Retranscoding

Retranscoding refers to the process of converting a digital media file from one encoded format to another, and then back again to the original format, or to a similar format. This is typically done for specific technical reasons, although it is often an inefficient practice.

One common scenario where retranscoding might occur is during the editing or distribution of video content. For example, a video file might be transcoded from a high-quality master format to a lower-quality editing format for easier manipulation. After editing, it might then be retranscoded to a distribution format suitable for streaming or broadcast. In some workflows, this might inadvertently involve a cycle where the edited file is then retranscoded back into a format that is very close to, or even identical to, the original master, but with the edits applied.

Another reason for retranscoding could be to attempt to fix issues with a media file. If a file is experiencing playback problems or has metadata errors, a user might transcode it to a new format, hoping that the process will correct the underlying problems. This is not always successful, and can sometimes introduce new artifacts or degrade the quality of the media.

In general, retranscoding is discouraged whenever possible because each transcoding step can lead to a loss of data and a reduction in the overall quality of the media. This is especially true for lossy compression formats, where information is discarded during the initial compression. Therefore, media professionals strive to minimize the number of transcoding steps in their workflows.