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
