Video compression
Video compression is a fundamental part of digital video technology that makes streaming and storing videos much easier. A compressed video has a smaller file size, and sending videos over networks is more efficient with video compression.
What is video compression?
Video compression compacts the data used to represent a digital video’s content without reducing its visual quality. This process is crucial for managing and transferring large video files over the internet and other networks.
Without video compression, sending video data would require significant bandwidth and storage space. High-definition (HD) video files can be extremely large and difficult to store without compressing them.
The importance of video compression
Many sites and services rely on video compression to deliver online content successfully. Video compression makes it possible to stream videos on platforms like YouTube and Netflix without constant buffering or taking up all the storage space on your device.
Video compression is essential for live streaming as well. It reduces the latency between the video capture and display, ensuring a seamless viewing experience. Without effective compression, live streaming would be nearly impossible due to the massive amount of data involved.
How video compression works
Temporal compression
Temporal compression, also known as interframe compression, is one of the primary methods used in video compression. This technique reduces redundancy between consecutive frames in a video sequence. In other words, temporal compression only encodes the differences between frames rather than encoding each frame individually.
For instance, in a video of a stationary room with a moving fan, the only change between frames is the fan's position. Temporal compression would only encode the fan's movement, significantly reducing the amount of data needed to represent the video.
Spatial compression
Spatial compression, or intraframe compression, is another key method in video compression. This technique decreases redundancy within each individual frame. It works by grouping similar or identical pixels together and encoding them as a single entity.
For example, in a frame depicting a vast blue ocean, many pixels will have the same or similar color values. Spatial compression would group these similar pixels together, reducing the data required to represent the image.
Common video compression standards
There are several video compression standards, also known as codecs, that dictate how video data should be compressed and decompressed. These standards ensure compatibility between different devices and platforms.
The most common video compression standards include H.264 (also known as AVC), H.265 (also known as HEVC), and VP9. These codecs are widely used due to their efficiency and compatibility with a range of devices and platforms.
Choosing the right video compression
Choosing the right video compression depends on factors like the intended use of the video, the available storage and bandwidth, and the required video quality. For instance, if storage space and bandwidth are limited, a more aggressive compression may be necessary. However, this could result in a lower video quality.
On the other hand, less video compression is ideal if maintaining high video quality is a priority. This comes at the cost of using more storage space and bandwidth. Therefore, it's crucial to strike a balance between these factors when choosing a video compression method.