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cl_cosmo(3dm)							 cl_cosmo(3dm)

NAME    [Toc]    [Back]

     cl_cosmo -	Cosmo Compress JPEG Accelerator	(in the	Compression Library)

SYNOPSIS    [Toc]    [Back]

     #include <dmedia/cl.h>

DESCRIPTION    [Toc]    [Back]

     Cosmo Compress is an optional hardware accelerator	for JPEG image
     compression.  The programming interface to	Cosmo is via the standard
     Compression Library.  For overviews of the	JPEG standard and the CL API,
     see jpeg(4) and CLintro(3dm).

     Cosmo Compress implements a subset	of the JPEG standard optimized for
     video originated images.  This subset is baseline JPEG, interleaved
     YCrCb, 8-bits per component.  Cosmo Compress is capable of	compressing
     and decompressing to and from memory, or to and from a special video
     connection	to IndyVideo, Galileo Video, or	Indigo2	Video.

     Cosmo also	supports an arbitrary scale down and clip of images being
     decompressed.  This scaling happens without any performance penalty and
     produces high quality results.


     Cosmo Compress is programmed via the Compression Library (CL) utilizing
     the base CL API as	well as	JPEG-specific and Cosmo-specific parameters.

   USING COSMO    [Toc]    [Back]
     The Cosmo Compress	JPEG Codec is invoked by specifying CL_JPEG_COSMO as
     the scheme	argument to clOpenCompressor.  Only one	application can	have
     Cosmo open	at a time.  An error will be returned to the program if
     another application has Cosmo open.

   SETTING UP TRANSFERS    [Toc]    [Back]
     Cosmo is capable of four different	modes of operation.  External video
     can be compressed to a memory buffer, a memory buffer can be decompressed
     and sent out to external video, an	image in memory	can be compressed to
     memory, and a compressed image can	be decompressed	to memory.  Video data
     is	always treated as non-interleaved fields.

     Memory to memory transfers	may be initiated using the standard CL calls.
     The size of the uncompressed image	must not be larger than	a PAL video
     field (768x288).  The uncompressed	data format must be CL_FORMAT_XBGR.

     Transfers to and from external video should use the CL direct buffered
     interface specifying CL_EXTERNAL_DEVICE as	the frameBuffer	parameter to
     clCompress	or clDecompress.  Additionally,	the call to clDecompress or
     clCompress	should either be made by a separate thread within the program
     or	with CL_CONTINUOUS_NONBLOCK as the frame count parameter since it will
     not return	until the transfer is complete.

									Page 1

cl_cosmo(3dm)							 cl_cosmo(3dm)

     The following general CL parameters are useful for	Cosmo. For more
     information, see CLintro(3dm).

     CL_IMAGE_WIDTH    [Toc]    [Back]
	  Uncompressed image width, in pixels.	When transfering to or from
	  external video using NTSC timing, the	width must be 640.  When
	  transfering to or from external video	using PAL timing, the width
	  must be 768.	The maximum width in memory to memory transfers	is
	  768.	The width must always be a multiple of 16.  With IndyVideo601
	  option or Galileo on Indigo2,	both CCIR 525 and CCIR 625 sizes are

     CL_IMAGE_HEIGHT    [Toc]    [Back]
	  Uncompressed image height in pixels.	Since Cosmo deals in fields
	  which	represent every	other line of a	video frame, the image height
	  is half of the full frame height.  The height	must always be a
	  multiple of 8.  The external video port on Cosmo transmits 243 lines
	  per field in NTSC mode which is not a	multiple of 8.	Applications
	  should therefore either specify 240 or 248 as	the height for NTSC.
	  The height for PAL should be 288.  With IndyVideo601 option or
	  Galileo on Indigo2, both CCIR	525 and	CCIR 625 sizes are supported.

     CL_INTERNAL_IMAGE_WIDTH    [Toc]    [Back]
	  Width	of compressed image.  This is normally the same	as
	  CL_IMAGE_WIDTH, but may be different when scaling is used.  Cosmo
	  has two types	of image scaling capability.  When decompressing from
	  memory to memory, the	image may be downsized from the	original.
	  This mode of scaling is enabled by setting CL_IMAGE_WIDTH to the
	  desired reduced size while setting CL_INTERNAL_IMAGE_WIDTH to	the
	  original size	contained in the JPEG data.  When compressing or
	  decompressing	from external video, Cosmo supports a limited form of
	  scaling.  If the CL_IMAGE_WIDTH is set to the	width of the video
	  field	(either	640 or 768), and CL_INTERNAL_IMAGE_WIDTH is set	to one
	  half of that (either 320 or 384), then Cosmo will scale the image by
	  a factor of two.  It is only necessary to set	this parameter if one
	  of these two types of	scaling	is desired.

     CL_INTERNAL_IMAGE_HEIGHT    [Toc]    [Back]
	  Height of compressed image.  This is normally	the same as
	  CL_IMAGE_HEIGHT, but may be different	when scaling is	used.  See the
	  discussion of	CL_INTERNAL_IMAGE_WIDTH	above.

     CL_FORMAT    [Toc]    [Back]
	  When decompressing or	compressing to or from memory, Cosmo only
	  recognizes 32-bit RGB	pixels which are called	CL_FORMAT_XBGR by the

     CL_ALGORITHM_ID    [Toc]    [Back]
	  The algorithm	identifier for Cosmo is	CL_JPEG_COSMO.

									Page 2

cl_cosmo(3dm)							 cl_cosmo(3dm)

     CL_ORIENTATION    [Toc]    [Back]
	  Cosmo	treats images as ``top down'' and has no support for flipping

     CL_ENABLE_IMAGEINFO    [Toc]    [Back]
	  Setting this parameter to ``TRUE'' enables the
	  clGetNextImageInfo(3dm) CL function which can	be used	to retrieve
	  time stamp and other information about compressed fields. In the
	  case of Cosmo	compressing from external video, the time stamp
	  returned represents the time at which	the first line of the
	  uncompressed field arrived at	the Cosmo board.

     The following JPEG	parameters may also be used.  See cl_jpeg(3dm) for

     CL_JPEG_QUALITY_FACTOR    [Toc]    [Back]


     CL_JPEG_STREAM_HEADERS    [Toc]    [Back]

     These parameters are specific to Cosmo.

     CL_COSMO_VIDEO_TRANSFER_MODE    [Toc]    [Back]
	  When transfering to or from external video, the video
	  may be played	continuously or	single stepped a field or frame
	  at a time.  Cosmo has	three different	transfer modes.
	  CL_COSMO_VIDEO_TRANSFER_AUTO_2_FIELD put the board in	continuous
	  mode.	CL_COSMO_VIDEO_TRANSFER_MANUAL puts the	board in single	step
	  mode.	 In any	mode, the frame	output is either composed of (every)
	  single field replicated twice, or two	different fields.

	  When the video transfer mode is set to manual, the output is
	  advanced one step by setting this parameter to
	  CL_COSMO_VIDEO_MANUAL_ADVANCE.  In order for the frame to actually
	  advance, there must be a decompressed	frame in Cosmo's output	queue.

     CL_COSMO_CODEC_CONTROL    [Toc]    [Back]
	  Setting to CL_COSMO_STOP will	cause compression or decompression
	  to halt.  If clCompress or clDecompress had been called with
	  CL_CONTINUOUS_BLOCK, it will now return.  If clCompress
	  or clDecompress had been called with CL_CONTINUOUS_NONBLOCK,
	  the associated thread	will terminate.

									Page 3

cl_cosmo(3dm)							 cl_cosmo(3dm)

     CL_COSMO_VIDEO_INPUT_CONTROL    [Toc]    [Back]
	  This is used to control how the external video device	sends
	  timing information to	Cosmo.	It is only needed when using Cosmo
	  with the IndyVideo/Galileo 601 Option.  It may be set	to either

   CONNECTING TO VIDEO    [Toc]    [Back]
     When using	external video with Cosmo, special attention needs to be given
     to	the video synchronization setting of the video device.	When
     capturing,	the video synchronization should be set	to ``slave''.  When
     playing back, it should be	set to either ``internal'' or ``genlock''.
     Cosmo interfaces with the external	video via two vl nodes,	one for
     sending video from	Cosmo to the video board, and one for sending video
     and timing	information from the video board to Cosmo.  When playing back
     to	external video,	both nodes have	to be used, one	providing video	timing
     to	Cosmo, the other connecting Cosmo output to the	video device.  Video
     from IndyVideo/Galileo is sent on port 2 and video	from Cosmo to
     IndyVideo/Galileo is sent back on port 1.

     The following will	set play back from Cosmo, into a window	with
     simultaneous video	output.

	   * Assume svr	is the server from vlOpenVideo(3),
	   * and dev is	device number for the ``ev1'' device
	   * obtained via vlGetDeviceList(3).

	   * First, make sure the timing is set	to internal
	   * or	genlock
	  devNode = vlGetNode( svr, VL_DEVICE, VL_ANY );

	  path = vlCreatePath( svr, dev, devNode, devNode );
	  vlSetupPaths(	svr, &path, 1, VL_SHARE, VL_READ_ONLY );
	  vlGetControl(	svr, path, devNode, VL_SYNC, &val );
	  if (val.intVal == VL_SYNC_SLAVE) {
	       val.intVal = VL_SYNC_INTERNAL;
	       vlSetControl( svr, path,	devNode, VL_SYNC, &val );
	  vlDestroyPath(svr, path);

	   * Now set up	the video transfer paths
	  cosmosrc  = vlGetNode( svr, VL_SRC, VL_VIDEO,	1 );
	  cosmodrn  = vlGetNode( svr, VL_DRN, VL_VIDEO,	2 );
	  videodrn  = vlGetNode( svr, VL_DRN, VL_VIDEO,	0 );
	  windowdrn = vlGetNode( svr, VL_DRN, VL_SCREEN, VL_ANY	);

									Page 4

cl_cosmo(3dm)							 cl_cosmo(3dm)

	 path =	vlCreatePath( svr, dev,	cosmosrc, windowdrn );
	  vlAddNode( svr, path,	videodrn );
	  vlAddNode( svr, path,	cosmodrn );
	  vlSetupPaths(	svr, &path, 1, VL_SHARE, VL_SHARE );

	   * Set window	for windowdrn
	  val.intVal = windowId;
	  vlSetControl(	svr, path, windowdrn, VL_WINDOW, &val );
	  vlBeginTransfer( svr,	path, 0, NULL );

     See galileo(7) and	vl(3dm)	for more information.

FILES    [Toc]    [Back]


SEE ALSO    [Toc]    [Back]

     jpeg(4), CLintro(3dm), cl_jpeg(3dm),
     vl(3dm), galileo(7)

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