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Digital Videotechnology

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  1. Digital Videotechnology • Basics • Analog Video • Composite, S-Video, Component • Digital Video • Sampling • Compression • Digital Camera • DV Format • Digital TV

  2. Digital Video Terrestrical OFDM Videotechnology: Actual Situation Studio Cable Digital 64 QAM Cable analog Digital Video compressed MPEG 2 Modulated QPSK Analog Video Terrestrical Distribution Set Top Box Direct Satellitereceiver

  3. Introduction to Videotechnology TV Systems (analog) Germany, Austria, Poland ... PAL: Phase Alternate Line 625 (576 active) Lines, 50 Hz Interlace aspect ratio 4:3 USA, Japan, latin America NTSC: 525 Lines (480 active) 60 Hz Interlace aspect ratio 4:3

  4. Introduction to Videotechnology Interlace + = Frame 1.Field 2.Field

  5. Introduction to Videotechnology Interlace • progressive • interlaced

  6. Principle of Videotransmission (analog) Camera CRT or Display

  7. Luminance Distribution in one line 0.7

  8. Introduction to Videotechnology Different Screen Format

  9. The Composite Signal How to transmit Color ?

  10. The Colorcompositing Additive Colorcompositing Subtractive Colorcompositing Print (Paper) Displays, CRT CMYK RGB

  11. In the Videotechnology people are working with Component Signals Y Luminance Cb = B-Y Cr = R-Y Y=0.299R+0,587G+0.114B

  12. S-Videosignal Y/C -Signal Component signal Introduction to Videotechnology Different Video Signals Y Luminance Videosignal (Composite) R Matrix Cr G QAM C Cb B Chrominace

  13. The Component Signal Generation of Luminance signal from RGB Y=0.299R+0,587G+0.114B 100 % intensityRed kamera 100 % Intensity 100 % Intensität Rot B/W Kamera 30% Intensity

  14. The Component Signal Generation of Luminance signal from RGB Y=0.299R+0,587G+0.114B 100 % IntensityGreen kamera 100 % Intensity 100 % Intensity Green B/W Kamera 59% Intensity

  15. The Component Signal Generation of Luminance signal from RGB Y=0.299R+0,587G+0.114B 100 % IntensityBlue kamera 100 % Intensity 100 % Intensity Blue B/W Kamera 11% Intensity

  16. Task The Colorbar Weiß Gelb Cyan Grün Magenda Rot Blau Schwarz How we can explain color bar with RGB ?

  17. Weiß Gelb Cyan Grün Magenda Rot Blau Schwarz

  18. Weiß Gelb Cyan Grün Magenda Rot Blau Schwarz 1 0,89 0,7 0,59 0,41 0,3 0,11

  19. Weiß Gelb Cyan Grün Mag. Rot Blau Schwarz

  20. Die Chrominanz QAM: Quadratur Amplitude Modulation • Principle of QAM: • (R-Y,B-Y) is a vector with angle and lenght :V=0,877(R-Y) und U=0,493(B-Y) • (U,V)(C,Φ)mit

  21. QAM: Quadrature Amplitude Modulation

  22. Composite Signal Saturation Hue

  23. Farbkreis

  24. Farbkreis

  25. Farbkreis

  26. Introduction to Videotechnology TV Systems (digital)

  27. Digital Component Signal • Die Components are digitized • Quantisation with 10 Bit Y, Cr,Cb Die Norm CCIR 601 4:2:2 Y: Digitalization with 13,5 MHz Cr: Digitalization with 6,75 MHz Cb: Digitalization with 6,75 MHz

  28. Digital Component Signal 3,375 MHz Basic frequency 4 2 13,5 MHz 6,75 MHz

  29. Digital Component Signal Sampling and Quantisation of Component CCIR 601 • Sampling 4:2:2 and Quantisation with 10 Bit • Datarate 270 Mbit/s • 1 hour Video material ca. 122 Gbyte

  30. Zeile 1 Zeile 2 Zeile 3 Zeile 4 Zeile 5 Zeile 6 Sampling 4:2:2

  31. Digital Component Signal 4:1:1 Zeile 1 Zeile 2 Zeile 3 Zeile 4 Zeile 5 Zeile 6

  32. DV - Format

  33. Digitalization of Videosignals Digital Videoformat 720 576

  34. Digitalization of Videosignals 1 Frame 2 Frames 3 Frames 25 Frames 1 Sekunde How big is the data rate ? What is the memory amount for storing 1 hour Video ?

  35. Digitalization of Videosignals DV Format MPEG 2 Standard Camcorder DVD DVB Digital Video Broadcasting

  36. Intraframe Codierung /DV Format • DV- Format was establish by Consortium of the leading Broadcast Companies (Sony, Thomson, Panasonic, Philips) • Standard since 1994 • Applications: Recording Video im consumer field • Compression algoritm is optimized of constant Byte/Frame

  37. Intraframe Codierung /DV Format • Resolution: 720*576 /25Hz (Luminanz) • Sampling 4:2:0 und Quantization 8 Bit • Input data rate : ca 125 Mbit/s • Compression 5:1 ; Discrete Cosinus Transformation DCT • Constant Outputdata rate: 25 Mbit/s

  38. Intraframe Coding /DV Format Preprocessing Y R Matrix Sampling(4:2:0) & Quantization 125 Mbit/s Cr G Cb B Y Cr Cb

  39. Zeile 1 Zeile 2 Zeile 3 Zeile 4 Zeile 5 Zeile 6 Intraframe Codierung /DV Format Digitalization of Videosignals 4:2:0 Grid

  40. Intraframe Codierung /DV Format DV Compression: DCT Transformation Huffman-Codierer DCT Transformation Treshold Coeffizients with small Energyare omitted 011010101 Inverse-Transformation Huffman-Decodierer

  41. Muster der 2 dimensionalen DCT 274 17 11 0 0 9 7 0 0 0 0 0 0 0 0 0 0 Treshold weighting & Quantization A04 A00 185 191 204 62 273,6 111,8 12,1 1,6 98 110 116 112 94,1 74,2 -3,8 1,2 101 108 104 106 DCT 100 99 97 101 -1,4 0,4 0,3 -0,6 0,5 0,7 0,2 0,125 Intraframe Codierung /DV Format DV (JPEG) : Codierung

  42. 274 112 0 0 94 74 0 0 0 0 0 0 0 0 0 0 Intraframe Coding/DV Standard Zig Zag Process Coeffizienten Matrix 274, 112, 94, 0, 74, 0, 0, 0, 0, 0 ,0 ,0 ,0 ,0 ,0 ,0 RLE Coding 274, 112, 94, 0, 74, 0, ! ,11

  43. Intraframe Codierung/DV Standard Zig Zag Process Block N Block 2 Block 1 RLE DC DPCM Huffman Codierung 011010101

  44. Intraframe Codierung/DV Standard Exsample of DV Compressions Original 133,5 KB Rekonstruktion 26,6 KB Compression 1:5

  45. Intraframe Coding/DV Standard Examples of DV Compression Original 133,5 KB Reconstruktion 26,6 KB Compression 1:5

  46. Intraframe Coding/DV Standard Examples of DV Compression Original 133,5 KB Rekonstruktion 3,8 KB Kompression 1:35

  47. Intraframe Coding/DV Standard Examples of DV Compression Original 133,5 KB Rekonstruktion 2,26 KB Compression 1:60

  48. DV Format Intraframe Verarbeitung, Block shuffling • 5 Makroblöcke aus unterschiedlichen Bereichen des Bildes werdenzu einem Videosegment zusammengefasst 1 Videosegment =5*384Bytes=1920 Bytes • 1 Frame 324 Videosegmente • Block Shuffling bewirkt gleichmäßige Verteilung der Kompressionseffekte M1 M1 M2 M3 M4 M5 M2 IntraframeMacroblock-Shuffling M4 M3 M5 1 Videosegment 1920 Bytes

  49. Intraframe Codierung/DV Standard Intraframe Processing, Block shuffling • Bilding Makroblocks • 1 Makroblock contain 6 DCT Blocks (8*8 or 2*4*8 Blocks) • The Size of Makroblocks is 6*8*8 Byte=384 Bytes • 1 Makroblock contain 4 Luminance and 2 Crominanzblocks