Name 	write_yuv

Type	Data Output

Inputs	Input Image	2D 4-vector byte field ( image )
	Frame number 		Integer

Parameters
	File path/name prefix 		string
	Filename integer precision 	integer slider
	Unix compress			boolean
	Enable overwrite		boolean
Output
	yuv file

Description

Update from write abekas A60

This module includes the code from Terry Myerson for conversion of images 
to yuv format. Added are features wherein the user can name the file 
as with the animate filename module, but with a fixed (.yuv) suffix. 
Since these files are huge, the user has the choice of compressing the 
output, a la write_compressed_image. In some nets it may be desireable 
to allow or prevent overwriting of filenames. A switch is provided to 
allow overwriting of the yuv files, and if compressing, use of the 
/usr/ucb/compress -f option to force overwrite of the compressed file. 

General

	This module was intended to be used with the AVS 
Animator application.  The module needs image and an integer
input. It accepts images, one at a time.  The image is then converted
into the Abekas A60 yuv format - with the same dimensions of
the Abekas A60 yuv format - and outputted to a file with name
(path) as below. If the image is not the same size as the A60 image 
standard, then the AVS image is centered within the view of the Abekas.  
This works well when you consider the degradation of the image borders 
on its path to NTSC.

The file path/name is concatenated from the filename prefix parameter 
string, the integer input padded as per the precision parameter, and 
".yuv" or ".yuv.Z" suffix depending on if compress is enabled. For example: 
with file path/name prefix set to "/u/data/image" integer input = "1",
precision set to "4", and compress enabled, the file /u/data/image.0001.yuv.Z
is created. With the animate integer module feeding sucessive integers
to it, the output file will be named sequentially with prefix, number
and suffix. If overwrite is enabled, writing occurs when (and anytime that) 
file path string is present, and both an int and a 2D 4-vector field 
are on its input ports, with any updated. With overwrite off, writing 
occurs when the filename (prefix, or integer input) is changed. With 
unix compress enabled, output is compressed in situ. Note that with 
overwrite enabled, the -f option is passed to compress to force overwrite 
of an existing file. With overwrite off, compress will ask on the console if 
an attempts is made to save to a previously existing filename.

	This module was adpated from Ian Currington's write_abekas
module and Abekas Inc.'s sample to_yuv program in their manual.
It writes out a temporary file in between conversions.  

Examples - A network to copy a sequence of saved compressed
images to the Abekas yuv format with prefix.number.suffix
filenames.

	animate integer
	    |
	    |____________________
	    |                    |
	    |		   animate filename
	    |			 |
	    |		   read compressed		
            |      ______________|
	    |	  |
	   write yuv    ( image ports connected, and integer
				   ports connected )