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)
+    }
+}