avfoundation

来源： https://stackoverflow.com/questions/63028486/ios-swift-avfoundation-video-recording-avcapturemoviefileoutput-isrecording-valu

来源： https://stackoverflow.com/questions/63002615/avfoundation-first-frame-from-recorded-mix-composition-video-is-black

来源： https://stackoverflow.com/questions/63002615/avfoundation-first-frame-from-recorded-mix-composition-video-is-black

来源： https://stackoverflow.com/questions/48646470/ios-device-not-listed-by-avcapturedevice-devices-unless-quicktime-is-opened

来源： https://stackoverflow.com/questions/55150887/capture-photo-with-a-different-dimension-than-displayed

问题 I have an AVMutableComposition with 2 audio tracks and one video track. I'm using the composition to string about 40 different video clips from .mov files, putting the video content of each clip in the video track of my composition and the audio in the audio track. The second audio track I use for music. I also have a synchronized layer for titles graphics. When I play this composition using an AVPlayer, the audio slowly gets out of sync. It takes about 4 minutes to start becoming noticeable.

问题 I was trying to use AVCaptureMovieFileOutput to record the device camera to a video file when my app starts. To my great frustration, I could not get it to work: I could view the video feed using a AVCaptureVideoPreviewLayer just fine, so my session was wired up properly. The file to which it would output did not already exist, and was in a writable directory. No errors were returned from API calls or via AVCaptureSessionRuntimeError notifications. My AVCaptureFileOutputRecordingDelegate

问题 I want to capture a picture from the camera with no preview. Though I am able to do that with a UIViewController with the help of AVFoundation framework. But now I have to do the same without the ViewController. #Issue When I trying to do the same with a NSObject class the AVCapturePhotoCaptureDelegate is not called. TestingCamera.h #import <AVFoundation/AVFoundation.h> NS_ASSUME_NONNULL_BEGIN @interface TestingCamera : NSObject <AVCapturePhotoCaptureDelegate> { AVCaptureSession

问题 I'm trying to build a custom progress bar for a video player app in tvOS, and would like to show thumbnails of the video while the user scans the video. I'm using AVPlayer and Fairplay HLS to play remote video files. I've tried to do this using 2 methods. One with AVAssetImageGenerator 's copyCGImage , and the other with AVPlayerItemVideoOutput 's copyPixelBuffer method. Both return nil. When I tried with a local video file, the first method worked. Method 1: let imageGenerator =

问题 In a WWDC 2016 video, Apple says create the AVPlayer without an AVPlayerItem, create the AVPlayerLayer, and then assign the AVPlayerItem to the AVPlayer. I got the above code from @matt's Programming iOS 10 book. In it he says: Apparently there is some sort of efficiency if you do things in this order. The reason, it turns out, is that when an AVPlayerItem is assigned to an AVPlayer that doesn't have and associated AVPlayerLayer, the AVPlayer assumes that only the audio track of the AVAssest