Struct v4l::buffers::mmap::MappedBuffer

pub struct MappedBuffer<'a> { /* fields omitted */ }

Memory mapped buffer

The buffer is backed by camera device or kernel memory. Read only access (e.g. by directly uploading it to the GPU) is permitted for the lifetime of the buffer instance. Acquiring ownership of the data in userspace is not possible, so it has to be copied.

Implementations

impl<'a> MappedBuffer<'a>

pub fn new(view: &'a [u8], meta: Metadata) -> Self

Returns a mapped memory region representation

Buffers created this way provide read-only access to the backing data, enforcing callers to copy the data before mutating it.

Arguments

• view - Slice of raw memory
• meta - Metadata, usually filled in by the driver

Example

use v4l::{buffer, MappedBuffer, Timestamp};

let data: Vec<u8> = Vec::new();
let ts = Timestamp::new(0 /* sec */, 0 /* usec */);
let flags = buffer::Flags::from(0);
let meta = buffer::Metadata::new(0, ts, flags);
let buf = MappedBuffer::new(&data, meta);

Trait Implementations

impl<'a> Buffer for MappedBuffer<'a>

fn data(&self) -> &[u8]

Slice of read-only data

fn len(&self) -> usize

Size of the backing memory region

fn is_empty(&self) -> bool

Whether the backing buffer is empty

fn meta(&self) -> &Metadata

Metadata such as allocation flags, timestamp and more