cheaptricks.md

August 4, 2026 ยท View on GitHub

[ Cheap Tricks ]

How to know what is required when encoding SCTE-35

  • Whenever you encode a Cue, a Splice Info Section, a Splice Command, or a Splice Descriptor, threefive will point out your mistakes. image

How to Parse SCTE-35 from HLS

  • ABR HLS master.m3u8 manifests as well as single rendition manifests.
  • all HLS SCTE-35 tags are supported as well as embedded SCTE-35 in the segments
threefive https://demo.unified-streaming.com/k8s/live/scte35.isml/.m3u8

How to Visually verify SCTE-35 splice points

  • use threefive with the proxy keyword.
  • threefive with the proxy keyword copies all packets from a MPEGTS stream to stdout for piping.
  • Play the video while you parse SCTE-35 over Multicast:
threefive proxy udp://@235.35.3.5:3535  | ffplay -

How to send a Multicast Stream

  • threefive includes The Grand Unified Multicast Sender, gums, for easy multicast.
  • gums has a default multicast address of udp://@235.35.3.5.3535, that can be changed.
  • gums is setup for mpegts streams. 1316 datagrams and video is throttled to playback speed (fake live)
  • gums -h for all the details.
a@fu:~$ gums -i ~/mpegts/cnn.ts

How to Show pts for iframes.

a@fu:~$ threefive iframes ~/mpegts/longb2.ts
/home/a/mpegts/longb2.ts
1.433
6.772
9.141
12.11
17.449
22.788