Struct Decoder 

pub struct Decoder { /* private fields */ }

A stateful V4L2 decode session on one device node.

Implementations

impl Decoder

pub fn open(path: impl AsRef<Path>, codec: Codec) -> Result<Self, VideoError>

Opens path and prepares the compressed side for codec.

The capture side is deliberately not touched: its geometry belongs to the stream, and the driver announces it through SOURCE_CHANGE once it has parsed the headers this session feeds it.

pub fn codec(&self) -> Codec

Which codec this session decodes.

pub fn ready_for_input(&mut self) -> bool

Whether a compressed buffer is free right now — feed only when true.

pub fn feed(&mut self, access_unit: &[u8]) -> Result<bool, VideoError>

Queues one access unit, starting the stream on the first.

Returns false — feeding nothing — when every buffer is in flight; call Decoder::pump and try again. An access unit larger than the buffer is truncated, which cannot happen inside the menu’s 1080p bound.

pub fn pump(&mut self) -> Result<Option<DecodedFrame>, VideoError>

Advances the session: handles the source-change handshake, and returns a decoded frame when one is ready. Never blocks.

pub fn dmabuf(&self, index: u32) -> Option<BorrowedFd<'_>>

The dmabuf backing capture buffer index.

pub fn recycle(&mut self, index: u32) -> Result<(), VideoError>

Gives a displayed frame’s buffer back to the decoder.

Call once scanout has moved past it — in practice, when the next frame has been flipped onto the plane.

pub fn restart(&mut self) -> Result<(), VideoError>

Stops both queues, forgetting all stream state; the next Decoder::feed starts the stream over. This is the whole of seeking: a promo loop restarts from its parameter sets.