fix： 树莓派gstreamer pipeline报错

src/camera/opencv.rs

@@ -63,7 +63,13 @@ impl OpenCVCamera {
             // For Linux device files like /dev/video0
             if let Some(num_str) = path_str.strip_prefix("/dev/video") {
                 if let Ok(device_index) = num_str.parse::<i32>() {
-                    return Ok(videoio::VideoCapture::new(device_index, videoio::CAP_ANY)?);
+                    // 在Linux下使用GStreamer pipeline
+                    let pipeline = format!(
+                        "v4l2src device={} ! videoconvert ! video/x-raw,format=BGR ! appsink",
+                        path_str
+                    );
+                    info!("Using GStreamer pipeline: {}", pipeline);
+                    return Ok(videoio::VideoCapture::from_file(&pipeline, videoio::CAP_GSTREAMER)?);
                 } else {
                     return Err(anyhow!("Invalid device number in path: {}", path_str));
                 }
@@ -193,6 +199,30 @@ impl OpenCVCamera {
             return Err(anyhow!("Camera is not open"));
         }
         
+        #[cfg(target_os = "linux")]
+        {
+            // 在Linux下创建一个使用GStreamer的流
+            if self.device.starts_with("/dev/video") {
+                let pipeline = format!(
+                    "v4l2src device={} ! videoconvert ! video/x-raw,width={},height={},format=BGR,framerate={}/1 ! appsink",
+                    self.device, self.width, self.height, 30 // 使用固定的30fps，或者从设置获取
+                );
+                info!("Starting stream with GStreamer pipeline: {}", pipeline);
+                let stream_capture = videoio::VideoCapture::from_file(&pipeline, videoio::CAP_GSTREAMER)?;
+                if !stream_capture.is_opened()? {
+                    return Err(anyhow!("Failed to open GStreamer camera stream"));
+                }
+                
+                self.is_streaming = true;
+                info!("Started camera streaming with GStreamer");
+                
+                return Ok(OpenCVCaptureStream {
+                    capture: stream_capture,
+                });
+            }
+        }
+        
+        // For non-Linux platforms or if GStreamer approach fails, use regular approach
         // Create a separate VideoCapture for the stream to avoid concurrent access issues
         let device = self.device.clone();
         let mut stream_capture = Self::create_capture_from_path(&device)?;