There are some older threads here on how to live stream for free. I just had a good experience doing this with YouTube, so here is my "howto" if anyone wants to know.
I have been feeding my video content from BlackMagic ATEM into a Matrox Monarch HD applicance for recording. The Monarch HD also can stream, I just never used it for that. It is overpriced at about $1000, but has been useful nonetheless over the last few years until I bought Atomos recorders.
I recently had a request to broadcast a live stream. I just went to my no-longer-used Matrox and pointed the Matrox Monarch HD at my YouTube account, using the URL and key YouTube provided me on its setup page, pressed the "stream" button and it worked just fine.
I can setup the quality inside the Monarch anywhere from full HD down to lower, but had no problem streaming HD up to YouTube from my office over its internet link. I do not think there is any restriction on number of users with YouTube, but I only had a few viewers across the US watch it, and had zero problems, and it was free.
I know Facebook and Twitter allow the same thing these days, and when I get a few moments, will try those two free platforms.
It does not seem to be a big problem these days to stream live for free using an appliance to encode, or software on a computer.
I have been working on the harder problem, getting mobile internet bandwidth suitable for streaming out in the field. That is a bigger challenge since cell companies have asymettrical bandwidth, set very low for the uplink side, which is the side I need. Despite the claims for 4G, if you test them out, you might get 5 - 10 mb downlink, but mostly about 1/2 mb uplink because of the asymettrical nature of consumer G4, cable, or DSL.
Not so with commercial links. In my office I have a symetrical gigabit fiber, and actually get that speed both ways. Otherwise, an uplink is poor on all other internet I have encountered.
I carefully studied various bonded cell phone solutions which are very expensive. I ruled out the Teredek because I did not like the fact that the encoder and modems were in one box. I expect H.264 to move at some point to H.265, and if I bought the Teredek with a built in encoder, and the technology changed, I would have to put the whole thing in my outmoded-junk-box.
The Peplink products are bonded cellphone routers without the encoder. So I can plug the Matrox Monarch HD into the Peplink Router, and later if H.265 comes out, just replace the Matrox, and keep the Peplink for as long as that technology lasts. Peplink was also somewhat cheaper than Teredek, which was part of my equation.
Thus I recently purchased a Peplink Pepwave Max 700 new for about $1900, and a companion Peplink 310 router (used on Ebay) for the other end, and am bonding four cellphones together, plus adding in a wif-fi if I can find one. I backhaul the video stream from the fileld using the Max 700 to my office using the Ebay 310, and from there over my gigabit fiber to YouTube or wherever I want.
Still not blazingly fast, but if I set the Matrox to 720 resolution, I can get by on about 2mb uplink through YouTube. I am getting that wil four cellphones bonded on the Peplink Max 700 in the Los Angeles area that has good Verizon coverage.
So far so good, but when I get out in the field it is still up for grabs as to how well the G4 cell service will be, and when a crowd shows up, it gets worse as other cell deviced compete for bandwidth. But after a few low intensity events where failure could be tolerated, I have had success. I am not yet ready to put a lot of risk on this solution just yet until I have success many times in a row, and find a way to get some redundancy as a backup plan.
To me the most flaky part of the equation is uplink bandwith out in the field with an unpredictable environment.
So my best "free" broadcast solution so far is Cameras > ATEM > Matrox Monarch HD > Pepwave Max 700 > Backhauled to my office 310 router for demuxing > YouTube (and then maybe Facebook, Twitter or wherever).
A second option is to make use of Amazon EC2 with bundled Adobe Media Server, or Wowza, both of which license their server software by the hour. I tried this, and it took many hours of my weak Linux skills to get it to work, The per hour cost can be justified by a paid viewer base if large enough. But all things being equal, I would prefer YouTube deal with that final distribution chain. I was not all that comfortable with all the things that can go wrong using an Amazon server, and related software, supported by a staff of just me. Most of the time I am a one-man-band out in the field with cameras, sound, ATEM to deal with all on my own, and one more task is not an option. No thanks!
I would appreciate feedback and critique of my live streaming scheme so far.