Multiple Streams

[Martini-man]

Make OBS able to make multiple streams with different screen sizes and bitrates.

At least in the OSX version using the hardware encoder.

That is useful if you want to make an HD version and a SD version of the stream.

Thanks.

 

[Jack0r]

It is planned for the future to support more than one outgoing stream. As with all things, its mainly a matter of a developer having time to implement the interface and necessary background "features/options".
I have to add, it is probably not the highest priority at the moment. Currently most people stream to different services using something like Restream.io for example but at the same quality of course.

 

[Martini-man]

It just doesn't seem that hard to do since your software does it all it is just transcoding.

I tried to use ffmpeg with h264 videotoolbox hardware encoding but the end result is black on a browser but you using the same codec were able to do it.

ffmpeg uses too much cpu using libx264.

Do you have any pointers?

 

[Jack0r]

You still need an UI to configure the different streams and an interface to start the different streams, as well as a setup in the background that lets you create several encoders at different settings and that can send them to different locations.

The CPU usage from ffmpeg in theory should be very similar to what OBS will use, since both use x264 as their encoder. If you "just" want to send out one stream to several locations the CPU usage would be pretty much the same as when you only send out one stream. But as long as you want different settings for each stream the cpu usage will increase with every stream you add.

So let's say OBS uses 25% of your CPU for one stream. 5-10% of that are probably used to render the Scene. So a second stream will use another 15% of your CPU for example, it could be more/less depending on its settings. This increase will be quite similar to what you see when transcoding with ffmpeg at the moment. Add a third stream with different settings, and the cpu usage will increase further.
Services like twitch(if you are partnered) or youtube do the transcoding for you as most people will not have enough CPU power nor Upload Bandwidth to do it themselves.

 

[Martini-man]

I am streaming private content so I don't want to post on public services.

The thing is OBS can make use of hardware acceleration on OSX and browsers are able to decode it.

I try it with ffmpeg and h264 encoder from VideoToolbox from Apple and they can't.

I just get a black screen but it is encoding.

Any pointers?