CS Spring 2014 CS 414 – Multimedia Systems Design Lecture 19 – Multimedia Transport Subsystem (Part 2) + Midterm Review Klara Nahrstedt Spring 2014

Midterm March 7 (Friday),1-1:50pm, 0216 SC Closed Book, Closed Notes You can bring calculator and 1 page cheat sheet CS Spring 2014

Covered Material Class Notes (Lectures 1-15) MP1 Book Chapters to read/study:  Media Coding and Content processing book Chapter 2, Chapter , 3.8, Chapter , Chapter 4.3 ( as discussed in lecture ) Chapter 5, chapter , 7.7 CS Spring 2014

Material Audio Characteristics  Samples, frequency, Nyquist theorem  Perception, psychoacoustic effects, loudness, pitch, decibel, intensity  Sampling rate, quantization Audio Characteristics  PCM, DPCM, signal-to-noise ratio CS Spring 2014

Material Image Characteristics  Sampling, quantization, pixels  Image properties: color CS Spring 2014

Material Video technology  Color perception: hue, brightness, saturation,  Visual representation: horizontal and vertical resolution, aspect ratio; depth perception, luminance, temporal resolution and motion  Flicker effect  Color coding: YUV, YIQ, RGB  NTSC vs HDTV formats CS Spring 2014

Material Basic Coding schemes  Run-length coding  Statistical coding Huffman coding Arithmetic coding Hybrid codes  JPEG: image preparation, DCT transformation, Quantization, entropy coding, JPEG-2000 characteristics CS Spring 2014

Material Hybrid Coding  Video MPEG: image preparation, I, P, B frames characteristics, quantization, display vs processing/transmission order of frames  Audio MPEG: role of psychoacoustic effect, masking, steps of audio compression  MPEG-4: differences to MPEG-2/MPEG-1 Audio-visual objects, layering  H.261, 263, 264, 265 CS Spring 2014

Sample Problems Consider the following alphabet {C,S,4,1}, with probabilities: P(C) = 0.3, P(S) = 0.2, P(4)= 0.25, P(1) = Encode the word CS414 using  Huffman coding and arithmetic coding  Compare which encoding requires less bits CS Spring 2014

Sample Problems Describe briefly each step in MPEG-1 audio encoding. Specify the functionality, which is performed in each step. You don’t have to provide equations, only a clear explanation of the functionality that is performed inside each step. CS Spring 2014

Sample Problems What is flicker effect and how to remove it? Provide five differences between MPEG-4 video encoding standard and the previous MPEG video encoding standards CS Spring 2014

Covered Aspects of Multimedia Image/Video Capture Media Server Storage Transmission Compression Processing Audio/Video Presentation Playback Audio/Video Perception/ Playback Audio Information Representation Transmission Audio Capture A/V Playback Image/Video Information Representation CS Spring 2014

We have discussed so far Quality of Service Multimedia Data Establishment Protocol  Negotiation and Translation of QoS CS Spring 2014

What we will talk about today Multimedia Call Establishment Protocol  Admission and Reservation Operations Bandwidth Admission Processing Admission Data Streaming/Transmission Operations  Traffic Shaping CS Spring 2014

Bandwidth Admission Test Consider  b i – reserved bandwidth for the ‘i’ connection  B max – maximal bandwidth at the network interface Admission test (if all connections declare their bandwidth requirements b i at the same time):  ∑ (i=1,…n) b i ≤ B max Example: B max = 100 Mbps, Bandwidth requirement of connection 1 b 1 = 10 Mbps Bandwidth requirement of connection 2 b 2 = 20 Mbps  Admission Control Condition: b 1 + b 2 < B max Step 1: if b 1 < B max then admit b 1, reserve b 1, adjust B max to B avail = B max – b 1 Step 2: if b 2 < B avai l then admit b 2, reserve b 2, adjust B avail to B avail = B avail – b 2 CS Spring 2014

Packet/Frame Scheduling Admission Systems have queues We need packet/frame scheduling policies for admitting new streams We need frame/packet schedulability tests  Note that in networking only NON- PREEMPTIVE scheduling exists!!! CS Spring 2014

Packet/Frame Scheduling Admission Control e i – processing of a packet ‘i’ in network node Admission Test: e i ≤ deadline ∑ (i=1,…,n) serve i / (1/r) ≤ 1 1/r – packet/frame period on processor serve – packet/frame service time at the processors – constant time due to hardware implementation q_in and q_out are queuing times N – number of packets in queue λ – service rate q = N/λ (Little Theorem) r – service rate of the switch CS Spring 2014

Resource Reservation/Allocation Bandwidth reservation  Pessimistic reservation with maximal bandwidth allocation: Given (M N, R A, and M A ) if then CS Spring 2014

Pessimistic Resource Reservation (Example) Example: Consider sequence of MPEG video frames of size 80KB, 60 KB, 20KB, 20 KB, 60KB, 20 KB, 20 KB (Group of Pictures I, P, B, B, P, B, B ), Pessimistic frame size calculation:  M A = max(80, 60, 20, 20, 60, 20, 20) = 80KB Given video frame rate RA = 20 fps If Given MN = 10 KB (network packet size, e.g., packet size for the transport layer like TCP/UDP), then need to consider bandwidth/ throughput reservation for  BN = 10KB x (8 network packets per application frame) x 20 application frames per second= 1600 KB/second = Kbps CS Spring 2014

Optimistic Resource Reservation/Allocation Optimistic reservation considers average bandwidth allocation Given MA, RA, MN, where Then CS Spring 2014

Optimistic Resource Reservation (Example) Example: Consider sequence of MPEG video frames of size 80KB, 60 KB, 20KB, 20 KB, 60KB, 20 KB, 20 KB (Group of Pictures I, P, B, B, P, B, B, ), Optimistic frame size calculation:  M A = 280/7 = 40 KB Given video frame rate RA = 20 fps If Given MN = 10 KB (network packet size, e.g., packet size for the transport layer like TCP/UDP), then need to consider bandwidth/ throughput reservation for  BN = 10KB x (4 network packets per application frame) x 20 application frames per second= 800 KB/second = 6400 Kbps CS Spring 2014

Sender-Oriented Reservation Protocol CS Spring 2014

Receiver-Oriented Reservation Protocol CS Spring 2014

Conclusion Multimedia Call Establishment Protocol requires  QoS Parameter negotiation (exchange)  QoS Parameter translation  Admission Control of resources needed to provide QoS requirements Bandwidth admission Frame/Packet scheduling admission  Reservation of resources for admitted multimedia streams CS Spring 2014