[Q] Filter SCTE35 Events and pass only what are necessary/ ignore what are not needed

[reckless-sergio]

I have a feed which has multiple SCTE35 markers with different splice event ids. I need to process or use a specific marker with event-id 6. Do we have this option in tsduck?

My input and output is UDP. I have to filter out and pass only SCTE markers with event-id 6. Please help me in solving this. Thanks

[lelegard]

Hi @reckless-sergio

What would you like to do exactly? Extract markers with event id 6 outside the TS for inspection, monitoring, etc? Or remove other SCTE35 markers and only leave those with event id 6 in the SCTE35 PID?

[reckless-sergio]

Hi @lelegard , I want to remove the other markers and only leave those with event-id 6.

[lelegard]

I see no immediate solution for such a specialized need with the current plugins. A new simple but specialized plugin would be necessary.

However, I am working on more generic solutions for section filtering which may solve this in the next few days or weeks.

[lelegard]

Hi @reckless-sergio

In the very latest push, new options --section-content and --section-mask have been added to tstables and plugins tables and sections. They let you select sections based on selected bits in their content.

Thus, the following command filters all sections in PID xxx and keeps only SCTE-35 sections with splice_insert() commands with event id 6:

tsp ... -P sections --pid xxx --keep --section-content FC0000000000000000000000000500000006 --section-mask FF000000000000000000000000FFFFFFFFFF ...

We select table id 0xFC (splice information table) with command type 0x05 (splice_insert) and event id 0x00000006.

You need version 3.31-2730. Either rebuild or check nightly builds.

EDIT: I forgot the --keep option, meaning keep the selected sections. By default, the selected sections are removed, all others are kept.

[reckless-sergio]

Hi @lelegard

I tried the same command you have suggested. Surprisingly, the start is good, but after few seconds(10-20) there is no output.

tsp --verbose -I ip 7700 -P sections --pid 1000 --keep --section-content FC0000000000000000000000000500000006
 --section-mask FF000000000000000000000000FFFFFFFFFF -O ip 127.0.0.1:50000

I have also tried below command

tsp --verbose -I ip 7700 -O ip 127.0.0.1:50000

Am I missing anything?

[lelegard]

If there is "no output" (I assume you mean no more sections on PID 1000), this means that there is no more section matching the filter & mask.

[reckless-sergio]

Hi @lelegard, It is working as expected with this feature. But can help me understand how do i build hexa-codes of section-content & section-mask? I have other requirements of filtering/masking scte events based on segmentation_type_id.

Thanks

[lelegard]

But can help me understand how do i build hexa-codes of section-content & section-mask?

These filters are typically used by hardware section demux in set-top-boxes. They are extremely generic but need a bit-and-byte understanding of the sections to filter. So, you need to read the SCTE-35 spec carefully, understand the binary patterns of the sections to filter, where are the various fields to filter (for the section-mask) and what are the values (for the section-content). And then experiment.

[reckless-sergio]

These are the values I came up with --section-content FC00000000000000000000000000000000000000000000000000000000000000000000000000000036 --section-mask FF000000000000000000000000FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF

I am trying to filter only 36 segmentation_type_id