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Digital Videotechnology. Basics Analog Video Composite, S-Video, Component Digital Video Sampling Compression Digital Camera DV Format Digital TV. Digital Video Terrestrical OFDM. Videotechnology: Actual Situation. Studio. Cable Digital 64 QAM. Cable analog. Digital Video
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Digital Videotechnology • Basics • Analog Video • Composite, S-Video, Component • Digital Video • Sampling • Compression • Digital Camera • DV Format • Digital TV
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
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
Introduction to Videotechnology Interlace + = Frame 1.Field 2.Field
Introduction to Videotechnology Interlace • progressive • interlaced
Principle of Videotransmission (analog) Camera CRT or Display
Introduction to Videotechnology Different Screen Format
The Composite Signal How to transmit Color ?
The Colorcompositing Additive Colorcompositing Subtractive Colorcompositing Print (Paper) Displays, CRT CMYK RGB
In the Videotechnology people are working with Component Signals Y Luminance Cb = B-Y Cr = R-Y Y=0.299R+0,587G+0.114B
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
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
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
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
Task The Colorbar Weiß Gelb Cyan Grün Magenda Rot Blau Schwarz How we can explain color bar with RGB ?
Weiß Gelb Cyan Grün Magenda Rot Blau Schwarz
Weiß Gelb Cyan Grün Magenda Rot Blau Schwarz 1 0,89 0,7 0,59 0,41 0,3 0,11
Weiß Gelb Cyan Grün Mag. Rot Blau Schwarz
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
Composite Signal Saturation Hue
Introduction to Videotechnology TV Systems (digital)
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
Digital Component Signal 3,375 MHz Basic frequency 4 2 13,5 MHz 6,75 MHz
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
Zeile 1 Zeile 2 Zeile 3 Zeile 4 Zeile 5 Zeile 6 Sampling 4:2:2
Digital Component Signal 4:1:1 Zeile 1 Zeile 2 Zeile 3 Zeile 4 Zeile 5 Zeile 6
Digitalization of Videosignals Digital Videoformat 720 576
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 ?
Digitalization of Videosignals DV Format MPEG 2 Standard Camcorder DVD DVB Digital Video Broadcasting
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
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
Intraframe Coding /DV Format Preprocessing Y R Matrix Sampling(4:2:0) & Quantization 125 Mbit/s Cr G Cb B Y Cr Cb
Zeile 1 Zeile 2 Zeile 3 Zeile 4 Zeile 5 Zeile 6 Intraframe Codierung /DV Format Digitalization of Videosignals 4:2:0 Grid
Intraframe Codierung /DV Format DV Compression: DCT Transformation Huffman-Codierer DCT Transformation Treshold Coeffizients with small Energyare omitted 011010101 Inverse-Transformation Huffman-Decodierer
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
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
Intraframe Codierung/DV Standard Zig Zag Process Block N Block 2 Block 1 RLE DC DPCM Huffman Codierung 011010101
Intraframe Codierung/DV Standard Exsample of DV Compressions Original 133,5 KB Rekonstruktion 26,6 KB Compression 1:5
Intraframe Coding/DV Standard Examples of DV Compression Original 133,5 KB Reconstruktion 26,6 KB Compression 1:5
Intraframe Coding/DV Standard Examples of DV Compression Original 133,5 KB Rekonstruktion 3,8 KB Kompression 1:35
Intraframe Coding/DV Standard Examples of DV Compression Original 133,5 KB Rekonstruktion 2,26 KB Compression 1:60
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
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