Method read

rustcv/src/videoio/mod.rs:168–265

(&mut self, mat: &mut Mat)

    }

    pub fn read(&mut self, mat: &mut Mat) -> Result<bool> {
        if !self.is_opened {
            return Ok(false);
        }
        if self.cmd_tx.send(Command::NextFrame).is_err() {
            return Err(anyhow!("Background worker is dead"));
        }

        let response = self
            .res_rx
            .recv()
            .map_err(|_| anyhow!("Failed to receive response"))?;

        match response {
            Response::FrameData {
                width,
                height,
                data,
                fourcc,
            } => {
                self.width = width as i32;
                self.height = height as i32;

                // 确保 Mat 大小匹配
                let target_len = (width * height * 3) as usize;
                if mat.data.len() != target_len {
                    mat.data = vec![0; target_len];
                }
                mat.rows = height as i32;
                mat.cols = width as i32;
                mat.channels = 3;
                mat.step = (width * 3) as usize;

                let fcc = FourCC(fourcc);
                if fcc == FourCC::YUYV {
                    yuyv_to_bgr(&data, &mut mat.data, width as usize, height as usize);
                } else if fcc == FourCC::BGRA {
                    bgra_to_bgr(&data, &mut mat.data, width as usize, height as usize);
                } else if fcc == FourCC::NV12 {
                    nv12_to_bgr(&data, &mut mat.data, width as usize, height as usize);
                } else if fcc == FourCC::MJPEG {
                    // === TurboJPEG v1.4.0 极速解码 ===
                    #[cfg(feature = "turbojpeg")]
                    {
                        // 1. 创建解压器
                        // v1.4.0 API: Decompressor::new() 返回 Result
                        let mut decompressor = Decompressor::new()
                            .map_err(|e| anyhow!("Failed to init TurboJPEG: {}", e))?;

                        // 2. 读取头部信息 (可选，但为了保险起见，获取精确的图像尺寸)
                        let header = decompressor
                            .read_header(&data)
                            .map_err(|e| anyhow!("Failed to read JPEG header: {}", e))?;

                        // 3. 构建 Image 视图，直接指向 Mat 的数据
                        // 这是一个 Zero-Copy 操作，Image 只是 Mat.data 的一个借用封装
                        let image = Image {
                            pixels: mat.data.as_mut_slice(), // 直接写入 Mat