What Is Bitrate? Best Audio and Video Bitrate Settings

If you have ever watched a video on YouTube or played music in a web browser, you have probably seen options like 128 kbps or 320 kbps or higher in the video or music player. Those figures are the Bitrate. In this article, let's look at MONA Media look at what bitrate is and how it affects audio, images and video.

What is bitrate?

By technical definition, bitrate is a word made from bit (a unit of data) and rate. It describes the amount of data transmitted over a given period of time.

Bitrate can be measured in several units. For video on YouTube, for example, the unit is kpbs (kilobit/s) and another unit commonly used is mpbs ( Megabite/s). Whichever unit you use, the quality of audio and images always rises with the bitrate. In other words, the higher the bitrate, the better the audio and image quality.

How is the term bitrate defined in different fields?

Audio

In audio, bitrate means kilobits per second. For example, a song you buy on iTunes at 256 kilobits per second stores 256 kilobits of data for every second of the song. The higher a track's bitrate, the more space it takes on your computer.

In practice, a real audio CD takes up a lot of space. That is why bitrate became popular for compressing those files so they fit better on a hard drive (or an iPod, Dropbox, or anything else). It is also where the debates about "lossless” and “lossy" audio began. There are now two types of bitrate encoding: CBR (Constant Bit Rate) and VBR (Variable Bit Rate).

Some audio bitrates used in the MP3 format include:

• 32 kbit/s – A very low audio bitrate, acceptable only for speech.
• 96 kbit/s – Commonly used for speech, streaming or low-quality broadcast.
• 128 or 160 kbit/s – Mid-range audio bitrate quality.
• 192 kbit/s – Audio bitrate with average quality.
• 256 kbit/s – A high-quality bitrate that is used quite widely.
• 320 kbit/s – The highest audio bitrate supported by the MP3 standard.

Video

In video, bitrate measures the amount of data used to encode one second of video. That is why bitrate is always measured per second, as in megabits per second (mbps), or kilobits per second (kbps),…

A higher video bitrate improves video quality, at the cost of a bigger file. Video bitrate rises along with image resolution: the higher the video resolution, the higher your bitrate needs to be.

Put simply, if you have a video bitrate of 5Mb/s and a resolution of 1920 x 1080 the image will be compressed less than with a resolution of 5Mb/s and 4K. Video with high resolution and a high frame rate needs a higher bitrate to hold its quality.

With all this in mind, it is clear why Full HD at 5 Mb/s became the standard for internet video. It shows the resolution steadily, it lets people with slow connections watch, and it keeps server and bandwidth costs to a minimum.

Here are some commonly used video bitrates today:

• 16 kbit/s: The lowest-quality bitrate, usually found on video phones.
• 128-384 kbit/s: The quality of business video conferencing that uses video compression
• 400 kbit/s: Quality equal to 240p video on YouTube
• 750 kbit/s: Quality equal to 360p video on YouTube.
• 1 Mkbit/s: Quality equal to 480p video on YouTube.
• 1.5 Mkbit/s: The quality of VCD.
• 2.5 Mkbit/s: Equal to the quality of 720p video on YouTube.
• 3.8 Mkbit/s: Quality equal to 720p video (60 fps mode).
• 4.5 Mbit/s: Quality equal to 1080p YouTube video (using H.264).
• 6.8 Mbit/s: Quality equal to 1080p YouTube video (60 fps mode).
• 9.8 Mbit/s: The quality of HD DVD (MPEG2 compression).

Images

For images, bitrate is the total amount of data a camera records each second. Bitrate, image quality and storage size rise together. A higher bitrate gives better image quality, but it also takes more storage. Can you improve image quality just by raising the bitrate? The answer is no. Remember that if the original file is already low quality, no amount of extra bitrate will rescue it.

In hard drives and SSDs

Bitrate determines the read and write speed of drives. So it has a big effect on how fast files, programs and heavy games open and save. Ordinary hard drives all have similar read/write speeds, so the difference comes from the spin speed in RPM: 5.400, 7.200 hay 10.000. An SSD, however, does not rely on RPM to set read/write speed. It uses a controller chip for those tasks.

A mid-range SSD reads at about 500 Mbps and writes at around 200 Mbps. So a mid-range SSD that costs about 2 million VND will typically read and write at a minimum of 200 Mbps and a maximum of 500 Mbps. Use these figures as a guide when you shop for a mid-range SSD.

The relationship between bitrate and resolution in images and video

Bitrate and resolution are two completely different concepts. You have probably seen many camera models with the same Full HD resolution, or that support Full HD video. Yet the exported files come out at different image quality.

For example, a Panasonic model shoots Full HD at a bitrate of 15Mbps, while a Sony model also shoots Full HD but at a bitrate of up to 24Mbps. If everything else is equal, the Sony's image quality will clearly be better than the Panasonic's.

So when you shop, do not look only at resolution. Look at the device's bitrate too, and pick devices with the highest bitrate you can get.

What bitrate should you set when livestreaming on YouTube?

Whether you have many viewers or few, YouTube automatically transcodes your stream. Put simply, viewers can pick any quality from 360p up to the highest quality you are broadcasting. So when you livestream on YouTube, broadcast at the highest quality you can, and viewers can choose the quality they want.

Here are some bitrates recommended by YouTube (kbps)

• 1080p 60FPS – 4.500-9.000Kbps
• 1080p 30FPS – 3.000-6.000Kbps
• 720p 60FPS – 2.250-6.000Kbps
• 720p 30FPS – 1.500-4.000Kbps
• 480p 60FPS – 500-2.000Kbps

While livestreaming on YouTube you may also run into problems such as lag, dropped frames or stuttering. This can happen when your connection speed does not match the video encoding. When it does, cut back on the following:

• Resolution.
• Lower the video resolution.
• Frame rate

What bitrate looks best?

In each real case there is a bitrate that fits:

• For audio files: The most common audio bitrate today is 320kpbs, and if you want to listen at higher quality, you can choose Lossless.
• For video: 720p is the minimum for good image quality. You can also go up to 1080p or 4K if your device's hardware and screen can display it. The bitrate for quay TVC depends on how you use it, but typically runs from Full HD up to 8K at the highest resolution.
• For image files: The right bitrate depends on the size of each image. For example, an image of 3120×3027 comes to 6.75MB, 720×960 (43.0 KB), 2048×2048 (983 KB), 5472×3648 (5.26 MB), and so on.

That is a detailed answer to the question That covers what bitrate is, and why bitrate matters for audio, images and video. We hope this information MONA helps you choose the right bitrate and improve the quality of your video, audio and images shoot a corporate profileand the products you use to promote your business. Good luck putting it to work.

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