DEV Community

Cover image for A Non-Video Engineer's Guide to Live Streaming Video Terms
Amara Graham
Amara Graham

Posted on

A Non-Video Engineer's Guide to Live Streaming Video Terms

I am in full on maximum absorption sponge mode as I learn a new technology, new developer community, and last but not least, a new company. I'm the Director of Developer Relations at Wowza Media Systems which means I need to hit the ground running... or perhaps "DO IT LIVE". I'll stop now, only if you promise to stop with the "Wowza" based dad jokes.

So far it hasn't been as overwhelming as it could be, but with planning for the next quarter right around the corner (how is it almost AUGUST?!) I'm going hands-on with my learning as fast as I can. It's week 3 and I've already broadcast a live stream from the API with Wowza Streaming Cloud and the GoCoder App. Sound interesting to you? Follow the instructions here.

The Terms

I'm all about learning in public, so I figured I'd put together a list of video and live streaming video terms that just didn't stick in my brain the first few times, because I bet you might be in the same boat.

Or maybe I confuse you even more, who knows!


Broadcast a live stream with these API calls.

This is the verb you want to use when you get your stream up and running to be visible to your viewers. I always want to think of this as a noun like a radio or tv show, but that's not quite right in this context.


Playback was so nice I almost felt like I was there!

I'm almost embarrassed to admit I've been so hung up on this one.

Playback (noun) == Play (verb)

I want to make playback some kind of retrospective, and that's probably from IBM Agile terminology. Playback was something you did at the end of an iteration to review what went on during said iteration.

But in the live streaming video context, it's just the video playing or the experience while the video was playing.

You can play the stream and see smooth playback.

Codec (Lossy & Lossless)

I know codec from working with audio processing and trying to just get things from OBS into YouTube or Twitch. And by "know" I mean I would read the documentation for what was accepted codec/format wise and try to make sure I never had audio or video in a different codec.

A codec can be hardware (like a physical appliance) or software that compresses audio and video into a file format for transmission then decodes the file to it can be played. Simply put, it's an algorithm.

Still with me?

Just like you've zipped files to send them to your coworkers because your powerpoint was filled with too many gifs, you can't expect your 4K video to seamlessly fly across the internets in the same format you captured it with.

There are two kinds of codecs, lossy and lossless. Lossy codecs are typically used in streaming since they are smaller. Lossless codecs are used in storage and archiving media. Don't you like making sure your things are pristine and in their original form before you store them away? Same.

Multicasting vs. Simulcasting vs. Re-stream

Broadcasting one stream from a server to multiple destinations in single transmission is referred to as multicast.

You can re-stream from a multicast address, but this is a re-broadcast and its not really live.

Simulcast is broadcasting across multiple platforms like Facebook Live and a web page, all live at the same time.

I just remember watching Football and hearing "Simulcast in SAP" when I was a kid. Same video, but the audio is different for the Spanish speaking audience.

Watch me continue to try to use these interchangeably and ruin my street cred.

Transcode vs. Transmux vs. Transrate

Transcode is converting from one codec to another, maybe something more common.

Transmux (transcode-multiplexing) is converting to a different container format, but keeping the file contents the same. This is important for supporting a variety of different playback types.

Transrate is the process of moving from one bitrate to another without changing the file format. Think of this move as going to a lower bitrate for file transfer.

Transize can also be included here, think of it as adjusting the resolution.

All of these are crucial during the live streaming video process as viewers watch on a variety of devices. These steps have to happen quickly and efficiently so no one gets stuck behind in the spoiler danger zone.

Wrap Up

There are definitely more terms out there, but these are great places to start as you learn the fundamentals. What's super cool is Wowza has a glossary! If you ever get stuck on terminology, its a great place to go. Keep in mind not every term is defined there... yet.

Totally lost on the whole live streaming video thing? This multi-part long read pulls it all together nicely.

Top comments (3)

codemouse92 profile image
Jason C. McDonald

FANTASTIC! You just defined a whole lot of things I never understood.

missamarakay profile image
Amara Graham

YAY! I knew there were other folks out there going "wait... what?!"

If you come across another video term you need distilled, let me know!

codemouse92 profile image
Jason C. McDonald

Well, although I know what they mean, I wonder if some readers might be confused still about "lossy" and "lossless"?