Struct AudioEncoder 

pub struct AudioEncoder { /* private fields */ }

Zero-allocation audio encoder for the streaming hot path.

Both encode_f32 and encode_i16_le write into pre-allocated internal buffers and return a borrowed &str. After the first call that establishes capacity, subsequent calls produce no heap allocations — critical for real-time audio where this runs every 100–250 ms.

Performance

For maximum throughput, keep a single AudioEncoder instance alive across the streaming loop and pair it with Session::send_raw to avoid the extra allocation in Session::send_audio.

let mut enc = AudioEncoder::new();
// In a streaming loop:
let b64 = enc.encode_i16_le(pcm_bytes);
// Build the message — only the to_owned() here allocates:
let msg = ClientMessage::RealtimeInput(RealtimeInput {
    audio: Some(Blob { data: b64.to_owned(), mime_type: INPUT_AUDIO_MIME.into() }),
    video: None, text: None, activity_start: None, activity_end: None,
    audio_stream_end: None,
});

Example

use gemini_live::audio::AudioEncoder;

let mut enc = AudioEncoder::new();
let samples: Vec<f32> = vec![0.0, 0.5, -0.5, 1.0, -1.0];
let base64 = enc.encode_f32(&samples);
assert!(!base64.is_empty());

Implementations

impl AudioEncoder

pub fn new() -> Self

Create a new encoder pre-allocated for ~250 ms at 16 kHz.

pub fn encode_f32(&mut self, samples: &[f32]) -> &str

Encode f32 samples (range [-1.0, 1.0]) to base64 i16-LE PCM.

Values outside [-1.0, 1.0] are clamped. The returned &str borrows the encoder’s internal buffer and is valid until the next encode_* call.

pub fn encode_i16_le(&mut self, pcm: &[u8]) -> &str

Encode raw i16 little-endian PCM bytes to base64 (zero-conversion path).

Use this when the audio source already provides i16-LE samples.

Trait Implementations

impl Default for AudioEncoder

fn default() -> Self

Returns the “default value” for a type.