Transcoding

Transcoding takes a digital media file encoded in one format — say, MP3 audio at 128 kbps — and re-encodes it in a different format — say, AAC at 64 kbps — or a different container, resolution, or bitrate. For audio, transcoding typically re-compresses the signal using a different psychoacoustic codec; for video, it may also involve resolution scaling, framerate conversion, and keyframe re-insertion.

In broadcast and programmatic audio, transcoding is an operational constant. An advertiser's commercial might arrive as a 48 kHz uncompressed WAV from the agency, get transcoded to a station's automation-native format, transcoded again when ingested into a DAI platform, and transcoded once more into the specific codec a streaming app expects. Each generation of transcoding introduces potential quality loss, which is why modern workflows preserve a high-quality master and transcode downstream versions from it rather than transcoding transcoded versions.