
mode (Goodies->stereo). Now go back to your starting view. Pause DAVE here.
Set the volume resolution sliders to 0 (set both the moving
and paused sliders). Then press Record. Finally, take DAVE out
of Paused mode. DAVE will now (slowly) rotate your image. As it
does, each one will be saved as a movie (up to the number of frames
specified in the RGB Movie widget).
Most of our computers now handle
2D textures (and the Dells handle 3D textures). Textures are always
in hi-res and are fast (Edit->Volume Data->Menu->Render Options-> 2D Texture).
So you probably want to use textures when possible.
Record
The basic idea here is that once "Record" is pressed, every image that
DAVE draws is saved. If you want to reposition/twiddle with a view (after
recording has been started) press Pause on this widget.
Takes the next 10 images (by default) created by DAVE and also
writes them out to a file (or two files if in stereo). The current
image number is displayed ("Frame Number = ").
DAVE should usually be in "Single Buffer-moving" mode (see Goodies menu)
prior to calling this. Also, each stereo frame is roughly 1.2MB when in
stereo mode (if making an i2i movie, see below). Thus you can create a
high resolution stereo movie for fast playback.
Pause
This pauses recording until it is pressed again.
STOP
Terminates the writing of the movie or the playback of a movie.
Whatever was recorded is saved as a movie file. Recording
can't be continued, a new movie must be started. If you just want to
pause a playback or a recording, use the Pause button on the Master widget
(but every drawn frame will still be recorded) or the Pause button
on this widget (then even frames which DAVE draws won't be recorded).
RGB Movie Menu
Choose filename...
The default root filename is "rgbmovie". If you are recording
in Mono (not stereo), one file will be created called rgbmovie_L.i2i
(L for left eye). If you are recording in stereo on an SGI, two files get
created, the second file called rgbmovie_R.i2i. This menu entry
lets you change the root name used (both for recording and playback).
If you are recording in stereo on a Linux box, only one file gets
created, without a _L extension (i.e., with exactly the name specified).
Choose number of frames...
This is the number of images to save in the movie. It is
10 by default. When an image is played, this number is reset to
the number of images in the file being read.
To record an arbitrary number of frames set this to a large number and
just press STOP when you've recorded the desired images. If you want to
rotate exactly 360 during the movie, set the rotation angle (on the Master
widget) to an exact divisor of 360 and set the number of frames
appropriately. If you have trouble setting the rotation angle to the
precise number desired, use the Edit->Misc Props widget.
frames per second...
This does not affect the actual movie produced, but rather some
of the header info stored with the movie. Some players look at the
header to determine how fast to play the movie back. For example, if you
want the player to pause for 1 second on each recorded frame, you should
set this to 1. The default is 15 frames per second. This information
is only stored in sgi and quicktime movie formats. Mpeg movies are always
stored with a header of 25 frames/second (I think).
Change Quicktime movie quality...
Higher quality takes more space.
i2i Movie
When chosen, this produces a movie in a format compatible with
"play_rgb" (if a mono movie). i2i movies take up about 10 times as much
space as sgi format movies; there is really no reason to create them.
sgi Movie
When chosen, this produces a movie in a format compatible with
"movieplayer". These images take much less space than i2i images.
You can only make an sgi movie when on an SGI computer.
Quicktime Movie
When chosen, will create a quicktime movie (.mov file). Only available on
Linux systems. On our Linux systems we have installed the Xine
player for quicktime files.
Mpeg Movie
When chosen, will create an mpeg movie (.mpg file). Only availiable on
Linux systems. You can use GTV Media Player (gtv), Xine, Noatun, plaympeg, or Kaboodle to
view mpeg movies (right click on a .mpg file and a list of players should
come up). GTV Media player has the useful "loop" playback mode.
Also, if you have crossover office, you can use mplayer2 to use Windows Media Player
(it also has a loop feature).
Note: currently "frames per second" is ignored when creating an mpeg movie.
Note: some playes (e.g., Window Media Player) may only play movies which have
an x dimension (and y dimension?) which is a factor of 16. You can start
DAVE up with -P to specify a good size (default is 700 by 700).
Playing a movie
There are several ways to playback a movie made in DAVE.
An i2i format movie can be played back outside of DAVE via the play_rgb
command. It cannot handle stereo, or large (greater than 40MB) movies.
Stereo i2i movies can be played back with ~jac/invitro/bin/sview.
Alternatively, you can use ~jac/invitro/bin/createmovie with the
-R option to convert the i2i movie into sgi movie (.mvc1) format.
This movie format is a compressed format (to about 1/10 the size), saving
disk space (movies can get VERY large). This movie format should not be used.
Sgi formatted movies can be displayed with /usr/sbin/movieplayer
(which works directly with the compressed format, so its size doesn't
expand). Stereo sgi movies can be played back with ~jac/invitro/bin/stereomovie.
These only work on SGI computers.
Some mpeg and quicktime players are described above. When on a Linux system, and
in stereo mode while recording, a stereo movie will be created. Unlike the SGI sytem,
stereo movies under Linux are in one file (not two) and do not require a special stereo
player. They do need to be displayed on a monitor with a stereographics sync doubler
(just as when stereo is normally viewed on our Linux boxes) and viewed with stereo glasses.
Copyright 1995 by Lawrence M. Lifshitz and the University of
Massachusetts Medical School. All rights reserved.