Multimedia Standards SS 2017 Lecture 12/13/14 Prof. Dr.-Ing. Karlheinz Brandenburg Karlheinz.Brandenburg@tu-ilmenau.de Contact: Dipl.-Inf. Thomas Köllmer thomas.koellmer@tu-ilmenau.de 1
SYSTEM STANDARDS AUDIO BROADCAST VIDEO BROADCAST STREAMING 2
DAB - Digital Audio Broadcasting Overview: Eureka-147-project Founded in 1986 with 16 partners (A partners) International consortium consisting of: Broadcasters Network operators Consumer electronics industry Research institutes Opening the consortium for further partners: 1992 3
DAB: Regional Coverage 4 Source: http://www.worlddab.org/country-information, June 2017
DAB: Regional Coverage 5 Source: Digitisation report 2015, http://www.diemedienanstalten.de/fileadmin/download/publikationen/digitalisierungsbericht/2 015/Digitisation_2015_english.pdf
DAB Main Standards DAB (1995) Main Document: ETSI EN 300 401 Guidelines of Use and Operation: ETSI TR 101 496 DAB+ (2007) Transport of AAC Audio: ETSI TS 102 563 6
DAB - Digital Audio Broadcasting Block Diagram Transmitter 7
DAB - Digital Audio Broadcasting Transmission channels 1. Synchronization channel Zero and phase reference symbol 2. FIC (Fast Information Channel) After analysis of the FIC the receiver can decode the payload 3. MSC (Main Service Channel) Payload (programs and data services of the ensemble) 8
DAB - Digital Audio Broadcasting Example Service Structure 9
DAB - Digital Audio Broadcasting Stream & Packet Mode Stream Mode Packet Mode Transmission of data streams Constant data rate: n x 8kBit/s E.g. radio programs, audio coded with MPEG-1 Layer II Transmission of data streams With low data rates (<8kBit/s) or Temporal varying data rates Asynchronous data rates Pure data services 10
DAB - Digital Audio Broadcasting Transport mechanisms for data services Fast Information Data Channel (FIDC) Traffic Message Channel (TMC) TS 102 368 (Extendend) Programme Associated Data (PAD/X-Pad) Dynamic Label Sequence (DLS) for Text EN 300 401 Slide Show Images (SLS) TS 101 499 Electronic Program Guide (EPG) TS 102 818 Packet Mode 11
DAB - Digital Audio Broadcasting Additional Services Dynamic Label (DLS) Displaying of short text messages on an alpha numerical display (labels) For the Transport: Segmentation of the labels in up to 8 segments with up to 18 characters, limited formatting possible Typical applications: Short messages Weather forecast Title / artist of a song Basic structure of a X-PAD data group: Prefix (2 Bytes) Character field (n Bytes) CRC (2 Bytes) 12
DAB - Digital Audio Broadcasting Additional Services Slide Show (SLS) Transmission of sequence of images for Logos, News, cover art, etc. Embedded within X-PAD Data stream using the MOT protocol (Multimedia Object Transfer) Most common resolution: 320 240 px Formats: JPEG (non-progressive) (animated) PNG 13
DAB - Digital Audio Broadcasting Additional Services Traffic Message Channel (TMC) Data service based on Alert C protocol digital coded traffic message Reference of the numerically coded values to the information tables Event Location Severity Duration Alternative routes Organization of the numerically coded values in groups consisting of < 38 Bit of information Transport of the messages in the FIDC in FIGs 14
DAB - Digital Audio Broadcasting Transmission Frequencies & Modes Transmi ssion Mode Frame Duration #FIB I 96ms 12 4 II 24ms 3 1 III 24ms 4 1 IV 48ms 6 2 #CIF Band III L-Band E.g. f= 224,25 MHz = TV channel 12 Mode I f=1452 1492 MHz Mode II or IV Terrestrial network = Single frequency network Spectrum and power efficient technologies ETS 300401 (30 MHz 3 GHz) Mode III 15
DAB+ DAB+ : ETSI TS 102 563: Digital Audio Broadcasting (DAB); Transport of Advanced Audio Coding (AAC) audio HE-AAC V2 audio coder Audio Super Framing Reed-Solomon Coder And Virtual interleaver DAB main service channel multiplexer Scope of ETSI TS 102 563 Receivers are backwards compatible to DAB More programs inside the same multiplex Surround possible Improved error correction more stable reception Prof. Dr.-Ing. Karlheinz Brandenburg, karlheinz.brandenburg@tu-ilmenau.de Seite 16
DAB - Digital Audio Broadcasting Relevant Standards (ETSI/CENELEC/IEC): EN 300 401 V1.4.1 (June 2006): Digital Audio Broadcasting (DAB); DAB to mobile, portable and fixed receivers EN 300 797 V1.2.1: Digital Audio Broadcasting (DAB); Distribution interfaces; Service Transport Interface (STI) EN 300 798 V1.1.1: Digital Audio Broadcasting (DAB); Distribution interfaces; Digital baseband In-phase and Quadrature (DIQ) Interface ETS 300 799: Digital Audio Broadcasting (DAB); Distribution interfaces; Ensemble Transport Interface (ETI) EN 301 234 V2.1.1: Digital Audio Broadcasting (DAB); Multimedia Object Transfer (MOT) protocol EN 301 700 V1.1.1: Digital Audio Broadcasting (DAB); Service Referencing from FM-RDS; Definition and use of RDS-ODA 17
DAB - Digital Audio Broadcasting Relevant Standards (ETSI/CENELEC/IEC): ES 201 735: Digital Audio Broadcasting4 (DAB); Internet Protocol Datagram Tunneling ES 201 736 V1.1.1: Digital Audio Broadcasting (DAB); Network Independent Protocols for Interactive Services ES 201 737 V1.1.1: Digital Audio Broadcasting (DAB); DAB Interaction Channel through GSM / PSTN / ISDN / DECT EN 50255/ IEC 62105: Digital Audio Broadcasting system - Specification of the Receiver Data Interface (RDI) EN 50248/IEC 62104: Characteristics of DAB receivers EN 50320: The DAB Command Set for receivers 18
Digital Video Broadcast Prof. Dr.-Ing. Karlheinz Brandenburg, karlheinz.brandenburg@tu-ilmenau.de Seite 19
Digital Video Broadcast Situation in Germany» TV Analog and digital reception in Germany 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 Exclusively Analog Exclusively Digital Mixed http://de.statista.com/statistik/daten/studie/5015/umfrage/empfang-von-analogem-und-digitalem-tv-in-haushalten/
Digital Video Broadcast Situation in Germany Prof. Dr.-Ing. Karlheinz Brandenburg, karlheinz.brandenburg@tu-ilmenau.de Seite 21
DVB - Digital Video Broadcasting 1993 1994 1995 2004 2005 2009 2011 EN 300 421 EN 300 429 EN 300 744 EN 302 304 EN 302 307 EN 302 755 EN 302 769 And many more: https://www.dvb.org/standards 22
DVB - Digital Video Broadcasting Overview of the family of DVB Standards EN 300 421: Framing structure, channel coding and modulation for 11/12 GHz satellite services EN 300 429: Framing structure, channel coding and modulation forcable systems EN 300 468: Specification for Service Information (SI) in DVB systems EN 300 472: Specification for conveying ITU-R System B Teletext indvb bit streams EN 300 473: Satellite Master Antenna Television (SMATV) distribution systems ETS 300 743: Subtitling systems EN 300 744: Framing structure, channel coding and modulation fordigital terrestrial television EN 300 748: Multipoint Video Distribution Systems (MVDS) at 10GHz and above 23
DVB - Digital Video Broadcasting Overview of the family of DVB Standards EN 301 193: Interaction channel through the Digital Enhanced Cordless Telecommunications (DECT) EN 301 195: Interaction channel through the Global System for Mobile communications (GSM) EN 301 199: Interaction channel for Local Multipoint Distribution Systems (LMDS) EN 301 210: Framing structure, channel coding and modulation for Digital Satellite News Gathering (DSNG) and other contribution applications by satellite EN 301 222: Co-ordination channels associated with Digital Satellite News Gathering (DSNG) EN 301 701: OFDM modulation for microwave digital terrestrial television EN 301 775: Specification for the carriage of Vertical Blanking Information (VBI) data in DVB bitstreams 24
DVB - Digital Video Broadcasting What shall be provided: More channels using the same bandwidth Flexible selection of the audio and video quality Transmission of additional services Several subtitles Internet access Paid additional content Interaction via backchannel 25
DVB - Digital Video Broadcasting Combined Baseband Processing 26
DVB - S Overview Satellite Transmission Uplink in frequency multiplex Allocation of single frequencies to transponders Downlink in frequency multiplex Full scale amplification No amplitude modulation Uniform power distribution Sufficient bandwidth available Typical transponder bandwidth 27 MHz in the gigahertz range Quadrature Phase Shift Keying (QPSK) Satellites on different geo stationary positions can use the same frequency 27
DVB - S Overview of the transmitting end 28
DVB - C Overview Cable Transmission High SNR Relatively low bandwidth: Requirements: Channel spacing of TV n * 7 MHz VHF n * 8 MHz UHF Existing networks must be usable Compability to the satellite channel Decoder hardware preferably similar to the satellite decoder (QPSK = 4 QAM) 29
DVB - C Overview of the transmitting end 30
DVB - C Overview of the receiving end 31
DVB - T Overview Terrestrial Transmission Channel properties Requirements: Multipath propagation In house reception Coding similar to the satellite- and cable standard Transmission in 8 MHz bands (7Mhz and 6 MHz bands are possible as well) Possibility for Single Frequency Networks Good area coverage for roof antennas (mobile reception desirable but not mandatory) Orthogonal Frequency Division Multiplex (OFDM) 32
DVB - T Overview of the transmitting end 33
DVB - Digital Video Broadcasting Comparison of the DVB- transmission systems 34
DVB - Digital Video Broadcasting Comparison of the DVB- transmission systems 35
DVB - Digital Video Broadcasting Payload MPEG bit stream PES Packetized elementary stream 36
DVB - Digital Video Broadcasting Program multiplex 37
DVB - Digital Video Broadcasting Service Hierarchy 38
DVB - Digital Video Broadcasting Additional Data / Program Content Description of the transport stream data Control of the receiver EPG (Electronic Service Guide) Table mapping via PID (Packet Identifier) Program Association Table (PAT) mapping of the PID to the corresponding program Network Information Table (NIT) System specific information (e.g. network name) Event Information Table (EIT) Name of a broadcast, EPG Service Description Table (SDT) Description of single programs 39
DVB Second Generation Modernization of all versions of DVB DVB-S2, -C2, -T2 Goals: More efficient usage of the channels (up to 30%) More robust reception (HDTV) Approaches: More efficient modulation More efficient error correction mechanisms Modern codecs H.264 and H.265 DVB-S2 already in use ETSI EN 302 307 DVB-T2 already in use in Austria, Sweden, UK, Germany (since March 2017) 40
DVB - Second Generation: Forward Error Correction DVB, 1st Generation DVB-X2, 2nd Generation 41
DVB-X2 Type of modulation: DVB-C: single carrier 16QAM, 32QAM, 64QAM, 128QAM, 256QAM DVB-S: single carrier QPSK DVB-T: OFDM QPSK, 16QAM, 64QAM Type of modulation: DVB-C2: OFDM 16QAM, 32QAM, 64QAM, 128QAM, 256QAM, 1024QAM, 4096QAM DVB-S2: single carrier QPSK, 8PSK, 16APSK, 32APSK DVB-T2: OFDM QPSK,16QAM, 64QAM, 256QAM 42
DVB-S2 43
DVB-C2 44
DVB-C2 45
DVB-T2 46
More DVB-Standards DVB-SI Service-Information Standard (EN 300 468) Integrate service information (e.g., EPG inside DVB Bitstream) DVB-CI (1997) / DVB-CI+ (2007) Describes interface between Conditional Acess Module (CAM) and Host (i.e., TV-set) Used for authentication and encryption DVB-TXT Standard Insert teletext into the MPEG-2 transport multiplex (EN 300 472 ) DVB-3DTV, DVB-IPTV, DVB-M (Measurement), DVB-S2X, 47
Streaming
What is Streaming? Simultaneous download and playout of media data (via Internet) Live Video, Movies, Music, etc. Additional Data: Additional tracks or camera views Subtitles Arbitrary media objects, advertisement
Streaming Implementations 1998: Real Time Transport Protocol (RTP) RTCP (Control Protocol) RTSP (Streaming Protocol) E.g. implemented in Darwin Streaming Manager / Quicktime Streaming But: Nowadays, the majority of streaming is done via HTTP Proprietary approaches: RTMP (Real Time Messaging Protocol), HTTP-encapsulation possible Apple HTTP Live Streaming Adobe HTTP Dynamic Streaming Microsoft Smooth Streaming
MPEG DASH Dynamic Adaptive Streaming over HTTP Standard for HTTP-streaming, organized by DASH-IF (Industry forum) Members: : Akamai, Microsoft, Adobe, Netflix, Cisco,... Released in April 2012 as ISO/IEC 23009-1:2012, update in May 2014 Does not specify the client or used codecs! (still, implementation guidelines exist) Features: Dynamic switching between codecs DRM / Encryption Interoperability (Cients may exist for any platform)
MPEG DASH Client controls what he wants to receive, not the server (in contrast to RTP) Structure of a Stream Period: independent time frame E.g,. 3 Periods: Movie 1 Ads Movie 2 Adaptation Set: Variants of a Period (e.g., Camera views, Languages) Representation: Link to the actual media data Representations are a list of Segments Installation Segments Media Segment Everything inside a Period is synchronized Dynamic switching possible
Media Presentation Description Dash specifies the format of the data on the HTTP server A client chooses representation by downloading from different urls Description is inside the Media Presentation Description (MPD) as XML Periods, Representations, Segments <Representation id="0" codecs="avc1" mimetype="video/mp4" width="320" height="240" startwithsap="1" bandwidth="45652"> <SegmentList duration="2">... <SegmentURL media="bunny_2s_50kbit/bunny_50kbit_dashnonseg.mp4" mediarange="863-13826" />... </SegmentList> </Representation> <Representation id="1" codecs="avc1" mimetype="video/mp4" width="320" height="240" startwithsap="1" bandwidth="89283">... <Representation id="18" codecs="avc1" mimetype="video/mp4" width="1920" height="1080" startwithsap="1" bandwidth="3840360">
MPEG DASH Many clients are available: http://dashif.org/clients/
Organisational issues Preliminary list of lectures updated version is on the website Tuesday, 17:00, K-Hs1 Thursday, 13:00, K-Hs2 CW* 14 Introduction CW15 Standardization I Standardization II CW16 CW17 CW18 Video Coding I CW19 Video Coding II Video Coding III CW20 CW21 Psychoacoustic Fundamentals CW22 Metadata Standards CW23 MPEG Audio I MPEG Audio II CW24 Speech Coding CW25 CW26 CW27 System Standards I CW28 System Standards II System Standards III Regular Date Alternate Date * ISO 8601 Representation of dates and times ch. 2.2.10 : calendar week number: ordinal number which identifies a calendar week within its calendar year according to the rule that the first calendar week of a year is that one which includes the first Thursday of that year and that the last calendar week of a calendar year is the week immediately preceding the first calendar week of the next calendar year 55