Online streaming and radio protocols

In this series of articles we will talk about the basic knowledge you need to have to conduct online broadcasts with your own hands. This series of articles will be useful for beginners in the field of broadcasting. Experienced colleagues are unlikely to learn anything new, we will talk about the basics. How do I do live broadcasts? This is a question that we will try to answer in as much detail as possible. From basic knowledge and theory, to super-serious sets.

You will get acquainted with action cameras, webcams, DSLR cameras, handycam, professional camcorders and learn a lot of details, for example - what is the difference between HDMI and SDI and why the sound quality is a key factor in the broadcast.

After studying these articles you will be able to make your broadcasts webinars and other events in good quality. There are many video tutorials and articles on how to do live broadcasts, but this course is different from all the others - it was prepared by Stream Park's technical director, who faces new and new projects in the field of online broadcasting every day.

We've compiled all the practical information we've been able to glean from five years of working in the field. Here are the topics of the articles that are currently available:

• Online Broadcasting Programs.
• Online radio streaming: SOUNDPARK DEEP
• Working with sound in an online broadcast
• Capturing video from a camera
• Cameras for online broadcasting

The article you're reading now is an introduction, we recommend you start there!

The genesis of streaming

Over the past 100 years, we've invented many wonderful things: cars, rockets, marmalade, and television. Suddenly, millions of people were able to see what was going on in the world from the comfort of their couch. Not surprisingly, many people began to dream of having their own television set. This idea of selling something to millions of people was becoming more and more exciting, but making your own television has always been extremely expensive. The industry is dominated by "big boys" who sit in big buildings and play with their big toys.

That all changed, thanks to the mad scientists working at Xerox Parc. They were a legendary company in research and development. They introduced inventions like the computer and laser printers.

In 1993, the broadcast of the Severe Tire Damage concert was the first time people from all over the world could see it sitting on the Internet. A year later, some stars decided to stream concerts on the Internet as well. The revolution had begun. Technology got better and better. And now, you can broadcast to thousands of people with your cell phone and almost for free. Whether it's a conference, a sports game, your child's first steps or a political debate. Live streaming is democratizing our world, but the big guys are still leading the market.

What is streaming and how does it work?

So what is live streaming? Live streaming delivers (transmits) content in real time to viewers using the Internet. You don't need a TV studio, satellite, or a lot of equipment to broadcast live. All you need is a signal source - such as a camera, a computer with a capture card and special software, and a live video server where your viewers will be set up to watch your broadcast. Of course, behind-the-scenes technology is very complicated; I won't dive into it because I was bored to death. I also don't think you need to know it all, but before we go any further, let's pick right here and do our first triumphs. There are a few definitions you need to understand. You probably know that you need to know the alphabet before you start learning a new language, right? So let's learn it!

The codecs are H.264 and AAC.

There are audio and video codecs. A codec is software that will reduce your audio/video signal without a huge loss of quality. Then, it can be transmitted using an Internet connection quite easily. Imagine you are going to Miami and you need to pack that whole white suit in a little bag, you can use vacuum bags, but be careful not to squeeze them too hard because you will damage your clothes. Codecs are similar to vacuum bags, but for audio and video signals.

The most popular codec for video compression is H.264 and AAC for audio. H.264 is very efficient and compresses huge video files, but requires a lot of processing power. That's why you need a fast computer to get good quality. The Intel i5 in orbit meets the bare minimum these days, so I recommend the Intel i7, especially if you want to set up work in HD. I use an MSI laptop with an Xeon processor, and it supports streaming HD Isley, but my MacBook Pro with an i5 processor has some issues with that - its hardware is already lacking. For audio, the AAC codec is by far the best. And it's recommended by most platforms that like YouTube. Mp3 was designed for compressed music, not live streaming,

Bitrate / broadcast bitrate

Now you should understand that the next definition for codecs is bitrate. This is very important to know. If you don't understand what bitrate is, your viewers will experience poor quality or even worse-buffering, so please focus on that. Bitrate tells the codec what kind of stream quality you want. It is usually measured in kilobits per second (kbps).

For example: 1000 kilobits per second. And means 1000 kilobits, so in this case you can also say 1 million bits per second.

Simply put, the higher the bitrate, the higher the quality. But if the broadcast server doesn't have transcoding, it's going to cause problems for the end viewer. If his incoming Internet channel is unstable or not fast enough to watch, the video and sound can stutter and freeze. That's why it's better to work with services that support real-time video transcoding, later we will tell you more about streaming services and discuss this point.

A bit is the basic unit of information in a computer. It is a variable with a volume of 1 or 0. The computer knows how to read a stream of these values and then know what to display on the computer screen.

Bits build everything we see on the computer screen. They are like the atoms that build our universe. The more bits, the more complex and beautiful the videos and pictures are. But they also require more processing power, bigger hard drives, and faster Internet.

The bitrate I set up for my live broadcasts depends on 3 inputs:

• The speed of my Internet connection.
• The resolution of the video I want.
• And the amount of traffic during the event.

For example, if I want to live stream a conference where there isn't much dynamic motion in the frame, but only mostly talking and presentation I can choose:

• 720p resolution (1280/720 pixels).
• Bitrate for video up to 2000 kbps (H.264).
• Bitrate for audio up to 128 kb/s (AAC).

This should give me a crisp image and make a really good sound. Accordingly, if there are more speakers in the frame - you need to increase the bitrate. If the site allows internet channel, we usually broadcast 1080p and 5000 kb, there is simply no need for more - Youtube bandwidth maximum 6000 kb, VK and FB about the same.