@mux/ai

Phil: Hey, Phil from Mux here with a quick demo of

how you can use SRT on Mux to deliver a great live streaming

experience even when the network you're sending a video

from is less than perfect.

Okay, so on the left I've got OBS playing my favorite movie,

Big Buck Bunny, and I've got my live stream on the right.

My live stream at the moment is going out over RTMP, it's

going out at about seven megabits a second, it's

completely stable, no drop frames, anything like that.

If we take a look at the live stream health, it seems fine,

completely stable, about 7 megabits, 30 frames a second.

So what I'm going to do is I'm going to use Network Link

Conditioner to introduce some problems on this network.

So I'm going to introduce 100 milliseconds of

extra latency, as well as introducing 5 percent

packet loss on both packets sent and packets received.

Let's see what that does to our RTMP stream.

So, if we keep an eye on the bottom of OBS, we'll

start to see really quickly, we start dropping frames.

Way above like the 5 percent of packet loss

that we introduced.

Um, eventually we'll probably actually see this gets a

full RTMP disconnect as well, and then we'll start

to see reconnects kicking in.

If we take a look at the mux dashboard, obviously

we see this big dive off in the bit rate and obviously

the frame rate as well, so you probably wouldn't

be able to watch this.

It would be a pretty stuttery mess on the playback side.

It's taking a lot longer than you want the frames

to get into the encoder.

Let's take a look at what this looks like with SRT instead.

Okay.

Now that live stream stopped, let's reconfigure

OBS to use SRT.

To do this, I need the SRT URL, stream key, passphrase,

but I'm also going to set up the latency of a connection.

So what this does is it tells.

SRT, how much buffer to keep on each end of a connection

to compensate for packet loss, reordering, jitter, latency,

all those sorts of things.

So I've set that to two seconds in this case,

which should be enough for the issues that we're

introducing on the network.

So let's start that stream again.

Okay, so our live stream's back up, now

let's do the same again.

Let's turn on our network link conditioner and see

what happens to our SRT stream with 5 percent packet

loss and that extra 100 milliseconds round trip time.

If we take a look down here, it doesn't look like

we're dropping any frames.

We might see the bitrate start to spike a little bit,

and that's because, hey, we're having to resend a

bunch of extra frames, so sending some extra data.

Let's see how it looks.

So far so good.

Our live stream looks pretty stable.

We're not dropping any frames.

Our frame rates consistent, bit rates are consistent.

So it looks like things going well, even though

we're dropping quite a lot of packets.

This is what SRT is designed for.

It's designed to handle these imperfect network conditions

and make sure you can still live stream when this happens.

Let's take a look at how our asset looks.

Looks pretty good to me.

Even with all of that packet loss and all

that extra latency.

So there you go That's how you can use SRT to improve

reliability of your live streams, even when the

network isn't perfect.

Hope you enjoy it