gradio-webrtc/docs/userguide/video.md

Video Streaming

Input/Output Streaming

We already saw this example in the Quickstart and the Core Concepts section.

=== "Code"

``` py title="Input/Output Streaming"
from fastrtc import Stream
import gradio as gr

def detection(image, conf_threshold=0.3): # (1)
    processed_frame = process_frame(image, conf_threshold)
    return processed_frame # (2)

stream = Stream(
    handler=detection,
    modality="video",
    mode="send-receive", # (3)
    additional_inputs=[
        gr.Slider(minimum=0, maximum=1, step=0.01, value=0.3)
    ],
)
```

1. The webcam frame will be represented as a numpy array of shape (height, width, RGB).
2. The function must return a numpy array. It can take arbitrary values from other components.
3. Set the `modality="video"` and `mode="send-receive"`

=== "Notes" 1. The webcam frame will be represented as a numpy array of shape (height, width, RGB). 2. The function must return a numpy array. It can take arbitrary values from other components. 3. Set the modality="video" and mode="send-receive"

Server-to-Client Only

In this case, we stream from the server to the client so we will write a generator function that yields the next frame from the video (as a numpy array) and set the mode="receive" in the WebRTC component.

=== "Code" ``` py title="Server-To-Client" from fastrtc import Stream

def generation():
    url = "https://download.tsi.telecom-paristech.fr/gpac/dataset/dash/uhd/mux_sources/hevcds_720p30_2M.mp4"
    cap = cv2.VideoCapture(url)
    iterating = True
    while iterating:
        iterating, frame = cap.read()
        yield frame

stream = Stream(
    handler=generation,
    modality="video",
    mode="receive"
)
```