ANSI SCTE 243-3-2017 pdf free download – Next Generation Audio Carriage Constraints for Cable Systems: Part 3 –MPEG-H Audio Carriage Constraints.
7.4.PES Packet stream_id and stream_type
The value of the stream_id field for MHAS formatted MPEG-H Audio packetized elementary streamsshall be ‘110x xxxx’, where each x can be either 0, or 1.The value of stream_type for MPEG-H Audiopacketized elementary streams shall be Ox2D or Ox2E(indicating ISO/IEC 23008-3 [6] Audio with MHAStransport syntax).
The stream_type value Ox2D shall be used for MPEG-H Audio single-stream delivery or for the mainstream in case of MPEG-H Audio multi-stream delivery.
The stream_type value Ox2E shall be used for auxiliary streams in case of MPEG-H Audio multi-streamdelivery (see SCTE 242-3 2017Clause 10 [1] regarding MPEG-H Audio multi-stream delivery).
7.5.STD Audio Buffer Size
lt is recommended that for MPEG-H Audio, the main audio buffer size (BSn) has a value as defined inISO/IEC 13818-l subclause 2.19.3[4].
7.6.Signaling of MPEG-H Audio in MPEG-2 Transport Streams
The descriptors specified in this section are used for signaling of MPEG-H Audio codec specificinformation and NGA features in MPEG-2 transport systems. For signaling NGA features in MPEG-2transport systems the concept of Audio Preselection is used, as described in Part 1 of this standard,subclause 7.1 [2].
7.6.1.MPEG-H_3dAudio_descriptor
The MPEG-H_3dAudio_descriptor provides information about individual MPEG-H Audio elementarystreams within a transport stream that are to be identified in the PSI PMT sections. The intended purpose isto provide configuration information for the receiver. It should be noted that multiple MPEG-H Audioelementary streams may be present in a multiplex for a given program.
The MPEG-H_3dAudio_descriptor is defined in ISO/IEC 13818-1 subclause 2.6.106 [4] and is locatedin the PMT of the PSI Tables defined in ETSI EN 300 468 [5].
The MPEG-H_3dAudio_descriptor shall be included in a program map section at most once in eachrelevant ES_info descriptor loop that describes an elementary stream carrying an MPEG-H Audio stream,coded in accordance with ISO/IEC 23008-3 [6] that is included in a transport stream.
7.6.1.1.Profiles and levels
The profile and level value is signaled in the mpegh3daProfileLevelIndication field in theMPEG-H_3dAudio_descriptor as specified in ISO/IEC 13818-1 subclause 2.6.106 [4].
The values for MPEG-H Audio Low Complexity (LC) Profile Level 1, Level 2 and Level 3 are “OxOB,”“OxOC,” and“OxOD” , respectively, as specified in ISO/IEC 23008-3 subclause 5.3.2 [6].
7.6.2. audio_preselection_descriptor
The audio_preselection_descriptor provides information about the available Audio Preselections for oneAudio Program contained in one or more MPEG-H Audio associated elementary streams within a transportstream that are to be identified in the PSI PMT sections.
All constraints specified in Part 1 of this standard, subclause 7.1.2 [2] shall apply.
The contents of the audio_preselection_descriptor and the Audio Scene Information carried in the MPEG-H Audio clementary should match. The Audio Scene Information is defined in ISO/IEC 23008-3 Clause15[6].
The fallowing mapping of the audio preselection descriptor fields to the Audio Scene Information fieldsshould apply:
. The num_preslections field in the audio_preselection_descriptor should correspond to the
mae_numGroupPresets field specified in ISO/EC 23008-3 subclause 15.3 [6].
The preselection_id field in the audio_preselection_descriptor should correspond to themae_groupPresetID field specified in IsO/iEC 23008-3 subclause 15.3 [6].
The first language indicated bythe ISO_639_language_code field in theaudio_preselection_descriptor should correspondto theinformation conveyed inmae_contentLanguage fieid of the default dialog element (i.e., the maeGroup which is markedas default in mae_switchGroupDefaultGroupID and is tagged in mae_contentKind as dialog)specified in lSO/IEC 23008-3 subclause 15.3[6].
The spoken_subtitles field in the audio_preselection_descriptor should be set to ‘1′, if themae_contentKind field specified in ISO/IEC 23008-3 subclause 15.3 [6] is set to ‘8’.
7.6.3. emergency_information_descriptor
The emergency_information_descriptor provides information about the available audiolauralrepresentation of the emergency information contained in one or more MPEG-H Audio associatedelementary streams within a transport stream that are to be identified in the PSI PMT sections.
All constraints specified in Part l of this standard, subclause 7.2.2 [2] shall apply.
7.6.4.Accesibility Information
For MPEG-H Audio the accessibility fields defined in Part l of this standard, subclause 7.3 [2] shouldcorrespond to the mae_groupPresetKind value in the mae_GroupPresetDefinition() structure and themae_contentKind values in the mae_ContentData() structures in the AudioSceneInformation() of theMPEG-H Audio stream as specified in ISO/IEC 23008-3 [6]. The mapping from the MPEG-H Audio meta-data fields should be done as follows:
audio_description field should be set to ‘1′ , if the mae_contentKind value of at least one
Audio Element is set to “9R(“”audio description/visually impaired””).ANSI SCTE 243-3 pdf download.