Pause Playback through code?

[Leonard30161191pug2]

I'm working on a transmitter plugin for Adobe Premiere Pro 2023, and long story short I need to pause playback when a specific function is called. Is there a way in c++, or alternatively through a js panel, to pause playback through suites or something?

Thank you 

[Bruce Bullis]

No such control is available to a Transmitter, or any other supported C++ plugin type. You're correct, ExtendScript (used from CEP panels) can control playback...

Under what circumstances would a Transmitter need to control playback? 

[Leonard30161191pug2]

The issue lies with the fact that as far as I know, the only place to start plugin audio is in the StartPlaybackClock function, as it receives clock parameters which are necessary.  When playing, this function is only called when the playback is started. 
My problem is that I have an external function starting or stopping the transmitter manually, but in the situation where the plugin starts in the middle of playback, initpluginaudio() won't be called until next time I stop and start playback, leading to a silent transmission. 

My solution therefore involves pausing playback at the same time so that the StartPlaybackClock() function will necessarely be called before transmission of video

Except if you have another solution, I would like to know how to do it through extendscript as i've been unable to find it in the documentation. Thank you!

[Bruce Bullis]

>I have an external function starting or stopping the transmitter manually...

You say starting or stopping the transmitter; does that differ, from starting/stopping playback?

> in the situation where the plugin starts in the middle of playback

I don't understand how a Transmitter could start in the middle of playback; Transmitters are only sent frames/samples by PPro, during playback. 

Why is that external control desirable/necessary? 

[Leonard30161191pug2]

I have a button on a panel that "activates" the transmitter, which in this context means that it can start sending frames to my external source. and while it is true that transmitters are always running, until the said start button is not pressed, the transmitter runs in the background, not interacting with frames in the buffer.

I'm working off two assumptions: 1. starting plugin audio silences playback for the user, therefore I only use this function when I know the transmitter is "active". 2. The only place I've found to start the audio is the StartPlaybackClock function, since it relies on a clock parameter thats passed in the function. Therefore if I start playback with sound, and then press the button to start the transmitter, the transmitter starts passing sending data from buffers, which have not been filled. Therefore, pausing playback seems to be the only solution which makes sure that the signal to send audio data to the buffers before playback starts.

And so in short, I need to be able to pause playback when a button on a panel is pressed, or through code

[Bruce Bullis]

> 1. starting plugin audio silences playback for the user...

That assumption is no longer true, in PPro beta releases. Have a look at this discussion thread, including my post about the updated pre-release SDK with a dual audio transmit sample. 🙂


https://community.adobe.com/t5/premiere-pro-beta-discussions/now-in-beta-transmit-using-srt-streamin...

[Leonard30161191pug2]

still, do you have a way to pause playback until this update is out of beta?

[Bruce Bullis · Accepted solution]

No.

[Plugin Play]

Hey Bruce, can I get some more context as to how you can control PPRO playback from CEP? I can't find a function in the PPRO extendscript docs. Thanks for the help!

[Bruce Bullis]

Just the source monitor, sorry: https://ppro-scripting.docsforadobe.dev/general/sourcemonitor.html#sourcemonitor-play

You can get/set the Program monitor CTI, but not play: https://github.com/Adobe-CEP/Samples/blob/e60d6a22ef44d8eb4cca3904c35a0c050576b697/PProPanel/jsx/PPR...