ETSI TS 102 796 V1.7.1 (2023-09)

Hybrid Broadcast Broadband TV

RTS/JTC-116

General Information

• Status: Not Published
• Technical Committee: BROADCAS - EBU/CENELEC/ETSI on Broadcasting
• Current Stage: 12 - Citation in the OJ (auto-insert)
• Due Date: 11-Sep-2023
• Completion Date: 11-Sep-2023

Standards Content (Sample)

TECHNICAL SPECIFICATION
Hybrid Broadcast Broadband TV

2 ETSI TS 102 796 V1.7.1 (2023-09)

Reference
RTS/JTC-116
Keywords
broadcasting, DVB, HTML, internet, multimedia

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© ETSI 2023.
© European Broadcasting Union 2023.
All rights reserved.
ETSI
3 ETSI TS 102 796 V1.7.1 (2023-09)
Contents
Intellectual Property Rights . 17
Foreword . 17
Modal verbs terminology . 17
Introduction . 18
1 Scope . 20
2 References . 20
2.1 Normative references . 20
2.2 Informative references . 24
3 Definition of terms, symbols and abbreviations . 26
3.1 Terms . 26
3.2 Symbols . 27
3.3 Abbreviations . 27
4 Overview . 31
4.1 Applications . 31
4.2 Architecture (informative) . 31
4.2.1 Introduction. 31
4.2.2 System overview . 32
4.2.3 Functional terminal components . 32
4.3 Terminal capabilities and extensions . 34
4.4 Specification overview . 34
4.5 Referenced W3C and WHATWG Specifications . 36
5 User experience (informative) . 36
5.0 Introduction . 36
5.1 Visual appearance of interactive applications . 36
5.1.1 Balance of video and application . 36
5.1.2 Service selection and event change . 37
5.2 User input . 38
5.3 Access to interactive applications . 39
5.3.1 Overview of ways of access . 39
5.3.2 Inaccessibility of applications . 40
5.3.3 Starting broadcast-related autostart applications . 40
5.3.3.1 Possible states of an autostart application . 40
5.3.3.2 "Red Button" applications . 41
5.3.4 Starting digital teletext applications . 41
5.3.5 Starting broadcast-independent applications . 42
5.4 Exiting and hiding broadcast-related applications . 43
5.5 Companion Screens . 43
5.6 User interface issues . 44
5.6.1 Advertising broadcast applications . 44
5.6.2 Co-existence with CI and CI Plus MMI. 44
5.6.3 Encrypted channels . 44
6 Service and application model . 44
6.1 Application model . 44
6.2 Application lifecycle . 45
6.2.1 Introduction. 45
6.2.2 Starting and stopping applications . 45
6.2.2.1 Summary (informative) . 45
6.2.2.2 Behaviour when selecting a broadcast service . 46
6.2.2.3 Behaviour while a broadcast service is selected . 48
6.2.2.4 Time-shifting behaviour . 50
6.2.2.5 Simultaneous broadcast/broadband/CI Plus application signalling . 51
6.2.2.5.1 Priority . 51
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4 ETSI TS 102 796 V1.7.1 (2023-09)
6.2.2.5.2 Not currently operational broadband connection . 51
6.2.2.5.3 Currently operational broadband connection and error accessing initial page . 51
6.2.2.5.4 Not currently operational CI Plus protocol . 51
6.2.2.5.5 Currently operational CI Plus connection and error accessing file system . 51
6.2.2.5.6 Application launch failure . 51
6.2.2.6 Broadcast-independent applications . 52
6.2.2.6.1 Lifecycle issues . 52
6.2.2.6.2 Launch context signalling (informative) . 53
6.2.2.7 Access to broadcast resources while presenting broadband-delivered A/V . 54
6.2.2.8 Behaviour on encrypted broadcast services . 54 ®
6.2.2.9 Applications launched from non-HbbTV application environments . 55
6.2.2.10 Parental ratings . 55
6.2.2.11 Other general behaviour . 55
6.2.3 Application lifecycle example (informative) . 57
6.2.4 Application visibility . 58
6.3 Application boundary . 59
6.3.1 Introduction. 59
6.3.2 Origin . 59
6.3.3 Application boundary definition . 60
7 Formats and protocols . 61
7.1 General formats and protocols . 61
7.1.1 Graphic formats . 61
7.1.2 Audio description . 61
7.2 Broadcast-specific format and protocols . 61
7.2.1 System, video, audio and subtitle formats . 61
7.2.2 Protocol for application transport . 62
7.2.3 Signalling of applications . 63
7.2.3.1 Broadcast signalling . 63
7.2.3.2 Broadcast-independent application signalling . 66
7.2.4 Synchronization . 69
7.2.5 DSM-CC carousel . 69
7.2.5.1 Mounting related constraints . 69
7.2.5.2 Initial carousel mounting . 69
7.2.5.3 Subsequent carousel mountings (during the lifecycle of an application) . 69
7.2.5.4 Constraints . 70
7.2.5.5 Performance (informative) . 70
7.2.6 Data services . 71
7.2.7 File system acceleration . 71
7.2.7.1 Introduction . 71 ®
7.2.7.2 HbbTV stored groups descriptor . 71
7.2.7.3 Group location descriptor . 72
7.2.7.4 Group Manifest file name . 72
7.2.7.5 File groups referenced by multiple carousels . 73
7.2.7.6 The use_version flag . 73
7.2.8 Protocol for download . 73
7.3 Broadband-specific format and protocols . 73
7.3.1 System, video and audio formats . 73
7.3.1.1 General requirements . 73
7.3.1.2 Systems layers . 75
7.3.1.3 Video . 76
7.3.1.4 Audio . 77
7.3.1.5 Subtitles . 78
7.3.1.5.1 TTML based subtitles . 78
7.3.1.5.2 Broadcast subtitles . 79
7.3.2 Protocols . 80
7.3.2.1 Protocols for streaming . 80
7.3.2.2 Protocols for download . 80
7.3.2.3 Void. 80
7.3.2.4 HTTP User-Agent header . 80
7.3.2.5 HTTP Redirects . 81
7.3.2.6 HTTP Caching . 81
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5 ETSI TS 102 796 V1.7.1 (2023-09)
7.3.2.7 Simultaneous HTTP connections . 82
7.3.2.8 HTTP/2 . 82
8 Browser application environment . 82
8.1 DAE specification usage . 82
8.2 Defined JavaScript APIs . 82
8.2.1 Acquisition of DSM-CC stream events . 82
8.2.1.1 Adding and removing stream event listeners . 82
8.2.1.2 DSM-CC StreamEvent event . 84
8.2.2 Carousel objects access with XMLHttpRequest . 84
8.2.3 APIs for media synchronization. 85
8.2.3.1 Introduction (informative) . 85
8.2.3.2 The MediaSynchroniser embedded object . 86
8.2.3.2.0 General . 86
8.2.3.2.1 Properties . 86
8.2.3.2.2 Methods . 89
8.2.3.2.3 DOM2 events . 93
8.2.3.2.4 Error codes . 93
8.2.3.3 The CorrelationTimestamp class . 94
8.2.3.3.1 General . 94
8.2.3.3.2 Properties . 94
8.2.4 APIs for automatic deletion of downloaded content . 95
8.2.5 APIs for obtaining the LCN of a service. 95
8.2.6 Companion Screen discovery APIs . 96
8.2.6.1 HbbTVCSManager embedded object . 96
8.2.6.2 DiscoveredTerminal class . 97
8.2.6.3 Void. 97
9 System integration . 98
9.1 Mapping from APIs to protocols . 98
9.1.1 Unicast streaming . 98
9.1.1.1 General streaming requirements. 98
9.1.1.2 HTTP streaming . 98
9.1.1.3 Media player implementations and API behaviour . 98
9.1.2 Unicast content download . 98
9.1.3 Seek accuracy . 98
9.2 URLs . 100
9.3 Other file formats . 102
9.3.1 Stream event . 102
9.3.2 MPEG DASH event integration. 102
9.3.2.1 General . 102
9.3.2.2 HTML5 media element . 103
9.4 Presentation of adaptive bitrate content . 105
9.4.1 General . 105
9.4.2 Behaviour for HTML5 media objects . 105
9.4.3 Behaviour for the A/V Control object . 107
9.5 Downloading content via FDP . 108
9.5.1 Download registration. 108
9.5.2 Single file with multiple URLs . 108
9.5.3 Properties of the Download object . 108
9.5.4 Download state diagram . 109
9.6 Media element integration . 111
9.6.1 General . 111
9.6.2 Resource management . 111
9.6.3 Transition behaviour . 113
9.6.4 Reporting and control of buffering . 113
9.6.5 Distinguishing multiple media tracks (informative) . 114
9.6.6 Controls attribute . 114
9.6.7 DRM . 114
9.6.8 Parental Rating Errors . 115
9.6.9 Downloaded Content . 115
9.6.10 Video presentation . 115
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6 ETSI TS 102 796 V1.7.1 (2023-09)
9.6.11 getStartDate method . 116
9.6.12 End of stream indication . 116
9.6.13 Media Source Extensions . 116
9.7 Synchronization . 118
9.7.1 Synchronization and video objects . 118
9.7.1.1 video/broadcast object . 118
9.7.1.2 HTML5 media element . 119
9.7.1.3 Void. 120
9.7.2 Tolerance . 121
9.7.3 Timeline availability . 121
9.7.4 Minimum synchronization accuracy . 122
9.8 Reliability and resilience . 123
9.9 WebSocket Server and JSON-RPC Implementation . 124
9.9.1 Introduction. 124
9.9.2 The Web Socket Server . 124
9.9.2.1 Discovery of the WebSocket Server . 124
9.9.2.2 Securing the WebSocket Server . 124
9.9.2.2.1 Mixed Content Issues . 124
9.9.2.2.2 Additional Security Considerations . 125
9.9.2.3 CORS Considerations . 125
9.9.3 JSON-RPC Messaging . 125
9.9.3.1 The JSON-RPC Message Format . 125
9.9.3.2 Message batching . 125
9.9.4 JSON-RPC Notifications from the terminal . 125
9.9.4.1 The JSON-RPC Notifications . 125
9.9.4.2 Registration for JSON-RPC Notifications (informative) . 126
9.9.4.3 Subscribe API . 126
9.9.4.4 Unsubscribe API . 127
9.9.5 Request capability negotiation . 127
9.9.6 Extensibility and compatibility . 129
9.9.7 JSON-RPC Response Error Codes . 129
9.9.8 JSON-RPC Response formats for non-Error Messages (informative) . 130
9.10 Switching between broadcast and broadband-delivered content . 130
10 Capabilities . 131
10.1 Display model . 131
10.2 Terminal capabilities and functions . 132
10.2.1 Minimum terminal capabilities . 132
10.2.2 User input . 137
10.2.2.1 Key events . 137
10.2.2.2 Mouse and wheel events . 139
10.2.3 Terminal functions . 139
10.2.3.1 Favourites and bookmarks . 139
10.2.3.2 Streaming and Download . 139
10.2.3.3 PVR . 140
10.2.3.4 Download via broadcast using FDP . 140 ®
10.2.4 HbbTV reported capabilities and option strings . 140
10.2.4.1 General structure . 140
10.2.4.2 Forward compatibility - Terminals . 140
10.2.4.3 Forward compatibility - Applications . 141
10.2.4.4 Third Party Extensions . 141
10.2.4.5 Namespaces . 142
10.2.4.6 Document Type Definition . 142
10.2.4.7 XML Contents . 142
10.2.4.8 Option strings . 148
10.2.5 Void . 149
10.2.6 Parental access control . 149
10.2.6.1 Broadcast channel . 149
10.2.6.2 Broadband delivered content . 150
10.2.6.3 Downloaded content. 150
10.2.6.4 PVR . 151
10.2.6.5 Synchronization and parental access control . 151
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7 ETSI TS 102 796 V1.7.1 (2023-09)
10.2.7 Component selection. 151
10.2.7.1 General . 151
10.2.7.2 Component selection by the terminal . 153
10.2.7.3 Component selection by the application . 154
10.2.7.4 Single decoder model . 155
10.2.7.5 Multi-decoder model . 155
10.2.7.6 Component selection with MSE (informative). 156
10.2.8 Multi-stream media synchronization . 156
10.2.8.1 General . 156
10.2.8.2 Void. 157
10.2.8.3 Other synchronization cases . 157
10.2.8.4 Supported combinations . 158
10.2.9 Inter-device media synchronization . 159
10.2.9.1 General . 159
10.2.9.2 Master terminal . 159
10.2.9.3 Void. 159
10.2.10 Application to media synchronization . 159
10.2.11 Combining audio from memory and broadcast/broadband audio/video . 159
10.2.12 Audio level adjustment for audio mixing . 160
11 Security. 161
11.1 Application and service security . 161
11.2 TLS and Root Certificates . 162
11.2.1 TLS support . 162
11.2.2 Cipher suites . 163
11.2.3 Root certificates . 164
11.2.4 Signature algorithms . 164
11.2.5 Key sizes and elliptic curves .
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