A lot of people consider me to be a subject matter expert on SCTE-35,
I see myself more as the undisputed heavy weight champion of SCTE-35. ~Adrian

[ threefive ]

Over 1.2 Million Installs.

Decodes SCTE-35 from MPEGTS✔ Base64✔ Bytes✔ DASH✔ Hex ✔ HLS✔ Integers✔ JSON✔ XML✔ XML+Binary✔
Encodes SCTE-35 to MPEGTS✔ Base64✔ Bytes✔ Hex✔ Integers✔ JSON✔ XML✔ XML+Binary✔

[ version ]

latest is v.3.0.97

[ really really quick start ]

Install

 python3 -m pip install threefive`

decoding SCTE-35

base64

decode SCTE-35 as base64

 threefive '/DAWAAAAAAAAAP/wBQb+AKmKxwAACzuu2Q=='

decode SCTE-35 as base64 and convert SCTE-35 to hex

 threefive '/DAWAAAAAAAAAP/wBQb+AKmKxwAACzuu2Q==' hex

Hex

decode SCTE-35 as hex

 threefive '0xfc301600000000000000fff00506fe00a98ac700000b3baed9'

decode SCTE-35 as hex and convert SCTE-35 to xml

 threefive '0xfc301600000000000000fff00506fe00a98ac700000b3baed9' xml

HLS

decode SCTE-35 from HLS ( a rendition or a master.m3u8)

 threefive 'https://demo.unified-streaming.com/k8s/live/scte35.isml/.m3u8'

MPEGTS

decode SCTE-35 from MPEGTS

 threefive 'https;//iodisco.com/longb2.ts'

decode SCTE-35 from MPEGTS and convert SCTE-35 to bytes

 threefive 'https;//iodisco.com/longb2.ts' bytes

Multicast
- decode SCTE-35 from MPEGTS over Multicast
```
 threefive udp://@235.3.5.35:3535
```

threefive does a lot more, that was just to get you started.

[ Documentation ]

A Lot of Examples | Tip of the Week | Cheap Tricks |

Need to inject SCTE-35 into HLS? X9k3.

web based SCTE-35 tools - threefive and friends over http.
install
quick start
SCTE-35 on the command line
- the threefive cli tool If you work with SCTE-35, this is as cool as it gets.
other included tools
- scte35fix ffmpeg changes scte-35 streams into bin data, scte35fix changes them back.
- scte35inject scte35inject inject scte-35 into mpegts.
- gums gums is a multicast sender(server) for video
the threefive library cool code for the cool kids.
- Using the threefive.Cue class
- Using the threefive library decode SCTE-35 with less than ten lines of code
- - threefive Classes threefive is OO, made to subclass
    - Cue Class this class you'll use often
    - Stream Class this is the class for parsing MPEGTS
SCTE-35 Sidecar Files threefive supports SCTE-35 sidecar files
SCTE-35 HLS parse SCTE-35 in HLS in MPEGTS,CMAF, or fmP4_
SCTE-35 XML and More XML threefive can parse and encode SCTE-35 xml
Encode SCTE-35 threefive can encode SCTE-35 in every SCTE-35 format
Make your threefive script an executable with cython threefive is compatible with all python tools

[Install]

threefive is curretnly tested on python-3.11, python-3.14, python-3.14t, pypy-7.3.11 and pypy-7.3.22
threefive is some of the fastest code you'll see on python3.
python3 via pip

python3 -mpip install threefive

pypy3 via pip

pypy3 -mpip install threefive

To add SRT support

python3 -m pip install srtfu

To add Automatic AES decryption

python3 -mpip install pyaes

From the git repo

git clone https://github.com/superkabuki/scte35.git
cd threefive
make install

I've jazzed up the makefile to make it easier to install for different python versions and pypy3

git clone https://github.com/superkabuki/scte35.git
cd threefive

make install py3=pypy3

# OR

make install py3=python3.14

# works for any python in your path or use a full path if needed.

⇧

[ CLI ]

threefive is designed to be easy to use. I'm not sure that it's served well by a long explaination, so I'm going to try and keep this brief.

The threefive cli tool.

the threefive cli tool decodes SCTE-35, formats are autodetected, and they all work the same way.

threefive [media to parse for SCTE-35]

examples:

threefive '/DAWAAAAAAAAAP/wBQb+AKmKxwAACzuu2Q=='

threefive 0xfc301600000000000000fff00506fe00a98ac700000b3baed9

threefive 1583008701074197245727019716796221242036302348025116111908569

threefive video.ts

threefive https://demo.unified-streaming.com/k8s/live/scte35.isml/scte35-audio_eng=64000-video=500000.m3u8

Formats like XML and JSON that may be to large to type on the command line,they can be redirected or piped in to threefive.
redirect

threefive < xml.xml

pipe

cat json.json | threefive

cli outputs and converting SCTE-35 Formats

the default output format for threefive is json
The cli tool can convert from one SCTE-35 format to another using keywords.
- The keywords are base64,bytes,hex, int,json,xml, and xmlbin
some conversion examples
SCTE-35 Base64 to SCTE-35 Hex

threefive '/DAWAAAAAAAAAP/wBQb+AKmKxwAACzuu2Q==' hex

SCTE-35 Int to SCTE-35 Xml

threefive 1583008701074197245727019716796221242036302348025116111908569 xml

SCTE-35 Hex to SCTE-35 xml+binary

threefive 0xfc301600000000000000fff00506fe00a98ac700000b3baed9 xmlbin

threefive cli and MPEGTS

threefive can parse MPEGTS from stdin, local files, HTTP(s), Multicast, SRT, and unicast UDP.
some mpegts examples
local

threefive video.ts

stdin

cat video.ts | threefive

https

threefive https://iodisco.com/longb2.ts

multicast

threefive udp://@235.35.3.5:3535

threefive cli MPEGTS outputs

the default output for MPEGTS is json
keywords can be used to specify other output formats
- The keywords are base64,bytes,hex, int,json,xml, and xmlbin
An example of mpegts with a keyword

threefive https://iodisco.com/longb2.ts xml

⇧

Other tools

threefive also comes with:

gums

the Grande Udp Multicast Server

$ gums -h
usage: gums [-h] [-i INPUT] [-a ADDR] [-b BIND_ADDR] [-t TTL]

options:
  -h, --help            show this help message and exit
  -i INPUT, --input INPUT
                        like "/home/a/vid.ts" or "https://futzu.com/xaa.ts"
                        [default: sys.stdin.buffer]
  -a ADDR, --addr ADDR  Destination IP:Port [default: 235.35.3.5:3535]
  -b BIND_ADDR, --bind_addr BIND_ADDR
                        Local IP to bind [default: 0.0.0.0]
  -t TTL, --ttl TTL     Multicast TTL (1 - 255) [default: 32]

gums is part of threefive.

⇧

HLS

parse HLS for SCTE-35. Supports all HLS SCTE-35 tags.

$ threefive hls help

[ Input ]

A m3u8 URI as input.

[what is supported]

    M3U8 formats: master, rendition
    Segment types: AAC, AC3, MPEGTS, CMAF,fMP4
    Video codecs: mpeg2, h.264, h.265
	Audio codecs: mpeg2, aac, ac3, mp3
    Protocols: File, Http(s), Multicast, SRT, Stdin, UDP
    Encryption: AES-128 (automatic)

[ SCTE-35 ]

  SCTE-35 Embedded Cues as well as all SCTE-35 HLS Tags can be parsed.

  [ Supported HLS Tags ]

	* #EXT-OATCLS-SCTE35
    * #EXT-X-CUE-OUT-CONT
    * #EXT-X-DATERANGE
    * #EXT-X-SCTE35
    * #EXT-X-CUE-IN
    * #EXT-X-CUE-OUT

[ SCTE-35 Parsing Profiles ]

    SCTE-35 parsing can be fine tuned by setting a parsing profile.

    running the command:  threefive hls profile

    will generate a default profile and write a file named hls.profile
    in the current working directory.

    a@fu:~$ cat hls.profile

    expand_cues = False
    parse_segments = False
    parse_manifests = True
    hls_tags = #EXT-OATCLS-SCTE35,#EXT-X-CUE-OUT-CONT,
    #EXT-X-DATERANGE,#EXT-X-SCTE35,#EXT-X-CUE-IN,#EXT-X-CUE-OUT
    command_types = 0x6,0x5
    descriptor_tags = 0x2
    starts = 0x22,0x30,0x32,0x34,0x36,0x44,0x46

    ( Integers are show in hex (base 16),
      base 10 unsigned integers can also be used in hls.profile )

    * expand_cues:       set to True to show cues fully expanded as JSON
    * parse_segments:    set to true to enable parsing SCTE-35 from MPEGTS.
    * parse_manifests:   set to true to parse the m3u8 file for SCTE-35 HLS Tags.
    * hls_tags:          set which SCTE-35 HLS Tags to parse.
    * command_types:     set which Splice Commands to parse.
    * descriptor_tags:   set which Splice Descriptor Tags to parse.
    * starts:            set which Segmentation Type IDs to use to start breaks.

    Edit the file as needed and then run threefive.

[ Profile Formatting Rules ]

    * Values do not need to be quoted.
    * Multiple values are separated by a commas.
    * No partial line comments. Comments must be on a separate lines.
    * Comments can be started with a # or //
    * Integers can be base 10 or base 16

[ Output Files ]
	scte35 hls creates a few output files.

	* Profile rules applied to the output:

		* hls.m3u8  - live playable rewrite of the m3u8 with the profile SCTE-35 rules.
        * hls.sidecar - list of ( pts, HLS SCTE-35 tag ) pairs

	* Profile rules not applied to the output:

		* hlsflat.m3u8  - hls live streams are flattened out into a vod playlist.
                     When the live m3u8  first loads, every line is written to hlsflat.m3u8
                     Wnen a live m3u8 is reloaded, everything except the headers
                    is appended to hlsflat.m3u8. This give you a VOD style m3u8
                    so you can fast forward or rewind while playing.
                    GREAT for debugging SCTE-35 live hls.

[ Cool Features ]

    * threefive can resume when started in the middle of an ad break.

            2023-10-13T05:59:50.24Z Resuming Ad Break
            2023-10-13T05:59:50.34Z Setting Break Timer to 17.733
            2023-10-13T05:59:50.44Z Setting Break Duration to 60.067

[ Example Usage ]

	* Show this help:   threefive hls help

	* Generate a new hls.profile:   threefive hls profile

	* parse an m3u8:    scte35hls  https://example.com/out/master.m3u8

⇧

scte35fix

when ffmpeg changes a SCTE-35 stream to bin data stream, scte35fix changes it back.

$ scte35fix -h

  scte35fix checks MPEGTS for SCTE-35 Streams
  that have been change to bin data (type 0x06)
  and changes them back to SCTE-35 (type 0x86) streams.
  Output files are created in the current directory
  and prefixed with 'sixfix-'.
  Only bin data streams containing SCTE-35 will be converted.
  Multiple files can be specified on the command line.
  Wild cards work too.

  Example Usage:
        scte35fix video.ts
        scte35fix video1.ts video2.ts
        scte35fix video*.ts
        scte35fix https://example.com/video.ts
        scte35fix srt://10.10.10.13:4201
scte35fix is part of threefive.

⇧

[ Using the library ]

Let me show you how easy threefive is to use.
reading SCTE-35 xml from a file

a@fu:~/threefive$ pypy3
Python 3.9.16 (7.3.11+dfsg-2+deb12u3, Dec 30 2024, 22:36:23)
[PyPy 7.3.11 with GCC 12.2.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>>> from threefive import reader
>>>> from threefive import Cue
>>>> data =reader('/home/a/xml.xml').read()

load it into a threefive.Cue instance

>>>> cue = Cue(data)

Show the data as JSON

>>>> cue.show()
{
    "info_section": {
        "table_id": "0xfc",
        "section_syntax_indicator": false,
        "private": false,
        "sap_type": "0x03",
        "sap_details": "No Sap Type",
        "section_length": 92,
        "protocol_version": 0,
        "encrypted_packet": false,
        "encryption_algorithm": 0,
        "pts_adjustment": 0.0,
        "cw_index": "0x00",
        "tier": "0x0fff",
        "splice_command_length": 15,
        "splice_command_type": 5,
        "descriptor_loop_length": 60,
        "crc": "0x7632935"
    },
    "command": {
        "command_length": 15,
        "command_type": 5,
        "name": "Splice Insert",
        "break_auto_return": false,
        "break_duration": 180.0,
        "splice_event_id": 1073743095,
        "splice_event_cancel_indicator": false,
        "out_of_network_indicator": true,
        "program_splice_flag": false,
        "duration_flag": true,
        "splice_immediate_flag": false,
        "event_id_compliance_flag": true,
        "unique_program_id": 1,
        "avail_num": 12,
        "avails_expected": 5
    },
    "descriptors": [
        {
            "tag": 0,
            "identifier": "CUEI",
            "name": "Avail Descriptor",
            "provider_avail_id": 12,
            "descriptor_length": 8
        },
        {
            "tag": 0,
            "identifier": "CUEI",
            "name": "Avail Descriptor",
            "provider_avail_id": 13,
            "descriptor_length": 8
        },
      

    ]
}

convert the data back to xml

>>>> print(cue.xml())
<scte35:SpliceInfoSection xmlns:scte35="https://scte.org/schemas/35"  ptsAdjustment="0" protocolVersion="0" sapType="3" tier="4095">
   <scte35:SpliceInsert spliceEventId="1073743095" spliceEventCancelIndicator="false" spliceImmediateFlag="false" eventIdComplianceFlag="true" availNum="12" availsExpected="5" outOfNetworkIndicator="true" uniqueProgramId="1">
      <scte35:BreakDuration autoReturn="false" duration="16200000"/>
   </scte35:SpliceInsert>
   <scte35:AvailDescriptor providerAvailId="12"/>
   <scte35:AvailDescriptor providerAvailId="13"/>
   <scte35:AvailDescriptor providerAvailId="14"/>
   <scte35:AvailDescriptor providerAvailId="15"/>
   <scte35:AvailDescriptor providerAvailId="16"/>
   <scte35:AvailDescriptor providerAvailId="17"/>
</scte35:SpliceInfoSection>

convert to xml+binary

>>>> print(cue.xmlbin())
<scte35:Signal xmlns:scte35="https://scte.org/schemas/35">
    <scte35:Binary>/DBcAAAAAAAAAP/wDwVAAAT3f69+APcxQAABDAUAPAAIQ1VFSQAAAAwACENVRUkAAAANAAhDVUVJAAAADgAIQ1VFSQAAAA8ACENVRUkAAAAQAAhDVUVJAAAAEQdjKTU=</scte35:Binary>
</scte35:Signal>

convert to base64

>>>> print(cue.base64())
/DBcAAAAAAAAAP/wDwVAAAT3f69+APcxQAABDAUAPAAIQ1VFSQAAAAwACENVRUkAAAANAAhDVUVJAAAADgAIQ1VFSQAAAA8ACENVRUkAAAAQAAhDVUVJAAAAEQdjKTU=

convert to hex

>>>> print(cue.hex())
0xfc305c00000000000000fff00f05400004f77faf7e00f7314000010c05003c0008435545490000000c0008435545490000000d0008435545490000000e0008435545490000000f000843554549000000100008435545490000001107632935

show just the splice command

>>>> cue.command.show()
{
    "command_length": 15,
    "command_type": 5,
    "name": "Splice Insert",
    "break_auto_return": false,
    "break_duration": 180.0,
    "splice_event_id": 1073743095,
    "splice_event_cancel_indicator": false,
    "out_of_network_indicator": true,
    "program_splice_flag": false,
    "duration_flag": true,
    "splice_immediate_flag": false,
    "event_id_compliance_flag": true,
    "unique_program_id": 1,
    "avail_num": 12,
    "avails_expected": 5
}

edit the break duration

>>>> cue.command.break_duration=30
>>>> cue.command.show()
{
    "command_length": 15,
    "command_type": 5,
    "name": "Splice Insert",
    "break_auto_return": false,
    "break_duration": 30,
    "splice_event_id": 1073743095,
    "splice_event_cancel_indicator": false,
    "out_of_network_indicator": true,
    "program_splice_flag": false,
    "duration_flag": true,
    "splice_immediate_flag": false,
    "event_id_compliance_flag": true,
    "unique_program_id": 1,
    "avail_num": 12,
    "avails_expected": 5
}

re-encode to base64 with the new duration

>>>> cue.base64()
'/DBcAAAAAAAAAP/wDwVAAAT3f69+ACky4AABDAUAPAAIQ1VFSQAAAAwACENVRUkAAAANAAhDVUVJAAAADgAIQ1VFSQAAAA8ACENVRUkAAAAQAAhDVUVJAAAAEe1FB6g='

re-encode to xml with the new duration

>>>> print(cue.xml())
<scte35:SpliceInfoSection xmlns:scte35="https://scte.org/schemas/35"  ptsAdjustment="0" protocolVersion="0" sapType="3" tier="4095">
   <scte35:SpliceInsert spliceEventId="1073743095" spliceEventCancelIndicator="false" spliceImmediateFlag="false" eventIdComplianceFlag="true" availNum="12" availsExpected="5" outOfNetworkIndicator="true" uniqueProgramId="1">
      <scte35:BreakDuration autoReturn="false" duration="2700000"/>
   </scte35:SpliceInsert>
   <scte35:AvailDescriptor providerAvailId="12"/>
   <scte35:AvailDescriptor providerAvailId="13"/>
   <scte35:AvailDescriptor providerAvailId="14"/>
   <scte35:AvailDescriptor providerAvailId="15"/>
   <scte35:AvailDescriptor providerAvailId="16"/>
   <scte35:AvailDescriptor providerAvailId="17"/>
</scte35:SpliceInfoSection>

show just the descriptors

>>>> _ = [d.show() for d in cue.descriptors]
{
    "tag": 0,
    "identifier": "CUEI",
    "name": "Avail Descriptor",
    "provider_avail_id": 12,
    "descriptor_length": 8
}
{
    "tag": 0,
    "identifier": "CUEI",
    "name": "Avail Descriptor",
    "provider_avail_id": 13,
    "descriptor_length": 8
}
{
    "tag": 0,
    "identifier": "CUEI",
    "name": "Avail Descriptor",
    "provider_avail_id": 14,
    "descriptor_length": 8
}
{
    "tag": 0,
    "identifier": "CUEI",
    "name": "Avail Descriptor",
    "provider_avail_id": 15,
    "descriptor_length": 8
}
{
    "tag": 0,
    "identifier": "CUEI",
    "name": "Avail Descriptor",
    "provider_avail_id": 16,
    "descriptor_length": 8
}
{
    "tag": 0,
    "identifier": "CUEI",
    "name": "Avail Descriptor",
    "provider_avail_id": 17,
    "descriptor_length": 8
}

pop off the last descriptor and re-encode to xml

>>>> cue.descriptors.pop()
{'tag': 0, 'identifier': 'CUEI', 'name': 'Avail Descriptor', 'private_data': None, 'provider_avail_id': 17, 'descriptor_length': 8}
>>>> print(cue.xml())
<scte35:SpliceInfoSection xmlns:scte35="https://scte.org/schemas/35"  ptsAdjustment="0" protocolVersion="0" sapType="3" tier="4095">
   <scte35:SpliceInsert spliceEventId="1073743095" spliceEventCancelIndicator="false" spliceImmediateFlag="false" eventIdComplianceFlag="true" availNum="12" availsExpected="5" outOfNetworkIndicator="true" uniqueProgramId="1">
      <scte35:BreakDuration autoReturn="false" duration="2700000"/>
   </scte35:SpliceInsert>
   <scte35:AvailDescriptor providerAvailId="12"/>
   <scte35:AvailDescriptor providerAvailId="13"/>
   <scte35:AvailDescriptor providerAvailId="14"/>
   <scte35:AvailDescriptor providerAvailId="15"/>
   <scte35:AvailDescriptor providerAvailId="16"/>
</scte35:SpliceInfoSection>

⇧

[web]

threefive SCTE-35 Online Parser hosted on my server iodisco.com
Parse SCTE-35 in MPEGTS over HTTP, in your browser with Go, Wasm and Super Karate Death Car hosted om my server bigcorp.ltd
Parse SCTE-35 in MPEGTS over HTTP, in your browser with threefive.js,javascript, and a little sed just to keep things interesting. hosted om my server bigcorp.ltd
SCTE-35 Online Parser powered by threefive another online parser powered by threefive not hosted on my servers.
SCTE-35 As a Service if you can make an http request, you can parse SCTE-35, no install needed. hosted on my server iodisco.com

⇧

[XML]

XML New! updated 05/01/2025

[HLS]

Advanced Parsing of SCTE-35 in HLS with threefive All HLS SCTE-35 tags, Sidecar Files, AAC ID3 Header Timestamps, SCTE-35 filters... Who loves you baby?

⇧

[Classes]

The python built in help is always the most up to date docs for the library.

a@fu:~/build7/threefive$ pypy3

>>>> from threefive import Stream
>>>> help(Stream)

Class Structure
Cue Class Cue is the main SCTE-35 class to use.
Stream Class The Stream class handles MPEGTS SCTE-35 streams local, Http(s), UDP, and Multicast.

⇧

[threefive now supports SRT]

( You have to unmute the audio )

https://github.com/user-attachments/assets/a323ea90-867f-480f-a55f-e9339263e511

more SRT and threefive info
checkout SRTfu

⇧

[more]

Encode SCTE-35 Some encoding code examples.

⇧

Metadata

Release files for threefive 3.0.97

For a detailed explanation of source distributions (sdists) and built distributions (wheels), please see the package formats documentation.

Source distribution (sdist)

Source distribution for threefive 3.0.97
File	Size	Uploaded
threefive-3.0.97.tar.gz	81.8 kB	Sep 22, 2026	Details

Built distribution (wheel)

Table of built distributions (wheels) for threefive 3.0.97
File	Interpreter	ABI	Platform	Reset
threefive-3.0.97-py3-none-any.whl 85.5 kB Sep 22, 2026	Python 3	none	any	Details

Total release size: 167.3 kB

Release files / threefive-3.0.97.tar.gz

Download URL	threefive-3.0.97.tar.gz
Size	81.8 kB
Tags	Source
SHA-256 checksum How to use checksums	`71399987b0be33aad83de40c27c0a5dfdec8777d26b58434f01d6955738122c0`
BLAKE2b-256 checksum How to use checksums	`88046ca28aa657132f6fd240517b891670c17852320e92d023acfc75b38d7fb4`
Upload date	Sep 22, 2026
Uploaded using Trusted Publishing? What is trusted publishing?	No
Uploaded via	`twine/6.2.0 CPython/3.14.6`

Release files / threefive-3.0.97-py3-none-any.whl

Download URL	threefive-3.0.97-py3-none-any.whl
Size	85.5 kB
Tags	Python 3
SHA-256 checksum How to use checksums	`ea4bbe04a90b12bdd807c098031e07e3017398f2cf5047e97c43118f5836075e`
BLAKE2b-256 checksum How to use checksums	`85520477d88dc60f66603888e271e4f26ca7c2daa1bca94bf6112df11562c6de`
Upload date	Sep 22, 2026
Uploaded using Trusted Publishing? What is trusted publishing?	No
Uploaded via	`twine/6.2.0 CPython/3.14.6`