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EncodingPipeMore.md

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More on Encoding.

A lot of people have been looking at the encoding page, and I think the encoding is a pretty good explanation but there is a little more encoding stuff in threefive and rather than complicated the encoding page, I wanted to put it here.

The Cue class has a lot of stuff I've never really mentioned. I wanted to wait a while and see if anything blew up. A lot of the Cue methods are for encoding.

Cues can be encoded as base64, hex, integers, or bytes

  • Docs
|  encode(self)
 |      Cue.encode() converts SCTE35 data
 |      to a base64 encoded string.
 |  
 |  encode_as_hex(self)
 |      encode_as_hex returns self.bites as
 |      a hex string
 |  
 |  encode_as_int(self)
 |      encode_as_int returns self.bites as an int.
 |
  • How to use
a@slow:~/SCTE-35-HLS-Sideways$ pypy3
Python 3.9.16 (7.3.11+dfsg-2, Feb 06 2023, 16:52:03)
[PyPy 7.3.11 with GCC 12.2.0] on linux
Type "help", "copyright", "credits" or "license" for more information.

>>>> from threefive import Cue,TimeSignal

>>>> cue = Cue()                                                                         

>>>> cue.command=TimeSignal()
>>>> cue.command.time_specified_flag=True
>>>> cue.command.pts_time=12345.13

>>>> cue.encode()                                                                        
'/DAWAAAAAAAAAP/wBQb+Qjl0xAAAMsxgbg=='                                                 

>>>> cue.encode_as_hex()
'0xfc301600000000000000fff00506fe423974c4000032cc606e'                                  

>>>> cue.encode_as_int()
1583008701074197245727019716796221242345910914446764125479022

## Note: it's Cue.bites, since bytes() is a builtin python function.

>>>> cue.bites
b'\xfc0\x16\x00\x00\x00\x00\x00\x00\x00\xff\xf0\x05\x06\xfeB9t\xc4\x00\x002\xcc`n'

>>>>

The Cue class also has methods to load data from a dictionary or JSON for encoding

|  load(self, stuff)
 |      Cue.load loads SCTE35 data for encoding.
 |      stuff is a dict or json
 |      with any or all of these keys
 |      stuff = {
 |          'info_section': {dict} ,
 |          'command': {dict},
 |          'descriptors': [list of {dicts}],
 |          }
 |  
 |  load_command(self, cmd)
 |      load_command loads data for Cue.command
 |      cmd should be a dict.
 |      if 'command_type' is included,
 |      the command instance will be created.
 |  
 |  load_descriptors(self, dlist)
 |      Load_descriptors loads descriptor data.
 |      dlist is a list of dicts
 |      if 'tag' is included in each dict,
 |      a descriptor instance will be created.
 |  
 |  load_info_section(self, isec)
 |      load_info_section loads data for Cue.info_section
 |      isec should be a dict.
 |      if 'splice_command_type' is included,
 |      an empty command instance will be created for Cue.command