H.264 File: How to Open and Play H264 File Format on PC and Mac? 

If you’ve watched or recorded a video, you’ve likely encountered an H.264 file. DVDs and broadcast TV use the H.264 file format to compress audiovisual footage. That’s partially due to how easy it is to open this type of file.

To understand an H.264 file, let’s first consider some of its other names. H.264 is also known as “codec H.264” and MPEG-4 Part 10, Advanced Video Coding. 

What does this tell us? First, that H.264 is part of the international standards for compressing and storing audiovisual data. These standards are collectively known as MPEG-4. Codec, meanwhile, is short for coder-decoder. Therefore, H.264 is a standard for encoding and decoding audiovisual footage. 

There are different types of codecs. Some are known as lossy codecs. As the name suggests, these impact the quality of the audiovisual data being encoded. MP3 is perhaps the most famous example of a lossy codec. Other codecs, including H.264, are known as lossless. These codecs do not affect the quality of the data being processed. However, they do still compress data. Lossless codecs like H.264 are popular for this very reason. You get a smaller file size, which helps save storage space and reduces the time required for uploading and downloading, while not having to compromise on media quality.

H.264 uses a number of clever techniques to achieve this. One method is called inter-frame compression. We might conceive of video footage visually. However, that’s not how it is stored. Like all information stored digitally, each frame of footage is represented by binary – sequences of ones and zeroes. Most video footage is shot at 24 frames per second. Therefore, each frame is usually quite similar to the one immediately before and after. In turn, the data representing each frame often shares many similarities. Identifying these similarities is the essence of inter-frame compression. It allows for the elimination of repeated data. As an example, imagine taking the first frame of a video and recording all of the data representing that frame. For the next frame, only save the data that is different from the keyframe. Do the same for all subsequent frames. The saved file can be decoded by using the same process, just in reverse.

Another, even more complex technique used in H.264 is called predictive coding. Put simply, predictive coding involves analyzing the data representing a frame, or a group of frames, and using it to generate an estimate for the data that will be needed to represent subsequent frames. This allows H.264 to further reduce the total amount of data required to encode an audiovisual file.

H.264 uses these and other advanced techniques to encode and compress audiovisual media efficiently and without loss in quality. These features have made it a very popular video format, and one that is therefore widely adopted, which in turn has given it the advantage of being widely supported – compatible with most platforms and devices.

If H.264 is so ubiquitous, you might be wondering why it’s not a more common file extension. Technically, H.264 is a codec, not a file type. Therefore, files encoded with H.264 are often labeled with the .mp4 or even .avi extension.

Learning how to play H.264 files is easy thanks to the popularity of the technology. There are plenty of free tools available that can open, play, and even convert H.264 files. One excellent H.264 player is VLC.

VLC was created and is maintained by VideoLAN, a nonprofit. It is not just free but open-source, which means that its code is available for you to examine. It’s available on most platforms, including Windows, macOS, Linux, Android, and iOS, and is relatively lightweight, meaning you won’t need much storage space to install it. Once you’ve done that, follow these instructions to open H.264 files:

1. In VLC, go to the preferences. On a Windows PC, you can access this via the Tools menu, or by using the shortcut Control + P. On a Mac, click on the VLC menu, then select Preferences, or use the shortcut Command + , (comma). 
2. Ensure you are viewing all possible settings, either by selecting the appropriate checkbox in the preferences window or by entering Advanced Preferences.
3. Go to Input / Codecs, then Demuxers. As VLC should explain, demuxers are tools that separate audio and video. You should see a drop-down menu labeled Demux module.
4.  In the drop-down menu, select H264 video demuxer. 
5. Click Save. 

By selecting the H264 video demuxer, you should have ensured that VLC will be able to open H.264 files. You can play these files by clicking File and Open in VLC, then locating and opening the relevant file. It should automatically start playing. Alternatively, locate the file you wish to open, and then right-click on it. Select Open with, and then select VLC. If you plan on opening these files with VLC often, then you can save time by making VLC the default application for opening files.

If you have videos encoded with the H.264 format and want to convert them to something else – or need to convert a more obscure format to the widely accepted H.264 standard – then Movavi Video Converter is a great option. It supports the H.264 compression standard and can convert between practically any format in just a couple clicks, from MP4 to MOV to AVI and beyond. Movavi Video Converter also comes with several powerful tools, including a compressor, subtitler, and AI upscaler, which can help you take your videos to the next level without needing to use additional applications.