Video formats: What you need to know
Currently there is a wide variety of video formats available to store multimedia content in a file and play it on our devices. Depending on this format (and other multiple factors) the video will basically have a different video quality and a more or less small file size.
However, if you are not very up to date on these issues, you may get lost since we enter concepts such as formats, codecs, containers or among related terminology such as AVI, MP3, MP4, DIVX, XVID, OGG, MKV, OGG , FLV, MPG, VP9, HEVC, AAC, H.264, AVC and a long etcetera.
Outline of a container format
To begin, we must be clear about the difference between these two concepts that are often very confused: the container format and the video codec. The first of them is really the file format, the one that surrounds everything (audio, video, etc …), while the second is the format directly related to the video part.
But let’s look at a description of each concept to make it even clearer:
Container format: A video file usually has a certain container format, such as AVI, MP4 or MKV, for example. As its name suggests, a file in this format contains several elements inside it (generally and at least, video and audio). However, it is possible that it only includes one of them, or for example multiple audio channels (to have several languages from the same file). Some container formats also allow you to include other elements such as images or integrated subtitles, without the need for external files.
Video codec: It is often confused with the video format, but it is not really the same, since it is related to the content video and not the container format. It is not a mandatory element, since if a codec is not specified, the video is RAW (uncompressed) content, taking up a lot of space (for example, 200MB about 10sec). For that reason, a codec is generally chosen to compress the video. Depending on the choice of the codec, better or worse quality will be achieved, and in turn, larger or smaller size.
Video specification: Each video codec is usually based on a specific video specification (H.262, H.263, H.264 …), which is nothing more than a set of rules that define how it should behave. This can serve as an orientation to know if one codec is more or less recent than another.
Audio codec: In the same way that happens with video, we have possible audio channels included in the file. They are also usually compressed with a certain codec to save space: MP3, OGG Vorbis, WMA …
