NAME:			Read/Write Abekas A60 image files

AUTHOR INFO:	Ian J. Curington
                Stardent Computer Limited
                15 Frederick Sanger Road
                The Surrey Research Park
                Guildford
                Surrey    GU2 5YD
                United Kingdom
                +44-483-505388
                email: ianc@Stardent.COM

SOURCE FILE:	read_a60rgb.c
                write_a60rgb.c
                rw_a60rgb.txt

TYPE:			data, renderer

INPUTS:			field 2d 4-vector byte

OUTPUTS:		Abekas A60 (rgb) binary image files

PARAMETERS:     File Name browsers

DESCRIPTION:
    This pair of modules provides I/O capability to images
in the native machine format used by the Abekas A60 digital video
disk recording system. The image file specification is for the PAL
(50Hz, 625 line) version, but can easily be modified to support
the NTSC version, or both. The Abekas A60 holds 750 frames, or
30 seconds of live broadcast standard video imagery, in the digital
storage format specified by the CCIR-601 specification. Although
the disk format is Y-uv, the disk has firmware processing to
encode/decode to 3-byte Red-Green-Blue images on-the-fly during
the tcp/ip file transfers.

Due to the precise video storage format, the file format has
no options, no header, and is always 720 pixels per line, 576 lines
per image. Please remember that pixels are NOT SQUARE. The 720 pixels
fill the space that 768 pixels would take if they were square.
These read/write modules to no processing to correct for pixel aspect,
so images will appear slightly narrow.

The read module always expects the same image format and size,
and passes on data as generic image data to the network. The write module
will accept any image size or aspect ratio. For big images, it will take the
top left hand corner, and write out an Abekas size image.
For small images, it will attempt to center the image inside a black
border, again writing a standard Abekas size frame.

The write module will only write the file if you really tickle the
file browser to change the name or re-post the same name.
Image input changes are not sufficient to cause a write.

The module directory contains Two example Abekas A60 format frames.
The example files are
    pic1_a60.rgb, and pic2_a60.rgb