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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Can you really hear the difference in the sound quality of music?

A brief discussion of the principle of audio compression

grade headphones – performance, equipment – can you really hear the difference in music quality? A brief discussion of the principle of audio compression
When you listen to music, most of the time the format being played is MP3 or AAC.

Both formats are smaller formats in which the audio is processed and compressed. To reduce size and save space, they actually remove a portion of the sound signal compared to the original audio. But can you hear it?

In this article, we will introduce the principles of music compression and discuss a question: Does music compression really affect the music you listen to?

The principle of musical compression.
Most of the digital audio we receive every day, whether played online or stored as a file, uses the principle of lossy compression. Lossy compression not only compresses the data, but also deletes the original data, and with lossy compression, some data is gone forever.

But keep in mind that this censored data is not randomly selected. Audio compression formats apply psychoacoustics to remove sounds that are beyond our hearing range and that we are not aware of.

audio compression – operation, equipment – can you really hear the difference in music quality? A brief discussion of the principle of audio compression
The human ear has a hearing range of about 20 Hz to 20 kHz, and sound signals beyond this range cannot be detected even if they are removed. And as we age, the range of hearing decreases. Therefore, it can be said that the sounds that everyone hears are not really absolutely the same, even if they come from the same sound source.

The audio below can help you find your hearing range, you can listen to it with headphones to see how far away you can hear the sound signal. Be careful to control the volume at any time during the listening process, otherwise it may damage your hearing.

Also, when high-frequency sounds and low-frequency sounds are present at the same time, high-frequency sounds will be more difficult to hear clearly. For example, the constant drumbeats in the music can cause you to ignore the slight differences between the melodies.

This phenomenon is called “shadowing” and is used in the principle of compression. If there are louder low-frequency sounds, it can mask the sonic loss of high-frequency sounds. High and low here are relative, so this principle can be applied globally. But sounds above 15 kHz are more susceptible to masking, so that’s also a prime issue for compression.

Although it is obvious that the sound signal removed by lossy compression should be mostly useless data, there are still people who believe that these “ambient sounds” being removed will affect the three-dimensionality of the sound and flatten it.

In general, the key to lossy compression is finding a balance between reducing size and preserving sound quality.

What video bitrate is appropriate for video? Part 2

Ultra Clear 720P>=1.5M (Standard 1280×720 resolution, minimum 960*540, this and higher resolutions are in MP4 era) [some websites have this minimum requirement to upload]

Blu-ray 1080P>=2.5M (1920 × 1080 standard resolution) [optimal 4-8M] [220M when the material is stored] [some websites have this higher requirement for uploading] (it is better to use 720P and 1080P when make videos )

2K=(2048×1080 resolution)
4K=(4096×2160 resolution) [Optimal 8-12M]
The most normative statement is:
reaching 720p resolution is the threshold for high definition signal sources, 720p is called the HD (high definition) standard;
up to 1080p resolution, known as the Full HD (full high definition) Blu-ray standard.
2K refers to 2048 × 1080, and the actual resolution of Quad HD (four times high definition, 2K can be called “four times ultra high definition”) has various specifications, and the ones listed above are just common specifications. ;

4K refers to 3840 × 2160, and the actual resolution of Quad Full HD (four times full HD, 4K is called “four times ultra full HD”) has various specifications, and the ones listed above are just common specifications. .
Blu-ray is the clearest and SD is the worst If your internet speed can’t bring you 1080p, then at least 720p won’t feel blurry to the naked eye.
P refers to the number of horizontal scan lines, and the higher the number, the higher the resolution of the image. The letter P stands for progressive scan.

1. What is the video bitrate?

Video bitrate is the number of bits of video data (color, brightness, and pixels) that are output per second. The unit generally used is kbps.

2. Recommended bitrate for video size and resolution

How much video bitrate is appropriate (above H.264 bitrate, 720P, 1080P output bitrate setting)

3. A set of formulas to set the bitrate is shared with you as follows:

How much video bitrate is appropriate (above H.264 bitrate, 720P, 1080P output bitrate setting)

Regarding the two items of “Use the highest rendering quality” and “Process with the maximum depth” when exporting from PR editing software, the effect of image quality is not obvious on the big screen and the output time can increase exponentially depending on the complexity of the track. I also encountered this problem in the morning. I have been there, it is a waste of time and the effect is average. So I usually don’t choose this.

What video bitrate is appropriate for video?

At present, 720p video recommended minimum bitrate is above, h.264 encoding 2M bitrate is adequate, 1080p is 4M enough
to get a high-quality video, convert it with different bitrates, and then compare the image quality.

The most commonly used are: h.264 encoding, 1080P, 2.5M bit rate or more.
Summary: [h.264 encoding, 2.5M bitrate (up to 4M), maximum 4M bitrate (add 2M to target), most platforms are Blu-ray. 】

1. If the bitrate is higher than the original video, it will not be a bit higher than the original video. When you move, you’ll pick a lower point to compress the file a bit.
2. 1080P 1M bitrate has distortion feeling to watch on computer, and 2M can’t see distortion, you can adjust the bitrate to 4M to get the best.
The following are the bitrate upload requirements for a platform:

How much video bitrate is appropriate (above H.264 bitrate, 720P, 1080P output bitrate setting)

***Normal 240p, 320p SD, 480p HD, 720p Ultra HD, 1080p Full HD (Blu-ray), 2K, 4k Ultra HD ***
Normal 240P (320×240 standard resolution, it was 3GP, this is basically nobody used)
SD 270P<0.8M (360×270 standard resolution, was 3GP, rarely used) [140M when storing 422 materials]

High definition 480P (360P)>=0.8M (standard resolution of 640 × 480, minimum 480 * 360, was 3GP) [480 re-advertising is called high definition, but the normative statement can only be regarded as standard definition]

What is the difference between 128k and 320k music? Part 2

Bit Rate

In simple terms, we can think of a sound wave as a curve.

Bit Rate

We know that the curve is made up of points, and the sampling rate is the number of points in the middle of the length per second (the horizontal axis in the figure above). Sampling precision is the number of points in the dynamic range (upper vertical axis). The finer the positioning of these two dimensions, the greater the true sound restoration and the better the sound quality. Of course, the larger the audio file will be. The customer mentioned by the above colleague said that the latest Hi-Res Audio format released by SONY is a 6-channel 192kHz/24-bit recorded audio file. The size of the lossless format, of course, will be more than 200 megabytes.

The sampling frequency is approximately the following depending on the type of use (k is the thousand-bit symbol, 1khz=1000hz):

8khz: used for phones etc, is enough to record human voices.

22.05khz: transmission use frequency.

44.1kb: Audio CD.

48khz: used in DVD and digital TV.

96khz-192khz: used for DVD-Audio, Blu-ray HD, etc.

The common range of sample precision is 8 bits to 32 bits, with 16 bits generally used on CD.

Having said that, my friends are starting to get confused. It’s not the bitrate that determines the sound quality, so why is everyone saying that 320kb sound quality is better than 128kb?

【Audio Compression】

Well, in fact, the bit rate should be said to be another dimension, it is a compression of audio files.

Nowadays, most of the audio formats we use regularly are based on the original “WAV” file of the audio CD (44.1khz sample rate, 16bit sample precision, 2ch). The original recorded sound data is stored in a matrix, which is in PCM format, while WAV format is an encoding format developed by Microsoft. Its function is to reproduce the data in PCM format through encoding.

Since the data in WAV basically completely restores the PCM data, MP3, AAC and other lossless encoding formats are basically recompressed based on the WAV files. Therefore, we can simply think that WAV is the original audio format and other audio formats are compressed formats.

When it comes to compression, storage and transmission are inseparable. The purpose of compression is to improve storage and transmission, so before we talk about compression, we need to understand the basic units of computers.

We all know that the computer is a binary number system, and the files stored by the computer are made up of two numbers, 0 and 1. Therefore, the computer’s transmission is based on each number, and each number is called 1 ” bit”. For example, for an audio piece, its basic data is “0,1,1,1,0,1, 1 ,0”, and when transmitting, these numbers are transmitted one by one. The sampling precision mentioned above is this unit.

The storage unit of the computer is “byte (Byte)”. In the computer, 1 byte consists of 8 bits, that is, 8b(bit)=1B(Byte). In computer parlance, data storage is expressed in decimal and data transmission is expressed in binary, so 1KB=1024B=1024×8b. This is also part of the reason why the hard drive capacity we see does not match the actual capacity.

Go back and talk about audio compression, the bitrate of the audio is actually the compression ratio. So the bitrate really just defines the size of the file, but because under normal conditions the larger the file, the less data you lose, so the sound quality is relatively higher. However, the bit rate itself does not directly affect the quality of the file. For example, if we take a 128kb file as the source file, even if it is converted to a 320kb file, the sound quality will not be better than 128kb. .

What is the difference between 128k and 320k music?

Bit rate comparision

192k is a turning point. Below 192K, the sound quality is relatively damaged, especially the high-frequency part above 16Khz will be cut off.

bitrate

In a nutshell, mp3s above 192k can no longer be listened to with CD sound quality on ordinary home devices, except for Golden Ears and Hifi devices. Of course, these data are not 100% reliable. There are always people on the internet sharing fake mp3 above 192K. In fact, they are converting low bitrate music to high bitrate through software, but the sound quality will not improve. be improved. Windows Media Player compresses it. The resulting mp3 is absolutely wonderful, no matter how high the compressed bitrate is, it will cut perfectly around 16K.

Some time ago, a colleague came across a very troubled client. The mess was said to have been caused by the client asking him to provide song files larger than 100MB-200MB in size. And my colleagues don’t know much about audio formats, so they started endlessly fumbling about FLAC, WAV and audio size. In the end, the colleague did not explain to the client what was going on.

After that, other things happened that made me feel that in the music industry there are too many practitioners around me who have an extremely poor understanding of music and even lack some basic knowledge related to music. I don’t even have the idea to understand, which makes me very sad. It seems that music has only one merchandise attribute, and our practitioners only need to organize the shelves, encode various merchandise, and use the big data of users’ purchase records to recommend merchandise to users, no matter why to users. they like this. features that these products have, and use cold data to provide users with various services.

Therefore, I think it is necessary to write something. I don’t expect practitioners to become people who really love music. I just hope that even if you still think of “her” as a commodity, you can first figure out what you’re selling. and what is..

PS: The content of the first lesson is about media files. Since the relevant content involves a lot of technical stuff, it seems a bit boring, but if you read it carefully, you will find that it is actually very easy to understand, but this basic knowledge can be very helpful.

Bit Rate, Sample Rate, Lossless, MP3, FLAC, APE, 320kb, 192kb, 128kb, 44.1khz, CBR, VBR. Does this bunch of various names make you both familiar and unknown?

The higher the bitrate, the better the sound quality. Lossless music is the highest sound quality, right? So, let’s start with the sound collection.

【Audio composition】

Nowadays, when we talk about audio, everything is digital audio. Digital audio consists of three parts: sample rate, sample precision, and number of sound channels.

Sample Rate: Both the sample rate, which refers to the number of samples per second when recording the sound, expressed in Hertz (Hz).

Sampling Precision: Refers to the dynamic range of the recorded sound, measured in bits (Bit).

What is bitrate in a video? | Improve QUALITY

Video Bitrate

Bitrate is, without a doubt, one of the main characteristics that determine the quality of a video.

I’m glad you made it this far to continue learning about video. If you still don’t know about video or editing, remember that you can learn the basics with my video courses (among others).

bit rate

What is video bitrate?

The bitrate or bit rate is the amount of information per second that the video has. It is measured in megabits per second and is directly proportional to its quality.

Generally, we tend to confuse the size of the video with its quality, thinking that 4k size is the video that offers the highest quality. However, this is flatly incorrect.

A high bitrate offers quality: Size VS Quality

Continuing with the topic I was talking about, it is very common for videos with 4k (at least those from professional cameras) have a higher bitrate. This is what makes the video look better quality, mainly, regardless of whether the video is larger or smaller.

How do you notice the difference between a high bitrate and a less high one?

The bitrate tends to show significant differences not simply when recording, but when editing. As I have already told you, with a bitrate of 10-15 mbps / s (at 25 fps) you have more than enough for most jobs. However, and if you are very exquisite, you may want to use a higher bitrate to have more margin for error when correcting and color grading. By the way, if you are interested in learning about color correction and color grading, check out my course.

With a higher bitrate you will notice the following differences than with a lower one:

Sharpness increase.

Superior ability to edit color without the appearance of banding or other unwanted disturbances.
Greater file weight (the higher the bitrate, the larger the file occupies).
However, this is not to say that it will be noticeable for most jobs. If you work in events, I assure you that you will not have a problem.

Bitrate types

If you are one of those who want to know more about everything you study, you can stay and delve deeper with me.

There are two types of bitrate, the constant bitrate and the variable bitrate.

CBR: this is the bitrate that always, whatever is on the plane, the exact same transfer rate will be used. The good news is that a video recorded at a specific size and bitrate will always occupy the same amount. However, it is not the most efficient.
VBR: this is the variable bitrate, and it consists in that a different bitrate will be applied depending on the information that is being recorded. Obviously, if you are recording a super dark black background, you don’t need as much information as if you are recording a scene with a very wide color gamut and a histogram that is padded from blacks to whites. In this case, the bit transfer rate will vary according to the needs of what is being recorded. Of course, we will try to keep an average (the chosen one).
How to know the bitrate of a video, both on Windows and Mac?
I am going to explain to you, both for Windows and Mac, how to find out the bitrate that a video clip has. This is very good because you can see that a video loses quality the more compressed it is. And one of the ways to compress it is by lowering the bitrate.

Windows: right-click on the clip> properties> details tab> video section> total bit rate
Mac: you open the video with the quicktime player> while it is playing press cmd + I> data rate
It is important that you pay attention to whether this data is in kbps or in mbps, because the first is 1000 times less than the second (so that you take it into account in case you want to compare looking from two different computers).

When to compress a video by lowering its bitrate?

There are times when you have already finished editing the video and obviously want to compress it. For this I recommend that you learn about codecs and video formats.

Obviously when you compress the video you will lose quality (the bitrate will decrease). This, a priori, should not be noticed in excess if it is a good compression, since you will no longer edit that video.

Of course I am talking about compressing the final file, never the raw ones used to create the video. You always have to lower the bitrate or compress the final file (in case you want to compress) to avoid losing image quality.

Bit rate factor – how does it contribute to video quality?

Bit rate is a very important factor for good video quality. In the camera settings we now find more numbers next to the resolution. The one behind Mbps interests us more now. This is the information about the bit rate.

Video Bit Rate

This number indicates how much information is processed in the video per second. The higher this rate, the better the quality. Of course, the final file the camera produces will increase with the bit rate.

In this way, you can also calculate how much information is available for each frame, that is, each individual image. Suppose you are shooting with 25p and you have an available bit rate of 100 Mbps. That would mean that each image carries 4 Mbps of information. If you shot 50p at the same bit rate, it would only be 2 Mbps per image! The result would be a loss of image quality.

Color depth factor – How does it contribute to video quality?

Bottom line: color depth is the maximum number of different color shades that a camera can display. Of course, the same applies to monitors, printers, televisions, etc.

The colors in general in our image consist of additive combinations of the three basic colors red, blue and green.

The gradations in each tone are again given in bits. Videos consist of pixels, that is, square image points. Each of these pixels carries with it certain color information. The higher the bit rate of the color depth, the more different shades of color each pixel can have.

The total number of color tones is calculated by adding 2 to the power of the number of bits; for an 8-bit camera, for example, that would be 256 colors per base color. Now you have to multiply the other two basic colors again to determine the total number of possible color tones. This means that an 8-bit sensor can display 28 * 28 * 28 colors. That’s over 16 million shades!

Thus, a 10-bit camera can display more than 1 billion colors, a 12-bit camera 68 billion colors, and a 14-bit camera even more than 4 billion color combinations.

Summary:

Many users are not fully aware of how bit rate influences video quality.
People usually see numbers next to the name of the format (Mp4, MOV, AVI) and do not know exactly what it is.

Here we have tried to explain that the higher the bit rate, the more colors.
Perhaps you think that speaking of so many millions of colors, and it is enough, but it is not like that. Actually reality has a practically infinite number of color gamut, so to capture it with realism, it is necessary to have as many colors as possible.