If you’ve watched any streaming video over the past two decades, chances are it was delivered from the H.264/AVC codec. H.264, also known as advanced video coding (AVC), has long been the dominant format for online video thanks to its high-quality results and efficient use of bandwidth.
Other video codecs like H.265, VP9, and AV1 have recently gained popularity, meaning that using AVC isn’t an automatic decision. In this article, we’ll explore why video compression and encoding are important, what AVC is, how the AVC codec works, and how AVC compares to other formats.
What’s video encoding?
In order to understand H.264 encoding, it’s important to have a firm understanding of video encoding first. Encoding is a way of compressing large video files so that they play smoothly without using too much bandwidth. Video files are often very large, so uploading them to the web directly from your camera means they’ll likely stutter or display at a lower resolution than you filmed.
The word “codec” refers to a kind of technology that encodes and decodes videos. It performs both of the encoding/decoding process’s two main stages:
- An encoder compresses the video for efficient storage.
- A decoder converts the compressed file back to a playable video format.
There are various methods used to complete this process. AVC has been the standard video codec for two decades and is still the most widely used and supported. H.265/HEVC is a newer format that’s great for high-quality HDR video, and AV1 is a powerful open-source alternative.
The main benefits of using video codecs include:
- Lower file size from video compression
- File compatibility with a wide range of devices
- Faster playback for users
- Support for a range of video file formats
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H.264 codec explained: What it is and why it’s important
H.264/AVC is the most commonly used video codec for online streaming. It’s also used in digital TV broadcasting and videoconferencing, among other applications. It’s a “lossy” form of video compression, meaning that non-critical information is stripped during the video encoding process to keep file sizes as small as possible.
The H.264/AVC codec supports common video file formats, such as .MP4 and .MOV. It’s also compatible with various streaming protocols, including dynamic adaptive streaming, which supports smooth playback by adjusting the bitrate depending on available bandwidth.
Some of the biggest perks of using H.264 encoding are:
- Efficient use of bandwidth
- Needs less storage space, reducing hosting costs
- High-quality video with smooth playback
- Compatibility with all modern devices and platforms
- Fast encoding and decoding
How does H.264/AVC work?
The AVC codec follows a standard encoding and decoding process for each video:
- Prediction: Predicts motion between frames and removes redundant information to save space.
- Transformation: Transforms the data, reducing file size along the way.
- Video encoding: Encodes the video in a smaller format for storage and transmission.
- Video decoding: Decodes the video so that it’s ready for playback.
- Inverse transformation: Reverses the original transformation.
- Reconstruction: Rebuilds the original frames of the video.
The AVC codec has become an industry standard — support is built into operating systems like Windows and macOS, as well as all modern browsers. Streaming platforms like Vimeo use it behind the scenes, and popular video-editing apps like Adobe Premiere Pro and DaVinci Resolve allow you to export videos in the H.264 codec.
H.264 vs. HEVC, VP9, and AV1: 3 key differences
H.264 may be the most common, but it isn’t the only codec available. Let’s examine the biggest differences between H.264 and other major codecs.
Performance
Here are the main differences in speed, compression ratios, and visual quality across codecs.
Codec | Speed | Compression | Quality |
H.264 | Fastest encoding and decoding | Good video compression, with significant file-size reductions | Good to very good quality for standard video streaming, often slightly reduced during compression |
HEVC | Slower than H.264 due to higher complexity | Around 35% bitrate reduction while delivering the same quality as H.264 | Excellent quality, better for handling 4K and 8K resolutions |
VP9 | Slower than H.264, similar speed to HEVC | Around 35% bitrate reduction while delivering the same quality as H.264 | Excellent for high-resolution video |
AV1 | Slowest of all | Around 50% more compression than H.264 | The best quality, especially for 4K and 8K video |
Compatibility
Here’s how each codec performs across devices and browsers.
Codec | Devices | Browsers |
H.264 | Universal support | Universal support |
HEVC | Broad support on modern devices | Very broad support, Opera preferred |
VP9 | Broad support on modern devices | Very broad support, Chrome preferred |
AV1 | Limited support on older devices | Newer technology means somewhat limited support — Firefox, Chrome, Edge, Opera, and Safari (update 16+) |
Royalties
While most small content creators don’t need to worry about royalties on codecs, larger media enterprises may need to pay royalties for using codecs.
Here’s when it’s necessary to pay royalties after making money on videos that use H.264, HEVC, VP9, and AV1 codecs.
Codec | Streaming | Editing | Mobile playback |
H.264 | Royalties for paid services only | Royalties for very large volumes only | Royalties paid by manufacturers |
HEVC | Royalties for paid services only | Royalties for very large volumes only | Royalties paid by manufacturers |
VP9 | Open-source and royalty-free, but subject to patent claims from third parties | Open-source and royalty-free, but subject to patent claims from third parties | Open-source and royalty-free, but subject to patent claims from third parties |
AV1 | Open-source and royalty-free, but subject to patent claims from third parties | Open-source and royalty-free, but subject to patent claims from third parties | Open-source and royalty-free, but subject to patent claims from third parties |
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What you need to know to produce H.264
The H.264 video codec contains a range of different sliders and production options, but the automatic preset options work well in most cases. The easiest way to produce H.264 video is simply to export from your favorite video editing app using the standard H.264 preset.
However, if you do find yourself needing to change something, here are the main areas you can change:
- Profiles: These are the tools used to technically encode a video file. Choose between baseline (BP), main (MP), and high (HiP). Baseline (fewer tools, lower quality) is best for maximum compatibility with older devices, but the other profiles offer higher quality and are more widely supported on modern devices.
- Levels: Less relevant now than when AVC first debuted, levels are additional coding tools that can determine things like video bitrate. Choose a lower level to support older devices (especially mobile ones), but modern devices can handle high levels.
- Quality: When creating H.264 videos, you can increase the quality preset to create higher-quality video, but keep in mind that higher qualities may affect playback speed.
Because the H.264 codec has been the standard for video encoding and compression for so long, it comes pre-installed on most computer systems. If you do need to install it manually, you can download the H.264 codec from a trusted source like the K-Lite Codec Pack. Only use reputable installers — unaffiliated sources can introduce security risks.
Streamline your video compression process with Vimeo
Choosing the right codec is important for video quality and compatibility. H.264 is a widely supported standard that boasts efficient compression rates and strong performance. Newer formats are great for very high-quality video, but keep in mind the tradeoff between quality and speed. The H.264/AVC codec is a good all-round option to pick.
If you want to efficiently stream H.264 content, Vimeo is an excellent option. It supports H.264 and other codecs, and it provides high-quality streaming with efficient video compression. Try Vimeo’s video compression software to easily shrink most video formats.
