# Sophia.net Signalling

When either a Private Data Descriptor or a Registration Descriptor with the value "0x534f5048" is found in any table
the following Signalling applies:

## Stream Types in PMT:

|Stream Type|Interpretation						|
|-----------|-----------------------------------|
|0x80		|STiD135 GS/GSE Packets				|
|0x81		|AC-3 Audio							|
|0x82		|PID only used for PCR, no payloads |
|0x83		|AC-3 True HD Audio                 |
|0x84       |AC-3+ Audio                        |
|0x85       |DTS Audio	                        |
|0x86       |SCTE 35 Splice Info                |
|0x87       |ATSC Enhanced-AC-3 Audio           |
|0x88       |ULE (RFC 4326)                     |
|0x91       |A52b/AC-3 Audio                    |

## Descriptors:

Sophia.net employs the following descriptors:

|Descriptor	|Interpretation							|
|-----------|---------------------------------------|
|0x80		|Encapsulated Transport Stream over MPE	|
|0x81       |Ignore Flags for Skyscraper            |

### 0x80: Encapsulated Transport Stream over MPE
When the following conditions all apply:
	- This Descriptor is encountered in the inner loop of a PMT
	- The Stream Type is 0x0D (data broadcast)
	- A data_broadcast_id_descriptor is present
	- data_broadcast_id is 5
THEN: This PID will contain an Encapsulated Transport Stream carried within MPE Packets.

Data within this descriptor should be a human readable description of what the Encapsulated Transport Stream is, but can be left empty.

### 0x81: Ignore Flags for Skyscraper
This descriptor is allowed in all tables and is exactly one byte long.
When this descriptor is present, skyscraper8 will not be writing any sort of data in the current table into it's Data Storage.
However, if this descriptor appears in an outer table of a PMT, skyscraper8 will still scan the PIDs, and attach parsers to it, but won't write them to it's Data Storage.


## Other Rules:

Aside from that, the following rules shall apply:

* The IRD MUST process any TDT/TOT tables, regardless of whether the Transport Stream ID and Network ID is known or not.