FastAPI return text and video with sound

Question

I need to return mp4 video with json in one endpoint. How can i do it?

Or do I need to return json with a link to the video stream and text?

My code sample below:

from http import HTTPStatus
from pathlib import Path

import uvicorn
from fastapi import FastAPI
from fastapi import Header
from fastapi import Request, Response
from fastapi.templating import Jinja2Templates

app = FastAPI()
templates = Jinja2Templates(directory="templates")
CHUNK_SIZE = 1024*1024
video_path = Path("dataclasses_part2.mp4")


@app.get("/")
async def read_root(request: Request):
    return templates.TemplateResponse("index.htm", context={"request": request})


@app.get("/video")
async def video_endpoint(range: str = Header(None)):
    start, end = range.replace("bytes=", "").split("-")
    start = int(start)
    end = int(end) if end else start + CHUNK_SIZE
    with open(video_path, "rb") as video:
        # some operations with video, returning data
        data_oper = "Some info"

        video.seek(start)
        video_data = video.read(end - start)
        filesize = str(video_path.stat().st_size)
        headers = {
            'Content-Range': f'bytes {str(start)}-{str(end)}/{filesize}',
            'Accept-Ranges': 'bytes'
        }
        data = {
            "video_data": video_data,
            "text_data": data_oper,
        }
        return Response(data, status_code=HTTPStatus.PARTIAL_CONTENT, headers=headers)


if __name__ == "__main__":
    uvicorn.run(app, host="0.0.0.0", port=8000)

Now it's falling with error, because i can do only this:

return Response(video_data, status_code=HTTPStatus.PARTIAL_CONTENT, headers=headers, media_type="video/mp4")

My html template below

<!DOCTYPE html>
<html>
    <head>
        <title>FastAPI video streaming</title>
    </head>
    <body>
        <video width="1200" controls muted="muted">
            <source src="http://localhost:8000/video"/>
        </video>
        <h1>
        # Text from responce
        </h1>
    </body>
</html>

This topic does not answer my question How to return video frame and text to HTML page using FastAPI? - i need to return video with sound
Also i saw this Streaming video with FastAPI - but i need to return text/json too

score 0 · Answer 1 · answered Feb 20 '23 at 17:02

Yeah, you're not gonna be able to send the video data in the JSON body. You could either have a separate API endpoint for your metadata, or you could put it in a custom header. The issue with putting it in the same endpoint is that you're not calling the /video endpoint manually, you're passing it to a <video> tag and letting the browser handle the streaming, so you're not ginna have access to the data anyway. The most reasonable thing would be to have two endpoints, one for metadata and one for the video content itself.

FastAPI return text and video with sound

1 Answers1