SC200x Video Subsystem

SC200x Video SubsystemSC200x Video Subsystem

Tony Sloan

DTV Source Applications

Broadband Entertainment Division

July 2001

SC200x Video Subsystem - July 20017-2LSI Logic Confidential

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SC200x Video Training AgendaSC200x Video Training Agenda

Digital Video Colour Space - Colour Space Conversion - Sampling - 4:2:0 - 4:2:2 - 4:4:4 -

Upsampling - Downsampling - ITU-R BT.656

SC200x Video Mixer - Encoder - DACs Still Plane & AV Decoder & Background Mixer - OSD & Cursor Mixer - Program

Channel - Composite Channel - Multi-standard Encoder - DACs

Test Signals - Terminology Line - Field - 525 / 625 - North American Test Signals - Terminology - Tests -

Measurement


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SC200x Video TrainingSC200x Video Training

Digital Video


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RGB Gamma CorrectionRGB Gamma Correction

RGB is the starting point for Video and Graphics But RGB Gamma Correction is required because:-

The CRT display is non-linear and computer generated graphics would lack light intensity at low amplitudes

Gamma Correction makes CRT intensity appear linear Gamma corrected RGB (R’G’B’) = RGB where:- Gamma () is 2.2 for NTSC Gamma () is 2.8 for PAL and SECAM

Writing a 1 to bit 0 of the MCTRL register (0xbe50.0034) enables Gamma Correction for the OSD


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R’G’B’ Sampling 4:4:4R’G’B’ Sampling 4:4:4

R`G`B` Sampling Sampled at 13.5MHz 6.75MHz Low Pass Filtering -40dB at 6.75MHz (1/2 Fs) 8 bit ADC for Consumer 10 bit ADC for Professional R`G`B` is 4:4:4

B `

G`

R` ADC

ADC

ADC

LPF

LPF

LPF

13.5M Hz


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R’G’B’ to Y Pb Pr MatrixR’G’B’ to Y Pb Pr Matrix

R`G`B` to Y Pb Pr Matrix Y = 0.299R` + 0.587G` + 0.114B` B-Y = - 0.229R` - 0.587G` + (1 - 0.114)B` R-Y = (1- 0.299)R` - 0.587G` - 0.114B`

This gives the following:- Y = 0.299R` + 0.587G` + 0.114B` B-Y = - 0.229R` - 0.587G` + 0.886B` R-Y = 0.701R` - 0.587G` - 0.114B`

But the maximum signal excursion allowable is 1V peak to peak


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Y Pb Pr NormalisingY Pb Pr Normalising

R`G`B` to Y Pb Pr Matrix (continued.) Y = 1Y Pb = 0.564(B`-Y) Pr = 0.713(R`-Y)

This gives the following:- Y = 0.299R` + 0.587G` + 0.114B` Pb = - 0.169R` - 0.331G` + 0.500B` Pr = 0.500R` - 0.419G` - 0.081B`

Now the maximum signal excursion is 1V peak to peak


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Y Pb Pr Sampling 4:4:4Y Pb Pr Sampling 4:4:4

Y Pb Pr Sampling #1 Full resolution Chrominance All sampled at 13.5MHz 6.75MHz Low Pass Filtering -40dB at 6.75MHz (1/2 Fs) 8 bit ADC for Consumer 10 bit ADC for Professional Y Pb Pr is 4:4:4

Pr

Pb

Y ADC

ADC

ADC

LPF

LPF

LPF

13.5M Hz

M ATRIX

R`

G`

B `


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Y Pb Pr Sampling 4:2:2Y Pb Pr Sampling 4:2:2

Y Pb Pr Sampling #2 Y Sampled at 13.5MHz 6.75MHz Y Low Pass Filtering Pb Pr Sampled at 6.75MHz 3.375MHz C Low Pass Filtering -40dB at 6.75MHz (1/2 Fs) 8 bit ADC for Consumer 10 bit ADC for Professional Y Pb Pr is 4:2:2

Pr

Pb

Y ADC

ADC

ADC

LPF

LPF

LPF

6.75M Hz

M ATRIX

R`

G`

B `

13.5M Hz


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ITU-R 601 Signal AmplitudesITU-R 601 Signal Amplitudes

601 Levels ITU-R.601 Formerly CCIR.601 601Y has 220 levels and is offset by 16 decimal 601Pb has 225 levels and is offset by 128 decimal 601Pr has 225 levels and is offset by 128 decimal Y is still referred to as Y 601Pb is referred to as Cb 601Pr is referred to as Cr


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601 Sampling (8 bits) 601 Sampling (8 bits)

601 Sample Acquisition (8 bits) Y Pb Pr Input 4:2:2 Sampling 601Y = (220/256)Y + 16 Cb = (225/256)Pb + 128 Cr = (225/256)Pr + 128

ADC

ADC

ADC

Y

Pb

6.75M Hz

Y to 601YLook Up

Table

13.5M Hz

Pr to CrLook Up

Table

Pb to CbLook Up

Table

Pr


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601 Signals Max. and Min.601 Signals Max. and Min.

601 Levels Y levels

16 to 235 decimal 0x10 to 0xeb

Cb levels 16 to 240 decimal 0x10 to 0xf0

Cr levels 16 to 240 decimal 0x10 to 0xf0

Cr

Cb

Y


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601 4:2:2 Luma samples per line601 4:2:2 Luma samples per line

601 4:2:2 Samples Luminance sampled at 13.5MHz

864 samples per line for 625 line standard 858 samples per line for 525 line standard 720 Active samples per line for both standards 144 Blanking samples per line for 625 line 138 Blanking samples per line for 525 line


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601 4:2:2 Chroma samples per line601 4:2:2 Chroma samples per line

Cb sampled at 6.75MHz 432 Cb samples per line for 625 line standard 429 Cb samples per line for 525 line standard 360 Active Cb samples per line for both standards 72 Blanking samples per line for 625 line standard 69 Blanking samples per line for 525 line standard

Cr sampled at 6.75MHz 432 Cr samples per line for 625 line standard 429 Cr samples per line for 525 line standard 360 Active samples per line for both standards 72 Blanking samples per line for 625 line standard 69 Blanking samples per line for 525 line standard


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Relationship between 4:4:4 and 4:2:2Relationship between 4:4:4 and 4:2:2

601 Sample Relationship

Line

LineCr1 Cr3 Cr5 Cr7

Y1 Y2 Y3 Y4 Y5 Y6 Y7 Y8

Cb1 Cb3 Cb5 Cb7

Cb1 Cb2 Cb3 Cb4 Cb5 Cb6 Cb7 Cb8

Cr1 Cr2 Cr3 Cr4 Cr5 Cr6 Cr7 Cr8

Y1 Y2 Y3 Y4 Y5 Y6 Y& Y8

4:2:2

4:4:4


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Upsampling from 4:2:2 to 4:4:4Upsampling from 4:2:2 to 4:4:4

601 4:2:2 to 4:4:4 Upsampling

Line

Line

Cr1 Cr3 Cr5 Cr7

Y1 Y2 Y3 Y4 Y5 Y6 Y7 Y8

Cb1 Cb3 Cb5 Cb7

Cb1 Cb2* Cb3 Cb4* Cb5 Cb6* Cb7 Cb8*

Cr1 Cr2* Cr3 Cr4* Cr5 Cr6* Cr7 Cr8*

Y1 Y2 Y3 Y4 Y5 Y6 Y7 Y8

4:4:4

4:2:2


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Downsampling from 4:4:4 to 4:2:2Downsampling from 4:4:4 to 4:2:2

601 4:4:4 to 4:2:2 Downsampling

Line

Line

4:4:4

4:2:2

Cb1 Cb2 Cb3 Cb4 Cb5 Cb6 Cb7 Cb8

Cr1 Cr2 Cr3 Cr4 Cr5 Cr6 Cr7 Cr8

Y1 Y2 Y3 Y4 Y5 Y6 Y7 Y8

Cr1* Cr3* Cr5* Cr7*

Y1 Y2 Y3 Y4 Y5 Y6 Y7 Y8

Cb1* Cb3* Cb5* Cb7*


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ITU-R BT.656 Specification basicsITU-R BT.656 Specification basics

ITU-R BT.656 Specification

European derivative EBU Tech. 3247 North American derivative SMPTE RP125 8 bits or 10 bits (8 bits only will be discussed) 0x00 and 0xff are reserved for timing 0x01 to 0xfe can be used for timing related data 0x10 to 0xf0 is used for video data


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ITU-R BT.656 MultiplexITU-R BT.656 Multiplex

ITU-R BT.656 Multiplex Structure

Line

Samples @ 27MHz Line

Cr1 Cr3 Cr5 Cr7

Y1 Y2 Y3 Y4 Y5 Y6 Y7 Y8

Cb1 Cb3 Cb5 Cb7

4:2:2

Y1 Y2 Y3 Y4 Y5 Y6 Y7 Y8Cb1

Cr1

Cb3

Cr3

Cb5

Cr5

Cb7

Cr7

ITU-R BT.656 Multiplex


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656 Timing Reference Signals (TRS)656 Timing Reference Signals (TRS)

ITU-R BT.656 Timing Reference Signals (TRS) Comprises 4 data bytes and occurs twice in a video line 1st - Indicates Start of Active Video - SAV 2nd - Indicates End of Active Video - EAV First 3 bytes of each TRS are common to both FVH* denotes whether TRS is SAV or EAV

Y1 Y2Cb1 Cr100 FVH*FF 00

TRS


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656 FVH* Byte656 FVH* Byte

ITU-R BT.656 FVH* Byte Bit 7 - Always logical ‘1’ Bit 6 - Field - (0 for Field 1, 1 for Field 2) Bit 5 - Vertical (0 for Active, 1 for V Blanking) Bit 4 - Horizontal (0 for Active, 1 for H Blanking) Bits [3:0] contains Hamming Protection

P0

P1

P2

P3

F

H

1

V


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656 Start of Active Video656 Start of Active Video

Start of Active Video - SAV FVH = 0x80

F = 0 Field 1 V = 0 Active Field area H = 0 Active Line area P = 0 Hamming Protection

Y1 Y2 Y3 Y4Cb1

Cr1

Cb3

Cr3

00 80FF 0010 1080 8010 1080 80

Blanking Active LineSAV


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656 End of Active Video656 End of Active Video

End of Active Video - EAV FVH = 0x9D

F = 0 Field 1 V = 0 Active Field area H = 1 Line Blanking P = D Hamming Protection

00 9DFF 00

EAV

10 1080 8010 1080 80

Blanking

Y Y Y YCb Cr Cb Cr

Active Line


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656 to Analog Line Relationship656 to Analog Line Relationship

ITU-R BT.656 to Analog Line Relationship

625 Line

Active Video

525 Line

Active Video

1440

1440

276 276

288 288

264

244


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656 to Analog Field Relationship656 to Analog Field Relationship

ITU-R BT.656 to Analog Field Relationship625 Line

Second FieldV = 0

First FieldV = 0

V = 1

V = 1

V = 1

Active Video

Active Video

525 Line

Second FieldV = 0

First FieldV = 0

V = 1

V = 1

V = 1

Active Video

Active Video

F = 0262 lines for 525312 lines for 625

F = 1263 lines for 525313 lines for 625

Line 4

Line 266

Line 1

Line 313


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ITU-R BT.656 Parallel InterfaceITU-R BT.656 Parallel Interface

ITU-R BT.656 Physical Interface #1 Parallel

10 Differential pair ECL Data lines 1 Differential pair ECL Clock line 2 Grounds 1 Unconnected 25 way Female D-Type connectors on equipment Voltage levels between - 0.9 volts and - 1.7 Data Rate of 27MHz


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ITU-R BT.656 Serial InterfaceITU-R BT.656 Serial Interface

ITU-R BT.656 Physical interface #2 Serial

1 High Speed 75 ohm interface 75 ohm BNC connections Voltage Levels between 740mV and 860mV Data Rate of 270MHz


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Mixer / Encoder / DACs


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Mixer Background ColourMixer Background Colour

Programmable Mixer Background Video Format

Address 0xbe50.0050 Background is a Flat field Data can be considered as 4:2:2 or 4:4:4

Y Cb Cr

1 Pixel


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AV Decoder Background ColourAV Decoder Background Colour

Programmable AV Decoder Background Video Format

Addresses are 0xbe42.0428 (Y) .042c(Cb) .0430(Cr) Background is a Flat field Selected when bits [7:6] of 0xbe42.0424 = 0x2 Data can be considered as 4:2:2 or 4:4:4

Y Cb Cr

1 Pixel


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Conversion from 4:2:0 to 4:2:2Conversion from 4:2:0 to 4:2:2

AV Decoder Video Format


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Still Plane Colour Still Plane Colour

Still Plane Video format Video Format is 4:2:2

Stored in SDRAM at sequential locations SDRAM Start Address is stored in 0xbe63.0010

Y2Y1Cb1 Cr1

2 Pixels


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Program MixerProgram Mixer

Background/AV Decoder/Still Plane Mixer

4:2:2

4:2:2

4:2:2

MIX 4:2:2

Control

To Upsampler for Final mixer

To Program Channel

Background

AV Decoderor

Background

Still Plane


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Program Mixer ControlProgram Mixer Control

Background/AV Decoder/Still Mixer Control Address 0xbe50.0034 Bits [9:8]

00 - Background only 01 - Video only 10 - Video and Still 11 - Black

Bits [3:2] 00 - Video over Still 01 - Still over Video 10 - Still only, Video off 11 - Video only, Still off


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OSD 32bpp Direct Colour ModeOSD 32bpp Direct Colour Mode

OSD Direct Colour Mode Format 32 bits per pixel

RGB or YCbCr

OSD Data is stored in SDRAM Video Format (with Alpha Blend) is 4:4:4:4

ALPHA R G B

1 Pixel

ALPHA Y Cb Cr

1 Pixel


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OSD 16bpp Direct Colour Mode RGBOSD 16bpp Direct Colour Mode RGB

OSD Direct Colour Mode Format 16 bits per pixel #1

Alpha RGB - 4:4:4:4 bits - 1:5:5:5 bits - 0:5:6:6 bits

1 Pixel

ALPHA R G B

A R G B

R G B

16 bits


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OSD 16bpp Direct Colour Mode YCbCrOSD 16bpp Direct Colour Mode YCbCr

OSD Direct Colour Mode Format 16 bits per pixel #2

Alpha YCbCr - 4:5:3:4 bits - 1:6:4:5 bits - 0:6:5:5

1 Pixel

ALPHA Y Cb Cr

A Y Cb Cr

Y Cb Cr

16 bits


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Multiple OSD PlanesMultiple OSD Planes

OSD Plane Only 1 OSD per line Mix of Colour Spaces Square Pixel support

Gustave Eiffel won the tower competition for the Universal Expositionin 1889 and left behind a lasting legacy.

32 bit YCbCr

32 bit - RGB

RGB16

SQPIX

720x576

YCbCr 16(one region)

OSD Plane


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Cursor ColourCursor Colour

Cursor Video Format

YCbCr only Data is stored in registers within the chip Addresses 0xbe62.0600 to 0xbe62.063c Video Format (with Alpha Blend) is 4:4:4:4

ALPHA Y Cb Cr

1 Pixel


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Cursor FeaturesCursor Features

Cursor 32 x 32 Pixels 16 Colour CLUT 129 Alpha Blends

32 pixels wide

32 pixelshigh


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OSD and Cursor MixerOSD and Cursor Mixer

OSD and Cursor Mixer

4:4:4:4

4:4:4

4

MIX

Control

Alpha OC

To FinalM ixer

OSD

Cursor

4:4:4:4RGB toYCbCr

4:4:4:4


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Composite MixerComposite Mixer

Composite Mixer

4:4:4

4:4:44

MIX

Control

ToComposite Channel

ProgramChannel

OSD/Cursor

4:4:4Up-

sample4:2:2

Alpha OC

Pre/PostWipe Alpha


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Upsampling Using ReplicationUpsampling Using Replication

Actual Upsampling in the SC200x

4:4:4 Multiplex from the Upsam pler at 54MHz

4:2:2 Multiplex into the Upsam pler at 54MHz

4:2:2 Multiplex into the Upsam pler at 27MHz

Y3 Y4Cr3

Y1 Y2Cb1

Cr1

Cb3

Cr1

Cb1

Cr3

Cb3

40 404040

Y3 Y4Cr3

Y1 Y2Cb1

Cr1

Cb3

Y1 Y2 Y3 Y4Cb1 Cr1 Cb3 Cr3


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Downsampling Using DecimationDownsampling Using Decimation

Actual Downsampling used in the SC200x

4:4:4 Multiplex into the Downsam pler at 54MHz

Y3 Y4Cr3

Y1 Y2Cb1

Cr1

Cb3

Cr2

Cb2

Cr4

Cb4

40 404040

4:4:4 Multiplex inside the Downsam pler at 54MHz

Y3Y1 Y2Cb1

Cr1

Cb3

4:2:2 Multiplex from the Downsam pler at 27MHz

Cb2

Y1Cr2

Y2Cb4

Y3

Y1 Y2 Y3Cb1* Cr1* Cb3*


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Program Channel PathProgram Channel Path

Program Channel

ITU-RBT.656

I/F

To the Encoder

DACs

4:4:4Up

sample4:2:2

Digital Video

Output


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Composite Channel PathComposite Channel Path

Composite Channel

ITU-RBT.656

I/F

To the Encoder

DACs

4:4:4

Dow nsample

Digital Video

Output


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Encoder YUV ScalingEncoder YUV Scaling

Multi-standard Encoder #1 YUV Derivation

9 tap Low Pass Filter to limit Chroma Bandwidth YCbCr to YUV Scaling


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Encoder Subcarrier ModulationEncoder Subcarrier Modulation

Multi-standard Encoder #2 Subcarrier Modulation

Burst phase is adjustable


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Phase Modulation for NTSC-MPhase Modulation for NTSC-M

Subcarrier Modulation for NTSC-M For all lines Yellow 167 degrees Cyan 283 degrees Green 241 degrees Magenta 61 degrees Red 103 degrees Blue 347 degrees Burst 180 degrees


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Luma/Chroma RelationshipLuma/Chroma Relationship

Luminance and Chrominance Relationship 75% Color Bars NTSC shown 75% Amplitude - 100% Saturation


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Y Pb Pr Output for Colour BarsY Pb Pr Output for Colour Bars

Y Pb Pr DACs Colour Bar Pattern

10 bits

10 bits

10 bits

Y DAC

Pb DAC

Pr DAC


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RGB Output for Colour BarsRGB Output for Colour Bars

R G B DACs Colour Bar Pattern

10 bits

10 bits

10 bits

G DAC

R DAC

B DAC


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Test Signals and Terminology


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525 and 625 Line Comparison525 and 625 Line Comparison

525 and 625 Line Comparison

Line Sync

625 Line

1V pp

Video Line 64uS

Active Video

HBlanking

12uS

Burst - 10 cycles of 4.43MHz for PAL

525 Line

1V pp

Video Line 63.556uS

Active Video

HBlanking

11uS

Burst - 9 cycles of 3.58MHz for NTSC

H Sync4.7uS

H Sync4.7uS

Line Sync


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525 and 625 Field Comparison525 and 625 Field Comparison

525 and 625 Field Comparison625 Line

Second Field288.5

Active lines

First Field287.5

Active lines

F ie ld B lanking

F ie ld B lanking

F ie ld B lanking

Active Video

Active Video

525 Line

Second Field242.5

Active lines

First Field241.5

Active lines

F ie ld B lanking

F ie ld B lanking

F ie ld B lanking

Active Video

Active Video

First Field262.5 lines for 525312.5 lines for 625

Second Field262.5 lines for 525312.5 lines for 625

Line 4

Halfw aythroughLine 266

Line 1

Halfw ay throughLine 313


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FCC Multiburst Test PatternFCC Multiburst Test Pattern

North American Test Patterns FCC Multiburst


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NTC7 Composite Test PatternNTC7 Composite Test Pattern

North American Test Patterns NTC7 Composite


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EIA Color Bar Test PatternEIA Color Bar Test Pattern

North American Test Patterns EIA Color Bars


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SMPTE Bars Test PatternSMPTE Bars Test Pattern

North American Test Patterns SMPTE Bars


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100% Colour Bars Test Pattern100% Colour Bars Test Pattern

General Test Patterns 100% Colour Bars (100.0.100.0)


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Luminance TestingLuminance Testing

Luminance Testing Using 75% or 100% Colour Bars


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Chrominance TestingChrominance Testing

Hue and Saturation Testing Using the 75% or 100% Colour Bars Amplitude - Saturation Phase - Hue


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Frequency Response TestingFrequency Response Testing

Frequency Response Testing Using the Multiburst Level at 0.5MHz is ref. Check level at each bar


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Impulse and Step Response TestingImpulse and Step Response Testing

2T Pulse and Bar testing Using NTC7 Composite


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Luminance Non-Linearity TestingLuminance Non-Linearity Testing

Luminance Non-linearity testing Using NTC7 Composite

Gain


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Differential Phase TestingDifferential Phase Testing

Differential Phase testing Using NTC7 Composite

Phase


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Differential Gain TestingDifferential Gain Testing

Differential Gain testing Using NTC7 Composite

Gain


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Luma/Chroma Delay TestingLuma/Chroma Delay Testing

Luma/Chroma Delay testing Using NTC7 Composite


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End of Presentation

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SC200x Video Subsystem