BBMetalCamera adds setFrameRate(_:) method

Silence-GitHub · May 21, 2019 · a9b7a40 · a9b7a40
1 parent 0184791
commit a9b7a40
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Showing 2 changed files with 41 additions and 1 deletion.
diff --git a/BBMetalImage/BBMetalImage/BBMetalCamera.swift b/BBMetalImage/BBMetalImage/BBMetalCamera.swift
@@ -345,6 +345,47 @@ public class BBMetalCamera: NSObject {
         return true
     }
 
+    /// Sets camera frame rate
+    ///
+    /// - Parameter frameRate: camera frame rate
+    @discardableResult
+    public func setFrameRate(_ frameRate: Float64) -> Bool {
+        var success = false
+        lock.wait()
+        do {
+            try camera.lockForConfiguration()
+            var targetFormat: AVCaptureDevice.Format?
+            let dimensions = CMVideoFormatDescriptionGetDimensions(camera.activeFormat.formatDescription)
+            for format in camera.formats {
+                let newDimensions = CMVideoFormatDescriptionGetDimensions(format.formatDescription)
+                if dimensions.width == newDimensions.width,
+                    dimensions.height == newDimensions.height {
+                    for range in format.videoSupportedFrameRateRanges {
+                        if range.maxFrameRate >= frameRate,
+                            range.minFrameRate <= frameRate {
+                            targetFormat = format
+                            break
+                        }
+                    }
+                    if targetFormat != nil { break }
+                }
+            }
+            if let format = targetFormat {
+                camera.activeFormat = format
+                camera.activeVideoMaxFrameDuration = CMTime(value: 1, timescale: CMTimeScale(frameRate))
+                camera.activeVideoMinFrameDuration = CMTime(value: 1, timescale: CMTimeScale(frameRate))
+                success = true
+            } else {
+                print("Can not find valid format for camera frame rate \(frameRate)")
+            }
+            camera.unlockForConfiguration()
+        } catch {
+            print("Error for camera lockForConfiguration: \(error as NSError)")
+        }
+        lock.signal()
+        return success
+    }
+
     /// Starts capturing
     public func start() { session.startRunning() }
 

diff --git a/BBMetalImageDemo/BBMetalImageDemo/CameraFilterVC.swift b/BBMetalImageDemo/BBMetalImageDemo/CameraFilterVC.swift
@@ -68,7 +68,6 @@ class CameraFilterVC: UIViewController {
 
         filePath = NSTemporaryDirectory() + "test.mp4"
         let url = URL(fileURLWithPath: filePath)
-        try? FileManager.default.removeItem(at: url)
         videoWriter = BBMetalVideoWriter(url: url, frameSize: BBMetalIntSize(width: 1080, height: 1920))
 
         camera = BBMetalCamera(sessionPreset: .hd1920x1080)