avfoundation

问题 I am trying to get subtitles to display regardless of what the device has set under the accessibilities. Currently, if the device is set to English with closed captioning enabled in settings, English subtitles will play, and if the device is set to Spanish, Spanish subtitles will play. I would like subtitles to play regardless of whether or not closed captioning is on. I attempted to add this code from apple's documentation, but it did not help. It seems to be reading the options fine,

问题 I use AVPlayerViewController to play short videos in my app. If there is an app playing audio in background before user plays a video in my app, I want the background audio playing of the other app to resume after my video player is dismissed. I currently use AVAudioSession.setActive(false, with: .notifyOthersOnDeactivation) to do that. Even though Apple's Music app and Podcasts app do resume playing after I call AVAudioSession.setActive(false, with: .notifyOthersOnDeactivation) —won't resume

问题 I use AVPlayerViewController to play short videos in my app. If there is an app playing audio in background before user plays a video in my app, I want the background audio playing of the other app to resume after my video player is dismissed. I currently use AVAudioSession.setActive(false, with: .notifyOthersOnDeactivation) to do that. Even though Apple's Music app and Podcasts app do resume playing after I call AVAudioSession.setActive(false, with: .notifyOthersOnDeactivation) —won't resume

问题 I am developing a custom video player to stream HLS videos from server. I can successfully play HLS videos using AVPlayerItem and AVPlayer. After that I want to add subtitle track and audio tracks for my video player. So I used AVMutableComposition to do so. So now the issue is when I am creating AVURLAsset for HLS Videos, I can't able to get video tracks from AVURLAsset. It is giving me always 0 tracks. I tried "loadValuesAsynchronously" of AVURLAsset and I tried adding KVO for "tracks" of

问题 I'm new to video programming. I'm trying to exercise it but I'm having trouble, which merges two video files to one. The merge I mean is as follows.. I have first video like this Second video also like this I want them to merge like this I didn't want to use 2 video players because I want to send the merged video file to someone. I searched all day to solve this, but I could't find how to. I wrote code referencing this link but it shows first video only, not merged. My Code: NSURL *firstURL =

问题 I'm trying to record segments of audio and recombine them without producing a gap in audio. The eventual goal is to also have video, but I've found that audio itself creates gaps when combined with ffmpeg -f concat -i list.txt -c copy out.mp4 If I put the audio in an HLS playlist, there are also gaps, so I don't think this is unique to ffmpeg. The idea is that samples come in continuously, and my controller routes samples to the proper AVAssetWriter . How do I eliminate gaps in audio? import

问题 I'm trying to adapt Apple's AVCamFilter sample to MacOS. The filtering appears to work, but rendering the processed image through Metal gives me a framerate of several seconds per frame. I've tried different approaches, but have been stuck for a long time. This is the project AVCamFilterMacOS - Can anyone with better knowledge of AVFoundation with Metal tell me what's wrong? I've been reading the documentation and practicing getting the unprocessed image to display, as well as rendering other

问题 I'm trying to adapt Apple's AVCamFilter sample to MacOS. The filtering appears to work, but rendering the processed image through Metal gives me a framerate of several seconds per frame. I've tried different approaches, but have been stuck for a long time. This is the project AVCamFilterMacOS - Can anyone with better knowledge of AVFoundation with Metal tell me what's wrong? I've been reading the documentation and practicing getting the unprocessed image to display, as well as rendering other

问题 This question already has answers here : How to use instance method as callback for function which takes only func or literal closure (2 answers) Closed 1 year ago . I'm currently trying to use VideoToolbox to encode video data from an AVCaptureVideoDataOutput , but I'm having an issue referencing self from within the VTCompressionOutputCallback . My code is as follows: ... var sessionRef: VTCompressionSession? let outputCallback: VTCompressionOutputCallback = { _, _, status, _, sampleBuffer

问题 I am creating an AVMutableComposition . I need the asset to be flipped horizontally, so I am setting the transform of the composition track like this: compositionTrack.preferredTransform = assetTrack.preferredTransform.scaledBy(x: -1, y: 1) If I export this (I use AVAssetPreset960x640 as my preset), this works as expected. However, I also need to add an AVMutableVideoComposition overlay to be rendered with this copmosition. This overlay shouldn't be flipped horizontally. I specify this like