Audio formats
Audio is PCM, 16-bit little-endian, mono. Pick the formats when you create the session; the session.ready event confirms them.
Formats
Section titled “Formats”| Value | Description |
|---|---|
pcm16_16k |
16,000 Hz (the input default). |
pcm16_24k |
24,000 Hz (the output default). |
pcm16_48k |
48,000 Hz. |
Defaults: input pcm16_16k, output pcm16_24k. Set them with audio.input_format and audio.output_format in the request that creates the session.
Binary frames
Section titled “Binary frames”JSON events travel as WebSocket text frames. Audio travels as binary frames.
Input audio (client to server)
Section titled “Input audio (client to server)”PCM16 little-endian mono in the session’s input format (default 16 kHz), 10–500 ms per frame, no header.
Reply audio (server to client)
Section titled “Reply audio (server to client)”8-byte header (kind u8 = 0x01, flags u8: bit0 first frame of a sentence, bit1 last frame of the reply; sentence u16 LE; reply_seq u32 LE) followed by PCM16 LE samples in the output format (default 24 kHz). The last frame of a reply may carry no samples.