chore: vendor trimmed v4l2r capture crate

libs/v4l2r/src/ioctl/g_selection.rs

@@ -0,0 +1,130 @@
+use std::os::unix::io::AsRawFd;
+
+use bitflags::bitflags;
+use enumn::N;
+use nix::errno::Errno;
+use thiserror::Error;
+
+use crate::bindings;
+use crate::bindings::v4l2_rect;
+use crate::bindings::v4l2_selection;
+
+#[derive(Debug, N, Clone, Copy, PartialEq, Eq)]
+#[repr(u32)]
+pub enum SelectionType {
+    Capture = bindings::v4l2_buf_type_V4L2_BUF_TYPE_VIDEO_CAPTURE,
+    Output = bindings::v4l2_buf_type_V4L2_BUF_TYPE_VIDEO_OUTPUT,
+}
+
+#[derive(Debug, N, Clone, Copy, PartialEq, Eq)]
+#[repr(u32)]
+pub enum SelectionTarget {
+    Crop = bindings::V4L2_SEL_TGT_CROP,
+    CropDefault = bindings::V4L2_SEL_TGT_CROP_DEFAULT,
+    CropBounds = bindings::V4L2_SEL_TGT_CROP_BOUNDS,
+    NativeSize = bindings::V4L2_SEL_TGT_NATIVE_SIZE,
+    Compose = bindings::V4L2_SEL_TGT_COMPOSE,
+    ComposeDefault = bindings::V4L2_SEL_TGT_COMPOSE_DEFAULT,
+    ComposeBounds = bindings::V4L2_SEL_TGT_COMPOSE_BOUNDS,
+    ComposePadded = bindings::V4L2_SEL_TGT_COMPOSE_PADDED,
+}
+
+bitflags! {
+    #[derive(Clone, Copy, Debug)]
+    pub struct SelectionFlags: u32 {
+        const GE = bindings::V4L2_SEL_FLAG_GE;
+        const LE = bindings::V4L2_SEL_FLAG_LE;
+        const KEEP_CONFIG = bindings::V4L2_SEL_FLAG_KEEP_CONFIG;
+    }
+}
+
+#[doc(hidden)]
+mod ioctl {
+    use crate::bindings::v4l2_selection;
+    nix::ioctl_readwrite!(vidioc_g_selection, b'V', 94, v4l2_selection);
+    nix::ioctl_readwrite!(vidioc_s_selection, b'V', 95, v4l2_selection);
+}
+
+#[derive(Debug, Error)]
+pub enum GSelectionError {
+    #[error("invalid type or target requested")]
+    Invalid,
+    #[error("ioctl error: {0}")]
+    IoctlError(Errno),
+}
+
+impl From<GSelectionError> for Errno {
+    fn from(err: GSelectionError) -> Self {
+        match err {
+            GSelectionError::Invalid => Errno::EINVAL,
+            GSelectionError::IoctlError(e) => e,
+        }
+    }
+}
+
+/// Safe wrapper around the `VIDIOC_G_SELECTION` ioctl.
+pub fn g_selection<R: From<v4l2_rect>>(
+    fd: &impl AsRawFd,
+    selection: SelectionType,
+    target: SelectionTarget,
+) -> Result<R, GSelectionError> {
+    let mut sel = v4l2_selection {
+        type_: selection as u32,
+        target: target as u32,
+        ..Default::default()
+    };
+
+    match unsafe { ioctl::vidioc_g_selection(fd.as_raw_fd(), &mut sel) } {
+        Ok(_) => Ok(R::from(sel.r)),
+        Err(Errno::EINVAL) => Err(GSelectionError::Invalid),
+        Err(e) => Err(GSelectionError::IoctlError(e)),
+    }
+}
+
+#[derive(Debug, Error)]
+pub enum SSelectionError {
+    #[error("invalid type or target requested")]
+    Invalid,
+    #[error("invalid range requested")]
+    InvalidRange,
+    #[error("cannot change selection rectangle currently")]
+    Busy,
+    #[error("ioctl error: {0}")]
+    IoctlError(nix::Error),
+}
+
+impl From<SSelectionError> for Errno {
+    fn from(err: SSelectionError) -> Self {
+        match err {
+            SSelectionError::Invalid => Errno::EINVAL,
+            SSelectionError::InvalidRange => Errno::ERANGE,
+            SSelectionError::Busy => Errno::EBUSY,
+            SSelectionError::IoctlError(e) => e,
+        }
+    }
+}
+
+/// Safe wrapper around the `VIDIOC_S_SELECTION` ioctl.
+pub fn s_selection<RI: Into<v4l2_rect>, RO: From<v4l2_rect>>(
+    fd: &impl AsRawFd,
+    selection: SelectionType,
+    target: SelectionTarget,
+    rect: RI,
+    flags: SelectionFlags,
+) -> Result<RO, SSelectionError> {
+    let mut sel = v4l2_selection {
+        type_: selection as u32,
+        target: target as u32,
+        flags: flags.bits(),
+        r: rect.into(),
+        ..Default::default()
+    };
+
+    match unsafe { ioctl::vidioc_s_selection(fd.as_raw_fd(), &mut sel) } {
+        Ok(_) => Ok(RO::from(sel.r)),
+        Err(Errno::EINVAL) => Err(SSelectionError::Invalid),
+        Err(Errno::ERANGE) => Err(SSelectionError::InvalidRange),
+        Err(Errno::EBUSY) => Err(SSelectionError::Busy),
+        Err(e) => Err(SSelectionError::IoctlError(e)),
+    }
+}