videoDevice.activeFormat只是当前格式。videoDevice.formats包含所有可能的格式。

矿山报告许多能够 60fps 的格式，例如

<CaptureDeviceFormat: 0x28337d7c0 'vide'/'420f' 1280x 720, { 1- 60 fps}, HRSI:2112x1188, fov:70.291, binned, supports vis, max zoom:24.00 (upscales @1.50), AF System:1, ISO:33.0-3168.0, SS:0.000015-1.000000, supports wide color, supports multicam>
...

所以选择最适合你的格式，然后让你的activeFormat并设置所需的帧持续时间如下：

try! videoDevice.lockForConfiguration()
videoDevice.activeFormat = my60FPSFormat
videoDevice.activeVideoMinFrameDuration = CMTime(value: 1, timescale: 60)
videoDevice.activeVideoMaxFrameDuration = CMTime(value: 1, timescale: 60)
videoDevice.unlockForConfiguration()

谢谢，这回答了我的问题！:)

对于任何人仍然想知道下面是我使用的代码：

    // Instantiate the video device: wide angle camera, back position
    let videoDevice = CaptureDevice.default(.builtInWideAngleCamera,
                                              for: .video,
                                              position: .back)
    
    
    // Set the frame rate to 60, as expected by the model
    try! videoDevice?.lockForConfiguration()
    
    videoDevice?.activeFormat = (videoDevice?.formats[30])!
    videoDevice?.activeVideoMinFrameDuration = CMTimeMake(value: 1, timescale: 60)
    videoDevice?.activeVideoMaxFrameDuration = CMTimeMake(value: 1, timescale: 60)
    
    videoDevice?.unlockForConfiguration()
    // Debug only
    // print(videoDevice?.activeFormat)

但是，请确保添加一些错误处理：D

再次感谢。

虽然其他答案提供了解决方案的大纲，但当我需要给定帧速率的最佳分辨率时，对我有用的是，如果你想进一步限制某些帧分辨率，你可以添加一个过滤器方法来确保尺寸的阈值。

extension CaptureDevice {
    func set(frameRate: Double) {
        do { try lockForConfiguration()
            activeFormat = formats.sorted(by: { f1, f2 in
                 f1.formatDescription.dimensions.height > f2.formatDescription.dimensions.height && f1.formatDescription.dimensions.width > f2.formatDescription.dimensions.width
            }).first(where: { format in
                format.videoSupportedFrameRateRanges.contains { range in
                    range.maxFrameRate == frameRate
                }
            }) ?? activeFormat
            guard let range = activeFormat.videoSupportedFrameRateRanges.first,
                  range.minFrameRate...range.maxFrameRate ~= frameRate
            else {
                print("Requested FPS is not supported by the device's activeFormat !")
                return
            }
            activeVideoMinFrameDuration = CMTimeMake(value: 1, timescale: Int32(frameRate))
            activeVideoMaxFrameDuration = CMTimeMake(value: 1, timescale: Int32(frameRate))
            unlockForConfiguration()
        } catch {
            print("LockForConfiguration failed with error: \(error.localizedDescription)")
        }
    }
}