alignment_type [MPEG-2 Semantics]
the alignment_type is an 8-bit unsigned integer field in an MPEG-2 data_alignment_descriptor describes the video alignment type when the data_alignment_indicator in the packet header of the packetized elementary steam (PES) has a value of '1' or 'True.'
valid video stream alignment_type values
| alignment_type | description |
| 1 / 0x01 | Slice, or video access unit |
| 2 / 0x02 | video access unit |
| 3 / 0x03 | Group of Pictures (GOP) or SEQ |
| 4 / 0x04 | SEQ |
valid audio stream alignment_type values
| alignment_type | description |
| 1 / 0x01 | syncword |
|