Question

我使用AVPlayer通过互联网播放音频直播。如果暂停时间超过1分钟，我想恢复播放。

我致电player.rate = 1.0继续。但是，如果流暂停> 1分钟，则不再播放。在这种情况下，我需要重新创建AVPlayerItem以使其再次工作。

所以我怎么能抓住这个案子，所以我知道播放没有恢复？

我在player.rate上尝试了KVO。它保持在1.0。玩家没有玩！
我在currentItem.playbackBufferEmpty上尝试了KVO。但是在这种情况下不会调用它。
currentItem.status未切换为.Failed。它完全没有变化。

在这种情况下，AVPlayer似乎什么都不做。有什么想法吗？

我构建了一个Playground代码来演示这个问题：

import UIKit
import AVFoundation

// keep it running forever so it plays audio
import XCPlayground
XCPSetExecutionShouldContinueIndefinitely(true)

class AVPlayerTest {

    let player = AVPlayer()
    let streamurl = NSURL(string: "http://detektor.fm/stream/mp3/musik/")!

    func startTest() {
        let item = AVPlayerItem(URL: streamurl)
        player.replaceCurrentItemWithPlayerItem(item)
        player.play()

        // give it some start time to build a buffer
        NSTimer.scheduledTimerWithTimeInterval(2, target: self, selector: #selector(timerTickedToPause), userInfo: nil, repeats: false)
    }

    @objc func timerTickedToPause(timer: NSTimer) {
        player.pause()
        // pause now for some time. 90s is not enough.
        NSTimer.scheduledTimerWithTimeInterval(120, target: self, selector: #selector(timerTickedToPlay), userInfo: nil, repeats: false)
    }

    @objc func timerTickedToPlay(timer: NSTimer) {
        // try to resume playback

        print(player.rate)

        player.play()

        print(player.rate)

        // check in some seconds if it recovered
        NSTimer.scheduledTimerWithTimeInterval(10, target: self, selector: #selector(timerTickedCheck), userInfo: nil, repeats: false)
    }

    @objc func timerTickedCheck(timer: NSTimer) {

        // it reports rate = 1.0 but is not playing here though!
        // there is no way to know for me it did not recover here!?
        print(player.rate)

        // recover by creating a new item works
        let item = AVPlayerItem(URL: streamurl)
        player.replaceCurrentItemWithPlayerItem(item)
        player.play()
    }
}

let test = AVPlayerTest()
test.startTest()

Answer 1

使用AVPlayer实例的 timeControlStatus “指示播放当前是否正在进行，无限期暂停，或在等待适当的网络条件时暂停。”

let status = player.timeControlStatus

switch status {
case .paused:
    print("timeControlStatus.paused")

case .playing:
    print("timeControlStatus.playing")

case .waitingToPlayAtSpecifiedRate:
    print("timeControlStatus.waitingToPlayAtSpecifiedRate")
    if let reason = player.reasonForWaitingToPlay {

        switch reason {
        case .evaluatingBufferingRate:
            print("reasonForWaitingToPlay.evaluatingBufferingRate")

        case .toMinimizeStalls:
            print("reasonForWaitingToPlay.toMinimizeStalls")

        case .noItemToPlay:
            print("reasonForWaitingToPlay.noItemToPlay")

        default:
            print("Unknown \(reason)")
        }
    }

}

我有同样的问题但在我的情况下，如果我在暂停状态下进入后台，则会发生这种情况。当我回到forground .play（）不起作用。它会遇到waitingToPlayAtSpecifiedRate.evaluatingBufferingRate模式。此时，AVPlayerItem.status实例是readToPlay。

在收到startCommand时的写入时间我重置AV播放器以确定。但这似乎很笨拙。寻找更顺畅的解决方案。

AVPlayer不会触发playbackBufferEmpty，但也不会播放

1 个答案: