1.1 Introduction Chap-1 (MM Comm) Multimedia. supports text, graphics, video, image, audio, etc. in one system with multiple input/output devices. multimedia services to be achieved via other systems Video image video Data LAN/WAN/PSTN
1.2 Multimedia information representation Multimedia data blocks of digital data represented by a fixed number of binary digits (bits) bit per seconds (bps) a measurement unit for digital data communication Compression digitalization progress to represent the multimedia types in a digital form MPEG : Motion Picture Expert Group JPEG : Joint Photographic Experts Group
Data Capabilities for Multimedia Services Audio 1.4 Mbps (each sample: 16 bits, 44.1 KHz sampling rate) stereo sound : 680 kbps, 340 kbps, or 170 kbps Voice/Phone 48-352 kbps: 8 khz/8bits (mono) Video 27.7 MB/s: 640 x 480 x 24 pixels x 30 frames (24-bit color) (220 Mbps) each sample: 8 bits, 13.5 MHz luminence Image simple: 64 kb/image (uncompressed) detailed: 7.5 MB/image (uncompressed) 60 Mbps Text 1 MByte (500 page x 2 kbytes per page)
Bandwidth for Multimedia Service Service Name Television & video service Video telephony Video Conferencing CATV HDTV Image Telemdecine (X-ray) Voice Audio (Stereo) Bandwidth 2 Mbps - 600 Mbps 2 Mbps - 40 Mbps 2 Mbps - 130 Mbps 130 Mbps - 600 Mbps 130 Mbps - 600 Mbps 0.5 Mbps - 60 Mbps 2 Mbps - 60 Mbps 48 kbps - 400 kbps 0.2 Mbps - 1.4 Mbps
MPEG 1, 2 MPEG1 : 디지털저장매체용컬러동화상및오디오의압축 / 부호화방식의국제표준 전송속도 -> 1.5Mbps MPEG2 ( 고화질, 고압축 ) : 디지털 TV 방송, 통신, 저장매체용컬러동화상및오디오의압축 / 부호화방식의국제표준 Part1 Systems Part6 System Extension- DSM- CC Part2 Video Part7 Advanced Audio Coding Part3 Part4 Audio Conformance testing Part8 Part9 Part10 VOID (withdrawn) System extension RTI Conformace Extension Part5 Software simulation Part11 IPMP on MPEG2 - Systems MP3 생성 MPEG1 에서추가된부분 : 데이터전송기술 (Transport Stream)
MPEG 4 원리 objects 1 2 3
MPEG 4 원리 obj 1 1 카메라로촬영한각각의 objects 를함수를이용하여압축하고보여준다 2 3 2 원본에서의 objects 이이동 3 촬영하였던장면에서이동이있었던 objects 의 data 에관해서만 catch 모든사물을 object 단위로구별하여코딩 => Individual coding MPEG4 압축의원리
MPEG 4 obj 1 [ 결론 ] 2 3 Object 단위로 coding 을분리 압축을더욱높이고! 용량은더욱줄이고! Object 단위로 player 실행
MPEG 4 MPEG4 - 멀티미디어통신을전제로만들어지고있는영상압축기술 - 낮은전송률로동화상을보내는것을전제로개발된데이터압축및복원기술에대한새로운표준 -MPEG4 와대응되는압축 Format 은? H.264 - MPEG21 의 target code 가바로 MPEG4 이다. Part13 Part14 Part15 IPMP Extensions MP4 File Format AVC File Format 모바일에서주로사용되는파일포맷 * IPMP : Intellectual Property Management and Protection * AVC : new generation of video coding algorithm
-MPEG7 은 contents 를표현할수있다. Chap-1 (MM Comm) MPEG 7 MPEG7 - Multimedia Content Description Interface - 멀티미디어로구성된데이터베이스에서정보를용이하게탐색하여추출할수있도록, 표준화된멀티미디어정보표현방식을제공하기위한국제표준또는그표준화그룹 - MPEG 7 에서는특징추출 (feature extraction), 영상의표현과압축방식들에대해서는관여하지않으며이것은 MPEG 4 에서담당. - MPEG7 은하나의 DB 로보여진다 -> video 에대한 META DB 의형태이다.
MPEG 21 MPEG21 - Multimedia Framework - MPEG21 sets out a vision for the future of an environment where delivery and use of all content types by different categories of users in multiple application domains will be possible. - 기술요소 1 digital Item Declaration 2 Digital Item Identification 3 Intellectual Property Management and Protection 4 Terminals and Networks 5 Digital Item Management and usage 6 Digital Item Representation 7 Event Reporting
1.3 Multimedia networks Telephone network to provide a telephony service (PSTN) data network to provide a data communication service (PSDN) broadcast television network (BN) to provide a broadcast television service Internet (IP based Network) Integrated Services Digital Networks (ISDN) to provide multiple service Broadband multi-service networks Broadband-Integrated Services Digital Network (B-ISDN) to provide multiple service
통신 방송 인터넷한번에 3 망융합 급부상 디지털타임스 2007 년 3 월 26 일 3 망융합 = 통신, 방송, 인터넷등 3 대네트워크의업무융합및이들이파생시킨관리와정책방면의통합적추세를일컫는말이다. 3 망융합의일차적인목적은사용자들에게보다신속하게풍부한정보를서비스하는것이다. 어떤업무에서사용하는문자나음성, 데이터, 이미지, 영상등은멀티매체업무로전환되며사용자들은단말기를통해각종정보와서비스를받을수있게된다. 통신망 인터넷망 방송망 네트워크측면에서 3 망융합은각각의독립적인네트워크를종합적인네트워크로전환시킬뿐아니라네트워크성능과자원이용의수준을한차원업그레이드시킨다. 이런점에서 3 망융합은확실히네트워크업무발전의필연적인추세이자전세계기술분야의창조혁신을위한중요한영역이다. TCP/IP 협력 신식산업부가최근공포한 2007 년업무요점 에서는올해 3 망융합의기초적연구와관리부처와의교류등에힘쓰기로했다. 또 11 5 규획 기간 (2006~2010 년 ) 동안통신기초설비를갖추고적극적으로 3 망융합을추진하도록했다. 3 망합일 3G 융합개념도
1.3.1 Telephone networks (1) Network components circuit mode, access circuits
1.3.1 Telephone networks (2) Digital transmission using modems Chap-1 (MM Comm) Multiple services via an high speed modem
1.3.2 Data networks (1) Chap-1 (MM Comm) Provide data communication services electronic mail, file transfer connected digital devices such as Handhold device, PCs, Servers packet mode : packet is a container = head + block of data + addresses two type of data network X.25 network low bit rate --> unsuitable for most MM applications Internet open systems interconnection
A selection of the network types connected to the Internet
1.3.3 Broadcast television networks Cable networks Satellite/terrestrial broadcast networks set-top box : controls of the television channel access to other services includes a cable modem/high-speed modem supports an interactive mode
Cable networks Chap-1 (MM Comm) Satellite/terrestrial broadcast networks
1.3.4 Integrated services digital networks Deployed in the early 1980s to provide PSTN users with the capability of having additional services: (ex, video conference, video phone) two telephone lines: two different telephone calls in simultaneously or a telephone call and a data call full data call two type lines cf: BRA (Basic rate access) two channel : 128kbps PRA (Primary rate access) 20 or 30 channel : 1.5 Mbps (T1) or 2Mbps (E1) Digital subscriber line (DSL)
Alternative services provided by an ISDN Chap-1 (MM Comm)
1.3.5 Broadband multi-service networks Designed in the mid-1980s to support a wide range of MM Communication Applications Broadband have bit rates in excess of the max bit rate of 2 Mbps called B-ISDN (so, ISDN is Narrowband ISDN) to support high quality video transmission cf: compression of data to support multiple service audio, video, text simultaneously basic transmission mode Asynchronous transfer mode (ATM) cell(54bytes) switching networks
Example of ATM broadband multi-service network Chap-1 (MM Comm)
Networking Technologies N-ISDN T1/E1 xdsl Cable T3 ATM (B-ISDN) Token Ring 10-Base T Fast Ethernet FDDI 64 kbps 1 Mbps 10 Mbps 100 Mbps 1 Gbps 10 Gbps
1.4 Multimedia applications Category interpersonal communication a single type of medium speech, Image, Text only two or more media types are integrated together Text and images, speech and video, multimedia interactive applications over Internet entertainment applications
Speech only (1) Computer Telephony Integration (CTI) using PCs instead of conventional telephones Voice-mail teleconferencing
Speech only (2) PC-to-PC telephone call voice over IP (VoIP)
Image only Chap-1 (MM Comm) Facsimile (Fax)
Text only Chap-1 (MM Comm) E-mail service (mailbox)
Example of E-mail service Chap-1 (MM Comm)
Text and images Computer-supported cooperative working (CSCW) see IEEE multimedia, Vol.7, No. 4, 2000 example : shared whiteboard
Speech and video (1) Chap-1 (MM Comm) Video telephony : Two-party video telephone call
Videoconference using an MCU Chap-1 (MM Comm)
Videoconference using a broadcast network Chap-1 (MM Comm)
The Java Media Framework API (JMF) enables audio, video and other time-based media to be added to applications and applets built on Java technology. This optional package, which can capture, playback, stream, and transcode multiple media formats, extends the Java 2 Platform, Standard Edition (J2SE) for multimedia developers by providing a powerful toolkit to develop scalable, cross-platform technology.
Speech and video (2) Chap-1 (MM Comm) Remote lecture and video conferencing
Multimedia Chap-1 (MM Comm) Multimedia mail
Interactive applications over Internet World Wide Web (WWW) Hyper links : HTML major application : E-business/Internet-business
Entertainment applications Movie/video-on-demand Interactive Television
Interactive Television (1) Chap-1 (MM Comm)
Interactive Television (2) Chap-1 (MM Comm)
IPTV 서비스형태 Chap-1 (MM Comm)
DMB Service Systems Chap-1 (MM Comm)
1.5 Application and networking terminology Media types
Communication modes Chap-1 (MM Comm)
Network types : Circuit-switched network Chap-1 (MM Comm)
Network types : packet-switched network Chap-1 (MM Comm)
1.5.5 Network QoS Chap-1 (MM Comm) QoS : Quality of Service bandwidth or delay time QoS in Circuit-switched network the bit rate the mean bit error rate the transmission delay QoS in Packet-switched network the maximum packet size the mean packet transfer rate the mean packet error rate the mean packet transfer delay the worst-case jitter the transmission delay
BER : bit error rate the probability of a bit being corrupted during its transmission across the channel in a defined time interval. BER of 10-3 : 1000 bit 중에서 1 bit이손상된경우 the probability of a block containing a bit error P B = 1 - (1 - P ) N, where P is a probability of BER and N is the number of bits in a block Unreliable service vs. Reliable service Best-try or Best-effort service Transmission Delay Propagation delay (Example 1.2)
Example 1.1 Derive the maximum block size the probability of a block containing an error is to be 10-1 over a channel which has a mean BER probability of 10-4 Answer P B = 1 - (1 - P ) N -> 0.1 = 1 - ( 1-10 -4 ) N and N = 950 bits the maximum block size is 950 bits
1.5.6 Application QoS Application itself has QoS parameters image resolution and size video service: digitization format and refresh rate The require bit rate or mean packet transfer rate the maximum startup delay the maximum end-to-end delay the maximum delay variation/jitter the maximum round-trip delay Buffering to resolve the Jitter (delay)
Application QoS Manage the requirement for applications Application QoS Network QoS Determine the suitability of channel Network QoS
Example : the file size is 100 Mbps Transmission media PSTN HSDPA Wibro ADSL T1 Line T3 Line E1 Line Transmission speed Transmission tiime
Transmission of a constant bit rate stream (a) Timing schematic
(b) FIFO Buffer operation Chap-1 (MM Comm)
Media Types used in Multimedia Applications Chap-1 (MM Comm)
Multimedia Applications Chap-1 (MM Comm) Category Media Applications Speech Image Text Text and Image Interpersonal Communications Interactive Application over The Internet Entertainment Services Speech and Video Text, Image, Audio and Video Text, Image, Audio and Video Audio and Video Telephony, voice-mail, Teleconferencing Facsimile Electronic mail Computer-supported cooperative working(cscw) Video telephony, video mail, Videoconferencing Multimedia electronic mail, multiparty video games etc. Information retrieval (news, weather, Books magazines, video games, Product literature etc) Audio/CD-on-demand Movie/Video-on-demand Near movied/video-on-demand Analog and digital television broadcasts Interactive television