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A video coding format [a] (or sometimes video compression format) is a content representation format of digital video content, such as in a data file or bitstream. It typically uses a standardized video compression algorithm, most commonly based on discrete cosine transform (DCT) coding and motion compensation .
For real-time and non-buffered video streaming when the available bandwidth is fixed – e.g., in videoconferencing delivered on channels of fixed bandwidth – a constant bitrate (CBR) must be used. CBR is commonly used for videoconferences, satellite and cable broadcasting. VBR is commonly used for video CD/DVD creation and video in programs.
They may recompress the video to another format in a process called transcoding, or may simply change the container format without changing the video format. The disadvantages of transcoding are that there is quality loss when transcoding between lossy compression formats, and that the process is highly CPU -intensive.
MPEG-1 is a standard for lossy compression of video and audio.It is designed to compress VHS-quality raw digital video and CD audio down to about 1.5 Mbit/s (26:1 and 6:1 compression ratios respectively) [2] without excessive quality loss, making video CDs, digital cable/satellite TV and digital audio broadcasting (DAB) practical.
A short video explaining the concept of video codecs. A video codec is software or hardware that compresses and decompresses digital video.In the context of video compression, codec is a portmanteau of encoder and decoder, while a device that only compresses is typically called an encoder, and one that only decompresses is a decoder.
The compression ratio (that is, the size of the compressed file compared to that of the uncompressed file) of lossy video codecs is nearly always far superior to that of the audio and still-image equivalents. Video can be compressed immensely (e.g., 100:1) with little visible quality loss
"In another life I'm a Disneyland duck swimming through 'Small World' at 11 pm," Lynda joked in the video's onscreen caption. People in the comments section were so charmed by the duck's adventure.
For signals of indefinite size, such as streaming audio and video, the compression ratio is defined in terms of uncompressed and compressed data rates instead of data sizes: C o m p r e s s i o n R a t i o = U n c o m p r e s s e d D a t a R a t e C o m p r e s s e d D a t a R a t e {\displaystyle {\rm {Compression\;Ratio}}={\frac {\rm ...