improve video, ignore same image

libs/scrap/src/common/mod.rs

@@ -30,3 +30,16 @@ pub use self::convert::*;
 pub const STRIDE_ALIGN: usize = 64; // commonly used in libvpx vpx_img_alloc caller
 
 mod vpx;
+
+#[inline]
+pub fn would_block_if_equal(old: &mut Vec<u128>, b: &[u8]) -> std::io::Result<()> {
+    let b = unsafe {
+        std::slice::from_raw_parts::<u128>(b.as_ptr() as _, b.len() / 16)
+    };
+    if b == &old[..] {
+        return Err(std::io::ErrorKind::WouldBlock.into());
+    }
+    old.resize(b.len(), 0);
+    old.copy_from_slice(b);
+    Ok(())
+}

libs/scrap/src/common/quartz.rs

@@ -8,6 +8,7 @@ pub struct Capturer {
     frame: Arc<Mutex<Option<quartz::Frame>>>,
     use_yuv: bool,
     i420: Vec<u8>,
+    saved_raw_data: Vec<u128>, // for faster compare and copy
 }
 
 impl Capturer {
@@ -38,6 +39,7 @@ impl Capturer {
             frame,
             use_yuv,
             i420: Vec::new(),
+            saved_raw_data: Vec::new(),
         })
     }
 
@@ -57,6 +59,7 @@ impl Capturer {
 
                 match frame {
                     Some(mut frame) => {
+                        crate::would_block_if_equal(&mut self.saved_raw_data, frame.inner())?;
                         if self.use_yuv {
                             frame.nv12_to_i420(self.width(), self.height(), &mut self.i420);
                         }

libs/scrap/src/common/x11.rs

@@ -17,7 +17,7 @@ impl Capturer {
     }
 
     pub fn frame<'a>(&'a mut self, _timeout_ms: u32) -> io::Result<Frame<'a>> {
-        Ok(Frame(self.0.frame()))
+        Ok(Frame(self.0.frame()?))
     }
 }
 

libs/scrap/src/dxgi/mod.rs

@@ -49,6 +49,7 @@ pub struct Capturer {
     rotated: Vec<u8>,
     gdi_capturer: Option<CapturerGDI>,
     gdi_buffer: Vec<u8>,
+    saved_raw_data: Vec<u128>, // for faster compare and copy
 }
 
 impl Capturer {
@@ -150,6 +151,7 @@ impl Capturer {
             rotated: Vec::new(),
             gdi_capturer,
             gdi_buffer: Vec::new(),
+            saved_raw_data: Vec::new(),
         })
     }
 
@@ -233,7 +235,13 @@ impl Capturer {
             let result = {
                 if let Some(gdi_capturer) = &self.gdi_capturer {
                     match gdi_capturer.frame(&mut self.gdi_buffer) {
-                        Ok(_) => &self.gdi_buffer,
+                        Ok(_) => {
+                            crate::would_block_if_equal(
+                                &mut self.saved_raw_data,
+                                &self.gdi_buffer,
+                            )?;
+                            &self.gdi_buffer
+                        }
                         Err(err) => {
                             return Err(io::Error::new(io::ErrorKind::Other, err.to_string()));
                         }

libs/scrap/src/quartz/frame.rs

@@ -29,10 +29,12 @@ impl Frame {
         }
     }
 
+    #[inline]
+    pub fn inner(&self) -> &[u8] {
+        self.inner
+    }
+
     pub fn nv12_to_i420<'a>(&'a mut self, w: usize, h: usize, i420: &'a mut Vec<u8>) {
-        if self.inner.is_empty() {
-            return;
-        }
         unsafe {
             let plane0 = IOSurfaceGetBaseAddressOfPlane(self.surface, 0);
             let stride0 = IOSurfaceGetBytesPerRowOfPlane(self.surface, 0);

libs/scrap/src/x11/capturer.rs

@@ -14,6 +14,7 @@ pub struct Capturer {
     size: usize,
     use_yuv: bool,
     yuv: Vec<u8>,
+    saved_raw_data: Vec<u128>, // for faster compare and copy
 }
 
 impl Capturer {
@@ -68,6 +69,7 @@ impl Capturer {
             size,
             use_yuv,
             yuv: Vec::new(),
+            saved_raw_data: Vec::new(),
         };
         Ok(c)
     }
@@ -97,15 +99,16 @@ impl Capturer {
         }
     }
 
-    pub fn frame<'b>(&'b mut self) -> &'b [u8] {
+    pub fn frame<'b>(&'b mut self) -> std::io::Result<&'b [u8]> {
         self.get_image();
         let result = unsafe { slice::from_raw_parts(self.buffer, self.size) };
-        if self.use_yuv {
+        crate::would_block_if_equal(&mut self.saved_raw_data, result)?;
+        Ok(if self.use_yuv {
             crate::common::bgra_to_i420(self.display.w(), self.display.h(), &result, &mut self.yuv);
             &self.yuv[..]
         } else {
             result
-        }
+        })
     }
 }