Geol 702H - Video Preparation Workshop

Roland Schweitzer
modified by J. Louie, March 15, 1995

Using the single frame animation equipment

Why record in single frame?
Preparing Files
Testing and Recording the Frames
Post Production
Examples

Why record in single frame?

Video plays at 30 frames per second
Software and hardware can rarely display frames (raster images) at that rate.
Video devices that can record one frame at a time can compensate for the slow computer.
We use a laser video disk recorder as the single frame recording device. A video disk recorder:
- can play frames back at any rate.
- is easily controlled via computer.
- uses high quality component video inputs.

Preparing Files

Delivering files to be recorded.

An account has been set up on acrobat.scs.unr.edu expressly for using the animation equipment.
The login is called video
To deliver your frames ftp to acrobat.scs.unr.edu and login as video. Note this uses a URL of the form ``ftp://video@acrobat.scs.unr.edu'', which prompts for the user's password.)
Under video's home directory there are links to 5 directories: animation[1-5].
Find an EMPTY directory and put your frames there.

Converting Image Files

Raster images MUST be in Silicon Graphics rgb format.
Raster image files MUST be 640x480.
Images can have up to 24-bit color.

Images should list alphabetically in the order they are to be recorded.

	Like this:	NOT like this:
	frame01.rgb	frame1.rgb
	frame02.rgb	frame10.rgb
	frame03.rgb	frame11.rgb
	. . .		. . .
	frame10.rgb	frame2.rgb
	frame11.rgb	frame20.rgb

If your files are not in Silicon Graphics rgb format, use imconv to convert them. You can obtain imconv as part of the San Diego Super Computer Center's imtools package for UNIX computers from the location


ftp://ftp.sdsc.edu/pub/sdsc/graphics/imtools/

, where you can also obtain the source code to compile on other computers. You may also want to investigate the raster image tools described in the list of Web Development Software available at the UNRSL.
imconv understands:

bmp     Microsoft Windows bitmap image file
cur     Microsoft Windows cursor image file
eps     Adobe Encapsulated PostScript file
gif     Compuserve Graphics image file
hdf     Hierarchical Data File
ico     Microsoft Windows icon image file
icon    Sun Icon and Cursor file
iff     Sun TAAC Image File Format
mpnt    Apple Macintosh MacPaint file
pbm     PBM Portable Bit Map file
pcx     ZSoft IBM PC Paintbrush file
pgm     PBM Portable Gray Map file
pic     PIXAR picture file
pict    Apple Macintosh QuickDraw/PICT file
pix     Alias image file
ppm     PBM Portable Pixel Map file
pnm     PBM Portable aNy Map file
ps      Adobe PostScript file
ras     Sun Rasterfile
rgb     SGI RGB image file
rla     Wavefront raster image file
rle     Utah Run length encoded image file
synu    SDSC Synu image file
tga     Truevision Targa image file
tiff    Tagged image file
viff    Khoros Visualization image file
x       AVS X image file
xbm     X11 bitmap file
xwd     X Window System window dump image file

Note that imconv does not understand the JPEG or MPEG formats. Under X-Windows you can run the xv program to display images and convert them between JPEG and the Sun raster, PBM, and TIFF formats.

To find out more about file formats the convertion software understands use the imformats command:
```
acrobat 66% imformats
acrobat 66% imformats -long -gif
```

To find out what a type of file you have use the imfile command:

acrobat 66% imfile -long rg.tif
rg.tif: 'tiff', Tagged image file, Aldus, MicroSoft, and NeXT
	Version:		42
	Byte Order:		Most Significant Byte First
	Image:			1
	Description:		none
	Resolution:		384 x 512
	Type:			24 bit RGB
	Plane Configuration: 	Chunky (Contiguous)
	Color Table:		none
	Compression Type:	none (Dump)
	Alpha Channel:		none

To convert to rgb use imconv:
```
acrobat 67% imconv rg.tif rg.rgb
```
If your file is not 640x480.
- Consider recreating it at the correct resolution.
If the image is too big:
- Use imcopy to trim the excess:
```
acrobat 68% imcopy -xsize 640 -ysize 480 rg.tif rg.rgb
```
- Use imscale to scale the image to the correct size (may cause unacceptable loss of image quality):
```
acrobat 68% imscale -xsize 640 -ysize 480 rg.tif rg.rgb
```
If the image is too small:
- Use impaste to paste it into the center of a black image:
```
acrobat 68% impaste myimage.tif /usr/local/lib/IMAGES/black.rgb new.rgb
```
- If your file is an 8-bit image convert it to an rgb image and then do the paste.
There is a sample script called convert_template, that you can use to help you convert your files to the form needed to record. Execute csh convert_template after copying the script and editing it for your set of frames.

Testing and Recording the Frames

The hardware setup:

Testing Files:

To see what the image looks like as a component analog video picture:
- Turn on the LVR 5000A and the monitor.
- Type /usr/local/bin/LVR/vd file_name.rgb
To view the image with NTSC-encoded colors (standard TV) at the same time:
- Turn on the television and VCR.
- Toggle the TV/VCR selection to VCR.
- Set the Input/Select to Line.
- Use the input select button on the VCR remote to set the input to A1 (Input source is shown on the front panel).
- Use the TV remote to put the TV on channel 3.

Recording frames

The video disk is a WRITE ONCE medium, so please be careful.

Create and test a script that will shoot your frames. Use shoot_template. Execute csh shoot_template after copying the script and editing it for your set of frames. You can test the script by running it with LVR and monitor on, but without the video disk inserted.
Insert the disk, with the write protect disabled.
Use side A first. The side being written is up.
The Local/Remote switch should be set to Remote. The Record Inhibit should be ON.
Press the Record/Stand By button.
- This searches the disk for all the available blank spots on the disk.
- The skip buttons move from one blank area to the next.
- Choose the blank area closest to the end of the disk (high frame numbers) that will hold your frames.
- Enter the frame range to be recorded.
  - Use the key pad to enter the frame number and press enter.
  - The In point is the FIRST frame to be recorded.
  - The Out point is one BEYOND the last frame to be recorded.
  - The DUR gives the duration in frames. It should be the same as the number of files you have.
  - The frame numbers being displayed on the monitor won't be recorded on the frame.
Run your shoot script.

CAVEATS for Recording

You need only record ONE copy of each frame in a sequence, regardless of the "speed" you wish to play frames in the final version. The LVR can smoothly play frames at below video rate.
The disk cannot smoothly play a random selection of frames. Any set of frames you wish to play back smoothly in sequence must be recorded in sequence.
The disk CAN play sequences in reverse.
Always look at your frames in NTSC mode before recording. What looks beautiful on the computer monitor can look terrible on video tape.
Avoid pure colors, especially pure red. They tend to bleed in video.
If you are generating frames using Data Visualizer, choose DOUBLE LINE THICKNESS. Thin lines look bad on video. You may also want to increase the line thicknesses of PostScript plots, by editing the code, before rendering into raster images for video recording.
Write down the frames you use in the log book.

Post Production

In order to have something you can take with you, you must record the frames from the disk to a video tape.
The LVR's playback capabilities can be controlled via tha computer.
The command /usr/local/bin/lvr can be used for play back.
man lvr describes the available options.
lvr_input is a sample file that can be used with the lvr command.
```
acrobat 69% /usr/local/bin/lvr lvr_input
```
The VCR can pause and begin recording without and distortion. This feature can be used to assemble sequences onto tape.
The Silicon Graphics program showcase can be used to create titles.
Titles can be arranged as a showcase 'slideshow' and played back onto tape in real time.

Examples

27 photographs of geophysical field work at Upheaval Dome in Canyonlands National Park, Utah were extracted as JPEG files from a Photo-CD. After converting to Portable Pixel Map (PPM) format manually with the xv utility, they were transferred to acrobat.scs.unr.edu. On acrobat the convert_dome script put them in RGB format. Then the shoot_dome script was run to record the 27 frames to the LVR optical disk. The lvr_dome LVR control script played the frames back at 1/150th the usual 30 frame/sec rate, to allow each photo 5 sec on the video tape.