threefive 2.3.49

Pythonic SCTE35

Install | Fast Start | Cue Class | Stream Class | Examples | ffmpeg and threefive | x9k3 | gumd | m3ufu| effbot

threefive is a SCTE35 parser.

Before we get into all that, I have a brief statement.

I am still looking for my Watergate, my defining scandal.
I dont mean to keep beating the same drum, 
but I still say that subliminal messages 
will be very effective over the Internet. 
It will take years before we see any laws 
against shttps.
(The first "s" is for subliminal)    

---

• All 2022 SCTE35 Commands and Descriptors and Upids

• Install threefive

• Versions and Releases

• Fast Start

• Cue Class

• Stream Class

• Super Cool Examples

• ffmpeg and SCTE35 and Stream Type 0x6 bin data and threefive

• Issues and `Bugs and Feature Requests No forms man, just open an issue and tell me what you need.

• Diagram of a threefive SCTE-35 Cue.

• x9k3 , SCTE35 hls segmenter powered by threefive

• m3ufu, m3u8 parser powered by threefive

Requirements

• threefive requires
  • pypy3 or python 3.6+
  • new_reader
• optional dependencies:
  • pyaes If you want AES decryption for HLS segments.

Install

python3 -mpip  install  threefive

# and / or

pypy3 -m pip install threefive

To install the optional dependencies

python3 -mpip  install threefive[all]

# and / or

pypy3 -mpip  install  threefive[all]

---

Versions and Releases

Python 3.10.6 (main, Aug 10 2022, 11:19:32) [GCC 12.1.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from threefive import version
>>> version()
'2.3.45'
>>> 

• I do Rolling Releases
• Release versions are odd.
• Unstable testing versions are even.

---

Easy Examples

Base64

>>> from threefive import Cue
>>> stuff = '/DAvAAAAAAAA///wBQb+dGKQoAAZAhdDVUVJSAAAjn+fCAgAAAAALKChijUCAKnMZ1g='
>>> cue=Cue(stuff)
>>> cue.decode()
True

Bytes

>>> import threefive 

>>> stuff = b'\xfc0\x11\x00\x00\x00\x00\x00\x00\x00\xff\xff\xff\x00\x00\x00O%3\x96'
>>> cue=Cue(stuff)
>>> cue.decode()
True
>>> cue.show()

Hex

import threefive 

cue = threefive.Cue("0XFC301100000000000000FFFFFF0000004F253396")
cue.decode()
cue.show()

Mpegts Multicast

• On my Debian Sid laptop I set the following,

## <dev> is the network device

ip link set <dev> multicast on allmulticast on

ethtool  -G <dev> rx 4096

sysctl -w net.core.rmem_default=5000000

sysctl -w net.core.rmem_max=15000000

import threefive 

strm = threefive.Stream('udp://@239.35.0.35:1234')
strm.decode()

---

Cue Class

• src cue.py
• The threefive.Cue class decodes a SCTE35 binary, base64, or hex encoded string.

    >>>> import threefive
    >>>> Base64 = "/DAvAAAAAAAA///wBQb+dGKQoAAZAhdDVUVJSAAAjn+fCAgAAAAALKChijUCAKnMZ1g="
    >>>> cue = threefive.Cue(Base64)

• cue.decode() returns True on success,or False if decoding failed

    >>>> cue.decode()
    True

• After Calling cue.decode() the instance variables can be accessed via dot notation.

    >>>> cue.command
    {'calculated_length': 5, 'name': 'Time Signal', 'time_specified_flag': True, 'pts_time': 21695.740089}

    >>>> cue.command.pts_time
    21695.740089

    >>>> cue.info_section.table_id

    '0xfc'

• When parsing Cues from MPEGTS, threefive tries to include,
  • pid of the packet
  • program of the pid
  • pts of the packet
  • pcr of the packet

class Cue(threefive.base.SCTE35Base)
 |  Cue(data=None, packet_data=None)
 

 |  __init__(self, data=None, packet_data=None)
 |      data may be packet bites or encoded string
 |      packet_data is a instance passed from a Stream instance

Cue.decode()

 |  decode(self)
 |      Cue.decode() parses for SCTE35 data

Cue.get()

 |  get(self)
 |      Cue.get returns the SCTE-35 Cue
 |      data as a dict of dicts.

Cue.get() Example

>>> from threefive import Cue
>>> cue = Cue('0XFC301100000000000000FFFFFF0000004F253396')
>>> cue.decode()
True
>>> cue
{'bites': b'\xfc0\x11\x00\x00\x00\x00\x00\x00\x00\xff\xff\xff\x00\x00\x00O%3\x96', 
'info_section': {'table_id': '0xfc', 'section_syntax_indicator': False, 'private': False, 'sap_type': '0x3', 
'sap_details': 'No Sap Type', 'section_length': 17, 'protocol_version': 0, 'encrypted_packet': False, 
'encryption_algorithm': 0, 'pts_adjustment_ticks': 0, 'pts_adjustment': 0.0, 'cw_index': '0x0', 'tier': '0xfff',
'splice_command_length': 4095, 'splice_command_type': 0, 'descriptor_loop_length': 0, 'crc': '0x4f253396'},
'command': {'command_length': None, 'command_type': 0, 'name': 'Splice Null'},
'descriptors': [], 'packet_data': None}

• Cue.get() omits cue.bites and empty values

>>> cue.get()
{'info_section': {'table_id': '0xfc', 'section_syntax_indicator': False,'private': False, 'sap_type': '0x3', 
'sap_details': 'No Sap Type', 'section_length': 17, 'protocol_version': 0, 'encrypted_packet': False,
'encryption_algorithm': 0, 'pts_adjustment_ticks': 0, 'pts_adjustment': 0.0, 'cw_index': '0x0', 'tier': '0xfff',
'splice_command_length': 4095, 'splice_command_type': 0, 'descriptor_loop_length': 0, 'crc': '0x4f253396'},
'command': {'command_type': 0, 'name': 'Splice Null'},
'descriptors': []}

Cue.get_descriptors()

 |  get_descriptors(self)
 |      Cue.get_descriptors returns a list of
 |      SCTE 35 splice descriptors as dicts.

Cue.get_json()

 |  get_json(self)
 |      Cue.get_json returns the Cue instance
 |      data in json.

Cue.show()

 |  show(self)
 |      Cue.show prints the Cue as JSON

Cue.to_stderr()

 |  to_stderr(self)
 |      Cue.to_stderr prints the Cue

---

Stream Class

• src stream.py
• The threefive.Stream class parses SCTE35 from Mpegts.
• Supports:
  • File and Http(s) and Udp and Multicast protocols.
  • Multiple Programs.
  • Multi-Packet PAT, PMT, and SCTE35 tables.

class Stream(builtins.object)
 |  Stream(tsdata, show_null=True)
 |  
 |  Stream class for parsing MPEG-TS data.

|  __init__(self, tsdata, show_null=True)
|      
|      tsdata is a file or http, https, 
|       udp or multicast url.
|       
|      set show_null=False to exclude Splice Nulls
|      
|      Use like...
|      
|      from threefive import Stream
|      strm = Stream("vid.ts",show_null=False)
|      strm.decode()

Stream.decode(func=show_cue)

|  decode(self, func=show_cue)
|      Stream.decode reads self.tsdata to find SCTE35 packets.
|      func can be set to a custom function that accepts
|      a threefive.Cue instance as it's only argument.

Stream.decode Example

import sys
from threefive import Stream
>>>> Stream('plp0.ts').decode()

• Pass in custom function

• func should match the interface func(cue)

Stream.decode with custom function Example

import sys
import threefive

def display(cue):
   print(f'\033[92m{cue.packet_data}\033[00m')
   print(f'{cue.command.name}')

def do():
   sp = threefive.Stream(tsdata)
   sp.decode(func = display)       

if __name__ == '__main__':
    do()

---

Stream.decode_next()

|  decode_next(self)
|      Stream.decode_next returns the next
|      SCTE35 cue as a threefive.Cue instance.

Stream.decode_next Example

import sys
import threefive

def do():
    arg = sys.argv[1]
    with open(arg,'rb') as tsdata:
        st = threefive.Stream(tsdata)
        while True:
            cue = st.decode_next()
            if not cue:
                return False
            if cue:
                cue.show()

if __name__ == "__main__":
    do()

Stream.decode_program(the_program, func = show_cue)

|  decode_program(self, the_program, func=show_cue)
|      Stream.decode_program limits SCTE35 parsing
|      to a specific MPEGTS program.

Stream.decode_program Example

import threefive
threefive.Stream('35.ts').decode_program(1)

---

Stream.decode_proxy(func = show_cue)

• Writes all packets to sys.stdout.

• Writes scte35 data to sys.stderr.

|  decode_proxy(self, func=show_cue_stderr)
|      Stream.decode_proxy writes all ts packets are written to stdout
|      for piping into another program like mplayer.
|      SCTE-35 cues are printed to stderr.

Stream.decode_proxy Example

import threefive
sp = threefive.Stream('https://futzu.com/xaa.ts')
sp.decode_proxy()

• Pipe to mplayer

$ python3 proxy.py | mplayer -

---

Stream.show()

|  show(self)
|   List programs and streams and info for MPEGTS

Stream.show() Example

>>>> from threefive import Stream
>>>> Stream('https://slo.me/plp0.ts').show()

Program: 1040
    Service:    fumatic
    Provider:   fu-labs
    Pcr Pid:    1041[0x411]
    Streams:
                Pid: 1041[0x411]        Type: 0x1b AVC Video
                Pid: 1042[0x412]        Type: 0x3 MP2 Audio
                Pid: 1044[0x414]        Type: 0x6 PES Packets/Private Data
                Pid: 1045[0x415]        Type: 0x86 SCTE35 Data

Program: 1050
    Service:    fancy ˹ 
    Provider:   fu-corp
    Pcr Pid:    1051[0x41b]
    Streams:
                Pid: 1051[0x41b]        Type: 0x1b AVC Video
                Pid: 1052[0x41c]        Type: 0x3 MP2 Audio
                Pid: 1054[0x41e]        Type: 0x6 PES Packets/Private Data
                Pid: 1055[0x41f]        Type: 0x86 SCTE35 Data
 

Stream.dump(fname)

|  dump(self, fname)
|      Stream.dump dumps all the packets to a file (fname).

Stream.strip_scte35(func=show_cue_stderr)

|  strip_scte35(self, func=show_cue_stderr)
|      Stream.strip_scte35 works just like Stream.decode_proxy,
|      MPEGTS packets, ( Except the SCTE-35 packets) ,
|      are written to stdout after being parsed.
|      SCTE-35 cues are printed to stderr.

---

UUID

• RFC 4122 aka UUID

A lot of folks have been searching this repo for uuid, I'm not sure if they are looking for uuid in a upid, or a randomly generated uuid for an HLS tag or something else. Here is what I know about it.

>>> from uuid import uuid4, UUID

# generate a random uuid
>>> uu= uuid4()
>>> uu
UUID('7ae2e37e-3018-4c4e-8a10-f69d075828b4')

# uuid as bytes
>>> uu.bytes
b'z\xe2\xe3~0\x18LN\x8a\x10\xf6\x9d\x07X(\xb4'

# bytes to uuid
>>> UUID(bytes=uu.bytes)
UUID('7ae2e37e-3018-4c4e-8a10-f69d075828b4')
>>> 

Adrian

python3 uuid