This file describes the actual protocol implemented by km_api 
(versus the one described in km.rfc.txt).


Reading from /proc/km/control? provides line-formatted information.
Line can start with special character

       +  indicates successful response to request
       :  indicates out-of-sequence information (like status update)
       
Field information is provided in the form:

FIELD_NAME=value

FIELD_NAME should be a valid C identifier (we have to choose something).


Writing to /proc/km/control is also line-based. 
Each line is a separate command to be executed and must be terminated with '\n'. 
So far the following commands are supported:

             STATUS            -  print the current value of all fields and finishes
	     			  with +END_STATUS (in case you don't want to use threads 
				  or non-blocking IO)
	     REPORT=FIELD_NAME -  turn on out-of-sequence updates if
	                          field value changes.
				  
	     VIDEO_STREAM_ACTIVE=1 - turn on video capture
	     VIDEO_STREAM_ACTIVE=0 - turn off video capture
	     VBI_STREAM_ACTIVE=1   - turn on vbi capture
	     VBI_STREAM_ACTIVE=0   - turn off vbi capture
	     

***** NOTES ******

For now, the write calls to controlX files should be done with one complete command 
per call.
	 
For example see test1.tcl or test3.tcl
