拍摄固定尺寸的视频

Question

无论如何，我都想捕获1280x720。我使用以下代码：

guard let capturer = self.videoCapturer as? RTCCameraVideoCapturer else {
            return
        }

        capturer.captureSession.sessionPreset = AVCaptureSession.Preset.hd1280x720

        guard
            let frontCamera = (RTCCameraVideoCapturer.captureDevices().first { $0.position == .front }),

            // choose highest res
            let format = (RTCCameraVideoCapturer.supportedFormats(for: frontCamera).sorted { (f1, f2) -> Bool in
                let width1 = CMVideoFormatDescriptionGetDimensions(f1.formatDescription).width
                let width2 = CMVideoFormatDescriptionGetDimensions(f2.formatDescription).width
                return width1 < width2
            }).last,



            // choose highest fps
            let fps = (format.videoSupportedFrameRateRanges.sorted { return $0.maxFrameRate < $1.maxFrameRate }.last) else {
                return
        }

       // capturer.startCapture(with: frontCamera, format: AVCaptureSession.Preset.hd1280x720, fps: 10)

        print(format)

        capturer.startCapture(
            with: frontCamera, format: format, fps: 10
        )

但这确实捕获了可用的最佳分辨率，而不是顶部定义的AcCaptureSession.Preset.hd1280x720。如何使用该设置捕获它？