PERPUSTAKAAN UMP 1100 I0 I0 I0 111111 000 II
0000087050
PERFORMANCE ANALYSIS OF VIDEO CODEC (H.263+, H.264) FOR VIDEOCONFERENCING OVER WIRELESS LOCAL AREA NET-WORK (WLAN)
WITHY NURUL JANAH BINTI MOHD HUSSEIN
A report submitted in partial fulfillment of the requirements for the award of the degree of Bachelor of Computer Science (Computer Systems & Networking)
Faculty of Computer Systems & Software Engineering University Malaysia Pahang
2013
UNVERS MALA\ A PAHANG
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(j QkAerolehan No. Pangilan Tarkh
ABSTRACT
Videoconferencing is widely use all over the world, whether on business corporate, distance learning, or as in video call. Market high demand on good video quality helps corporation in reducing financial needs on travelling, but keep the budget-in for bandwidth usage. High bandwidth or good compression techniques. Both maintain a high video quality. Videoconferencing have high sampling rate, to convert audio and video analog to digital signals. Therefore, there is need of high bandwidth to support the sampling rate. Inadequate bandwidth may lead to pixilation, where, in congested network, a sample can be received in out of sequences. Thus, undesirable video-image quality.
In this research, H.263+ and H.264 will be use as video engine. A real device simulation is used to demonstrate the selection of video codecs with good quality of video resolution. Testbed are measure based on video resolution (240p, 480p, and 720p). The test is carry out in predefine wireless network (WLAN) whereby, performances are measure on MO score, packet jitter and packet loss.
Convergence of applications (file sharing, video steaming and etc.) in internet put fluctuation in the network. Therefore, simulations are tested in optimum network (utilizing the bandwidth without any disturbance) and in 'converge' network (network with other traffic) to observe the behavior of each codec in different resolutions. A codec with high quality of video resolution is expected to perform in the simulations.
TABLE OF CONTENTS CONTENT Page DECLARATION ACKNOWLEDGMENTS ABSTRACT iv CONTENTS v LIST OF TABLES vi LIST OF FIGURES vii Section Content Page Chapter 1 INTRODUCTION 1.0 Introduction 1 1.1 Problem Statement 3 1.2 Objective 4 1.3 Scope 4 1.4 Thesis Organization 5 V
Chapter 2 LITERATURE REVIEW
2.0 Introduction to VoIP, SIP and Video Conference 6
2.1 Session Initiation Protocol (SIP) 7
2.1 .1 Real-Time Protocol (RTP) 9
2.2 Video Conference Codec 9
2.2.1 H.263+ 10
2.2.2 H.264 10
2.3 Video Resolution 10
2.4 Quality, Performance Measurement 13
2.4.1 Mean Opinion Score (MOS) 13
2.4.2 R-factor 14
2.4.3 Packet loss 15
2.4.4 Packet latency/Jitter 15
2.5 Existing Research 16
2.5.1 Effect of Delay and Delay Jitter on Voice/Video 16 over IP
2.5.2 A Study of H.263 traffic modeling in Multipoint 18 Videoconference Sessions over IP Networks
2.5.3 H.263 Based Video Codec for Real-Time Visual 18 Communications Over Wireless Radio Networks
2.5.4 High Definition Videoconferencing: Codec 19 Performance, Security, and Collaboration Tools
Chapter 3 RESEARCH METHODOLOGY
3.0 Introduction 23
3.1 Overview of the Methodology 25
3.1.1 Preliminary Study Phase 25
3.1.2 Research Planning Phase 26
3.1.3 Architecture Design Phase 28
3.1.4 Testing Phase 29
3.1.5 Data Analysis Phase 29
Chapter 4 DESIGN IMPLEMENTATION AND RESULT
4.0 Introduction 30
4.1 Design of the Experiment 31
Chapter 5 RESULTS AND DISCUSSION
5.0 Introduction
5.1
Optimum Network Environment (Testbed 1)
41 42 5.1.1 Jitter and Packet Loss in Optimum Network
42 (H.263+ vs. H.264)
5.1.2
MOS and R-Factor in Optimum Network (H.263+ 45 vs. H.264)
5.1.3
Average Bandwidth Uses in Optimum Network 47 (H.263+ vs. H.264)
5.1.4
Total Traffic Exist in Optimum Network (H.263+ 48 vs. H.264)
5.2
Network with Other Traffic Environment 49 (Testbed 2)
5.2.1 Jitter and Packet Loss in Network with Other
so Traffic (H.263+ vs. H.264)
5.2.2 MOS and R-Factor in Network with Other Traffic
52 (H.263+ vs. H.264)
5.2.3
Average Bandwidth Uses in Network with Other
55
Traffic (H.263+ vs. H.264)
Total Traffic Exist in Network with Other Traffic 56 (H.263+ vs. H.264)
Chapter 6 DISCUSSION AND CONCLUSION
6.0 Introduction 58
6.1 Selection of a Video Codec Based on QOS 58
Parameters 60
6.1.1 Jitter Comparison Based on Networks Environment
(Optimum vs. Other Traffic) 62
6.1.2 Packet Loss Comparison Based on Networks
Environment (Optimum vs. Other Traffic) 64 6.1.3 MOS and R-Factor Comparison Based on
Networks Environment (Optimum vs. Other
Traffic) 66
6.1.4 Result Summary
Chapter 7 REFERENCES 67
LIST OF TABLES
Table Number Page
1 SIP Messages 8
2 MOS Table 13
3 MOS and R-Factor comparison with user satisfaction level 14
4 Comparison between Researchers 16
5 Methodology of the research 24
6 Tools used in Videoconferencing session 27
7 MOS Sample of data 29
Videoconferencing of H.263+ in optimum network based on 8
MOS score
Videoconferencing of H.264 in optimum network based on MOS
9 score 34
Videoconferencing of H.263+ in network with other traffic based 10
onMOS score
Videoconferencing of H.264 in network with other traffic based onMOS score
Videoconferencing of H.263+ in network with other traffic based 12
on Jitter
Videoconferencing of H.264 in network with other traffic based 13
35
on Jitter
14 Videoconferencing of H.264 in optimum network based on Jitter 36 Videoconferencing of H.263+ in optimum network based on
15 36
Jitter
Videoconferencing of H.263+ in optimum network based on
16 36
Packet Loss
Videoconferencing of H.264 in optimum network based on
17 36
Packet Loss
Videoconferencing of H.264 in network with other traffic based
18 36
Packet Loss
Videoconferencing of H.263+ in network with other traffic based
19 37
Packet Loss
Videoconferencing of H.263+ in network with other traffic based
20 37
on R-Factor
21 Videoconferencing of H.264 in optimum network based on R-1' nn+r.r
Videoconferencing of H.264 in network with other traffic based
22 37
on R-Factor
Videoconferencing of H.263+ in optimum network based on R-
23 38
Factor
Videoconferencing of H.263+ in network with other traffic based
24 38
on Average Bandwidth uses
Videoconferencing of H.264 in optimum network based on
25 38
Average Bandwidth uses
Videoconferencing of H.264 in network with other traffic based
26 38
on Average Bandwidth uses
Videoconferencing of H.263+ in optimum network based on
27 39
Videoconferencing of H.263+ in network with other traffic based 28
39
on Total Traffic in a session
Videoconferencing of H.264 in optimum network based on Total 29
39
Traffic in a session
Videoconferencing of H.264 in network with other traffic based 30
39
on Total Traffic in a session
Videoconferencing of H.263+ in optimum network based on 31
40
Total Traffic in a session
Optimum Network: Mean Readings of Jitter between Resolution 32
Type of H.263+ and H.264 43
Optimum Network: Mean Readings of Packet Loss between 33
Resolution Type of 11.263+ and H.264 44
Optimum Network: Mean Readings of MOS Between 34
Resolution Type of H.263+ and H.264 45
35 Optimum Network: Mean Readings of R-Factor Between
Resolution Type of H.263+ and H.264 46
Optimum Network: Mean Readings of Average Bandwidth Uses 36
between Resolution Type of H.263+ and H.264 48 Optimum Network: Mean Readings of Total Traffic between
37
Resolution Type of H.263+ and H.264 49
Network with Other Traffic: Mean Readings of Jitter between 38
Resolution Type of H.263+ and H.264 50
Network with Other Traffic: Mean Readings of Packet Loss 39
Network with Other Traffic: Mean Readings of MOS between 40
53
Resolution Type of H.263+ and H.264
Network with Other Traffic: Mean Readings of R-Factor 41
53
between Resolution Type of H.263+ and H.264
Network with Other Traffic: Mean Readings of Average 42
55
Bandwidth Uses between Resolution Type of H.263+ and H.264 Network with Other Traffic: Mean Readings of Total Traffic 43
56
between Resolution Type of H.263+ and H.264
44 Type of Resolution with respective bandwidth usage 58
45 Optimum Network results for H.263+ and H.264 59
46 Network with Other Traffic results for H.263+ and H.264 59
47 Jitter Comparison on Both Networks 61
48 Average Bandwidth Comparison on Both Networks 61
49 Total Traffic Comparison on Both Networks 62
50 Packet Loss Comparison on Both Networks 63
52 MOS Comparison on Both Networks 65
LIST OF FIGURES
Figure Number Page
1 Examples of SIP operation 8
2 A call using SIP for signaling and RTP for transmission of video and voice
3 Example of differences in Size between Resolutions 12
4 Example of Video Performance over Net Bandwidth Uses 12 PDF frame delay jitter of video and audio at different level of 17 bustiness
6 Simulation for studying the performance of video over radio 19 channels
7 Test bed setup for HD/SD comparison 20
8 Diagram of Setup 28
9 Videoconferencing in Optimal Network condition 32 10 Videoconferencing in Network with other traffic condition 33
Packet Jitter Comparison Between Resolution Type Of H.263+
43 and H.264 on Optimum Network
12 Packet Loss over Resolution Type Of H.263+ and H.264 on 44 Optimum Network
13 MOS over Resolution Type of H.263+ and H.264 on Optimum 46 Network
14 R-Factor over Resolution Type of H.263+ and H.264 on 47 Optimum Network
Average Bandwidth Uses over Resolution Type of H.263+ and 48 H.264 on Optimum Network
16 Total Traffic over Resolution Type of H.263+ and H.264 on Optimum Network
17 Packet Jitter Comparison between Resolution Type of H.263+
51 and H.264 on Network with Other Traffic
18 Packet Loss over Resolution Type of H.263+ and H.264 on
52
Network with Other Traffic
19 MOS over Resolution Type of H.263+ and H.264 on Network 53 with Other Traffic
20 R-Factor over Resolution Type of H.263+ and H.264 on Network
54
with Other Traffic
21 Average Bandwidth Uses over Resolution Type of H.263+ and H.264 on Network with Other Traffic
22 Total Traffic over Resolution Type of H.263+ and R.264 on Network with Other Traffic
23 Jitter Comparison on Type of Resolution against two network
60 conditions
24 Average Bandwidth Uses Comparison on Type of Resolution 61 against two network conditions
25 Total Traffic Comparison on Type of Resolution against two 62 network conditions
26 Packet Loss Comparison on Type of Resolution against two 63 network conditions
27 R-Factor Comparison on Type of Resolution against two 64 network conditions
28 MOS Comparison on Type of Resolution against two network 65 conditions
Chapter 1
INTRODUCTION
1.0 Introduction
Mainstream of videos are increase in directly proportional over year. Corporates have been using both audio/voice and video communication. Recent advancements in communication technology have cut lose some unnecessary budget in operational values of businesses. VoIP that enables users to make calls over the Internet and Video over IP that actually, enabling users to meet and see other user. This research will study on the functional of Video over IP across global stream and hardware devices.
Developments of Video over IP have reached many sectors of communications such as Video on Demand (VOD), Audio and Video on Demand (AVOD), digitized video, video streaming, interactive video, and real-time audio/video. In presenting videos over the Internet, video signals must be captured and digitalized before it can be stream. Therefore, devices are needed to capture sequence of motions (analog signal) and turning it into digital signal that can be transmitted over the Internet.
From developments of Video over IP, video presentations have been grouped that is video broadcasting, Video on Demand (VOD) and videoconferencing. Video broadcasting and Video on Demand are categorized as one-way transmissions, while video conferencing is a full duplex. Therefore, this research will specify on videoconferencing that provide real-time communication.
2
Videoconferencing allows people in different location to communicate (see and hear) as they faced and converse each other in digitalized world. Videoconferencing is a combination of a full duplex audio and video transmission. It is real time and a two-way communication. Videoconferencing can be point-to-point (one-to-one user communication) or multipoint (multiple users in communication).
Performance and quality of videoconferencing can be check using monitoring tools/network analyzer. Monitoring tools can assessed the voice quality of degraded calls, troubleshooting error and network problem, and meaning of logged event. Monitoring tools also provided a performance checker that will check the video quality and audio quality based on scales (voice quality measurement) —whether MOS or R Factor.
3
1.1 Problem Statement
Performance of videoconferencing are not only determined by the equipment, bandwidth usage but also by the type of codecs (video and audio) used. Some conferencing clients offer the selection of codecs to user, whereas user can choose the quality of its own video and speech sessions in basis of high quality codec (higher bandwidth requirement or lower quality codec (lower bandwidth requirement).
With the various available video codec in market, mainly H.263+ and H.264 plus the availability of video resolution ranging from 240p up to 1080p, it is a challenge to identify which video codec and resolution perform the best at a given wireless network condition. Many studies have been done with focusing on video codecs without taking the resolution into consideration. Furthermore, previous studies also did not focus on effect of network bandwidth toward video conferencing.
The question here is, how the performance of a specific video codec and resolution behave when being tested on a ubiquitous campus wireless network. With the variety of Internet applications, network congestion cannot be avoided. Therefore, network bandwidth fluctuated and affects the quality of videoconferencing.
4
1.2 Objective
The primary objectives that need to be achieved in this study are:
i. To simulate videoconferencing session using H.263+ and H.264 video codec with resolution of 240p (low resolution), 480p (standard resolution), and 720p (high resolution) on predefined wireless LAN network.
ii. To analyze the performance of H.263+ and H.264 video codec with resolution of 240p (low resolution), 480p (standard resolution), and 720p (high resolution) on predefine wireless LAN network based on scales in the MOS, R-Factor, packet loss, packet jitter, average bandwidth uses and total traffic. iii. To suggest the best video codec and resolution based on MOS, R-Factor,
packet loss, packet jitter and the resolution quality for the predefined wireless network.
1.3 Scope
Limitations during this research are focused on the following: i. Video codecs use in the simulation is H.263+ and H.264 ii. Speech codec use in the simulation is Speex.
iii. Resolutions to be use in the simulation are 240p, 480p, 720p. These resolutions are grouped into three categories: 240p of low resolution (128 kbps), 480p of standard resolution (256 kbps) and 720p of high resolution
(512 kbps).
iv. Implementation of wireless local area network is set on IEEE 802.1 in standard in wireless local area network.
V. Simulation is based on SIP architecture only.
vi. Performances for conferencing are each measures and scales using MOS (Mean Opinion Score), R-Factor, packet loss, packet jitter, average bandwidth uses, total traffic and the resolution quality.
5
1.4 Thesis Organization
The research consists of five chapters:
Chapters 1 provide the overall overview of the thesis. Here, the problem statement will be introduced. Then based on the problem statement, the objective of the research is being defined. Lastly, chapter one also will explain about the research scope.
Chapter 2 introduces video codecs that will be used in this research project. Protocols and resolutions type or categories involved in the video conferencing will be explained in briefly. The literature review is organized in a way that readers can understand this.
Chapter 3 explains the methodology that will be used to progress in this research. Step by step process or phases will be elaborate in this research. All tools used in this research will first introduce in this chapter.
Chapters 4 design the model or know as architecture that will be developed in order to perform the test. It then followed with the continuously design on data analysis.
Chapter 5 explains the result and discussion. One by one analysis and result on parameters will be discussed. Based on this chapter, summary of selection will be made on next Chapter.
Chapter 6 concludes all the chapters and the recommendations for future researchers explain most of the configurations of hardware and software involved in the research. Detail test result will be included in this chapter.
Chapter 2
LITERATURE REVIEW
2.0 Introduction to VoIP, SIP and Video Conference
Nowadays, videoconferencing solution has emerged based on IP protocol - SIP. SIP has long been implementing in many network real-time applications, mainly in VoIP. VoIP is a transmission of voice data over the Internet. Most VoIP applications using SIP rather than H.323 because of its simplicity and easy-to-use standard. VoIP managed to cut out many unnecessary costs for users. With Internet implementation, users can call and receive data for as long as they like within a small budget (pay to the provider/ISP).
Advancements in communication technology and the success implement on VoIP have giving opportunity for video/voice application over Internet (Videoconferencing). Believing that video conference will widely use, this application can be real success to VoIP. SIP also can be used as signaling protocol in video conference. Many have chosen SIP over H.323 in videoconferencing after seeing the features success in VoIP. In terms of voice sent-over, quality will be the same as in VoIP but, for video quality will be differ as no other applications that can be put as a benchmark success.
2.1 Session Initiation Protocol (SIP)
Session Initiation Protocol is an application-layer control that covers on signaling. This is the IETF's standard proposed for establishing VoIP connections. SIP is not responsible for transmitting data; rather its purpose is initiating (create), modifying (coordinate) and terminating (tear down) sessions. In terms of traditional telephone, SIP is the ringing of a phone, the busy tone and the ending of a call. Architecture of SIP is similar to the HTTP, where both are client-server protocol.
SIP depends on SDP[] (Session Description Protocol) to carry out negotiation for codec identification. It is important in a videoconferencing because participants can join and leave dynamically. SDP specifies details such as the media encoding, protocol port numbers, and multicast address. SIP invitations used to create sessions carry session descriptions that allow participants to agree on a set of compatible media types. SIP makes use of elements called proxy servers to help route requests to the user's current location, authenticate and authorize users for services, implement provider call-routing policies, and provide features to users. SIP also provides a registration function that allows users to upload their current locations for use by proxy servers. SIP runs on top of several different transport protocols. SIP services that been provided include: User Location, Call Setup, User Availability, User Capabilities and Call Handling.
SIP system consists of two components: user agents and network servers. User
Agents is SIP users' end station that acts as User Agent Client (issue request) and User Agent Server (received and response to requests). Network Servers receives updates on users' current locations, received and forward request to the server that have more information of called party, and determine next-hop server and return address to the client.
S
SIP messages are used for client-server communication. Figure 1 shows the basic SIP operation using SIP messages communication. Method in SIP messages:
Method (SIP Message) Description
INVITE Invite user to call
BYE Terminate connection between two endpoints
ACK Exchange of invitation messages OPTIONS Get information on call's capabilities REGISTER Gives information about user's location
to SIP registration server CANCEL Terminate search for a user
Table 1 SIP Messages
7ACK SACK
SIP
RTP
-
NOW
2.1.1 Real-Time Protocol (RTP)
Real-time protocols are used by H.323 and SIP as transmission protocol. RTP [9] supports the transfer of real-time audio and video over packet-switched network. RTP protocol is standardized by the IETF, in RFC 3550. RTP is a complex protocol and it is used together with many protocols. Functions that include in RTP: Sequencing, Payload Identification, Frame Indication, Source Identification, and Intramedia Synchronization.
Figure 2 A call using SIP for signaling and RTP for transmission of video and voice
2.2 Video Conference Codec
Videoconferencing depends on video codecs to compress and decompress data being transmitted. Using raw data would increase network resources. Compression and decompression allow limiting network bandwidth. Performance of videoconferencing is related to the video codec's ability coping with different network conditions. The primary codecs used in videoconferencing are H.263 and H.264.
'U
2.2.1 H.263+
The ITU Recommendation H.263+ is a video codec compression designed as a low-bitrate compression format for videoconferencing over narrowband channels. As advancement of ISO H-261, H.263 was used for development of MPEG (high data rates). Generally, H.263 has better quality than H.261. In any circumstances, H.263 has a strong compression component, enabling high performance on movies where there is a little change in frames. H.263+ streaming are packetized for transportation via Real Time Protocol (RIP) over networks. Coding algorithm is similarly used in H.261.
2.2.2 H.264
ITU-T Recommendation H.264 also known as ITU-T H.264, MPEG-4 Part 10, AVC (Advanced Video Coding). It is widely recognized as future video compression for applications such as HDTV services. H.264 was developed to provide high-quality video at lower bit rate than standard MPEG-4 or JPEG. Subsequently, represents a significant benefit to network camera (CCTV, etc.) operations with reduced bandwidth and better pixels.
2.3 Video Resolution
Resolution is important to clearly see an image. Higher resolution means that high number of pixels is used in creating crisper, cleaner image. Video resolution is composed of analog and digital. Analog video resolution is derived from television industry where the image consists of lines, while digital video resolution is derived from digitalized system where an image is made up of pixels. Digital video resolution makes up single image or frame. Video will have many frame or sequential of images• to produce moving picture. This number of frames in video is called frame rate. Frame rate show a single second of movement in certain number of frames. Example: QCIF-NTSC has a resolution of 176 x,120 with a frame rate of 30fps, frame per