5

I have developed a proxy which lets me consume catchup video provided by my ISP as udp unicast m2tp streams through http. For that I am using python, asyncio and Sanic.

It is working beautifully yet there is something I cannot explain. Some streams use less than 8% of one cpu core (i7-3770), while other specific ones consume as much as 30%. All the streams are in principle the same and I do not do any processing on them, just read from a udp socket and write to a streamed sanic.Response, basically this:

import asyncio_dgram
import socket

from contextlib import closing
from Sanic import Sanic, response

app = Sanic()

MIME = 'video/MP2T'

@app.get('/some/url')
async def handle_url(request):
    host = socket.gethostbyname(socket.gethostname())
    client_port = 43545
    async def my_streaming_fn(response):
        with closing(await asyncio_dgram.bind((host, client_port))) as stream:
            while True:
                data, remote_addr = await stream.recv()
                await response.write(data)

    return response.stream(my_streaming_fn, content_type=MIME)

All the streams arrive on a separate vlan, all the ts packets are 1344 bytes (1316 without headers). I see the difference with streams of the same bitrate, even from the same original tv channel.

What I am missing which could explain the huge difference in cpu usage between some and other streams? Any idea?

Javier Marcet
  • 51
  • 2
  • minor point, but I think you should be able to use `bind(('', client_port))` instead of binding to any specific address. a couple of questions: 1. what packet rates are you getting? 2. could you write some code emulating the (m2tp) sender that provokes the behaviour? – Sam Mason Feb 08 '21 at 18:09

0 Answers0