Struct ProbeContext 

#[non_exhaustive]
pub struct ProbeContext<'a> {
    pub tag: &'a CodecTag,
    pub header: Option<&'a [u8]>,
    pub packet: Option<&'a [u8]>,
    pub bits_per_sample: Option<u16>,
    pub channels: Option<u16>,
    pub sample_rate: Option<u32>,
    pub width: Option<u32>,
    pub height: Option<u32>,
}

Context passed to a codec’s probe function during tag resolution.

Built by the demuxer from whatever it has already parsed (stream format block, a peek at the first packet, numeric hints like bits_per_sample). Probes read fields directly; the struct is #[non_exhaustive] so additional hints can be added later without breaking codec crates that match on it.

The canonical construction pattern, for a demuxer:

let tag = CodecTag::wave_format(0x0001);
let ctx = ProbeContext::new(&tag)
    .bits(24)
    .channels(2)
    .sample_rate(48_000);

Codec authors read fields like ctx.bits_per_sample / ctx.tag directly — #[non_exhaustive] forbids struct-literal construction from outside this crate but does not restrict field access.

Fields (Non-exhaustive)

Non-exhaustive structs could have additional fields added in future. Therefore, non-exhaustive structs cannot be constructed in external crates using the traditional Struct { .. } syntax; cannot be matched against without a wildcard ..; and struct update syntax will not work.

tag: &'a CodecTag

The tag being resolved — always set.

header: Option<&'a [u8]>

Raw container-level stream-format blob if available (e.g. WAVEFORMATEX, BITMAPINFOHEADER, MP4 sample-entry bytes, Matroska CodecPrivate). Format is container-specific.

packet: Option<&'a [u8]>

First packet bytes if the demuxer has already read one. Most demuxers resolve tags at stream-discovery time before any packet exists; this is None in that case.

bits_per_sample: Option<u16>

Audio: bits per sample (from WAVEFORMATEX, MP4 sample entry, Matroska BitDepth, etc.).

channels: Option<u16>

Audio: channel count from the container’s stream header.

sample_rate: Option<u32>

Audio: sample rate in Hz from the container’s stream header.

width: Option<u32>

Video: coded frame width in pixels from the container’s stream header.

height: Option<u32>

Video: coded frame height in pixels from the container’s stream header.

Implementations

impl<'a> ProbeContext<'a>

pub fn new(tag: &'a CodecTag) -> Self

Start building a context for tag with every hint field empty.

pub fn header(self, h: &'a [u8]) -> Self

Builder method: attach the raw container-level stream-format blob (WAVEFORMATEX, BITMAPINFOHEADER, MP4 sample-entry bytes, Matroska CodecPrivate, …).

pub fn packet(self, p: &'a [u8]) -> Self

Builder method: attach the first packet’s bytes, when the demuxer has already read one.

pub fn bits(self, n: u16) -> Self

Builder method: set the audio bits-per-sample hint.

pub fn channels(self, n: u16) -> Self

Builder method: set the audio channel-count hint.

pub fn sample_rate(self, n: u32) -> Self

Builder method: set the audio sample-rate hint (Hz).

pub fn width(self, n: u32) -> Self

Builder method: set the video frame-width hint (pixels).

pub fn height(self, n: u32) -> Self

Builder method: set the video frame-height hint (pixels).

Trait Implementations

impl<'a> Clone for ProbeContext<'a>

fn clone(&self) -> ProbeContext<'a>

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<'a> Debug for ProbeContext<'a>

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

Formats the value using the given formatter.