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()?))
     }
 }