Understanding Video Bitrates and Codecs

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Understanding Video Bitrates and Codecs

Video bitrate and codec are two important concepts that every video creator should understand. In this article, I will explain what they are, how they work together, and how to choose the right settings for your videos.

What is Video Bitrate?

Video bitrate is the amount of data that is encoded per second in a video file. It is measured in bits per second (bps), or kilobits per second (kbps) or megabits per second (Mbps).

The higher the bitrate, the more data is encoded, and the higher the quality of the video will be. However, a higher bitrate also means a larger file size.

What is a Video Codec?

A video codec is a software program that compresses and decompresses video data. It is responsible for encoding the video data into a format that can be stored or streamed, and then decoding it back into its original form when it is played back.

There are many different video codecs available, each with its own strengths and weaknesses. Some of the most popular video codecs include:

H.264: This is the most widely used video codec. It is a lossy codec, which means that some data is lost during the compression process. However, H.264 is very efficient, and it can produce high-quality video with a relatively small file size.
H.265: This is a newer codec that is designed to be more efficient than H.264. It can produce the same quality of video with a smaller file size.
VP9: This is a free and open-source video codec that is developed by Google. It is similar to H.265 in terms of efficiency, but it is not as widely supported.

How Do Bitrate and Codecs Work Together?

Bitrate and codec work together to determine the quality and file size of a video. The higher the bitrate, the more data is encoded, and the higher the quality of the video will be. However, a higher bitrate also means a larger file size.

The codec determines how the video data is compressed. Some codecs are more efficient than others, and they can produce the same quality of video with a smaller file size.

How to Choose the Right Bitrate and Codec for Your Videos

The right bitrate and codec for your videos will depend on a number of factors, including:

The intended use of the video. If you are uploading your video to YouTube, you will need to choose a bitrate that is compatible with YouTube’s streaming requirements.
The target audience. If you are creating a video for mobile devices, you will need to choose a lower bitrate than if you are creating a video for high-definition televisions.
The file size. If you are limited by the file size, you will need to choose a lower bitrate.

Final Words About Video Bitrates and Codecs

Video bitrate and codec are two important concepts that every video creator should understand. By understanding how they work together, you can choose the right settings for your videos to ensure that they are both high quality and have a reasonable file size.

I hope this article has been helpful. If you have any questions, please feel free to leave a comment below.

Bonus Tips

If you are not sure what bitrate or codec to use, you can always start with a high bitrate and then lower it until you find a balance between quality and file size that you are happy with.
You can use a video bitrate calculator to help you determine the right bitrate for your videos.
There are many different video codecs available, so it is important to do some research to find the best codec for your needs.

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Bitrate vs. Video Resolution

which is more important for streaming video?

Many people have this confusion because these two factors can have a profound effect on the encoder’s output.

How do you think it should be chosen?

Choose 1080p or 720p?

Choose 5mbps or 3mbps?

Choose 1080p@5mbps or 1080p@7mbps?

If you don’t know what to choose, great. That’s why I wrote this article: to explain the relationship between bitrate and resolution in simple terms, and to help you choose the right encoder settings.

Let’s start by understanding bitrate.

What is the bitrate of the video?

Video bitrate or bit rate refers to the number of bits transmitted per second of video information. The code rate unit is usually:

kbps or kilobits per second

mbps or megabits per second

When you are compressing video, you usually need to set the video compression software not to exceed a certain bit rate.

For example, if you set the video compression software’s bitrate to 3mbps, the software will compress the video at 3mb per second (on average) and stream it to the decoder or player. This is the code rate.

When you talk about bitrate, you’re really talking about: the relationship between video compression and video quality loss. The more you compress, the lower the quality of the video (and this is not always the case, as we will see later).

When compressing video, the following algorithms can be used for speed control, these are:

CBR (Constant Bitrate) – It is best to keep the bitrate constant if video quality is lost.

VBR (Variable Bitrate) – Maintains consistent video quality, allowing for bitrate fluctuations.

Capped VBR – Keep the video quality as constant as possible, allowing the bitrate to fluctuate within a set range.

This article will not discuss the above frequency control methods in detail. Friends who want to know more, welcome to read: Understanding Frequency Control Modes: What are CBR, VBR, CRF and Capped-CRF?

So when we talk about the bit rate, we should pay attention to the following points:

The quality of high bitrate video is usually higher than that of low bitrate video. I say generally, because the video quality reaches a certain point where it will no longer improve (no matter how much the bitrate increases).

The code rate refers to bits (bit) instead of bytes (byte).

The bit rate alone does not determine the quality of the video, you have to take into account factors like resolution, frame rate, screen size, etc.

Codecs for video compression: H.264/AVC, HEVC, VP9, AV1? If you change the video codec and its settings (or encoding tools), the same bitrate will provide a very different video quality.

What is the bit rate?

What is the bit rate?

The bit rate, or as they also say the width of the stream, is the amount of data transmitted or processed in 1 second. The concept mainly applies to multimedia content, for example, video bit rate is nothing more than the amount of video information that is displayed on the screen in one second. To measure the bit rate, the designation “Kbit / s (kbps)” is used, that is, kilobits per second, less frequently Mbit / s, and so on. The more information that is transmitted during a specific period of time, the higher the quality of the image.

When people say “low bit rate video” they are generally referring to low quality video. Blur, opacity, and pixelation are characteristic features of such video, while high-bit-rate video has a detailed image with a rich color gamut. Like video, audio also comes with low and high bit rates. Music with a low bit rate loses in the frequency range, words and chords become less distinguishable, and itself takes on an unnatural sound, as if it were an electronic sound.

Bit rate types

It is not enough to understand what the video or audio bit rate is. To successfully work on programs for editing and converting multimedia content, you need to know what types of bit rates exist. These are constant, variable, and average, and each of them can be used in a specific situation.

Constant bit rate

Constant refers to a bit rate that does not change throughout the file, providing an accurate estimate of the size of the output material. On the other hand, it is not very suitable for multimedia with dynamically variable audio and video streams, as it does not provide an optimal balance of size and quality. Constant bit rate is mainly used at home level, as well as when processing files with relatively constant picture and sound characteristics.

Variable bit rate

In files with variable bitrate, the latter is changed by the codec for each frame according to its characteristics. For example, in frames that are not very informative and easy to encode, the video bit rate is lowered, which saves space, and this saving can differ significantly. Variable bit rate technology is often used to achieve the best quality / size ratio. The downside of this method is the unpredictability of the final size of the media file.

Average bit rate

A more flexible option is the averaged bitrate, which is a hybrid of the first and second types. Unlike Variable Bitrate, by choosing Average Bitrate the codec can only work within the user defined range. Professionals use this method when creating large projects, allowing you to achieve high-quality encoding with a relatively small file size. The precision of calculating the size is much higher.

How to find out the bitrate of the file

Novice users are often interested in how to find out the video bit rate and if special programs are needed for this. With few exceptions, it is not necessary to use third-party tools for these purposes, since the bit rate of the file can be obtained by the operating system itself. Right-click on the video file and select “Properties” from the menu. Then switch to the “Details” tab in the window that opens and look for the item “Data transfer rate”. This will be the bitrate of the video. In the case of audio files, the item will be named “Bitrate”. If the required information is missing from the properties, for example in the case of MKV files, use the MediaInfo utility.

What bit rate value to set

But much more relevant is the question of what bit rate should be set for a video when creating or converting it. It will not be possible to answer it unequivocally, it all depends on the situation and the purpose of the content. If you focus on average values, you should configure 2.5-5 Mbit / s for video and approximately 192 kbit / s for audio. When choosing, you should also consider the video format. Therefore, for 1920 x 1080 SDR video, the bit rate is better to set 8 and 12 mbps (60 frames / s), and for HDR video with the same resolution – 10 and 15 mbps, respectively.

What is the bit rate?

Bit rate measures the speed at which information can be transmitted between two locations. The standard unit for this speed is “bits per second”, but a kilo or mega value is often prepended to indicate the high speeds of modern digital technology. Communication technology measures speed as a function of bit rate, especially on the Internet. The transfer rate indicates how fast the data can be downloaded. This measure is also widely used to describe audio and video. higher rates mean higher quality.

In its simplest form, bit rate describes how many bits per second are transmitted between two different locations. The higher the rate, the faster information can be exchanged between them. For this reason, the bit rate can be particularly important for communication technologies such as broadband, as it defines how quickly a user can download or upload information.

The standard unit for bit rate is bits per second (bps). However, this measurement is often too small to be practical in modern communication technology, as millions of bits can be transmitted per second. To solve this problem, the device is usually prefixed by a different letter indicating its size. For example, kbit / s means kilobits per second or 1000 bits per second. Megabits per second are written as Mbit / s and represent millions of bits per second.

Bit rate is an important measure for a large number of different areas of computing. Broadband, for example, is often specified as a certain number of Mbit / s, with speeds of around 2 Mbit / s being common. Fiber broadband, which is much faster, can deliver speeds of up to 5 Mbps. This measure also describes the speed of mobile connections such as 3G and Bluetooth.

Audio and video quality are commonly reported in terms of bit rate, with higher rates indicating a higher quality picture or sound. In multimedia, this metric is a quick way to show how much information is stored in each second of recording, so higher rates lead to increased quality. The bit rate can depend on a variety of factors, including whether the information has been compressed.

The standard bit rate for audio is between 100 and 160 kbit / s, while higher quality recordings can reach up to 320 kbit / s. Video speeds can be significantly higher for Blu-ray discs with speeds up to 40 Mbps. Standard DVDs are only about 9 Mbit / s, so there is a difference in quality.