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Subject: ftp://rah.star-gate.com/pub/bt848-yuv.tar.gz
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Date: Sat, 11 Oct 1997 01:37:35 -0700
From: Amancio Hasty <hasty@rah.star-gate.com>
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This version of the bt848 driver can capture yuv12 frames. The yuv
support is preliminary however so far it is proving to be useful.
For instance we can now capture yuv12 frames to a single file
and feed the file to mpeg_encode as opposed to creating N frame
files of type X format . 

The size of a yuv12 frame is :
width*height + (width*height/4)*2

so a frame of size  320x240 has this many bytes:

115200 = 320*240 + (320*240)/4 * 2



The tar ball includes:

1. bt848 driver with yuv12 functionality

2. yuv12capture.c 
	sample program to store frames to a file. It is a very simple
        program.

3. foo.param 
    mpeg_encode's param file to encode mpeg files.


two steps to generate your mpeg file

	yuv12capture
        mpeg_encode -float_dct <scratch


	Read yuv12capture.c to modify the geometry and number of 
        frames to capture.

{hasty} ls -ald scratch foo.mpg
-rw-r--r--  1 hasty wheel    1710674 Oct 11 01:04 foo.mpg
-rw-r--r--  1 hasty wheel  115315200 Oct 10 23:33 scratch

The file scratch has a 1000 frames
The file foo.mpg is an mpeg sequence of the frames.

The video capture was done to a EIDE drive and you need a bandwith
of at least 3.5MB/s in order not to drop frames while capturing
yuv frames.

If you like you can download ftp://rah.star-gate.com/pub/foo.mpg
to check out the quality . I will keep foo.mpg for a couple of
days on my ftp site after that I will remove it.


	Have fun,
	Amancio