In the same way that you can save a still image as a JPEG, a HEIF file or a RAW file, there are also multiple file format options for storing video files. Things are a little more complicated with video formats, however, because there are more variables. Here we'll explain the most common video formats and help you make sense of the related menu options available.
Unlike image files, video files have multiple components, including a codec and a container. The codec is a software layer for encoding and decoding the video data at recording and playback. This is the video counterpart of the compression algorithms used for image files. The majority of codecs are described as "lossy" because when the data is compressed to save space, some of the original video data is discarded in the process.
The container or wrapper bundles the video's picture and audio data together, along with subtitles and other metadata. The container behaves like a single file, and when people talk about video file formats this usually means container file formats, such as MP4 or XF-AVC. However, when you select a video format in the menu on your camera, you usually choose a container plus codec combination, such as MP4 (HEVC) or MP4 (H.264), not just MP4.
It is possible to save RAW video, and some cameras do offer this option, but RAW video files are huge – if you're filming at 25 frames per second, this means saving 25 RAW files for every second of video, which will really test your kit's data bandwidth and card write speeds, as well as filling up its storage space very quickly.
For this reason, just as with image files, various methods are used to reduce the size of video files and make them easier to handle. This includes different compression methods and colour sampling systems. Usually, you can choose between compression methods in your camera's menu under Movie recording size, but the colour sampling is determined by the file format settings. So let's look at the common video formats available, and then consider other settings that affect video file size.