YOLOv8 frames to FASTAPI Streaming Response

[gustavosett]

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Example Code

from fastapi import APIRouter, HTTPException
from fastapi.responses import StreamingResponse
import cv2
import numpy as np
from app.core.database import get_db
from app.manager import FireWatchCameraManager
from app.services.utils import LOGGER

router = APIRouter(
    prefix="/api",
    tags=["stream"]
)

# Instanciando o gerenciador de câmera. Esse objeto será responsável por gerenciar múltiplas câmeras
CAMERA_MANAGER = FireWatchCameraManager()

# Definindo o cabeçalho de imagem HTTP que será usado para cada frame do vídeo
IMAGE_HEADER = (b"--frame\r\n"
                b"Content-Type: image/jpeg\r\n\r\n")

async def frame_stream(index):
    while CAMERA_MANAGER[index].is_running:
        frame = CAMERA_MANAGER[index].get_frame()
        _, buffer = cv2.imencode(".jpg", frame)
        yield IMAGE_HEADER + buffer.tobytes() + b"\r\n"

# Rota de streaming
@router.get("/video_feed/{index}", responses={200: {"content": {"multipart/x-mixed-replace": {}}}})
async def video_feed(index: int):
    camera_quant = len(CAMERA_MANAGER)
    if index < 0 or index >= camera_quant or camera_quant == 0:
        raise HTTPException(status_code=404, detail="Camera not found.")
    
    return StreamingResponse(frame_stream(index), media_type="multipart/x-mixed-replace")

Description

Good morning, I would like to know why my stream route isn't working. It's a camera system with yolov8, but I'm testing it only with my webcam. If I use cv2.imshow to show me the frames, I receive them correctly, but this route doesn't work. No error appears, it runs the loop once or twice and then stops, even though my camera is available to send the frames.

Operating System

Windows

Operating System Details

No response

FastAPI Version

0.99.1

Python Version

Python 3.11.3

Additional Context

No response

[gustavosett]

it's working now, just missing the "boundary=frame"

async def frame_stream(index):
    while CAMERA_MANAGER[index].is_running:
        frame = CAMERA_MANAGER[index].get_frame()
        _, buffer = cv2.imencode(".jpg", frame)
        yield (b'--frame\r\n'
                       b'Content-Type: image/jpeg\r\n\r\n' + buffer.tobytes() + b'\r\n')

# Rota de streaming
@router.get("/video_feed/{index}", responses={200: {"content": {"multipart/x-mixed-replace;boundary=frame": {}}}})
async def video_feed(index: int):
    camera_quant = len(CAMERA_MANAGER)
    if index < 0 or index >= camera_quant or camera_quant == 0:
        raise HTTPException(status_code=404, detail="Camera not found.")
    
    return StreamingResponse(frame_stream(index), media_type="multipart/x-mixed-replace;boundary=frame")