ExoPlayer 无法与摄像机 IP 地址建立连接

Question

我正在尝试使用 RTMP 协议在应用程序中流式传输相机预览。从一个星期开始，我正在调试 ExoPlayer 和 Librtmp 客户端，但不知何故 Librtmp 客户端无法建立连接并触发 RtmpIOException 内部ECONNREFUSED出错。尝试使用 Socket 编程但得到了同样的错误。IP ping 工作正常。我的同事最近在 Librtmp GitHub 存储库上提交了一个问题。自 1 月以来，Devs 没有回复。

我们尝试使用其他库，如 IJKPlayer（内部使用 FFmpeg），它能够流式预览，但在流式预览之前有更多延迟，还有相机 wifi 断开连接问题。由于使用 JNI 构建，无法在内部进一步调试。

代码：

private val bandwidthMeater = DefaultBandwidthMeter()
private val adaptiveTrackSelectionFactory = AdaptiveTrackSelection.Factory(bandwidthMeater)
private val trackSelector = DefaultTrackSelector(adaptiveTrackSelectionFactory)

private val player = ExoPlayerFactory.newSimpleInstance(context, trackSelector)

fun init() {
    player.setVideoSurface(holder.surface)
}

fun startStream(streamUrl: String, startListener: () -> Unit) {
    //e.g. streamUrl = rtmp://192.168.42.5:1936/live/myStream (IP is Android device IP provide by camera when connected to its wifi)
    val rtmpDatasourceFactory = RtmpDatasource.RtmpDataSourceFactory()
    val factory = ExtractorMediaSource.Factory(rtmpDatasourceFactory)
    val extractorMediaSource =factory.createMediaSource(Uri.parse(streamUrl))   

    player.prepare(extractorMediaSource)
    player.playWhenReady = true
}

ExoPlayer 错误：

E/ExoPlayerImplInternal: Source error.
       net.butterflytv.rtmp_client.RtmpClient$RtmpIOException
           at net.butterflytv.rtmp_client.RtmpClient.open(RtmpClient.java:56)
           at com.google.android.exoplayer2.ext.rtmp.RtmpDataSource.open(RtmpDataSource.java:57)
           at com.google.android.exoplayer2.source.ExtractorMediaPeriod$ExtractingLoadable.load(ExtractorMediaPeriod.java:841)
           at com.google.android.exoplayer2.upstream.Loader$LoadTask.run(Loader.java:308)
           at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113)
           at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588)
           at java.lang.Thread.run(Thread.java:818)

连接错误：

java.net.ConnectException: failed to connect to /192.168.42.5 (port 1936): connect failed: ECONNREFUSED (Connection refused)

Answer 1

您是否在运行时请求了许可？

每次我遇到这种类型的错误时，这就是我忘记做的事情。

https://developer.android.com/training/permissions/requesting#java