Describe the bug
When we output metadata, we can do sync or async. We're mixing the stream ID and stream types for those.

From ST1402.1, on sync:

ISO/IEC 13818-1 Table-34 defines a stream_type = 0x15 for “Metadata carried in PES packets,”
and Table 2-22 defines a stream_id = 0xFC for “metadata stream.”

From ST1402.1, on async:

In ISO/IEC 13818-1, Table-34 defines a stream_type = 0x06 for “PES packets containing private
data,” and Table 2-22 defines a stream_id = 0xBD for “private_stream_1.”

We are doing 0x06 with 0xFC.

To Reproduce
Steps to reproduce the behavior:

1. Run the VideoFileInputOutputIT::testWithData() integration test
2. Inspect the testWithData.ts file (I used tsanalyze from tsduck)
3. Note:

|=============================================================================|
|  PID: 0x0101 (257)                                 MPEG-2 PES private data  |
|  PES stream id: 0xFC (MPEG-7 metadata stream)                               |
|  Service: 0x0001 (1) Service01                                              |
|-----------------------------------------------------------------------------|
|  Single Service PID        Transport:                Discontinuities:       |
|  Bitrate: .... 43,057 b/s  Packets: ........... 240  Expected: ......... 0  |
|  Access: .......... Clear  Adapt.F.: .......... 120  Unexpect: ......... 0  |
|                            Duplicated: .......... 0  PES:                   |
|                            PCR: ................. 0  Packets: ........ 120  |
|                                                      Inv.Start: ........ 0  |
|=============================================================================|

That should say:
MPEG-2 PES private data and PES stream id: 0xBD
or
MetaData in PES packets and PES stream id: 0xFC

This is a non-conformance in CMITT 1.3.0, and is a likely interoperability problem.

Expected behavior
Conformance with ST1204. Ideally we'd be able to select either, but at least one would be enough to solve this ticket (with the other being a future feature).

N/A

Configuration (please complete the following information):

• OS: Linux
• JDK: java version "1.8.0_201"
• jMISB version or commit: f081146

Additional context
I tried setting the metadata stream identifier in VideoOutput (i.e. metadataStream.stream_identifier(0xBD);) but that didn't have any effect.

@wlfgang any ideas?