How to choose Resolution 480p, 720p, 1080p, 4K and bandwidth for video stream in your application

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Trembit helped Learnster salvage the project, switched the engineering team and tuned software development processes

Let’s be honest, most business people don’t care about 720p vs 4k, bandwidth, bitrate or any other buzzwords, they want video stream looks nice and that’s it!

But engineers keep asking “dumb” questions, pushing you to make a choice for settings for a stream. Logically you select the highest possible settings and usually stream looks great, but you end up with a hefty bill for the streaming server. Then you start tuning settings back and forth, eventually, you end up with optimized parameters and hopefully “ok” bill.

In this article, we will try to clearly explain how to save time and make choices faster. I promise to put a high level description in a simple way 🙂

Pixels

First of all, what is 480p, 720p, 1080p, 4K? These abbreviations represent the rectangle areas of pixels and nothing more. 

For example, 480p is 640 pixels horizontally x 480 pixels vertically or simply 640 x 480

1080p is 1920 pixels horizontally x 1080 pixels vertically or 1920 x 1080

Click on the image below to open it  in a new browser tab in real size and get an understanding of how these sizes look on your screen.

So one more time, these all abbreviations are just differently sized blocks of pixels.

Let’s address some popular questions:

Question 1: Is 4K TV better than 1080p TV?

Simple answer: 4K TV screen can show 3840 pixels x 2160 pixels. And 1080P (FullHD) TV can show 1920 x 1080 pixels. But in reality, you won’t notice any difference when you watch movies on a big screen. Because people usually sit on a sofa keeping comfort distance between the eyes and the TV screen. And you simply don’t see those tiny pixels. So for your brain, there is no difference between 4K or 1080p.

However when you work on a big (27 inches or larger) 4K monitor then probably you start seeing the difference. Because you sit close to the monitor.

Question 2: “But wait, I went to the Electronics store and clearly saw the difference on TV. They showed a split screen with FullHD (1080p) and 4K. There is a big difference.

Simple answer: In the Electronics store they specifically create a video with different color saturation, quality degradation, etc just to show you the difference. But this is cheating. Also, they keep you in the 1-meter short distance to the TV. 


Bitrate

Ok, let’s move to another factor, and the name of it is Bitrate!

Long story short, when you save the video on the hard drive, it takes some hard drive space. For example, your favorite movie needs 4GB (Gigabytes) on a hard drive. Let’s assume that the movie is Full HD (1080p). That means that when you pause the movie technically you should count 1920 x 1080 pixels. 

What if I say that the same movie can take 10GB of data? How? Because of the different levels of quality. If movie takes more data, technically it should contain more visual details. And we can measure that level of quality and name it Bitrate.

Technically speaking Bitrate represents the amount of data in one second of the video. But you can think of Bitrate as a measurement for quality. The bigger Bitrate the better video visually. And on the other hand, the bigger bitrate the more movie takes space on your hard drive. Or the bigger the bitrate the more you pay for data transfer in case of the streaming.

Do you remember the night scenes from the last season of “Game of Thrones”? What a disappointment, it’s all black! And the reason is simple, not enough Bitrate. It looked well for day scenes and awfully at night.

Funny story, during one conference I’ve met a person from a company that supports HBO users. And they were getting on average 1000 requests per second when that night scene was streaming live 🙂

So how do I choose that Bitrate and video stream size?

The answer is simple: Ask your engineers to make streaming samples with all different settings and check the results. Test it in real-life situations. If you stream video to smartphones, get iPhone/Androids and see how it looks. If you stream to desktop browsers, launch the browser and see the results.

Start from the lowest quality and go up. When you see the ok result visually then stop, you are done!

Oh, and if you don’t have engineers to ask to prepare different video samples, then ask me, I will be glad to help: sz@trembit.com

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