Building a gstreamer app with streamlit

[Enigma]

Gstreamer support in Streamlit

As the topic suggests I am looking for some solution if gstreamer framework support is in Streamlit or not.

I am able to make some sample gstreamer apps on Streamlit but all of them runs on the same thread

Steps to reproduce

Code snippet:

class GstreamerPlayer:
    def __init__(self):
        # Initialize GStreamer
        Gst.init(None)

        # Define the GStreamer pipeline string
        if "pipeline_str" not in st.session_state:
            st.session_state.pipeline_str = """videotestsrc pattern="ball" ! autovideosink"""

        # Define the GStreamer pipeline status
        if "status" not in st.session_state:
            st.session_state.status = "🔴"

        # Define GStreamer pipeline need to update or not
        # Also create/(update with defualt) the pipeline for the 1st time
        if "update_pipeline_enable" not in st.session_state:
            st.session_state.update_pipeline_enable = True
            self.update_pipeline()

    def consol(self):
        # Define the Streamlit app
        st.title(st.session_state.status+" Gst-Launch App "+st.session_state.status)

        # Input the gst-pipeline string 
        st.text_input(' ',value=st.session_state.pipeline_str,key="input_pipeline",on_change=self.update_pipeline_str,label_visibility="collapsed")

        # Define the start and stop buttons
        col1,col2,col3,col4 = st.columns(4)
        col1.button("Start",on_click=self.start)
        col2.button("Pause",on_click=self.pause)
        col3.button("Stop",on_click=self.stop)
        col4.button("Restart",on_click=self.restart)

    def update_pipeline(self):
        if st.session_state.update_pipeline_enable:
            try:
                # Define the new GStreamer pipeline
                st.session_state.pipeline = Gst.parse_launch(st.session_state.pipeline_str)
            except Exception as e:
                st.error(str(e))

            # Disable the pipeline updation until next update call
            st.session_state.update_pipeline_enable = False

    def start(self):
        # Start the pipeline
        st.session_state.pipeline.set_state(Gst.State.PLAYING)
        st.session_state.status = "🟢"

    def pause(self):
        # Pause the pipeline
        st.session_state.pipeline.set_state(Gst.State.PAUSED)
        st.session_state.status = "🟡"

    def stop(self):
        # Stop the pipeline when the stop button is clicked
        st.session_state.pipeline.set_state(Gst.State.NULL)
        st.session_state.status = "🔴"

    def restart(self):
        # Stop the current pipeline
        self.stop()
        # Start the current pipeline
        self.start()

    def update_pipeline_str(self):
        # Stop the current pipeline
        self.stop()
        
        # Update the pipeline string
        st.session_state.pipeline_str = st.session_state.input_pipeline.strip().replace("gst-launch-1.0 ", "")

        # Updating the pipeline
        st.session_state.update_pipeline_enable = True
        self.update_pipeline()

        # Start the pipeline with new pipeline string
        self.start()

## I thought the bellow method is enough to run the gstreamer pipeline in  a separate thread in the background
def gstreamer_player_thread():
    # Initialize threads and GStreamer
    Gst.init(None)
    
    # Create an instance of the GTK_Main class
    player = GstreamerPlayer()
    
    # Start the GTK_Main instance in a new thread
    thread = threading.Thread(target=player.consol)
    add_script_run_ctx(thread)
    thread.start()
    thread.join()

If applicable, please provide the steps we should take to reproduce the error or specified behavior.

Expected behavior:

The app should start/stop/restart the test-stream on click.

Actual behavior:

The app is working fine when there is no work is being in the main thread.
if i add a sample code like below in main thread … then the behaviour of the app is random

while True:
    print("wait.....")
    time.sleep(2)

which means the app is not truly running in multithreading mode safely

Debug info

My doubt is that since gstreamer is also a multithreaded framework… so due to this some inconsistency is occurring.

So is it possible to run the gstreamer pipeline in the background thread with Streamlit app??