From 31b60ae28e6aff6d23b378cd77e288c96c7db148 Mon Sep 17 00:00:00 2001
From: dyknon <dyknon@r5f.jp>
Date: Sun, 23 Feb 2025 08:33:02 +0900
Subject: abstruction

---
 src/v4l2cairo.rs | 88 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 88 insertions(+)
 create mode 100644 src/v4l2cairo.rs

(limited to 'src/v4l2cairo.rs')

diff --git a/src/v4l2cairo.rs b/src/v4l2cairo.rs
new file mode 100644
index 0000000..322a14b
--- /dev/null
+++ b/src/v4l2cairo.rs
@@ -0,0 +1,88 @@
+use anyhow::{anyhow, Result};
+use crate::gtk;
+use crate::v4l2;
+use crate::color::yuv2rgb;
+use zune_jpeg::JpegDecoder as JpegDec;
+use zune_jpeg::zune_core::options::DecoderOptions as JpegOptions;
+use zune_jpeg::zune_core::colorspace::ColorSpace as JpegColorSpace;
+
+pub struct V4l2Cairo(v4l2::CaptStream);
+impl V4l2Cairo{
+    pub fn new(inner: v4l2::CaptStream) -> Self{
+        V4l2Cairo(inner)
+    }
+}
+impl gtk::Source for V4l2Cairo{
+    type Attr = ();
+    fn next(&mut self, fbpool: impl gtk::FbSourceOnce)
+    -> Result<gtk::Packet<()>>{
+        let mut fbpool = Some(fbpool);
+        let (w, h) = (self.0.width(), self.0.height());
+        let s = self.0.bytesperline();
+        let pixelformat = self.0.pixelformat();
+        loop{
+            let img = self.0.next(|frame, _|{
+                if &pixelformat == "YUYV"{
+                    if w % 2 != 0{
+                        return Err(anyhow!("invalid width of YUYV"));
+                    }
+                    if frame.len() < w*h*2{
+                        return Err(anyhow!("invalid size of YUYV"));
+                    }
+                    let mut img = fbpool.take().unwrap().get(w, h)?;
+                    let stride: usize = img.stride().try_into()?;
+                    let mut imgslice = img.data()?;
+                    for (x, y) in (0..h).map(
+                            |y| (0..w).map(move |x|(x, y))).flatten(){
+                        let p = s*y + x*2;
+                        let (r, g, b) = yuv2rgb(
+                            frame[p], frame[p/4*4 + 1], frame[p/4*4 + 3]);
+                        imgslice[stride*y + x*4 + 0] = b;
+                        imgslice[stride*y + x*4 + 1] = g;
+                        imgslice[stride*y + x*4 + 2] = r;
+                        imgslice[stride*y + x*4 + 3] = 0;
+                    }
+                    drop(imgslice);
+                    Ok(img)
+                }else if &pixelformat == "MJPG" || &pixelformat == "JPEG"{
+                    // Jpeg is not placed in start of slice in some situation.
+                    // It is even possible that there are no Jpeg data.
+                    let jindex = (0..frame.len()-1)
+                        .filter(|i| frame[*i] == 0xff && frame[i+1] == 0xd8)
+                        .next()
+                        .ok_or(anyhow!("jpeg not found"))?;
+
+                    let mut jpeg = JpegDec::new_with_options(
+                        &frame[jindex..],
+                        JpegOptions::new_fast()
+                            .jpeg_set_out_colorspace(JpegColorSpace::BGRA));
+                    let b = jpeg.decode()?;
+                    let info = jpeg.info().unwrap();
+
+                    if info.width as usize != w || info.height as usize != h{
+                        return Err(anyhow!("invalid size of jpeg"));
+                    }
+                    let mut img = fbpool.take().unwrap().get(w, h)?;
+                    let stride: usize = img.stride().try_into()?;
+                    let mut imgslice = img.data()?;
+                    for y in 0..h{
+                        imgslice[stride*y..stride*y+w*4]
+                            .copy_from_slice(&b[y*w*4..((y+1)*w)*4]);
+                    }
+                    drop(imgslice);
+                    Ok(img)
+                }else{
+                    unimplemented!()
+                }
+            })?;
+
+            if let Ok(img) = img{
+                return Ok(gtk::Packet{
+                    image: img.take_data()?,
+                    attr: (),
+                });
+            }
+        }
+    }
+}
+
-- 
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