Function open

rustcv-backend-msmf/src/device.rs:210–235

Opens a camera device and negotiates the video format based on configuration This is the main entry point for opening a camera. The function: 1. Initializes Media Foundation if not already initialized 2. Creates a hardware MediaSource for the specified device 3. Probes supported formats directly from the MediaSource 4. Selects the best matching format based on configuration requirements 5. Create

(id: &str, config: CameraConfig)

/// - `Box<dyn Stream>` - The initialized camera stream for frame capture
/// - `DeviceControls` - Control interface for device-specific operations (exposure, focus, etc.)
pub fn open(id: &str, config: CameraConfig) -> Result<(Box<dyn Stream>, DeviceControls)> {
    initialize_mf()?;

    // 1. Find and create hardware MediaSource
    let media_source = unsafe { create_media_source(id)? };

    // 2. Directly probe supported formats from MediaSource without creating Reader yet
    let negotiated_fmt = negotiate_format(&media_source, &config)?;

    tracing::info!(
        "Camera opened: {}x{} @ {}fps ({:?})",
        negotiated_fmt.width,
        negotiated_fmt.height,
        negotiated_fmt.fps,
        negotiated_fmt.format
    );

    // 3. Create MsmfStream
    // Async Reader creation and callback binding are now fully encapsulated inside MsmfStream
    let stream = MsmfStream::new(&media_source, negotiated_fmt)
        .map_err(|e| CameraError::Io(std::io::Error::other(e.to_string())))?;

    let controls = create_controls(stream.get_reader());

    Ok((Box::new(stream), controls))
}

/// Creates a MediaSource for a specific camera device
///