Struct AudioRef 

pub struct AudioRef<'a, S: FrameFree<RawFrame = NDIlib_audio_frame_v3_t>> { /* private fields */ }

A zero-copy borrowed audio frame, generic over its free strategy S.

This type wraps an RAII Guard that owns the NDI frame buffer lifetime, exposing a safe, zero-copy view of the audio data. The frame is automatically freed when dropped, via whichever NDIlib_*_free_audio* call the strategy S encodes.

The shared accessors and the Debug impl are written exactly once here; the two public spellings are aliases that layer their differing format/owned/empty policy on top:

• AudioFrameRef<'rx> — frames captured from a Receiver (always concrete: format() -> AudioFormat, to_owned() -> AudioFrame).
• FrameSyncAudioRef<'fs> — frames captured from a FrameSync, which additionally model a validated empty query/no-source state (is_empty, Option-returning format/to_owned).

Key characteristics:

• Zero allocations: References NDI SDK buffers directly
• Zero copies: No memcpy of audio samples
• RAII lifetime: Exactly one free per frame, enforced at compile time
• Not Send: Prevents accidental cross-thread use of FFI buffers

Implementations

impl<'a, S: FrameFree<RawFrame = NDIlib_audio_frame_v3_t>> AudioRef<'a, S>

pub fn sample_rate(&self) -> i32

Get the sample rate in Hz.

pub fn num_channels(&self) -> i32

Get the number of audio channels.

pub fn num_samples(&self) -> i32

Get the number of samples per channel.

pub fn timecode(&self) -> i64

Get the timecode.

pub fn timestamp(&self) -> i64

Get the timestamp.

pub fn channel_stride_in_bytes(&self) -> i32

Get the channel stride in bytes.

pub fn metadata(&self) -> Option<&str>

Get frame metadata as UTF-8 text, if present.

pub fn data(&self) -> &[f32]

Get a zero-copy view of the audio data as 32-bit floats.

This returns a slice directly into the NDI SDK’s buffer. No allocation or memcpy is performed.

Safety Guarantee

The slice length is computed once at construction time using checked arithmetic and validated against MAX_AUDIO_BYTES. This eliminates the possibility of integer overflow or unbounded slice creation. A validated empty (query/no-source) layout yields an empty slice.

pub fn channel_data(&self, channel: usize) -> Option<&[f32]>

Get the zero-copy samples for a single channel.

This respects channel_stride_in_bytes, so it works for tightly packed and strided planar FLTP audio.

impl<'rx> AudioRef<'rx, AudioKind>

pub fn format(&self) -> AudioFormat

Get the audio format (FourCC code).

This is guaranteed to be a valid, supported format since it’s validated during construction.

pub fn to_owned(&self) -> Result<AudioFrame>

Convert this borrowed frame to an owned AudioFrame.

This performs a single memcpy of the audio data and metadata, allowing the frame to outlive the NDI buffer and be sent across threads.

impl<'fs> AudioRef<'fs, FrameSyncAudioFree>

pub fn is_empty(&self) -> bool

Returns true for a valid query/no-source state with no sample buffer.

pub fn format(&self) -> Option<AudioFormat>

Get the audio format (FourCC code), or None for an empty query/no-source state.

pub fn to_owned(&self) -> Result<Option<AudioFrame>>

Convert this borrowed frame to an owned AudioFrame.

This performs a single memcpy of the audio data and metadata, allowing the frame to outlive the NDI buffer and be sent across threads.

Returns Ok(None) for a valid query/no-source state with no sample buffer to own.

Trait Implementations

impl<'a, S: FrameFree<RawFrame = NDIlib_audio_frame_v3_t>> Debug for AudioRef<'a, S>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.