Crate rusty_esp_core 

rusty_esp_core — the shared vocabulary of the Janus ESP family.

Every Janus package (rusty_esp_audio, rusty_esp_image, rusty_esp_video, rusty_esp_signal, rusty_esp_iroh, rusty_esp_mid) speaks these types at its boundary, so a camera frame from one crate flows into an encoder in another and onto the mesh in a third with no conversion and no copy.

What lives here, and the rule that keeps it small:

Module	Holds	Rule
time	Micros, a monotonic device timestamp; WallOffset, the host’s device→wall mapping with its error bound	value type, no clock
error	Error, one Copy error for the family	no String, no alloc
frame	Frame, a borrowed image/video frame	planes over caller memory
pcm	PcmBlock, a borrowed interleaved PCM block	same
capability	Manifest, what a device can do, canonically encoded; capability::ParsedManifest reads it back (alloc)	signed by rusty_esp_mid
media	MediaPacket, a borrowed coded packet and its Codec	the shape every transport frames
hal	Clock, Rng, Kv — the three seams every backend fills	traits only

Nothing here is a driver, an allocator, a codec, or a product type. If a type needs esp-hal, ESP-IDF, or a codec crate to define it, it does not belong in this crate.

Why borrowed frames. The FFmpeg-shaped Vec<Vec<u8>>-per-frame model is one-plus-N heap allocations per frame, returned by value. On a chip with 512 KB of SRAM that is the wrong shape at every level: allocation count, ownership, and the trait signatures it forces. Janus frames are views over memory the caller (a DMA ring, a static arena, a Vec on the host) already owns. Sources write into caller buffers; encoders read views.

Feature ladder: std ⊃ alloc ⊃ core-only. The crate compiles for riscv32imac-unknown-none-elf with --no-default-features.

Re-exports

pub use capability::Capability;

pub use capability::Chip;

pub use capability::Declared;

pub use capability::Manifest;

pub use capability::Status;

pub use error::Error;

pub use frame::Frame;

pub use frame::FrameMut;

pub use frame::Geometry;

pub use frame::PixelFormat;

pub use frame::Plane;

pub use frame::PlaneMut;

pub use frame::Planes;

pub use frame::PlanesMut;

pub use hal::Clock;

pub use hal::Kv;

pub use hal::Rng;

pub use media::Codec;

pub use media::MediaPacket;

pub use pcm::PcmBlock;

pub use pcm::PcmFormat;

pub use pcm::SampleFormat;

pub use time::Micros;

pub use time::WallOffset;

Modules

capability

The capability manifest — what a device can do, stated honestly.

error

One small, Copy, allocation-free error for the whole family.

frame

Borrowed image and video frames.

hal

The three seams every Janus backend fills.

media

The one coded-packet type the media packages share.

pcm

Borrowed PCM audio blocks.

prelude

The names a sketch, a backend or a function crate wants in scope.

time

Monotonic device time.

Constants

FORMAT_VERSION

The wire/format version of every canonical encoding this crate defines. Bump only with an accept-both reader already shipped (see the Janus plan, “changing a format others already read”).

VERSION

Crate version, for capability manifests and logs.