ANSI SCTE 194-2-2018 pdf free download – DTS-HD AUDIO SYSTEM – Part 2: Constraints for Carriage over MPEG-2 Transport.
6. Transport of DTS-HD audio
6.1. MPEG-2 Systems Signaling
The following sections specify the signaling of DTS-HD audio streams in MPEG programs.
6.1.1. Stream Type
For DTS audio formats, stream_type shall be set to 0x88 indicating carriage in PES packets containing DTS-HD elementary stream data.
Note: The stream type value of 0x88 for signaling DTS-HD in North America was chosen to be compatible with the ATSC approach for signaling new codecs. DTS-HD is signaled as stream type 0x06 by DVB. The SCTE standard for DTS-HD differs significantly from the DVB version, for example in theaudio descriptor.
6.1.2. Buffering Model
The DTS buffering model and buffer management is designed in accordance with ISO/IEC 13818-1 [4].For DTS core streams, the main audio buffer size(BSn) shall have a fixed value of 9088 bytes, with adrain rate(Rxn) of 2 Mbps.The fixed value above(9088 bytes) was calculated from a double buffer(2*4096 bytes) plus jitter (384 bytes)+ packet bursts (512 bytes).
For DTS-HD Lossless formats, the value of BSn shall have a fixed value of 66,432 bytes, with an Rxnvalue of 32 Mbps.
For all other DTS-HD formats, the value of BSn shall have a fixed value of 17,814 bytes, with an Rxnvalue of 8 Mbps.
6.1.3. Registration Descriptor
When DTS-HD audio is present in the transport stream, a registration_descriptor with theformat_identifier set to “SCTE”, as described in SCTE 54 [2], shall be included.
6.1.4. DTS-HD Audio Descriptor
The DTS-HD Audio Descriptor shall be included in the program map section following the relevantES_info_length field for any DTS-HD audio stream component coded in accordance with SCTE 194-1that is included in the MPEG program.
The syntax for the DTS-HD Audio Descriptor is shown in Table 1, Table 2, and Table 3. Semantics forthese syntax elements are defined in Sections 6.1.4.1, Section 6.1.4.2 with Table 4, and Section 6.1.4.3with Table 5 to Table 9.
6.1.4.1.Semantics for Table 1
All syntax elements in the DTS-HD Audio Descriptor shall be set consistent with these elements in theaudio elementary stream. In the event of a conflict between the descriptor and the bitstream, the bitstreamshall be the preferred resource.
descriptor_tag: this shall be set to Ox7B.
descriptor_length: this 8-bit field specifies the total number of bytes following the descriptor_length field.lt shall also be used to determine the number of additional_info_bytes contained in the audio descriptor.substream_core_flag: shall be set to 1 if a core substream exists in the audio stream.
substream_O_flag: shall be set to 1 if an extension substream with nuExtSSIndex =0 exists in the audiostream.
substream_1_flag: shall be set to 1 if an independent extension substream with nuExtSSIndex =1 exists inthe audio stream.
substream_2_flag: shall be set to 1 if an independent extension substream with nuExtSSIndex =2 exists inthe audio stream.
substream_3_flag: shall be set to 1 if an independent extension substream with nuExtSSIndex =3 exists inthe audio stream.
reserved: the reserved bits throughout the various sub-structures serve to force byte alignment of severalmajor subcomponents in the DTS-HD descriptor. These bits shall be set to ‘0’’ and are reserved for future definition. The reserved field shall be ignored by receivers built to this version of specification should they become defined in the future.
additional_info_byte: this byte array of from 0 to N bytes is reserved for future use. The number of bytes in this array is determined by comparing descriptor_length to the number of bytes parsed up to the end of the last substream element.ANSI SCTE 194-2 pdf download.