Introduction to audio encoding

For information about audio encoding, see Introduction to audio encoding in the Speech-to-Text documentation.

Supported audio encodings

The Media Translation API supports a number of different encodings. The following table lists supported audio codecs:

Codec Name Lossless Usage Notes
AMR Adaptive Multi-Rate Narrowband No Sample rate must be 8000 Hz
AMR_WB Adaptive Multi-Rate Wideband No Sample rate must be 16000 Hz
FLAC Free Lossless Audio Codec Yes 16-bit or 24-bit required for streams
LINEAR16 Linear PCM Yes 16-bit linear pulse-code modulation (PCM) encoding
MP3 MPEG Audio Layer III No MP3 audio. Support all standard MP3 bitrates (which range from 32-320 kbps). When using this encoding, sample_rate_hertz has to match the sample rate of the file being used.
MULAW μ-law No 8-bit PCM encoding
OGG_OPUS Opus encoded audio frames in an Ogg container No Sample rate must be one of 8000 Hz, 12000 Hz, 16000 Hz, 24000 Hz, or 48000 Hz