Struct nokhwa::Camera

pub struct Camera { /* private fields */ }

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: CameraIndex, format: RequestedFormat<'_> ) -> Result<Self, NokhwaError>

Create a new camera from an index and format

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 with_backend( index: CameraIndex, format: RequestedFormat<'_>, backend: ApiBackend ) -> 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: CameraIndex, width: u32, height: u32, fps: u32, fourcc: FrameFormat, backend: ApiBackend ) -> Result<Self, NokhwaError>

👎Deprecated since 0.10.0: please use new instead.

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 with_custom( idx: CameraIndex, api: ApiBackend, device: Box<dyn CaptureBackendTrait> ) -> Self

Allows creation of a Camera with a custom backend. This is useful if you are creating e.g. a custom module.

You must have set a format beforehand.

pub fn index(&self) -> &CameraIndex

Gets the current Camera’s index.

pub fn set_index(&mut self, new_idx: &CameraIndex) -> 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) -> ApiBackend

Gets the current Camera’s backend

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

Forcefully refreshes the stored camera format, bringing it into sync with “reality” (current camera state)

Errors

If the camera can not get its most recent CameraFormat. this will error.

pub fn set_camera_requset( &mut self, request: RequestedFormat<'_> ) -> Result<CameraFormat, NokhwaError>

Will set the current CameraFormat, using a [RequestedFormat.] This will reset the current stream if used while stream is opened.

This will also update the cache.

This will return the new CameraFormat

Errors

If nothing fits the requested criteria, this will return an error.

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

👎Deprecated since 0.10.0: please use set_camera_requset instead.

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

This will also update the cache.

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( &mut 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 UnsupportedOperationError.

pub fn compatible_fourcc(&mut 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 UnsupportedOperationError.

pub fn compatible_camera_formats( &mut self ) -> Result<Vec<CameraFormat>, NokhwaError>

A Vector of available CameraFormats.

Errors

This will error if the camera is not queryable or a query operation has failed. Some backends will error this out as a UnsupportedOperationError.

pub fn resolution(&self) -> Resolution

Gets the current camera resolution (See: Resolution, CameraFormat). This will force refresh to the current latest if it has changed.

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.

This will also update the cache.

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.

This will also update the cache.

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). This will force refresh to the current latest if it has changed.

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.

This will also update the cache.

Errors

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

pub fn supported_camera_controls( &self ) -> Result<Vec<KnownCameraControl>, NokhwaError>

Gets the current supported list of KnownCameraControl

Errors

If the list cannot be collected, this will error. This can be treated as a “nothing supported”.

pub fn camera_controls(&self) -> Result<Vec<CameraControl>, NokhwaError>

Gets the current supported list of CameraControls keyed by its name as a String.

Errors

If the list cannot be collected, this will error. This can be treated as a “nothing supported”.

pub fn camera_controls_string( &self ) -> Result<HashMap<String, CameraControl>, NokhwaError>

Gets the current supported list of CameraControls keyed by its name as a String.

Errors

If the list cannot be collected, this will error. This can be treated as a “nothing supported”.

pub fn camera_controls_known_camera_controls( &self ) -> Result<HashMap<KnownCameraControl, CameraControl>, NokhwaError>

Gets the current supported list of CameraControls keyed by its name as a String.

Errors

If the list cannot be collected, this will error. This can be treated as a “nothing supported”.

pub fn camera_control( &self, control: KnownCameraControl ) -> Result<CameraControl, NokhwaError>

Gets the value of KnownCameraControl.

Errors

If the control is not supported or there is an error while getting the camera control values (e.g. unexpected value, too high, etc) this will error.

pub fn set_camera_control( &mut self, id: KnownCameraControl, value: ControlValueSetter ) -> Result<(), NokhwaError>

Sets the control to control in the camera. Usually, the pipeline is calling camera_control(), getting a camera control that way then calling value() to get a ControlValueSetter and setting the value that way.

Errors

If the control is not supported, the value is invalid (less than min, greater than max, not in step), or there was an error setting the control, this will 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(&mut self) -> Result<Buffer, 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(&mut self) -> Result<Cow<'_, [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 write_frame_to_buffer<F: FormatDecoder>( &mut self, buffer: &mut [u8] ) -> Result<(), NokhwaError>

Directly writes the current frame into said buffer.

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

Available on crate feature output-wgpu only.

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(&mut 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.

impl Send for Camera