Request / solution: srt streaming status saved to settings.xml ? Or OSC command / keyboard shortcut to toggle srt stream?

[ThomZenTury]

Hi again!
I get very close to finally finish my setup for online live performances including sound, visuals, sensors, midi devices and custom built controllers. Not much is left to make me happy. Of course, also thanks to you!

Since I want to broadcast to a WebXR site I am using the very useful srt stream from vimix. And since you gave me the wonderful hint on using vimix headless in combo with my O-S-C template I am trying to find out how I could dis-/enable the streaming function in headless mode. Maybe via OSC?
Or even better, being able to save the streaming status into the settings.xml file and thus being able to load it on startup?

Maybe I am blind but I could not find any hints on that in the wiki or in the discussions.
Even flying through the settings.xml file could not give me a clue. What I could find in there were following params that I thought would be useful, but changing them was not successful:

stream_protocol="1"

<Hosts>
    <SRT protocol="srt://"/>
</Hosts>

Starting vimix from terminal and trying to get the command when changing stream on/off via Display widget also did not deliver useful information.

I thought I was close, but... Would be awesome to get some info so I could help myself.
Thanks in advance

[ThomZenTury]

Working but maybe ugly solution:

Hi there!
I really hope this project is not abandoned since there is not much feedback at the moment. But moreover, I hope you are healthy and doing well.

Since I am completely unexperienced with all C-related coding I hope the following does not hurt any pros reading this. But after wrapping my cells around the issue I can come up with a working solution for OSC commands and a keyboard shortcut to start/stop srt streams (only OSC in headless mode).

1. Add OSC commands to start srt stream
   (proper commands:
   start srt stream: "/vimix/peertopeer/srt_start"
   stop srt stream: "/vimix/peertopeer/srt_stop")

   Add these lines to file ".../vimix/src/ControlManager.h"

// add definitions at start of file
#define OSC_SRT_START "/srt_start"
#define OSC_SRT_STOP "/srt_stop"

// create class beneath the existing ones
class VideoBroadcast;

// class Control {
// frame grabbers
VideoBroadcast *video_broadcaster_;

Add following lines to ".../vimix/src/ControlManager.cpp"

// beneath #include "ControlManager.h"
#include "VideoBroadcast.h"

// within "void Control::receiveStreamAttribute" function
// add following

// Start srt stream with /vimix/stream/srt_start
if (attribute.compare(OSC_SRT_START) == 0)
{
  // FrameGrabbing::manager().verify((FrameGrabber **)&video_broadcaster_);
  if (Settings::application.broadcast_port < 1000)
      Settings::application.broadcast_port = BROADCAST_DEFAULT_PORT;
  video_broadcaster_ = new VideoBroadcast(Settings::application.broadcast_port);
  FrameGrabbing::manager().add(video_broadcaster_);
  //Log::Info("trying to START SRT stream");
}
// Stop srt stream with /vimix/stream/srt_stop
// OSC_SRT_STOP "/srt_stop"
else if (attribute.compare(OSC_SRT_STOP) == 0)
{
  if (video_broadcaster_)
  {
      video_broadcaster_->stop();
      //Log::Info("trying to STOP SRT stream");
  }
}

2. Keyboard shortcut (F8) to toggle srt stream:
   add following lines to ".../vimix/src/UserInterfaceManager.cpp"

// search for "GLFW_KEY_F9" to put following block above
else if (ImGui::IsKeyPressed( GLFW_KEY_F8, false ))
outputcontrol.ToggleVideoBroadcast();

Of course you have to recompile vimix after doing these changes

cd vimix-build
cmake --build .

I know this somehow ugly (throwing the OSC into the "peertopeer" attribute) but I am just glad I got it working.
Improvements are always welcome! Don't hesitate to teach me.

I really hope you are well, up and running!
Have a nice day!
T

[brunoherbelin]

Thanks ThomZenTury, was just too busy at work and also spent more time outdoor 😄 ! I'm back to vimix.

Cool solution you implemented !

First thing I see is that the streaming status should be stored to settings, and restored on load: easy. Will do next.
Adding OSC command to on/off streaming, also doable.

It has been a long time since i tried streaming with vimix.. and I do not really use it so can't say what's best.
I saw gstreamer recently improved WebRTC protocol support: https://gstreamer.freedesktop.org/documentation/rswebrtc/webrtcsink.html?gi-language=c
would that help ?

[brunoherbelin]

Hey There !

So, to enable multiple ways to launch and stop SRT broadcasting (and other shm and loopback output sharing), the problem was to ensure vimix keeps track of the pointers and stops and clears things properly. In particular, a pointer becomes invalid if a streaming stops of fails, causing crash when using it afterwards (e.g. video_broadcaster_->stop(); would crash vimix if the SRT was stopped independently of vimix). Anyways, long story short, after trying different options, I decided for a singleton mechanism with a Broadcast::manager() that accesses only existing (and valid) frame grabbers. With this the lanch from OSC is safe, and I added a launch from command line.

On osc; /vimix/output/srt-start 7070 and /vimix/output/srt-stop

On command line vimix --broadcast 7078 --headless

All this can be tested in the latest Beta commit 4f84675. Here is how to make your own Beta package to install : https://github.com/brunoherbelin/vimix/tree/master/flatpak