IOS Determines the number of frames in a video.

Question

If I have an MPMoviePlayerController in Swift:

MPMoviePlayerController mp = MPMoviePlayerController(contentURL: url)

Is there a way to get the number of frames in a video located in url? If not, is there another way to determine the number of frames?

Answer 1

I do not think that MPMoviePlayerControllercan help you.

Use AVAssetReaderand calculate the amount CMSampleBufferthat it returns to you. You can configure it so that you don’t even have to decode the frames by analyzing the file efficiently, so it should be fast and efficient in terms of memory.

Sort of

    var asset = AVURLAsset(URL: url, options: nil)
    var reader = AVAssetReader(asset: asset, error: nil)
    var videoTrack = asset.tracksWithMediaType(AVMediaTypeVideo)[0] as! AVAssetTrack

    var readerOutput = AVAssetReaderTrackOutput(track: videoTrack, outputSettings: nil) // NB: nil, should give you raw frames
    reader.addOutput(readerOutput)
    reader.startReading()

    var nFrames = 0

    while true {
        var sampleBuffer = readerOutput.copyNextSampleBuffer()
        if sampleBuffer == nil {
            break
        }

        nFrames++
    }

    println("Num frames: \(nFrames)")

, , .

Answer 2

Swift 5

 func getNumberOfFrames(url: URL) -> Int {
        let asset = AVURLAsset(url: url, options: nil)
        do {
            let reader = try AVAssetReader(asset: asset)
        //AVAssetReader(asset: asset, error: nil)
            let videoTrack = asset.tracks(withMediaType: AVMediaType.video)[0]

            let readerOutput = AVAssetReaderTrackOutput(track: videoTrack, outputSettings: nil) // NB: nil, should give you raw frames
            reader.add(readerOutput)
        reader.startReading()

        var nFrames = 0

        while true {
            let sampleBuffer = readerOutput.copyNextSampleBuffer()
            if sampleBuffer == nil {
                break
            }

            nFrames = nFrames+1
        }

        print("Num frames: \(nFrames)")
            return nFrames
        }catch {
            print("Error: \(error)")
        }
        return 0
    }