fix： 树莓派gstreamer pipeline报错

src/camera/opencv.rs

@@ -69,7 +69,7 @@ impl OpenCVCamera {
                         path_str
                     );
                     info!("Using GStreamer pipeline: {}", pipeline);
-                    return Ok(videoio::VideoCapture::from_file(&pipeline, videoio::CAP_FFMPEG)?);
+                    return Ok(videoio::VideoCapture::from_file(path_str, videoio::CAP_V4L2)?);
                 } else {
                     return Err(anyhow!("Invalid device number in path: {}", path_str));
                 }