chore: vendor trimmed v4l2r capture crate

libs/v4l2r/src/memory/dmabuf.rs

@@ -0,0 +1,91 @@
+//! Operations specific to DMABuf-type buffers.
+use log::warn;
+
+use super::*;
+use crate::{bindings, ioctl};
+use std::os::fd::RawFd;
+use std::os::unix::io::{AsFd, AsRawFd};
+
+pub struct DmaBuf;
+
+pub type DmaBufferHandles<T> = Vec<DmaBufHandle<T>>;
+
+impl Memory for DmaBuf {
+    const MEMORY_TYPE: MemoryType = MemoryType::DmaBuf;
+    type RawBacking = RawFd;
+
+    unsafe fn get_plane_buffer_backing(
+        m: &bindings::v4l2_plane__bindgen_ty_1,
+    ) -> &Self::RawBacking {
+        &m.fd
+    }
+
+    unsafe fn get_single_planar_buffer_backing(
+        m: &bindings::v4l2_buffer__bindgen_ty_1,
+    ) -> &Self::RawBacking {
+        &m.fd
+    }
+
+    unsafe fn get_plane_buffer_backing_mut(
+        m: &mut bindings::v4l2_plane__bindgen_ty_1,
+    ) -> &mut Self::RawBacking {
+        &mut m.fd
+    }
+
+    unsafe fn get_single_planar_buffer_backing_mut(
+        m: &mut bindings::v4l2_buffer__bindgen_ty_1,
+    ) -> &mut Self::RawBacking {
+        &mut m.fd
+    }
+}
+
+impl Imported for DmaBuf {}
+
+pub trait DmaBufSource: AsRawFd + AsFd + Debug + Send {
+    fn len(&self) -> u64;
+
+    /// Make Clippy happy.
+    fn is_empty(&self) -> bool {
+        self.len() == 0
+    }
+}
+
+impl DmaBufSource for std::fs::File {
+    fn len(&self) -> u64 {
+        match self.metadata() {
+            Err(_) => {
+                warn!("Failed to compute File size for use as DMABuf, using 0...");
+                0
+            }
+            Ok(m) => m.len(),
+        }
+    }
+}
+
+/// Handle for a DMABUF plane. Any type that can provide a file descriptor is
+/// valid.
+#[derive(Debug)]
+pub struct DmaBufHandle<T: DmaBufSource>(pub T);
+
+impl<T: DmaBufSource> From<T> for DmaBufHandle<T> {
+    fn from(dmabuf: T) -> Self {
+        DmaBufHandle(dmabuf)
+    }
+}
+
+impl<T: DmaBufSource + 'static> PlaneHandle for DmaBufHandle<T> {
+    type Memory = DmaBuf;
+
+    fn fill_v4l2_plane(&self, plane: &mut bindings::v4l2_plane) {
+        plane.m.fd = self.0.as_raw_fd();
+        plane.length = self.0.len() as u32;
+    }
+}
+
+impl<T: DmaBufSource> DmaBufHandle<T> {
+    pub fn map(&self) -> Result<PlaneMapping, ioctl::MmapError> {
+        let len = self.0.len();
+
+        ioctl::mmap(&self.0, 0, len as u32)
+    }
+}

libs/v4l2r/src/memory/mmap.rs

@@ -0,0 +1,58 @@
+//! Operations specific to MMAP-type buffers.
+use super::*;
+use crate::{bindings, ioctl};
+use std::fmt::Debug;
+use std::os::fd::AsFd;
+
+#[derive(Default)]
+pub struct Mmap;
+
+impl Memory for Mmap {
+    const MEMORY_TYPE: MemoryType = MemoryType::Mmap;
+    type RawBacking = u32;
+
+    unsafe fn get_plane_buffer_backing(
+        m: &bindings::v4l2_plane__bindgen_ty_1,
+    ) -> &Self::RawBacking {
+        &m.mem_offset
+    }
+
+    unsafe fn get_single_planar_buffer_backing(
+        m: &bindings::v4l2_buffer__bindgen_ty_1,
+    ) -> &Self::RawBacking {
+        &m.offset
+    }
+
+    unsafe fn get_plane_buffer_backing_mut(
+        m: &mut bindings::v4l2_plane__bindgen_ty_1,
+    ) -> &mut Self::RawBacking {
+        &mut m.mem_offset
+    }
+
+    unsafe fn get_single_planar_buffer_backing_mut(
+        m: &mut bindings::v4l2_buffer__bindgen_ty_1,
+    ) -> &mut Self::RawBacking {
+        &mut m.offset
+    }
+}
+
+impl SelfBacked for Mmap {}
+
+/// Dummy handle for a MMAP plane, to use with APIs that require handles. MMAP
+/// buffers are backed by the device, and thus we don't need to attach any extra
+/// information to them.
+#[derive(Default, Debug, Clone)]
+pub struct MmapHandle;
+
+// There is no information to fill with MMAP buffers ; the index is enough.
+impl PlaneHandle for MmapHandle {
+    type Memory = Mmap;
+
+    fn fill_v4l2_plane(&self, _plane: &mut bindings::v4l2_plane) {}
+}
+
+impl Mappable for MmapHandle {
+    fn map<D: AsFd>(device: &D, plane_info: &QueryBufPlane) -> Option<PlaneMapping> {
+        ioctl::mmap(device, plane_info.mem_offset, plane_info.length).ok()
+    }
+}

libs/v4l2r/src/memory/userptr.rs

@@ -0,0 +1,77 @@
+//! Operations specific to UserPtr-type buffers.
+
+use super::*;
+use crate::bindings;
+
+pub struct UserPtr;
+
+impl Memory for UserPtr {
+    const MEMORY_TYPE: MemoryType = MemoryType::UserPtr;
+    type RawBacking = core::ffi::c_ulong;
+
+    unsafe fn get_plane_buffer_backing(
+        m: &bindings::v4l2_plane__bindgen_ty_1,
+    ) -> &Self::RawBacking {
+        &m.userptr
+    }
+
+    unsafe fn get_single_planar_buffer_backing(
+        m: &bindings::v4l2_buffer__bindgen_ty_1,
+    ) -> &Self::RawBacking {
+        &m.userptr
+    }
+
+    unsafe fn get_plane_buffer_backing_mut(
+        m: &mut bindings::v4l2_plane__bindgen_ty_1,
+    ) -> &mut Self::RawBacking {
+        &mut m.userptr
+    }
+
+    unsafe fn get_single_planar_buffer_backing_mut(
+        m: &mut bindings::v4l2_buffer__bindgen_ty_1,
+    ) -> &mut Self::RawBacking {
+        &mut m.userptr
+    }
+}
+
+impl Imported for UserPtr {}
+
+/// Handle for a USERPTR plane. These buffers are backed by userspace-allocated
+/// memory, which translates well into Rust's slice of `u8`s. Since slices also
+/// carry size information, we know that we are not passing unallocated areas
+/// of the address-space to the kernel.
+///
+/// USERPTR buffers have the particularity that the `length` field of `struct
+/// v4l2_buffer` must be set before doing a `QBUF` ioctl. This handle struct
+/// also takes care of that.
+#[derive(Debug)]
+pub struct UserPtrHandle<T: AsRef<[u8]> + Debug + Send + 'static>(pub T);
+
+impl<T: AsRef<[u8]> + Debug + Send + Clone> Clone for UserPtrHandle<T> {
+    fn clone(&self) -> Self {
+        UserPtrHandle(self.0.clone())
+    }
+}
+
+impl<T: AsRef<[u8]> + Debug + Send + 'static> AsRef<[u8]> for UserPtrHandle<T> {
+    fn as_ref(&self) -> &[u8] {
+        self.0.as_ref()
+    }
+}
+
+impl<T: AsRef<[u8]> + Debug + Send> From<T> for UserPtrHandle<T> {
+    fn from(buffer: T) -> Self {
+        UserPtrHandle(buffer)
+    }
+}
+
+impl<T: AsRef<[u8]> + Debug + Send + 'static> PlaneHandle for UserPtrHandle<T> {
+    type Memory = UserPtr;
+
+    fn fill_v4l2_plane(&self, plane: &mut bindings::v4l2_plane) {
+        let slice = AsRef::<[u8]>::as_ref(&self.0);
+
+        plane.m.userptr = slice.as_ptr() as std::os::raw::c_ulong;
+        plane.length = slice.len() as u32;
+    }
+}