視訊系統概論及量測
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視訊系統概論及量測

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視訊系統概論及量測 視訊系統概論及量測 Presentation Transcript

  • µø°T¨t²Î·§½×¤¶q´úÀ³¥1
  • Seminar Agenda • Basic of Analog baseband video signal • Basic of Digital baseband Video signal • Demo : Measure analog & SDI Video signal by VM700T • DTV (Digital Television Video) Introduction and Theory • Digital Television Video SD/HD Testing2
  • Basics of Analog Video3
  • Class Content • Additive Color System • Raster Scan Concepts • Analog Component Signals • Analog Composite Signals • Test Equipment • Testing Concepts • List of Additional Study Material4
  • Additive Color System5
  • Additive Color System Different Luminance ( «G«× ) ( no chrominance ) ©ú«G¤Æ«×ÅÜ Chrominance (±m«× ) with different Luminance ( same hue ¦â¬Û & saturation ¹¡©M«× ±m«×ÅÜ¤Æ Chrominance with different saturation ¹¡©M«¤Æ×ÅÜ ( same luminance & hue ) Chrominance with different hue ( same luminance & saturation ) ¦â¬ÛÅܤÆ6
  • Class Content • Additive Color System • Raster Scan Concepts • Analog Component Signals • Analog Composite Signals • Test Equipment • Testing Concepts • List of Additional Study Material7
  • Camera Scanning Patterns Electron Gun Horizontal Retrace Video Signal Active Video8
  • Camera Interlace Scanning Patterns A B C D 1 3 2 4 5 6 Odd lines in Inactive lines in Even lines in Inactive lines in 1st vertical trace. 1st vertical retrace. 2nd vertical trace. 2nd vertical retrace. 625 - 1st Field = 312.5 Lines (25/sec) 625 - 2nd Field = 312.5 Lines (25/sec) 525 - 1st Field = 262.5 Lines (30/sec) 525 - 2nd Field = 262.5 Lines (30/sec) 625 - Frame = 625 Lines (25Hz) 525 - Frame = 525 Lines (30Hz) 525 = North American 625 = Europe and Most of the World9
  • Camera Scanning Patterns • Vertical Resolution – 525 horizontal lines per picture. (North America) – 625 horizontal lines per picture. (Most of world) • Vertical Scan Rate – Scan at least 48 times per second to reduce flicker. – 525 or 625 lines at 48 times per second difficult to achieve. • Interlaced Scan – Show all odd lines one time, all even lines next. – Field – 525 - ~60 Fields – 625 - 50 Fields – Frame – 525 - ~30 Frames – 625 - 25 Frames10
  • Class Content • Additive Color System • Raster Scan Concepts • Analog Component Signals • Analog Composite Signals • Test Equipment • Testing Concepts • List of Additional Study Material11
  • Television Transmission Red Light Signal Blue Light Signal Green Light Signal Color Camera Color Transmission System Receiver Red Light Signal Blue Light Signal Green Light Signal12
  • Analog Component Signals13
  • Component RGB WHT YEL CYN GRN MGT RED BLU BLK +700 mV CHANNEL 1 GREEN 0 mV -300 mV +700 mV • Defined by SMPTE CHANNEL 2 BLUE 0 mV • +700 mV max value -300 mV • Each channel is 4 MHz • Sync pulse on each +700 mV channel CHANNEL 3 RED 0 mV -300 mV14
  • Y, B-Y, R-Y Color Bars +714 mV WHT (700 mV) YEL CYN GRN CHANNEL 1 MGT Y* RED (Y) BLU BLK 0 mV -286 mV (-300 mV) +636 mV • Y - Luminance (+620 mV) CHANNEL 2 B-Y* (U) 0 mV • B-Y (U) -636 mV (-620 mV) • R-Y (V) +500 mV (+490 mV) 0 mV CHANNEL 3 -500 mV R-Y* (-490 mV) (V) * Derived from 714 mV RGB signals (Derived from 700 mV RGB signals- PAL ref burst values not shown)15
  • Component Vectorscope Display • Gives X/Y R M display of Y R-Y (V) and R-Y or V B-Y (U) B chrominance G CY components Tek B-Y or U16
  • Component Measurement • Bowtie Measurement Component Test Signal Generator CH1 CH2 CH3 – System Hook Up – Test Signals – CH 1 is 500 kHz sinewave Component Signal Waveform Monitor CHs 2 and 3 are CH1 CH2 CH3 502 kHz sinewaves – Resultant Waveforms – If the signals are timed and of the same amplitude, the Bowtie waveform results17
  • Component Measurement • Bowtie Measurement – Purpose – Compares the amplitude and timing of the three component signals – Test Signals CH1 CH2 CH3 – Channel 1 is 500 kHz sinewave. Test Signals Channels 2 and 3 are 502 kHz sinewaves – Resultant Waveforms – If the signals are timed and of the same amplitude, the Bowtie CH1-2 CH1-3 waveform results Resultant Waveforms18
  • Class Content • Additive Color System • Raster Scan Concepts • Analog Component Signals • Analog Composite Signals • Test Equipment • Testing Concepts • List of Additional Study Material19
  • Component to Composite +714 mV WHT (700 mV) YEL CYN GRN CHANNEL 1 MGT Y* RED (Y) BLU BLK 0 mV Composite -286 mV (-300 mV) +636 mV (+620 mV) CHANNEL 2 B-Y* 0 mV (U) -636 mV (-620 mV) QAM Modulator +500 mV (+490 mV) 0 mV CHANNEL 3 -500 mV R-Y* (-490 mV) (V) * Derived from 714 mV RGB signals (Derived from 700 mV RGB signals- PAL ref burst values not shown)20
  • NTSC Color Encoding Y S Adder Transmitter Matrix R-Y C 90 Degree R-Y C Phase Shift Modulator -27 Offset =Yellow o B-Y 3.579545MHz Subcarrier B-Y Oscillator Modulator21
  • Luminance and Chrominance 100 100 80 80 60 60 40 40 20 20 0 0 -20 -20 -40 -40 Luminance Chrominance22
  • Transmitted NTSC Color Burst 100 80 60 Color 40 Breezeway Burst 20 0 -20 -40 Tek Front Porch H Sync Back Porch Pulse23
  • Waveform Monitor NTSC Signal Peak Active Picture White 100 .714V 100 IRE 80 60 Setup Level 40 53.5mV 7.5 IRE 20 0 0 Blanking 0V, 0 IRE -20 -40 Sync Tip Tek -.286V -40 IRE Horizontal Sync Pulse Horizontal Blanking Interval24
  • Transmitted NTSC Color Burst Color Burst Local Color oscillator frequency and phase based on the color burst of input signal25
  • NTSC Receiver Luminance and Chrominance Decoding RF, IF and S Video Y Detector R Amplifier Circuirts B-Y Matrix G R-Y B Chrominance Filter and Amplifier Color burst C B-Y Demodulator 3.579545MHz R-Y 90 Degree Demodulator Subcarrier Phase Shift Oscillator26
  • NTSC - Not Really 60 Fields Per Second • North America uses NTSC and the 525 scan rate with is suppose to be 30 Frames/60 Fields. • NTSC field and frame rate is actually: – 29.97 Frames per Second – 59.94 Fields per Second • Why these weird numbers??????27
  • NTSC - Not Really 60 Fields Per Second Luminance (Y) Chrominance Sound Carrier Carrier Carrier .75 0 1.0 2.0 3.0 3.58 4.0 4.2 4.5 MHz • Changed field/frame rate to correct audio distortion caused by color carrier.28
  • Broadcast Standards • The table in the notes section below shows several broadcast standards: – Code – Number of frames – Number of scan lines – Frequency band use – Sound offset • Codes B, G and M are most commonly used29
  • Broadcast Standards Name Field/Frame Stds Encoding Scan Subcarrier Aspect Rate Org System Lines Frequency Ratio NTSC 29.97/59.94 EIA NTSC 525 3.58MHz 4:3 PAL-M 29.97/59.94 EIA PAL 525 3.58MHz 4:3 SECAM-M 29.97/59.94 EIA SECAM 525 ?.??MHz 4:3 PAL 25/50 ITU PAL 625 4.43MHz 4:3 SECAM 25/50 ITU SECAM 625 4.25MHz 4:3 4.40MHz PALplus 25/50 ITU PAL 625 4.43MHz 4:330
  • MEASUREMENTS31
  • Test Equipment • Waveform Monitor – Special oscilloscope that has been optimized for video signals – 75 Ohm Termination – Passive Loop Through – Optimized TV frame, Field, Line Triggering – Optimized Graticule – Optimized Frequency Response – Line Select Capability • Vectorscope – Shows the resulting colors generated by the color signals • Test Signal Generator – Video and audio signal generation capability32
  • Measurement Categories 1. Video Amplitude and Time Measurements 2. SCH Phase (SubCarrier to Horizontal) 3. Linear Distortions 4. Non-linear Distortions 5. Noise33
  • NTSC Luminance and Chrominance • QAM 3.58 MHz color information mixed with the luminance. • This is the display for 100 the color bar test 80 signal. 60 40 20 0 0 -20 -40 Tek34
  • Video Amplitude and Time Measurements (Amplitude) Composite 525 Format Signal Levels Luminance (Y) Peak White 100 .714V 100 IRE 80 60 Setup Level 40 53.5mV 7.5 IRE 20 0 Blanking 0V, 0 IRE -20 -40 Sync Tip Tek -.286V -40 IRE Horizontal Sync Pulse Horizontal Blanking Interval35
  • Composite 625 Format Signal Levels Luminance (Y) Peak White 100 .700V 80 60 40 20 Blanking 0 0V -20 -40 Sync Tip Tek -.300V Horizontal Sync Pulse Horizontal Blanking Interval36
  • Chrominance & Luminance Chrominance : refers to the color information in a TV picture. includes Hue and Saturation Luminance : represents brightness, or the amount of light in the picture. In color system it is obtained as a weighted sum Y=.3R+.59G+.11B of the R,G,& B signals Luminance Saturation Chrominance Hue37
  • NTSC Vectorscope Display • Displays phase of the R-Y (NTSC) chrominance signals. • X/Y display of R M R-Y and B-Y Y components. -(B-Y) B-Y (NTSC) (NTSC) B Y Y G CY Tek Y Y Phase of -(R-Y) (NTSC) the Color Subcarrier38
  • Video Amplitude and Time Measurements (Time) ¡@ Measurements of horizontal and vertical synchronization pulse widths ¡@ Both RS-170A and FCC provide recommended limits ¡@ Cause the picture breakup ¡@ Any composite signal containing horizontal, vertical and burst sync. BLANKING 10.49¡@ SEC ~ 11.49¡@ SEC 10.9¡@ ¡@ SEC0.2 ¡@ SEC 9.22¡@ SEC MIN. 9.4¡@ ¡@ SEC0.1¡@ SEC 7.94¡@ SEC MAX. 1.27¡@ SEC 7.8¡@ SEC MIN. 100IRE 714mV FRONT REF BURST COLOR WHITE 0.254¡@ SEC 0.254¡@ SEC PORCH BACK MAX. MAX. 2.5¡@ SEC 4 IRE 1.5¡@ SEC BREEZWAY PORCH 90% TO 110% REF BLACK 0 IRE ¡@ +.1¡@ SEC0.6¡@ SEC 1.6¡@ SEC OF M SYNC LEVEL -4 IRE AMPLITUDE SYNC 7.5IRE 4 IRE 4.7¡@ SEC  ¡@ 4 IRE 40IRE 0.1 ¡@ SEC 8 TO 11 BLANKING 20IRE LEVEL 0.38¡@ SEC CYCLES 40IRE REF SYNC MIN. 286mV AMPLITUDE -36 IRE -40 IRE RS-170A Horizontal Pulse FCC39
  • SCH Phase (SubCarrier to Horizontal) ¡@ Timing relationship between the 50 % point of the leading edge of sync. and the zero crossings of the reference subcarrier ¡@ RS-170A SCH Phase within + 40 deg. Modern facilities < few deg. ¡@ Two or more sources are combined or sequentially switched - ¡@ Any signal with both sync and burst Phase =0.0Deg Zero crossing 50% Leading edge point40
  • Linear Distortions Frequency Response 0.5 1.25 2.0 3.0 3.58 4.1 MHz • Linear Distortions 4 8 10 14 16 18 Cycles – Definition: – Waveform distortions that are independent of signal amplitude are referred to as linear distortions. – Example: – Frequency Response - Higher frequency signal components (such as the color information) are attenuated.41
  • NonLinear Distortion Measurements Differential Phase and Gain • Purpose – Checks to see if either the chrominance phase or gain is affected by luminance level changes. • Test Signals – Modulated Five Step Staircase42
  • Noise Measurement Signal to Noise Ratio ( S/N or SNR )43
  • STANDARDS  No standards ,Depends on governments and experiences  Timing and Amplitude ¡@ EIA RS-170A ¡@ FCC73.699 Diagram#6  Distortions ¡@ NTC-7 ¡@ RS-250 (EIA-250C)44
  • 1740A/50A/60 Combination Waveform Monitors/Vectorscopes45
  • WVR500 Waveform/Vector Rasterizer • Application: Studio applications where space is at a premium. Signal is monitored at point of use and display is routed to a convenient picture monitor. • Customer: Production studios, house and remote monitoring systems, video training.46
  • VM700T Video Measurement Set • Automated Video Measurement Set • Video Parametric Testing on Test Patterns – NTSC (525/59.94i) Option 1 – PAL (625/50i) Option 11 – Component (RGB/YPbPr 525/625) Option 30 – Audio (Analog) Option 40/41 – SDI (143/270/360Mbs) Option 1S47
  • Manual Mode Waveform Monitor48
  • Manual Mode Vectorscope49
  • Manual Mode Picture50
  • Measure Mode Screen In /nvram0/Executable~Files/Video~Measurements Bar Bounce Burst LineTime Frequency ChromLum Chrominance Chrominance GainDelay AMPM FreqResp Chrominance ColorBar DGDP NonLinearity GroupDelay H_Blank H_Timing Sin X/X ICPM Jitter Jitter Audio Diags Video Previous Leave Options Selection Directory51
  • VmtWin© Software: PC Remote Control Software for the VM700T • Access and Remote control the measurement capabilities of the VM700T • Windows based interface for simple, intuitive PC control • Manual or full automatic screen capture and display of VM700T graphics. • Capability to remotely create, edit and run user defined functions • Multiple connection capabilities: Direct RS 232, Network via Serial Server, or RS 232 with modem • Available as a free download from the Tektronix Web site52
  • TG2000 Multi-Format TV Signal Generator• TG2000 Modules – HDVG1/HDTV Digital Video Generator – 14 Formats of HDTV SDI signal generation – 8 Channels of Embedded Audio support – AVG1/Analog Video Generator – NTSC, PAL, PAL-M, PAL-N, SECAM, Y/By/Ry, R/G/B, Beta-Cam and other major formats support – AWVG1/Analog Wide-band Video Generator – 525/625/HDTV and other wide-band signal support – Moving Zone-Plate Signal with variable parameter
  • TG2000 General• TG2000 Modules – DVG1/Digital Video Generator – 525/625-270MHz, 525/625-360MHz, 525-143MHz SDI and Parallel Digital Signals generation – SDI Stress Test (Option S1) – Variable Jitter, Amplitude, Through-rate and Rise/Fall Time of SDI signal – High Level Embedded Audio Support – AGL1/Analog GenLock – Adds GenLock capability to TG2000 – Lock to NTSC/PAL, CW (Continuous Wave)
  • SDP2000 Basic• SDP2000 – Signal Generation Tool for TG2000 – Works on MS-Windows (95, 98, NT) – Huge Test Signal Libraries for TG2000 Modules – Powerful set of Waveform Functions – Easy to use Editing Features
  • TG700 Multiformat Generator – AGL7 • Built for flexibility and upgradability Analog GenLock module – AG7 • Consists of mainframe (TG700) Audio Generator module Holds up to 4 modules per frame – ATG7 Analog Test Generator module – AVG7 Analog Video Generator module – AWVG7 Analog WideBand Video Generator module – BG7 Black Generator module – DVG7 SDTV Generator module – HDVG7 HDTV Generator module56
  • ATG7 Analog Test Generator Module • Four Independent Outputs – NTSC/PAL Analog Test Signals – 2 Black Bursts – BARS with ID TEXT • ID Text Overlay – ID Text overlay for Test Signal and Color Bar (1 Row x 18 Characters) • Output Formats – NTSC/PAL Independent selection for 4 outputs – Timing Pulse output (1Vpeak to peak) • Output Timing – Independent Timing adjustment with Full Color Frame range57
  • AVG7 Analog Video Generator Module 4 Analog Test Signal 0NTSC/PAL analog composite signal 0525/625 analog component signal 0APL and Bounce 4 High Quality Test Signal Generator 03 channel with 12 bits, 27 MHz clock 4 Frame Picture Feature (TG700 with Option FP) 0Create PIC file from Windows BMP 4 Active Picture Scroll Pr Pb YComposite Composite Composite 0For both test signals and frame picturesComposite C Y 4 Overlay Support 0Logo, ID text and circle overlay 4 Output Timing 0Full (color) frame timing adjustment with fin resolution58
  • AWVG7 Analog WideBand Video Generator Module 4 2 Identical HD Analog Test Signal 03 Channel with 30 MHz band width 0Supports major HD formats 1080/720p 4 High Quality Signal Generation 0 3 channel with 12 bits, 74.25 MHz clock 4 Frame Picture Feature (TG700 with Option FP) 0Can create PIC file from Windows BMP 4 Active Picture Scroll Pr/R Pb/B Y/G 0For both test signals and frame picture 4 Overlay Support 0Logo, ID text and circle overlay 4 Output Timing 0Full (color) frame timing adjustment with fine resolution59
  • 1. 75% Color Bar (With 100% White) ¡@ Full Amplitude 140 IRE ¡@ Hue and Saturation of Chrominance ¡@ Level of Luminance (Video Filter) ¡@ Amplitude, Timing, SCH Phase60
  • 2. FCC, NTC-7 Composite  Combine four kind of signal to one  Amplitude, Timing, SCH Phase, C to Y Gain &Delay, Short & Line time distortion, K Factor Rating, DGDP61
  • 3. Multiburst Test Signal ¡@ Six frequency from 0.5MHz to 4.1 or 4.2MHz ¡@  Frequency Response 0.5 1.25 2.0 3.0 3.58 4.1 MHz 4 8 10 14 16 18 Cycles62
  • Television Signal Formats Analog Composite Parallel Digital Composite Video PAL=17.7MHz (PAL/NTSC) NTSC=14.3MHz M R a B-Y t Serial Digital Composite G R-Y Composite A to D 143Mb/sec (NTSC) r Conv 10 Bits Parallel Serializer B Y Encoder 177Mb/sec (PAL) i x Color Difference Component 4Fsc Clock X10 Analog Video (PAL=17.7MHz) (Y, B-Y, R-Y) (NTSC=14.3MHz) DVD Component Digital Versatile Analog Video MPEG2 (Video) Disk (RGB) Protocol Program Stream B-Y R-Y Y 6.75MHz MPEG2 Sample 13.5MHz Protocol A to D A to D A to D Sample TransmissionRate for B-Y Audio Transport Stream Conv Conv Conv Rate for Y MPEG2 Channel and R-Y Data Program Tx Encoder Clock ITU-R BT.601-2 Picture SDH, ATM, Multiplexed 27MB/sec X10 MPEG2 Transmission Serial Digital Quality SONET or B-Y/Y/R-Y/Y/B-Y/Y Protocol Channel Analysis Component Analysis Modulated 10 Bits Parallel Analysis 270MB/sec RF Signals. Serializer ITU-R BT.601-2 Serial Digital Transmission Component 270MB/sec Channel ITU-R BT.601-2 Analog Composite MPEG2 Program MPEG2 Rx Parallel Digital Component Video (PAL/NTSC) 27MB/sec Decoder Protocol Data Transport Stream