[FFmpeg-devel] Live Transcoding: SCTE35 passthrough

[Devin Heitmueller]

On Tue, Jul 19, 2022 at 9:44 AM Shane Warren <shanew at innovsys.com> wrote:
>
> I have been working on getting scte35 pass through working in FFmpeg. I have the SIT pid being passed through fine, but I need to adjust the pts_adjustment field since I'm doing a live transcode and using vsync 1.
>
> I'm struggling with finding how to match up an incoming frame of video to a transcoded frame of video so I can figure out the pts adjustment. Am I missing something, or is there some way to match up an incoming frame to a encoded frame and figure out their pts difference?

I've got this working in a branch that isn't upstream.  This includes
a BSF which deals with the pts_adjust field.  It should do what you
need (although the branch point is a bit stale):

https://github.com/LTNGlobal-opensource/FFmpeg-ltn/commits/n4.3.1-scte35

If you're comfortable recompiling from source, you can incorporate a
variant of these patches into your local tree.

Devin

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Devin Heitmueller, Senior Software Engineer
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