Know the “bit rate” that is important in determining the amount of video data and image quality.
This time, we will learn about “bit rate” which is one of the important factors in determining the image quality of video.
It is deeply related to this article, but you can learn more about video screen resolutions and frame rates in another article.
If you are unsure, we recommend that you read the article on screen resolutions and frame rates before reading this article.
Points to consider when deciding the frame rate (fps) of a video
The optimal resolution of the video screen is not always Full HD! Consider the screen resolution of the video.
Table of Contents
What is a bit rate?
Relationship between screen resolution, frame rate, and bit rate
Based on the above, let’s consider the relationship between resolution / frame rate, amount of data, and bit rate.
What to do to improve image quality
Consider the optimal resolution, frame rate, and bit rate for each type of content.
Points for building a video distribution service Free distribution
Production of video content that can be done in-house Learning materials are being distributed
What is a bit rate?
Bit rate is expressed in bps.
Short for bits per second, which indicates how many bits of data a video creates per second.
For example, a 1 Mbps video has 0.125 megabytes of data per second. It will be 7.5 MB in 1 minute.
As with screen resolution and frame rate, you can decide what bit rate you want.
Since 8 bits are 1 byte, it becomes “1 Mbit ÷ 8 = 0.125 Mbytes”.
Relationship between screen resolution, frame rate, and bit rate
Let’s review a bit.
The screen resolution indicates the number of pixels in the video.
The frame rate shows how many images a video is made up of per second.
Bit rate represents the amount of data per second.
Based on the above, let’s consider the relationship between resolution / frame rate, amount of data, and bit rate.
4K resolution is four times the area of Full HD, so more data is required to draw.
A 60fps video has twice as many frames as 30fps, so more data is required to draw.
for instance
If you want to make a “1Mbps Full HD / 30fps” video with the same image quality in “4K / 60fps”
Resolution area 4 times x frame rate 2 times = 8 times
The amount of data required is 8 Mbps in theory.
However, as mentioned above, the bit rate can be set arbitrarily, so it can be set to “1Mbps video at 4K / 60fps”.
There is no point in converting a Full HD / 30fps video into a 4K / 60fps video.
Even if you double the number of 30 videos per frame to 60, the same image will continue for 2 frames and the number of frames will be wasted.
Similarly, when it comes to resolution, it doesn’t make sense to extend what originally only had Full HD resolution to 4K.
Therefore, it is advisable to prepare the video, which is the material for creating video content, with the highest possible resolution and frame rate. It is not in vain when converting to lower numbers.
If you’re not ready, don’t forget to set the resolution and frame rate below the footage video.
What to do to improve image quality
It turned out that the higher the resolution and the bit rate, the better the video cannot be drawn without using a large amount of data.
So to improve the image quality, should the bitrate be increased anyway?
This is not bad, but the article on screen resolutionBut the same thing that I wrote happens.
In other words, the higher the bit rate, the larger the file size.
If the file size is large, the transfer of video data to the viewer will be slow, and in the case of smartphones, the monthly data traffic will soon disappear.
With that in mind, we need to find the best bit rate.
When distributing videos on the Internet, the lower the amount of data, the better.
The correct answer is to aim for a video with a small amount of data and sufficient image quality.
Next, I prepared two videos of the same video with different bit rates. See how the image quality changes with the bit rate.
Both are Full HD, 30 FPS. Compare them in full screen.
