Video formats CODECS Containers

This article will mainly discuss these three terms - Video formats, Video containers, and Video codecs. And how these terms are inter-connected.

Since digital video came into existence in 1988, a myriad of video formats, containers, and codecs have been developed with the aim to provide advancements in quality, file size, and playback compatibility.

Video content is currently booming, with the online audience streaming video on varying devices and platforms every single day.

However, there is still rampant confusion among people with regards to video formats, video containers, and video codecs.

Whether you are looking to convert video files for playback on different browsers or devices, or you are a video distributor looking to build your knowledge base, here's learning about the basics of video formats, codecs, and containers.

Let's first understand what a video format is.

Video Formats

In practice, file extensions are used synonymously with video formats. For instance, MP4 in "Videofile.mp4''. However, this isn’t entirely correct.

Most file formats comprise a combination of files, folders, and playlists (TS, M3U8, etc)—which are necessary to play a video properly.

It is important to understand that Video Formats are different from Video File formats/File extensions, i.e: MOV (QuickTime Movie), WMV (Windows Media Viewer), AVI (Audio Video Interleave), MP4 (MPEG-4 Part 14), etc.

Some of the most popular video streaming formats today are MP4, MPEG-DASH, and HLS.

Before we dive deep into video formats, let's understand what containers and codecs are.

Video Containers

File extensions for video files actually represent Containers—which contain the entire gamut of files required to play a video. This information includes the metadata and video & audio stream.

The video stream is to instruct the video player as to what should be displayed on the screen, whereas—

The audio stream ensures the right sound is played for the specific video.

The metadata, or “data about data”, comprises a slew of information on the video file, for instance, its resolution, date of creation or modification, bit-rate type, subtitles, and so on.

The most important piece of information the metadata carries is however, the codec.

Video Codecs

As is evident, codec is a combination word resulting from coder and decoder. Codecs encode video or audio streams to create more manageable and streamable sizes of video and audio files.

The video player or platform on which the video is played then decodes it depending on the information contained in that codec and plays back the video while maintaining the quality of the original.

Similar to containers, there are a slew of different codecs in existence today to be used with different audio and video files—some of which include H.264, H.265, VP9, AAC, MP3, and so on.

Companies like Gumlet help you convert video files to all the popular codecs.

Here's covering the most commonly used video and audio codecs.

Most Important Video codecs

H.264 (AVC)

H.264 or AVC is without a doubt the most popularly used video codec.

Better bitrate than H263: It delivers a significantly better bitrate for the same file size when compared to its predecessors.

Widely supported: H.264 is the most widely supported codec with users hardly ever running into any support issues.

H.265

H.264's successor is H.265—also referred to as HEVC which stands for High Efficiency Video Coding.

Half the bitrate of H.264: Its compression rate is almost twice as much as H.264. This essentially implies that if you encode a file using HEVC, it will be roughly 50% smaller in size as compared to a file encoded in AVC. This is an excellent advantage if you are streaming resolutions above 2k.

Requires triple the resources: The down side of HEVC is that it’s much harder to encode and demands almost triple the resources for video preparation.

Proprietary codec: It should be noted that H.265 is not a royalty-free codec like its predecessor H264.

Not widely supported: Although HEVC adoption has been significant, it is yet to reach the level of popularity its predecessor enjoyed. Apple recently announced that it would provide support for HEVC video, however considering the new codecs emerging (like VP9), only time will tell if HEVC will prove to be a dominant codec in the coming years.

VP9

Better bitrate than VP8: VP9 is Google's royalty-free creation which is open source and was initially used by YouTube—since it effectively decreased bitrate by at least 50% more than VP8.

Suitable for high resolutions and live streaming: Like H.265, VP9 works wonderfully for high resolutions and live streaming, however, it is relatively more difficult to decode and is also not as widely supported as H.264 is.

VP9 vs HEVC

It should be noted though that the technology that backs VP9 is designed to produce more stable and seamless streams, whereas H.265 is concerned with delivering a better image quality.

AV1

A new royalty-free codec, AV1, was released in 2018 to facilitate video transmissions over the Internet and compete with its predecessor HEVC/H.265.

While AV1 is poised to ensure massive data efficiency savings while maintaining video quality, it is yet to undergo widespread adoption.

Not to mention, it's significantly more complicated and time-consuming to encode videos in AV1.

https://www.gumlet.com/learn/understanding-video-formats-codecs-containers/