moq-v4l 0.1.0

Safe Video4Linux 2 bindings, forked from raymanfx/libv4l-rs with the kernel bindings checked in (no bindgen, no libclang)
Documentation 
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use std::convert::TryFrom;
use std::fmt;

use crate::format::FourCC;
use crate::sys::*;

#[derive(Debug)]
/// Format description as returned by [`crate::v4l2::vidioc::VIDIOC_ENUM_FRAMESIZES`]
pub struct FrameSize {
	pub index: u32,
	pub fourcc: FourCC,
	pub typ: u32,
	pub size: FrameSizeEnum,
}

impl fmt::Display for FrameSize {
	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
		self.size.fmt(f)
	}
}

#[derive(Debug)]
pub enum FrameSizeEnum {
	Discrete(Discrete),
	Stepwise(Stepwise),
}

impl FrameSizeEnum {
	pub fn to_discrete(self) -> impl IntoIterator<Item = Discrete> {
		match self {
			Self::Discrete(discrete) => vec![discrete],
			Self::Stepwise(stepwise) => {
				let mut discrete = Vec::new();

				for width in (stepwise.min_width..=stepwise.max_width).step_by(stepwise.step_width as usize) {
					for height in (stepwise.min_height..=stepwise.max_height).step_by(stepwise.step_height as usize) {
						discrete.push(Discrete { width, height });
					}
				}

				discrete
			}
		}
	}
}

impl fmt::Display for FrameSizeEnum {
	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
		match self {
			FrameSizeEnum::Discrete(val) => write!(f, "Discrete({})", val)?,
			FrameSizeEnum::Stepwise(val) => write!(f, "Stepwise({})", val)?,
		}

		Ok(())
	}
}

impl TryFrom<v4l2_frmsizeenum> for FrameSizeEnum {
	type Error = String;

	fn try_from(desc: v4l2_frmsizeenum) -> Result<Self, Self::Error> {
		unsafe {
			// Unsafe because of access to union __bindgen_anon_1
			#[allow(non_upper_case_globals)]
			match desc.type_ {
				v4l2_frmsizetypes_V4L2_FRMSIZE_TYPE_DISCRETE => Ok({
					FrameSizeEnum::Discrete(Discrete {
						width: desc.__bindgen_anon_1.discrete.width,
						height: desc.__bindgen_anon_1.discrete.height,
					})
				}),
				v4l2_frmsizetypes_V4L2_FRMSIZE_TYPE_STEPWISE | v4l2_frmsizetypes_V4L2_FRMSIZE_TYPE_CONTINUOUS => Ok({
					FrameSizeEnum::Stepwise(Stepwise {
						min_width: desc.__bindgen_anon_1.stepwise.min_width,
						max_width: desc.__bindgen_anon_1.stepwise.max_width,
						step_width: desc.__bindgen_anon_1.stepwise.step_width,
						min_height: desc.__bindgen_anon_1.stepwise.min_height,
						max_height: desc.__bindgen_anon_1.stepwise.max_height,
						step_height: desc.__bindgen_anon_1.stepwise.step_height,
					})
				}),
				typ => Err(format!("Unknown frame size type: {}", typ)),
			}
		}
	}
}

#[derive(Debug)]
pub struct Discrete {
	/// Width of the frame (in pixels).
	pub width: u32,
	/// Height of the frame (in pixels).
	pub height: u32,
}

impl fmt::Display for Discrete {
	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
		write!(f, "{}x{}", self.width, self.height)?;
		Ok(())
	}
}

#[derive(Debug)]
pub struct Stepwise {
	/// Minimum frame width (in pixels).
	pub min_width: u32,
	/// Maximum frame width (in pixels).
	pub max_width: u32,
	/// Frame width step size (in pixels).
	pub step_width: u32,
	/// Minimum frame height (in pixels).
	pub min_height: u32,
	/// Maximum frame height (in pixels).
	pub max_height: u32,
	/// Frame height step size (in pixels).
	pub step_height: u32,
}

impl fmt::Display for Stepwise {
	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
		write!(
			f,
			"{}x{} - {}x{} with step {}/{}",
			self.min_width, self.min_height, self.max_width, self.max_height, self.step_width, self.step_height,
		)?;
		Ok(())
	}
}

impl TryFrom<v4l2_frmsizeenum> for FrameSize {
	type Error = String;

	fn try_from(desc: v4l2_frmsizeenum) -> Result<Self, Self::Error> {
		Ok(FrameSize {
			index: desc.index,
			typ: desc.type_,
			fourcc: FourCC::from(desc.pixel_format),
			size: FrameSizeEnum::try_from(desc)?,
		})
	}
}