7. MPEG data specifications

Describe constants, data types, access macros, etc. used in the MPEG communication interface.

(1) Format

In the figure, the reserved area is represented by "-". Be sure to specify 0 for the reserved area.

7.1 MPEG data list

Table 7.1 shows the data list of the MPEG communication interface.

Table 7.1 MPEG data list

data		data name	number
constant		Constant	20.0
Status and MPEG report		Status & MPEG Report	21.0
	MPEG operation status	actst	21.1
	Operation section counter	vcnt	21.2
	Picture information	pict	21.3
	MPEG/Audio status	stat_a	21.4
	MPEG/Video status	stat_v	21.5
MPEG interrupt factor flag		Intreq	22.0
data type			23.0
	MPEG status information	CdcMpStat	23.1
	time code	CdcMpTc	23.2
	MPEG decoder connection destination parameters	CdcMpCon	23.3
	MPEG stream parameters	CdcMpStm	23.4
	Screen special effect parameters	CdcMpVeff	23.5

7.2 MPEG data details

7.2.1 Constants

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Title data specifications

Data constant

Data Name Constant

No 20.0

(1) Error code (MPEG part)

constant name	explanation
CDC_ERR_MP_COMU	The MPCM flag is not set to 1 when issuing the command.

(2) Next stream flag

Used in the following functions to select the current and next stream.

• CDC_MpSetCon
• CDC_MpGetCon
• CDC_MpSetStm
• CDC_MpGetStm

constant name	explanation
CDC_MPSTF_CUR	Specifying the current connection destination/stream
CDC_MPSTF_NEXT	Specifying the next connection destination/stream

(3) Maximum window size/coordinates

Use the following functions to set the window size and coordinates.

• CDC_MpSetWinFpos
• CDC_MpSetWinDpos
• CDC_MpSetWinDsiz
• CDC_MpSetImgPos
• CDC_MpSetImgSiz

The maximum values are different for NTSC/PAL format, normal/high definition output.

constant name	value	explanation
CDC_MPNT_NSX	352	NTSC	Ordinary	size	X direction
CDC_MPNT_NSY	240				Y direction
CDC_MPNT_NPX	351			Coordinate	X direction
CDC_MPNT_NPY	239				Y direction
CDC_MPNT_HSX	704		High-definition	size	X direction
CDC_MPNT_HSY	480				Y direction
CDC_MPNT_HPX	703			Coordinate	X direction
CDC_MPNT_HPY	479				Y direction
CDC_MPPL_NSX	352	PAL	Ordinary	size	X direction
CDC_MPPL_NSY	288				Y direction
CDC_MPPL_NPX	351			Coordinate	X direction
CDC_MPPL_NPY	287				Y direction
CDC_MPPL_HSX	704		High-definition	size	X direction
CDC_MPPL_HSY	576				Y direction
CDC_MPPL_HPX	703			Coordinate	X direction
CDC_MPPL_HPY	575				Y direction

7.2.2 Status and MPEG Report (MPEG Status Information)

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Title data specifications

Data Status and MPEG report

Data Name Status & MPEG Report

No 21.0

(1) MPEG status information

A CD report is not returned in response to an MPEG command. Normally, an MPEG report is often returned. Whether to return an MPEG report or other information depends on the command. (Regular responses always return a CD report.)
The status and MPEG report together are called MPEG status information.

byte     0        1        2        3        4         5        6         7    
     +--------+--------+--------+--------+---------+--------+---------+---------+
     | Status |                        Report                                   |
     +--------+--------+--------+--------+---------+--------+---------+---------+

(2) MPEG Report

The MPEG report is disabled during REJECT and enabled during WAIT.

MPEG Report
byte     1        2        3        4        5        6    
     +--------+--------+--------+--------+--------+--------+
     | actst  |       vcnt      |  pict  | stat_a | stat_v |
     +--------+--------+--------+--------+--------+--------+
     actst: MPEG operation status
     vcnt: Operation interval (VSYNC) counter
     pict: Picture information
     stat_a: MPEG/Audio status
     stat_v: MPEG/Video status

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Title data specifications

Data MPEG operation status

Data Name actst

No 21.1

(1) MPEG operation status

    bit 7 6 5 4 3 2 1 0
       ┌─┬─┬─┬─┬─┬─┬─┬─┐
  actst│−│     │ │     │ Initial value: 19H
       └─┴─┴─┴─┴─┴─┴─┴─┘
            │   │   │
            │   │   └────MPEG/Video operating status
            │   │
            │   └────────MPEG decoding status
            │            CDC_MPASTD_STOP    1: Stopped  0: Decoding
            │
            └────────────MPEG/Audio operating status

(2) Operating status of MPEG decoder

For state transitions, see " 5.1.2 Transfer block state transitions ."

MPEG/Video operating status		MPEG/Audio operating status		explanation
constant name	value	constant name	value
CDC_MPSTV_STOP	01H	CDC_MPSTA STOP	10H	Stop
CDC_MPSTV_PREP1	02H	CDC_MPSTA PREP1	20H	Preparation 1
CDC_MPSTV_PREP2	03H	CDC_MPSTA PREP2	30H	Preparation 2
CDC_MPSTV_TRNS	04H	CDC_MPSTA TRNS	40H	Transfer (playback)
CDC_MPSTV_CHNG	05H	CDC_MPSTA CHNG	50H	switching
CDC_MPSTV_RCV	06H	CDC_MPSTA RCV	60H	Resurrection process

(3) MPEG decoding status

1 represents a stopped state, and 0 represents a decoding state. The state transition diagram is shown below.

                 Input picture start code
        ┌───────┐────────────→┌────────┐
Initial │Stopped│             │Decoding│
state   └───────┘←────────────└────────┘
                   Sequence end input

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Title data specifications

Data Operation section counter

Data Name vcnt

No 21.2

This is a counter that increases by 1 for each VSYNC. It is cleared to 0 when the MPEG decoder initialization function (CDC_MpInit) is executed.
When decoding by host synchronization, this value is increased by 2 when the CDC_MpOutDsync function is executed.

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Title data specifications

Data Picture information

Data Name pict

No 21.3

(1) Picture information

    bit 7 6 5 4 3 2 1 0
       ┌─┬─┬─┬─┬─┬─┬─┬─┐
   pict│−│−│−│−│−│     │ Initial value: 00H
       └─┴─┴─┴─┴─┴─┴─┴─┘
                 └──Picture type being decoded

(2) Picture type

Picture type at the time the decoder detects the picture start code.
If the decoder is stopped, the type of picture waiting to be decoded is obtained.

constant name	explanation
CDC_MPPICT_I	I picture
CDC_MPPICT_P	P picture
CDC_MPPICT_B	B picture
CDC_MPPICT_D	D picture

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Title data specifications

Data MPEG/Audio status

Data Name stat_a

No 21.4

(1) MPEG/Audio status

    bit 7 6 5 4 3 2 1 0
       ┌─┬─┬─┬─┬─┬─┬─┬─┐
 stat_a│ │ │ │ │ │−│−│ │
       └┬┴┬┴┬┴┬┴┬┴─┴─┴┬┘
        │ │ │ │ │     └─CDC_MPSTA_DEC     1: Decoding in progress
        │ │ │ │ └───────CDC_MPSTA_ILG     1: Audio illegal
        │ │ │ └─────────CDC_MPSTA_BEMPTY  1: Buffer section is empty
        │ │ └───────────CDC_MPSTA_ERR     1: Audio error occurred
        │ └─────────────CDC_MPSTA_OUTL    1: Left channel is being output
        └───────────────CDC_MPSTA_OUTR    1: Right channel is being output

(2) Meaning of each flag

bit	flag	explanation
0	Audio decoding operation	Indicates that the audio decoder is operating. (0: Stopped)
3	audio illegal	Indicates that there is an abnormality in the MPEG/Audio layer, sampling frequency, or bit rate.
4	audio buffer section empty	Indicates that the audio buffer section is empty and there is no more stream data for audio playback.
5	audio error	Indicates that an audio-related error has occurred. The error cause can be obtained using the CDC_MpGetInt function.
6	left channel output	Indicates that the left channel is being output. (0: muted)
7	right channel output	Indicates that the right channel is being output. (0: muted)

The value of each flag is updated every VSYNC.

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Title data specifications

Data MPEG/Video status

Data Name stat_v

No 21.5

(1) MPEG/Video status

    bit 7 6 5 4 3 2 1 0
       ┌─┬─┬─┬─┬─┬─┬─┬─┐
 stat_v│ │ │ │ │ │ │ │ │
       └┬┴┬┴┬┴┬┴┬┴┬┴┬┴┬┘
        │ │ │ │ │ │ │ └─CDC_MPSTV_DEC     1: Decoding in progress
        │ │ │ │ │ │ └───CDC_MPSTV_DISP    1: Picture displayed
        │ │ │ │ │ └─────CDC_MPS TV_PAUSE  1: Pausing
        │ │ │ │ └───────CDC_MPSTV_FREEZE  1: Freezing
        │ │ │ └─────────CDC_MPSTV_LSTPIC  1: Displaying the last picture
        │ │ └───────────CDC_MPSTV_FIELD   1: Odd field
        │ └─────────────CDC_MPSTV_UPDPIC  1: Picture updated
        └───────────────CDC_MPSTV_ERR     1: Video error occurred

   bit  15  13  11  9
          14  12  10  8
       ┌─┬─┬─┬─┬─┬─┬─┬─┐
 stat_v│ │−│−│ │ │−│−│ │
       └┬┴─┴─┴┬┴┬┴─┴─┴┬┘
        │     │ │     └─CDC_MPSTV_RDY     1: Ready for output
        │     │ └───────CDC_MPSTV_1STPIC  1: Displaying first picture
        │     └─────────CDC_MPSTV_BEMPTY  1: Buffer section is empty
        └───────────────Undefined

(2) Meaning of each flag

bit	flag	explanation
0	Video decoding operation	Indicates that the video decoder is operating. (0: Stopped) When this flag is 1, if there is an empty frame bank, the decoder performs decoding using that bank.
1	picture display	Indicates that a decoded picture is being displayed.
2	Pause	Indicates that the video decoder is paused.
3	Freeze	Indicates that the video decoder is frozen.
4	Final picture display	Indicates that the currently displayed picture is the last picture of the stream.
5	odd field (Frame synchronization signal)	Indicates that an odd field is being displayed. (1: even field) When outputting to VDP2, the frame starts with an odd field and consists of two fields.
6	Picture update	Indicates that the picture has been updated. Changes in units of 2 operation sections (VSYNC x 2 or CDC_MpOutDsync). It becomes 1 when the display is updated and when a picture is discarded in a frozen state.
7	video error	Indicates a video-related error. The error cause can be obtained using the CDC_MpGetInt function.
8	Ready for output	Indicates that the image can now be output. It becomes 1 when the number of decoded frame banks becomes two (I, P). When decoding is started in the paused state, the output preparation completion flag becomes 1 without being displayed. If you move frame by frame in this state, the first image will be output immediately.
11	First picture display	Indicates that the currently displayed picture is the first picture of the stream. "First" refers to the media or decoding order, not the display order.
12	Video buffer section empty	Indicates that the video buffer section is empty and there is no more stream data for video playback.

The value of each flag is updated every VSYNC.

7.2.3 MPEG interrupt factor flag

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Title data specifications

Data MPEG interrupt factor flag

Data Name Intreq

No 22.0

The cause of the MPEG interrupt is notified in the following format (4 bytes) by the CDC_MpGetInt function.
The same bit arrangement is used when masking interrupts using the CDC_MpSetIntMsk function.

MPEG interrupt factor flag
byte     0         1         2         3
    ┌─────────┬─────────┬─────────┬─────────┐
    │    −    │Audio    │       Video       │
    │         │Interrupt│     Interrupt     │
    └─────────┴─────────┴─────────┴─────────┘

In the following explanatory diagrams, V/A represents video/audio, respectively.

(1) Video interrupt

bit 7 6 5 4 3 2 1 0
   ┌─┬─┬─┬─┬─┬─┬─┬─┐
   │ │ │ │ │ │ │ │ │ Initial value: 00H
   └┬┴┬┴┬┴┬┴┬┴┬┴┬┴┬┘
    │ │ │ │ │ │ │ └─CDC_MPINT_VSRDY    1: V stream ready
    │ │ │ │ │ │ └───CDC_MPINT_VSCHG    1: V stream switching complete
    │ │ │ │ │ └─────CDC_MPINT_VORDY    1: Video output ready
    │ │ │ │ └───────CDC_MPINT_VOSTRT   1: Start video output
    │ │ │ └─────────CDC_MPINT_VDERR    1: Video decoding error
    │ │ └───────────CDC_MPINT_VSERR    1: V stream data error
    │ └─────────────CDC_MPINT_VBERR    1: V buffer partition connection error
    └───────────────CDC_MPINT_VNERR    1: Next V stream data error


bit 15  13  11  9
      14  12  10  8
   ┌─┬─┬─┬─┬─┬─┬─┬─┐
   │ │ │ │ │ │ │ │ │ Initial value: 00H
   └┬┴┬┴┬┴┬┴┬┴┬┴┬┴┬┘
    │ │ │ │ │ │ │ └─CDC_MPINT_PSTRT    1: Picture start detection
    │ │ │ │ │ │ └───CDC_MPINT_GSTRT    1: GOP start detection
    │ │ │ │ │ └─────CDC_MPINT_SQEND    1: Sequence end detection
    │ │ │ │ └───────CDC_MPINT_SQSTRT   1: Sequence start detection
    │ │ │ └─────────CDC_MPINT_VTRG     1: V sector trigger bit detection
    │ │ └───────────CDC_MPINT_VEOR     1: V sector EOR bit detection
    │ └─────────────CDC_MPINT_ATRG     1: A sector trigger bit detection
    └───────────────CDC_MPINT_AEOR     1: A sector EOR bit detection

(2) Audio interrupt

bit 23  21  19  17
      22  20  18  16
   ┌─┬─┬─┬─┬─┬─┬─┬─┐
   │ │ │ │ │ │ │ │ │ Initial value: 00H
   └┬┴┬┴┬┴┬┴┬┴┬┴┬┴┬┘
    │ │ │ │ │ │ │ └─CDC_MPINT_ASRDY    1: A stream ready
    │ │ │ │ │ │ └───CDC_MPINT_ASCHG    1: A stream switching complete
    │ │ │ │ │ └─────CDC_MPINT_AORDY    1: Audio output ready
    │ │ │ │ └───────CDC_MPINT_AOSTRT   1: Start audio output
    │ │ │ └─────────CDC_MPINT_ADERR    1: Audio decoding error
    │ │ └───────────CDC_MPINT_ASERR    1: A stream data error
    │ └─────────────CDC_MPINT_ABERR    1: A buffer partition connection error
    └───────────────CDC_MPINT_ANERR    1: Next A stream data error

(3) Video interrupt factor

bit flag

0 video stream ready

Indicates that data exceeding (STD buffer size + 16KB) has been stored in the video buffer section. (In case of automatic transfer)

1 Video stream switching completed

Indicates that the next stream has started to be transferred to the VBV buffer.

2 Video output ready

This indicates that two pictures have been decoded into the frame buffer and can be output in the next operation section. Check with field interrupt and interrupt the host. (Valid only once before switching streams)

3 Start video output

Indicates that the first picture of the video stream has been output. (valid even after stream switching)

4 video decoding error

Indicates that a decoding error has occurred in the video LSI.

5 Video stream data error

Indicates that an error occurred in the stream being played. (Data other than video exists in the buffer section)

6 Video buffer section connection error

Indicates that the connection between the buffer partition and the decoder was broken while data was being transferred from the buffer partition.

7 video stream data error

Indicates that an error occurred in the next stream. (Data other than video exists in the next buffer section)

8 Picture start detection

Indicates that a picture start code (PSC) has been detected.

9 GOP start detection

Indicates that a GOP start code has been detected.

10 sequence end detection

Indicates that a sequence end code was detected.

11 Sequence start detection

Indicates that a sequence start code has been detected.

12 Trigger bit detection for video sectors

Indicates that the trigger bit in the video sector subheader was detected before the rear aperture.

13 EOR bit detection for video sectors

Indicates that the EOR bit in the video sector subheader was detected before the rear aperture.

14 audio sector trigger bit detection

Indicates that the trigger bit in the audio sector subheader was detected before the rear aperture.

15 EOR bit detection for audio sectors

Indicates that the EOR bit in the audio sector subheader was detected before the rear aperture.

16 audio streams ready

Indicates that one or more sectors of data has been stored in the audio buffer section.

17 Audio stream switching completed

Indicates that the next stream has started to be transferred to the audio decoder.

18 audio output ready

Indicates that stream data has started to be transferred to the audio decoder. (Valid only once before switching streams)

19 Start audio output

Indicates that stream data has started to be transferred to the audio decoder. (valid even after stream switching)

20 audio decoding errors

Indicates that a decoding error occurred in the audio LSI.

21 Audio stream data error

Indicates that an error occurred in the stream being played. (Data other than audio exists in the buffer section)

22 Audio buffer compartment connection error

Indicates that the connection between the buffer partition and the decoder was broken while data was being transferred from the buffer partition.

23 Next audio stream data error

Indicates that an error occurred in the next stream. (Data other than audio exists in the next buffer section)

7.2.4 Data types

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Title data specifications

Data MPEG status information

Data Name CdcMpStat

No 23.1

The CD block status and MPEG report are collectively referred to as MPEG status information.

(1) MPEG status information...CDC_MpGetCurStat, CDC_MpGetLastStat functions

CdcMpStat *mpstat

access macro	mold	explanation
CDC_MPSTAT_STS(mpstat)	Uint8	Status (see CD part)
CDC_MPSTAT_AST(mpstat)	Uint8	MPEG operation status
CDC_MPSTAT_VCNT(mpstat)	Uint16	Operating interval (VSYNC) counter
CDC_MPSTAT_PICT(mpstat)	Uint8	Picture information
CDC_MPSTAT_STA(mpstat)	Uint8	MPEG/Audio status
CDC_MPSTAT_STV(mpstat)	Uint16	MPEG/Video status

(2) Related macros

access macro	explanation
CDC_MPGET_STC(mpstat)	Get status code from MPEG status information
CDC_MPGET_ASTV(mpstat)	Obtain MPEG/Video operating status from MPEG status information
CDC_MPGET_ASTA(mpstat)	Obtain MPEG/Audio operating status from MPEG status information

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Title data specifications

Data time code

Data Name CdcMpTc

No 23.2

(1) Time code...CDC_MpGetTc function

CdcMpTc *mptc

access macro	mold	explanation
CDC_MPTC_HOUR(mptc)	Uint8	Time (0-23)
CDC_MPTC_MIN(mptc)	Uint8	Minutes (0-59)
CDC_MPTC_SEC(mptc)	Uint8	seconds (0-59)
CDC_MPTC_PIC(mptc)	Uint8	Picture (0-63)

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Title data specifications

Data MPEG decoder connection destination parameters

Data Name CdcMpCon

No 23.3

(1) MPEG decoder connection destination parameters...CDC_MpSetCon, CDC_MpGetCon functions

CdcMpCon *mpcon

access macro	mold	explanation
CDC_MPCON_CMOD(mpcon)	Uint8	connection mode
CDC_MPCON_LAY(mpcon)	Uint8	Layer specification and picture search specification
CDC_MPCON_BN(mpcon)	Uint8	buffer partition number

(2) MPEG/Audio connection mode

bit 7 6 5 4 3 2 1 0
   ┌─┬─┬─┬─┬─┬─┬─┬─┐
   │ │−│−│−│−│ │ │ │ Initial value: 00H     Unchanged: CDC_PARA_NOCHG
   └┬┴─┴─┴─┴─┴┬┴┬┴┬┘
    │         │ │ └─CDC_MPCMOD_EOR    1: Switch by EOR detection
    │         │ └───CDC_MPCMOD_SEC    1: Switch by SEC detection
    │         └─────CDC_MPCMOD_DEL    1: Delete sectors within the partition
    └────────────────1: Do not change settings     0: Change settings

(3) MPEG/Video connection mode

bit 7 6 5 4 3 2 1 0
   ┌─┬─┬─┬─┬─┬─┬─┬─┐
   │ │ │   │ │ │ │ │ Initial value: 00H     Unchanged: CDC_PARA_NOCHG
   └┬┴┬┴─┴─┴┬┴┬┴┬┴┬┘
    │ │  │  │ │ │ └─CDC_MPCMOD_EOR    1: Switch by EOR detection
    │ │  │  │ │ └───CDC_MPCMOD_SEC    1: Switch by SEC detection
    │ │  │  │ └─────CDC_MPCMOD_DEL    1: Switch by sector within partition Erase
    │ │  │  └───────CDC_MPCMOD_IGPTS  1: Do not identify PTS
    │ │  └──────────Video decode buffer clearing method
    │ │                  0 (00B): Do not clear
    │ │                  1 (01B ): Clear VBV (CDC_MPCMOD_VCLR)
    │ │                  2 (10B): Clear VBV+WBC (CDC_MPCMOD_VWCLR)
    │ └─────────────CDC_MPCMOD_BEF (always specify 0 in GAME-CD)
    └───────────────1: Do not change settings     0: Change the settings

constant name	explanation
CDC_MPCMOD_EOR CDC_MPCMOD_SEC	Specify conditions for natural switching. The EOR bit/SEC (system end code) detection bits can be combined using OR conditions. If the next stream is unregistered, this condition becomes the termination condition.
CDC_MPCMOD_DEL	During decoding, sectors within the buffer section are erased. (0: keep)
CDC_MPCMOD_IGPTS	Transfer the sector to the decoder without identifying the PTS. Sectors without PTS can also be transferred. However, an inconsistency occurs in the synchronization of audio and video.
CDC_MPCMOD_VCLR CDC_MPCMOD_VWCLR	Specifies the method for clearing the video decoding buffer when connecting to the first stream. It is not a clear method when switching. Valid only when setting the current connection destination.
CDC_MPCMOD_BEF	The termination condition is determined before the rear aperture. Be sure to specify 0 for normal GAME-CD. When getting a value, 0 is always returned. (Video CD only)

(4) MPEG/Audio layer specification

access macro	mold	explanation
CDC_MPLAY_SYS	00H	System layer...Initial value
CDC_MPLAY_AUDIO	01H	video layer

(5) MPEG/Video layer specification and picture search specification

Picture search is a search for SHC (sequence header code) in a video stream.

bit 7 6 5 4 3 2 1 0
   ┌─┬─┬─┬─┬─┬─┬─┬─┐
   │   │−│−│−│−│−│ │ Initial value: 00H
   └─┴─┴─┴─┴─┴─┴─┴┬┘
     │            └─Layer specification
     └──────────────Picture search specification
 

(a) Layer specification

constant name	value	explanation
CDC_MPLAY_SYS	00H	System layer...Initial value
CDC_MPLAY_VIDEO	01H	video layer

(b) Picture search specification

Specify the picture search when connecting to the first stream.
It is not a picture search when switching. Valid only when setting the current connection destination.

constant name	value	explanation
CDC_MPSRCH_OFF	00H	Do not search for pictures...Initial value
CDC_MPSRCH_VIDEO	80H	Do a picture search
CDC_MPSRCH_AV	C0H	Discard audio data according to picture search

(6) Buffer section number

Specifies the buffer partition number to which the audio or video decoder is connected.
Settings can be canceled by specifying CDC_NUL_SEL for the buffer partition. However, depending on the operating state of the MPEG decoder, the settings cannot be canceled. (It will become WAIT.)

stream	Cancellable state	irrevocable condition
starting stream	Stop, Preparation 1, Preparation 2	Transfer (play), switch, restore
Next stream	Stop, Preparation 1, Preparation 2, Transfer	switching

Use the CDC_MpChgCon function to disconnect (forcibly terminate) the connection of the preceding stream in the transfer (playback) state.

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Title data specifications

Data MPEG stream parameters

Data Name CdcMpStm

No 23.4

Used when setting/obtaining the stream number and channel number of the stream to be decoded.

(1) MPEG stream parameters...CDC_MpSetStm, CDC_MpGetStm functions

CdcMpStm *mpstm

constant name	value	explanation
CDC_MPSTM_SMOD(mpstm)	Uint8	stream mode
CDC_MPSTM_ID(mpstm)	Uint8	Stream number (stream ID)
CDC_MPSTM_CN(mpstm)	Uint8	channel number

(2) Stream mode

bit 7 6 5 4 3 2 1 0
   ┌─┬─┬─┬─┬─┬─┬─┬─┐
   │ │−│ │ │−│−│ │ │ Initial value: 00H    Unchanged: CDC_PARA_NOCHG
   └┬┴─┴┬┴┬┴─┴─┴┬┴┬┘
    │   │ │     │ └─CDC_MPSMOD_SNSET    1: Set the stream number
    │   │ │     └───CDC_MPSMOD_SNIDF    1: Identify the stream number
    │   │ └─────────CDC_MPSMOD_CNSET    1: Set the channel number Do
    │   └───────────CDC_MPSMOD_CNIDF    1: Identify the channel number
    └───────────────1: Do not change the settings    0: Change

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Title data specifications

Data Screen special effect parameters

Data Name CdcMpVeff

No 23.5

(1) Screen special effect parameters...CDC_MpSetVeff function

CdcMpVef *mpvef

constant name	value	explanation
CDC_MPVEF_ITP(mpvef)	Uint8	Interpolation mode
CDC_MPVEF_TRP(mpvef)	Uint8	transparent bit mode
CDC_MPVEF_MOZH(mpvef)	Uint8	Horizontal mosaic mode
CDC_MPVEF_MOZV(mpvef)	Uint8	Vertical mosaic mode
CDC_MPVEF_SOFTH(mpvef)	Uint8	horizontal blur mode
CDC_MPVEF_SOFTV(mpvef)	Uint8	Vertical blur mode

(2) Interpolation mode

Specify whether to perform horizontal/vertical interpolation for luminance (Y) and color difference (C).

bit 7 6 5 4 3 2 1 0
   ┌─┬─┬─┬─┬─┬─┬─┬─┐
   │ │−│−│−│ │ │ │ │ Initial value: 00H    Unchanged: CDC_PARA_NOCHG
   └┬┴─┴─┴─┴┬┴┬┴┬┴┬┘
    │       │ │ │ └─CDC_MPITP_YH     1: Perform horizontal interpolation of Y
    │       │ │ └───CDC_MPITP_CH     1: Perform horizontal interpolation of C
    │       │ └─────CDC_MPITP_YV     1: Perform vertical interpolation of Y
    │       └───────CDC_MPITP_CV     1: Perform vertical interpolation of C
    └───────────────1: Do not change settings    0: Change

(3) Transparent bit mode

If the brightness of each pixel is below the specified brightness level, set the transparency bit in the MPEG register to 1.
The transparent area is also called a priority area.

bit 7 6 5 4 3 2 1 0
   ┌─┬─┬─┬─┬─┬─┬─┬─┐
   │ │−│−│−│−│ │   │ Initial value: 00H    Unchanged: CDC_PARA_NOCHG
   └┬┴─┴─┴─┴─┴┬┴─┴─┘
    │         │  │
    │         │  └──Brightness level
    │         └─────CDC_MPTRP_MAG     1: Enlarge the transparent area
    └─────────────────1: Do not change settings   0: Change

(a) Brightness level

constant name	value	explanation
CDC_MPTRP_DFL	00H	Normal (no transparent bit processing)
CDC_MPTRP_64	01H	brightness 64
CDC_MPTRP_96	02H	brightness 96
CDC_MPTRP_128	03H	brightness 128

(4) Mosaic mode (horizontal/vertical direction)

value	explanation
00H	Normal (no mosaic applied)...Initial value
01H～0AH(n)00H	2 times the nth power (2,4,8,16,32,64,128,256,512,1024 times)
FFH	Do not change settings (CDC_PARA_NOCHG)

(5) Blur mode (horizontal/vertical direction)

bit 7 6 5 4 3 2 1 0
   ┌─┬─┬─┬─┬─┬─┬─┬─┐
   │ │−│−│−│−│−│−│ │ Initial value: 00H   Unchanged: CDC_PARA_NOCHG
   └┬┴─┴─┴─┴─┴─┴─┴┬┘
    │             └─CDC_MPSOFT_ON    1: Blur 
    └───────────────1: Do not change settings   0: Change

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★ PROGRAMMER'S GUIDE ★ CD communication I/F (MPEG part)

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Copyright SEGA ENTERPRISES, LTD., 1997