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.


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.


This pauses recording until it is pressed again.


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.