Bitrate: Meaning, Usage, Importance
Every frame of any video you watch is full of information, and a high bitrate ensures that the end result is also high in clarity. Many factors go into a video’s quality, but these usually pivot around the bitrate. Want to make sure you have the best display? Understanding bitrate and its importance could help you find a video system that suits your requirements. Read on to learn more about how this affects your videos.
What is bitrate: definition
Bitrate is effectively the ‘depth’ of data within a video or audio file. It represents the amount of information this file transfers each second, mainly in kilobits (kbps) or megabits (Mbps). In video systems, bitrate specifically refers to the data that is necessary to fully represent a file’s content.
Generally speaking, higher bitrates result in better video quality, but usually require an increase in processing power. This also often leads to much greater file sizes. The same is true for audio files; and most online media streaming services aim for a balance of both clarity and bandwidth.
Why and how does bitrate matter?
Bitrate directly affects the quality of a file, with higher bitrates often meaning a frame (or second of audio) contains more data. For videos in particular, this results in higher detail and smoother motion. If watching a movie with fast, intense sequences, for example, a high bitrate is vital.
Bitrate is critical for reasons beyond sheer quality; especially in terms of both storage space and bandwidth. More data means a higher file size, so only make use of high bitrates if you have the right hardware. Similarly, devices may struggle to load the video without enough bandwidth.
Whether you are creating or viewing a video, you have to be mindful of bitrate. In the case of the former, others may find it difficult to watch if you prioritize a high-bitrate experience. If you view a high-bitrate video without the right hardware, it could suffer frame drops and screen tears.
Most video players allow you to adjust quality, often by changing the resolution. As this ‘shrinks’ the image, the video contains (and has to transfer) less data and can run more smoothly. Your hardware’s processor, GPU, and network connectivity will also affect the video’s performance.
How does bitrate affect video quality?
With the right hardware, you can play high-bitrate videos in their original, intended quality. There are still a number of factors that affect the level of detail, however. This includes issues that can emerge when playing low-bitrate videos.
With this in mind, here are the main ways that bitrate affects your video:
1. Quality
Higher bitrates again lead to better video quality by carrying more data. This can bring out more vivid and accurate colors, finer textures, and more details. In contrast, low bitrates may result in visual artifacts, including pixelated ‘fuzziness’.
2. File size
Every kilobit of data in a video has information on textures, colors, and other visual elements. As this data needs more space, high-bitrate videos are often larger. Compressing a video to reduce file size typically involves lowering the bitrate.
3. Resolution
The resolution you select will also be a factor in the video’s quality, affecting how much data you receive from the video and audio. 4K resolution videos, with around 4,000 pixels, usually have a very high bitrate (44–85 Mbps) to maintain this quality.
4. Frame rate
A video’s frame rate is how many individual images it has for each second of footage. 24 frames per second is the standard for most digital media, though some videos are 60 FPS and naturally require a higher bitrate to compensate.
5. Complexity
Scenes with a high level of detail or motion generally require higher bitrates to display in full with no errors. Low-bitrate videos will struggle to render complicated visual elements such as confetti and even grass, creating blurry artifacts.
6. Display size
Larger screens generally have higher resolutions and pixel densities, and require higher bitrates in order to maintain their sharpness. A video which renders well on a 15-inch monitor may show more flaws on a 30-inch screen, for example.
7. Compression
Depending on a video’s compression method, you can tip the balance of size and quality in your favor. HEVC (high efficiency video coding) compression, for example, keeps a high bitrate with a smaller file, though this can require stronger hardware.
How can we measure video bitrate?
Bitrate measurements can range from roughly 10 kilobits per second for very low-quality files to 120–240 megabits per second for 8K resolution files. Knowing a video’s bitrate can highlight the best way to play it, up to and including the most appropriate resolution that fits your hardware.
There are several ways to check the bitrate of a video. Many of these files store this information in their metadata, which you can easily check by inspecting the video’s properties. The media player you use might provide real-time insight into the video’s bitrate, codec, and frame rate.
You can also make use of various online tools that manually analyze individual files to determine their bitrate. If you are hoping to render a video, an online bitrate calculator can help you identify the right target bitrate. Encoding software should similarly offer details on your video’s bitrate.
What are the best video bitrates?
The best bitrate for a video primarily depends upon its resolution and frame rate. A standard definition (480p) video bitrate is around 2.5 megabits per second. According to YouTube, HD formats such as 720p and 1080p need 5–8 Mbps, or more if the videos use high dynamic range.
Videos with faster frame rates also have a higher recommended bitrate. For example, a video in 1080p resolution will likely require around 12 Mbps if it exceeds 30 FPS. These are only general guidelines, however; as compression and complexity again play a role in the necessary bitrate.
Online video players typically use adaptive bitrate streaming, which adjusts the bitrate of a video in response to the user’s network settings. This balance ensures you do not encounter too much lag while watching. It also automatically raises the quality if your device can accommodate this.
Ultimately, the best bitrate is one that fits the video’s target audience - especially if there are no options to change the quality. For example, sharing a high-bitrate video without also providing a low-bitrate alternative can stop people with certain hardware or devices from accessing the file.
How does AV technology use bitrate?
Audiovisual technology uses bitrate when streaming (or encoding) content to determine the file’s quality and size. When watching a video, this again makes use of adaptive bitrate streaming to deliver a balanced experience. In contrast, encoding utilizes compression algorithms to reduce the data, with some methods maintaining the full quality.
Software such as media players should also be compatible with the video’s codec. For example, only some of these tools are able to play high-quality HEVC files without severe stuttering. Your hardware is an even bigger consideration; you need a processor and GPU which can render the video’s full data without issues.
Final thoughts
Bitrate is a vital part of any video file, offline or online. This number can be the main factor which affects a video’s quality - though many people are unaware of its importance. As AV technology continues to evolve, we can expect higher bitrate standards over the coming decades.
Whether you are watching a video at home to relax or hosting a virtual meeting with dozens of live camera feeds, a good bitrate ensures a smooth, high-quality experience. When working with audiovisual formats in any form, the file’s bitrate could inform every decision you make.
Latest Blog
