Decoder firmware API description
  ================================
  
  Note: this API is part of the decoder firmware, so it's cx23415 only.
  
  -------------------------------------------------------------------------------
  
  Name 	CX2341X_DEC_PING_FW
  Enum 	0/0x00
  Description
  	This API call does nothing. It may be used to check if the firmware
  	is responding.
  
  -------------------------------------------------------------------------------
  
  Name 	CX2341X_DEC_START_PLAYBACK
  Enum 	1/0x01
  Description
  	Begin or resume playback.
  Param[0]
  	0 based frame number in GOP to begin playback from.
  Param[1]
  	Specifies the number of muted audio frames to play before normal
  	audio resumes. (This is not implemented in the firmware, leave at 0)
  
  -------------------------------------------------------------------------------
  
  Name 	CX2341X_DEC_STOP_PLAYBACK
  Enum 	2/0x02
  Description
  	Ends playback and clears all decoder buffers. If PTS is not zero,
  	playback stops at specified PTS.
  Param[0]
  	Display 0=last frame, 1=black
  	Note: this takes effect immediately, so if you want to wait for a PTS,
  	then use '0', otherwise the screen goes to black at once.
  	You can call this later (even if there is no playback) with a 1 value
  	to set the screen to black.
  Param[1]
  	PTS low
  Param[2]
  	PTS high
  
  -------------------------------------------------------------------------------
  
  Name 	CX2341X_DEC_SET_PLAYBACK_SPEED
  Enum 	3/0x03
  Description
  	Playback stream at speed other than normal. There are two modes of
  	operation:
  	    Smooth: host transfers entire stream and firmware drops unused
  		    frames.
  	    Coarse: host drops frames based on indexing as required to achieve
  		    desired speed.
  Param[0]
  	Bitmap:
  	    0:7  0 normal
  		 1 fast only "1.5 times"
  		 n nX fast, 1/nX slow
  	    30   Framedrop:
  		     '0' during 1.5 times play, every other B frame is dropped
  		     '1' during 1.5 times play, stream is unchanged (bitrate
  			 must not exceed 8mbps)
  	    31   Speed:
  		     '0' slow
  		     '1' fast
  	Note: n is limited to 2. Anything higher does not result in
  	faster playback. Instead the host should start dropping frames.
  Param[1]
  	Direction: 0=forward, 1=reverse
  	Note: to make reverse playback work you have to write full GOPs in
  	reverse order.
  Param[2]
  	Picture mask:
  	    1=I frames
  	    3=I, P frames
  	    7=I, P, B frames
  Param[3]
  	B frames per GOP (for reverse play only)
  	Note: for reverse playback the Picture Mask should be set to I or I, P.
  	Adding B frames to the mask will result in corrupt video. This field
  	has to be set to the correct value in order to keep the timing correct.
  Param[4]
  	Mute audio: 0=disable, 1=enable
  Param[5]
  	Display 0=frame, 1=field
  Param[6]
  	Specifies the number of muted audio frames to play before normal audio
  	resumes. (Not implemented in the firmware, leave at 0)
  
  -------------------------------------------------------------------------------
  
  Name 	CX2341X_DEC_STEP_VIDEO
  Enum 	5/0x05
  Description
  	Each call to this API steps the playback to the next unit defined below
  	in the current playback direction.
  Param[0]
  	0=frame, 1=top field, 2=bottom field
  
  -------------------------------------------------------------------------------
  
  Name 	CX2341X_DEC_SET_DMA_BLOCK_SIZE
  Enum 	8/0x08
  Description
  	Set DMA transfer block size. Counterpart to API 0xC9
  Param[0]
  	DMA transfer block size in bytes. A different size may be specified
  	when issuing the DMA transfer command.
  
  -------------------------------------------------------------------------------
  
  Name 	CX2341X_DEC_GET_XFER_INFO
  Enum 	9/0x09
  Description
  	This API call may be used to detect an end of stream condition.
  Result[0]
  	Stream type
  Result[1]
  	Address offset
  Result[2]
  	Maximum bytes to transfer
  Result[3]
  	Buffer fullness
  
  -------------------------------------------------------------------------------
  
  Name 	CX2341X_DEC_GET_DMA_STATUS
  Enum 	10/0x0A
  Description
  	Status of the last DMA transfer
  Result[0]
  	Bit 1 set means transfer complete
  	Bit 2 set means DMA error
  	Bit 3 set means linked list error
  Result[1]
  	DMA type: 0=MPEG, 1=OSD, 2=YUV
  
  -------------------------------------------------------------------------------
  
  Name 	CX2341X_DEC_SCHED_DMA_FROM_HOST
  Enum 	11/0x0B
  Description
  	Setup DMA from host operation. Counterpart to API 0xCC
  Param[0]
  	Memory address of link list
  Param[1]
  	Total # of bytes to transfer
  Param[2]
  	DMA type (0=MPEG, 1=OSD, 2=YUV)
  
  -------------------------------------------------------------------------------
  
  Name 	CX2341X_DEC_PAUSE_PLAYBACK
  Enum 	13/0x0D
  Description
  	Freeze playback immediately. In this mode, when internal buffers are
  	full, no more data will be accepted and data request IRQs will be
  	masked.
  Param[0]
  	Display: 0=last frame, 1=black
  
  -------------------------------------------------------------------------------
  
  Name 	CX2341X_DEC_HALT_FW
  Enum 	14/0x0E
  Description
  	The firmware is halted and no further API calls are serviced until
  	the firmware is uploaded again.
  
  -------------------------------------------------------------------------------
  
  Name 	CX2341X_DEC_SET_STANDARD
  Enum 	16/0x10
  Description
  	Selects display standard
  Param[0]
  	0=NTSC, 1=PAL
  
  -------------------------------------------------------------------------------
  
  Name 	CX2341X_DEC_GET_VERSION
  Enum 	17/0x11
  Description
  	Returns decoder firmware version information
  Result[0]
  	Version bitmask:
  	    Bits  0:15 build
  	    Bits 16:23 minor
  	    Bits 24:31 major
  
  -------------------------------------------------------------------------------
  
  Name 	CX2341X_DEC_SET_STREAM_INPUT
  Enum 	20/0x14
  Description
  	Select decoder stream input port
  Param[0]
  	0=memory (default), 1=streaming
  
  -------------------------------------------------------------------------------
  
  Name 	CX2341X_DEC_GET_TIMING_INFO
  Enum 	21/0x15
  Description
  	Returns timing information from start of playback
  Result[0]
  	Frame count by decode order
  Result[1]
  	Video PTS bits 0:31 by display order
  Result[2]
  	Video PTS bit 32 by display order
  Result[3]
  	SCR bits 0:31 by display order
  Result[4]
  	SCR bit 32 by display order
  
  -------------------------------------------------------------------------------
  
  Name 	CX2341X_DEC_SET_AUDIO_MODE
  Enum 	22/0x16
  Description
  	Select audio mode
  Param[0]
  	Dual mono mode action
  	    0=Stereo, 1=Left, 2=Right, 3=Mono, 4=Swap, -1=Unchanged
  Param[1]
  	Stereo mode action:
  	    0=Stereo, 1=Left, 2=Right, 3=Mono, 4=Swap, -1=Unchanged
  
  -------------------------------------------------------------------------------
  
  Name 	CX2341X_DEC_SET_EVENT_NOTIFICATION
  Enum 	23/0x17
  Description
  	Setup firmware to notify the host about a particular event.
  	Counterpart to API 0xD5
  Param[0]
  	Event: 0=Audio mode change between mono, (joint) stereo and dual channel.
  	Event: 3=Decoder started
  	Event: 4=Unknown: goes off 10-15 times per second while decoding.
  	Event: 5=Some sync event: goes off once per frame.
  Param[1]
  	Notification 0=disabled, 1=enabled
  Param[2]
  	Interrupt bit
  Param[3]
  	Mailbox slot, -1 if no mailbox required.
  
  -------------------------------------------------------------------------------
  
  Name 	CX2341X_DEC_SET_DISPLAY_BUFFERS
  Enum 	24/0x18
  Description
  	Number of display buffers. To decode all frames in reverse playback you
  	must use nine buffers.
  Param[0]
  	0=six buffers, 1=nine buffers
  
  -------------------------------------------------------------------------------
  
  Name 	CX2341X_DEC_EXTRACT_VBI
  Enum 	25/0x19
  Description
  	Extracts VBI data
  Param[0]
  	0=extract from extension & user data, 1=extract from private packets
  Result[0]
  	VBI table location
  Result[1]
  	VBI table size
  
  -------------------------------------------------------------------------------
  
  Name 	CX2341X_DEC_SET_DECODER_SOURCE
  Enum 	26/0x1A
  Description
  	Selects decoder source. Ensure that the parameters passed to this
  	API match the encoder settings.
  Param[0]
  	Mode: 0=MPEG from host, 1=YUV from encoder, 2=YUV from host
  Param[1]
  	YUV picture width
  Param[2]
  	YUV picture height
  Param[3]
  	Bitmap: see Param[0] of API 0xBD
  
  -------------------------------------------------------------------------------
  
  Name 	CX2341X_DEC_SET_PREBUFFERING
  Enum 	30/0x1E
  Description
  	Decoder prebuffering, when enabled up to 128KB are buffered for
  	streams <8mpbs or 640KB for streams >8mbps
  Param[0]
  	0=off, 1=on