Struct nokhwa::Camera

pub struct Camera { /* fields omitted */ }

The main Camera struct. This is the struct that abstracts over all the backends, providing a simplified interface for use.

Implementations

impl Camera

pub fn new(
    index: usize,
    format: Option<CameraFormat>,
    backend: CaptureAPIBackend
) -> Result<Self, NokhwaError>

Create a new camera from an index, format, and backend. format can be None.

Errors

This will error if you either have a bad platform configuration (e.g. input-v4l but not on linux) or the backend cannot create the camera (e.g. permission denied).

pub fn new_with(
    index: usize,
    width: u32,
    height: u32,
    fps: u32,
    fourcc: FrameFormat,
    backend: CaptureAPIBackend
) -> Result<Self, NokhwaError>

Create a new Camera from raw values.

Errors

This will error if you either have a bad platform configuration (e.g. input-v4l but not on linux) or the backend cannot create the camera (e.g. permission denied).

pub fn index(&self) -> usize

Gets the current Camera’s index.

pub fn set_index(&mut self, new_idx: usize) -> Result<(), NokhwaError>

Sets the current Camera’s index. Note that this re-initializes the camera.

Errors

The Backend may fail to initialize.

pub fn backend(&self) -> CaptureAPIBackend

Gets the current Camera’s backend

pub fn set_backend(
    &mut self,
    new_backend: CaptureAPIBackend
) -> Result<(), NokhwaError>

Sets the current Camera’s backend. Note that this re-initializes the camera.

Errors

The new backend may not exist or may fail to initialize the new camera.

pub fn info(&self) -> CameraInfo

Gets the camera information such as Name and Index as a CameraInfo.

pub fn camera_format(&self) -> CameraFormat

Gets the current CameraFormat.

pub fn set_camera_format(
    &mut self,
    new_fmt: CameraFormat
) -> Result<(), NokhwaError>

Will set the current CameraFormat This will reset the current stream if used while stream is opened.

Errors

If you started the stream and the camera rejects the new camera format, this will return an error.

pub fn compatible_list_by_resolution(
    &self,
    fourcc: FrameFormat
) -> Result<HashMap<Resolution, Vec<u32>>, NokhwaError>

A hashmap of Resolutions mapped to framerates

Errors

This will error if the camera is not queryable or a query operation has failed. Some backends will error this out as a Unsupported Operation (NokhwaError::UnsupportedOperation).

pub fn compatible_fourcc(&self) -> Result<Vec<FrameFormat>, NokhwaError>

A Vector of compatible FrameFormats.

Errors

This will error if the camera is not queryable or a query operation has failed. Some backends will error this out as a Unsupported Operation (NokhwaError::UnsupportedOperation).

pub fn resolution(&self) -> Resolution

Gets the current camera resolution (See: Resolution, CameraFormat).

pub fn set_resolution(&mut self, new_res: Resolution) -> Result<(), NokhwaError>

Will set the current Resolution This will reset the current stream if used while stream is opened.

Errors

If you started the stream and the camera rejects the new resolution, this will return an error.

pub fn frame_rate(&self) -> u32

Gets the current camera framerate (See: CameraFormat).

pub fn set_frame_rate(&mut self, new_fps: u32) -> Result<(), NokhwaError>

Will set the current framerate This will reset the current stream if used while stream is opened.

Errors

If you started the stream and the camera rejects the new framerate, this will return an error.

pub fn frame_format(&self) -> FrameFormat

Gets the current camera’s frame format (See: FrameFormat, CameraFormat).

pub fn set_frame_format(
    &mut self,
    fourcc: FrameFormat
) -> Result<(), NokhwaError>

Will set the current FrameFormat This will reset the current stream if used while stream is opened.

Errors

If you started the stream and the camera rejects the new frame format, this will return an error.

pub fn open_stream(&mut self) -> Result<(), NokhwaError>

Will open the camera stream with set parameters. This will be called internally if you try and call frame() before you call open_stream().

Errors

If the specific backend fails to open the camera (e.g. already taken, busy, doesn’t exist anymore) this will error.

pub fn is_stream_open(&self) -> bool

Checks if stream if open. If it is, it will return true.

pub fn frame(&self) -> Result<ImageBuffer<Rgb<u8>, Vec<u8>>, NokhwaError>

Will get a frame from the camera as a Raw RGB image buffer. Depending on the backend, if you have not called open_stream() before you called this, it will either return an error.

Errors

If the backend fails to get the frame (e.g. already taken, busy, doesn’t exist anymore), the decoding fails (e.g. MJPEG -> u8), or open_stream() has not been called yet, this will error.

pub fn frame_raw(&self) -> Result<Vec<u8>, NokhwaError>

Will get a frame from the camera without any processing applied, meaning you will usually get a frame you need to decode yourself.

Errors

If the backend fails to get the frame (e.g. already taken, busy, doesn’t exist anymore), or open_stream() has not been called yet, this will error.

pub fn min_buffer_size(&self, rgba: bool) -> usize

The minimum buffer size needed to write the current frame (RGB24). If rgba is true, it will instead return the minimum size of the RGBA buffer needed.

pub fn frame_to_buffer(
    &self,
    buffer: &mut [u8],
    convert_rgba: bool
) -> Result<usize, NokhwaError>

Directly writes the current frame(RGB24) into said buffer. If convert_rgba is true, the buffer written will be written as an RGBA frame instead of a RGB frame. Returns the amount of bytes written on successful capture.

Errors

If the backend fails to get the frame (e.g. already taken, busy, doesn’t exist anymore), or open_stream() has not been called yet, this will error.

pub fn frame_texture<'a>(
    &mut self,
    device: &WgpuDevice,
    queue: &WgpuQueue,
    label: Option<&'a str>
) -> Result<WgpuTexture, NokhwaError>

Directly copies a frame to a Wgpu texture. This will automatically convert the frame into a RGBA frame.

Errors

If the frame cannot be captured or the resolution is 0 on any axis, this will error.

pub fn stop_stream(&self) -> Result<(), NokhwaError>

Will drop the stream.

Errors

Please check the Quirks section of each backend.

Trait Implementations

impl Drop for Camera

fn drop(&mut self)

Executes the destructor for this type.