All Video is Compressed
All video that we shoot on tape or watch on TV is compressed. This has been true since the beginning of time — or, well, the beginning of video at least.
Some video, like DV or HDV, is significantly compressed in a number of ways. Other video, like DigiBetacam is compressed less.
The reason for all this compression is that video files are HUGE and engineers are always looking for ways to make them smaller without sacrificing too much quality. That’s where codecs (short for: COmpressor/DECompressor) come in. A codec provides specific instructions on how to compress video to reduce its size, then decompress it to “full quality” for playback.
There are four principal goals to consider when choosing a codec:
- The size of the compressed file
- The speed of compression
- The speed of decompression
- The quality of the final image
For instance, if you are posting a file to the Internet, the size of the file and the speed of decompression are more important than how long it takes to compress the file in the first place or the quality of the final image. That is not to say these last two are unimportant, just less important.
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