There is a standard for Cable TV called SCTE 35 that can signal ad insertion. I need to play around with this signal.

I have a ATSC receiver now, and I can record TV into .TS file format. How can I check if a channel includes SCTE 35 signals?

UPDATE: Upon checking, unfortunately none of my current 4 channels include SCTE-35 signal (US ATSC receiver: Bounce, Escape, LAFF, Create, KUVN). Do we have any digital TV channels in the US that have that signal?

  • What are you trying to accomplish and what software are you using?
    – AJ Henderson
    Dec 5, 2017 at 16:55
  • Actually I used TVHeadend which also shows if a channel has SCTE-35 (0x52 PID). DVB Inspector as said below also does that. Unfortunately none of my current channels include that. Do we even any one channel having that signal in the US?
    – Tina J
    Dec 5, 2017 at 17:12
  • I asked about what you are trying to accomplish because I somewhat expect that they would be stripped before going to consumers. The purpose is to allow for a local broadcaster to insert their local advertisements in to the stream automatically. There is no reason that information would need to be sent to the end consumers and I don't see why it would be forwarded in to the signals being sent out to consumers.
    – AJ Henderson
    Dec 5, 2017 at 17:54
  • You are right. The provider probably removes it at the time we receive it. I was trying to use that signal to classify videos and ads.
    – Tina J
    Dec 5, 2017 at 18:28

2 Answers 2


To determine if a channel has SCTE-35, you will need to have the Program Map Table (PMT) recorded. From the PMT, you should be able to find the Packet Identifiers (PIDs) of all of the streams associated with the channel you are interested in. There will be a PID for the video and at least one audio PID. If SCTE-35 is present, there will be at least one PID with a stream type of 0x52.

Keep in mind, the PMT and the SCTE-35 PID will either need to be in the clear or you will need to be able to decrypt the conditional access.

The easiest way to check all of this is with a transport stream analyzer. Most of the freely available ones, like DVB Inspector, will show you the PMT. However, you will probably need a commercial analyzer to get it to display something more than just the raw SCTE-35 bytes.

  • Thanks. So if I record a channel into a .ts file, the dvb inspector can say if it includes the flag? For now i only need to know if it has scte 35. Not really the value.
    – Tina J
    Dec 5, 2017 at 7:48
  • I haven't personally used DVB Inspector, but it came recommended by a reliable source. In theory it should be able to at least show you if the PID exists. It may not show more than stream type in hex and the raw content of the PID. Dec 5, 2017 at 13:34
  • Here is a screenshot of the table: i.imgur.com/liPBoNr.png I tested for a few channels (Bounce, Escape, Laff), and none had PID of 0x52.
    – Tina J
    Dec 5, 2017 at 16:39
  • Do you know of any channels having that? Where can I find a list of ATSC channels which have SCTE 35?
    – Tina J
    Dec 5, 2017 at 16:40
  • If you are are capturing the transport stream off an offer the air channel of a cable system, they are likely grooming out the SCTE-35. You would need to look at the provider feed to the station or MPVD. Most major cable networks should have DPI triggers at that point. Dec 5, 2017 at 18:09

Try threefive. threefive returns all SCTE-35 data (Splice Info Section, Splice Command, and Splice Descriptors) in the proper format according to the 2019 specification.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.