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Hardware Encoding

Discussion in 'Live Streaming & Content Creation' started by riccoo, Jun 12, 2019.

  1. riccoo

    riccoo Member

    Jan 15, 2014
    hey All

    got a little project i want to tackle for work, we want to live stream some events and i stream to twitch using my pc but that at best of times can have issues, i want to look at a hardware encoding option like the blackmagic web presenter, but i havent had much use of hardware like this.

    I guess what i am asking is has anyone used a hardware encoder and can help me piece together what i would need.

    looking at either 1080 or 720 res stream
    HDMI or + SDI in
    Ability to stream to multiple locations such as FB, YT, TWITCH.tv
  2. HyRax1

    HyRax1 ¡Viva la Resolutión!

    Jun 28, 2001
    At a desk
    Bit of a late reply, but I'm sure you aren't the only person looking for how to tackle streaming live work events, so I provide you with my 2c:

    My portable live stream setup for events at work is a Lenovo W541 i7 laptop running Linux and OBS.

    Connected is two Magewell USB HDMI capture units (there are SDI versions too along with PCI versions of the capture units with multiple inputs too), one for capturing the output of the presenter's laptop, and the other for capturing the feed from a video camera pointed at the presenter. The great thing about Magewell is that they are hardware accelerated, doing all scaling on the unit rather than on your CPU. They can capture up to 60fps (I only use the 2K version, but there's a 4K version too). The other benefit is that they are driverless - plug in and go. The unit will present as a webcam to most software, and the audio capture will appear as another mic to other software as well, so you could feed directly into other applications such as Hangouts, Skype, etc. You can tell OBS to scale the input (eg: 1080p to 720p or vice-versa) and the Magewell will do the work for you before the data gets to OBS.

    I use OBS to mix these two captured inputs into a single display - presentation left of screen, presenting speaker scaled and cropped at the top-right of screen, and a wallpaper in the background filling up the remaining space with a company logo. I have some space left over to add any live captioning generated through something like Web Captioner or a private captioning company. I use a Sony A6000 camera with its HDMI output feeding OBS via the Magewell capture unit, and just pan the camera and zoom with a 55-200mm lens as required to keep up with the presenter.

    I capture presentation PC audio over HDMI, but have a Swamp 2-channel mixer that takes XLR audio from the speaker's mic and feeds it directly into OBS via USB. The unit also gives me an easy way to monitor what the computer "hears" though the same headphones I'm listening to the live audio with. I don't use the camera's audio feed.

    In OBS, I have several scenes created which are switched between using the numeric keypad on the laptop: combined presentation (both capture inputs), camera only, presentation only, attract mode ("event starting soon"), end logo (played when the event finishes), etc. This allows me to do easy live editing of the event and saves me doing any post-production later as OBS not only streams, but records a high quality version of the stream locally for archiving.

    The encoded stream from OBS sends to the streaming server at 2mbps 1920x1080, but the recording locally is done at 5mbps 1920x1080. I only stream to one place, but I believe OBS can send to multiple streaming services at once.

    The events I do at work are usually confidential in nature, so I can't use external services like YouTube, even on a private or passworded channel, just in case something goes wrong and data leaks publically, so I have MistServer setup on a relatively well-specced Linux VM for OBS to stream to (not on the laptop - this is on a proper VM host in the server room), and then MistServer is what provides that stream to employees to watch. In my case, I have another server that has a pretty webpage on a simple URL that people connect to and the page has an embedded MistServer player in it. This way the page is ultra-accessible even to those who are not technically minded. It's literally a case of "click the broadcast URL in your calendar invite" and that's it. The player is platform agnostic, working in PC web browsers, Android, iOS, etc. You can full-screen it like any normal player as you'd expect too. Those not in the office can still watch the live stream by connecting to the office VPN from home.

    I use the free version of MistServer which is very scalable - I've had more than 300 concurrent connections on the modest setup of the server without any dropout. The paid version can relay the stream to other MistServers so you can have a server that serves your Australian offices, another for Europe, another for the US, etc so everyone connects only to their local server.
    Last edited: Jan 9, 2020
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