feat: Add Livestream Latency Metrics (#15)

* Add some methods that parse tags

* Add livestream metrics

* Add example

app/src/main/java/com/mux/stats/muxdatasdkformedia3/MainActivity.kt

@@ -38,9 +38,19 @@ class MainActivity : AppCompatActivity() {
       destination = Intent(this, ImaAdsActivity::class.java)
     ),
     Example(
-      title = "Background playback",
-      destination = Intent(this, BackgroundPlayActivity::class.java)
+      title = "Live Playback",
+      destination = Intent(this, BasicPlayerActivity::class.java).apply {
+        putExtra(
+          BasicPlayerActivity.EXTRA_URL,
+          "https://stream.mux.com/v69RSHhFelSm4701snP22dYz2jICy4E4FUyk02rW4gxRM.m3u8"
+        )
+      }
     ),
+    // TODO: post-beta, add APIs for talking to a `MediaSessionService`
+//    Example(
+//      title = "Background playback",
+//      destination = Intent(this, BackgroundPlayActivity::class.java)
+//    ),
   )
 }
 

app/src/main/java/com/mux/stats/muxdatasdkformedia3/examples/basic/BasicPlayerActivity.kt

@@ -39,7 +39,9 @@ class BasicPlayerActivity : AppCompatActivity() {
 
   override fun onResume() {
     super.onResume()
-    startPlaying(Constants.VOD_TEST_URL_DRAGON_WARRIOR_LADY)
+    startPlaying(
+      intent.getStringExtra(EXTRA_URL) ?: Constants.VOD_TEST_URL_DRAGON_WARRIOR_LADY
+    )
   }
 
   override fun onPause() {
@@ -92,9 +94,14 @@ class BasicPlayerActivity : AppCompatActivity() {
         addListener(object : Player.Listener {
           override fun onPlayerError(error: PlaybackException) {
             Log.e(javaClass.simpleName, "player error!", error)
-            Toast.makeText(this@BasicPlayerActivity, error.localizedMessage, Toast.LENGTH_SHORT).show()
+            Toast.makeText(this@BasicPlayerActivity, error.localizedMessage, Toast.LENGTH_SHORT)
+              .show()
           }
         })
       }
   }
+
+  companion object {
+    const val EXTRA_URL: String = "com.mux.video.url"
+  }
 }

build.gradle

@@ -10,6 +10,6 @@ allprojects {
   project.ext {
     media3Version = '1.0.2'
 //    coreVersion = "0.7.4"
-    coreVersion = 'dev-releases-v0.7.5-aab9aec'
+    coreVersion = 'dev-feat-live-069a758'
   }
 }

library-exo/src/main/java/com/mux/stats/sdk/muxstats/ExoPlayerBinding.kt

@@ -18,6 +18,7 @@ import com.mux.stats.sdk.core.util.MuxLogger
 import com.mux.stats.sdk.muxstats.bandwidth.BandwidthMetricDispatcher
 import com.mux.stats.sdk.muxstats.bandwidth.TrackedHeader
 import com.mux.stats.sdk.muxstats.internal.createExoSessionDataBinding
+import com.mux.stats.sdk.muxstats.internal.populateLiveStreamData
 import com.mux.stats.sdk.muxstats.internal.createErrorDataBinding
 import java.io.IOException
 import java.util.regex.Pattern
@@ -96,6 +97,7 @@ private class MuxAnalyticsListener(
     eventTime.timeline.takeIf { it.windowCount > 0 }?.let { tl ->
       val window = Timeline.Window().apply { tl.getWindow(0, this) }
       collector.sourceDurationMs = window.durationMs
+      collector.populateLiveStreamData(window)
     }
   }
 

library-exo/src/main/java/com/mux/stats/sdk/muxstats/internal/HlsUtils.kt

@@ -0,0 +1,90 @@
+package com.mux.stats.sdk.muxstats.internal
+
+import androidx.annotation.OptIn
+import androidx.media3.common.Timeline
+import androidx.media3.common.Timeline.Window
+import androidx.media3.common.util.UnstableApi
+import androidx.media3.exoplayer.hls.HlsManifest
+import com.mux.stats.sdk.core.util.MuxLogger
+import com.mux.stats.sdk.muxstats.MuxStateCollector
+
+/*
+ * HlsUtils.kt: Utility functions for working with HLS playlists in exoplayer
+ */
+
+// lazily-cached check for the HLS extension, which may not be available at runtime
+@OptIn(UnstableApi::class) // opting-in to HlsManifest
+private val hlsExtensionAvailable: Boolean by lazy {
+  try {
+    Class.forName(HlsManifest::class.java.canonicalName!!)
+    true
+  } catch (e: ClassNotFoundException) {
+    MuxLogger.w("isHlsExtensionAvailable", "HLS extension not found. Some features may not work")
+    false
+  }
+}
+
+/**
+ * True when Exoplayer's HLS extension is available at runtime
+ */
+@JvmSynthetic
+internal fun isHlsExtensionAvailable() = hlsExtensionAvailable
+
+/**
+ * Add livestream data to a [MuxStateCollector] if the given [Window] represents a live stream
+ */
+@JvmSynthetic
+internal fun MuxStateCollector.populateLiveStreamData(window: Window) {
+  if (window.isLive()) {
+    hlsManifestNewestTime = window.windowStartTimeMs
+    hlsHoldBack = parseManifestTagL(window, "HOLD-BACK")
+    hlsPartHoldBack = parseManifestTagL(window, "PART-HOLD-BACK")
+    hlsPartTargetDuration = parseManifestTagL(window, "PART-TARGET")
+    hlsTargetDuration = parseManifestTagL(window, "EXT-X-TARGETDURATION")
+  }
+}
+
+/**
+ * Parses manifest tags representing a named numerical value, returning the value as a Long
+ */
+@JvmSynthetic
+internal fun parseManifestTagL(currentWindow: Window, tagName: String): Long {
+  var value: String = parseManifestTag(currentWindow, tagName)
+  value = value.replace(".", "")
+  try {
+    return value.toLong()
+  } catch (e: NumberFormatException) {
+    MuxLogger.exception(e, "Manifest Parsing", "Bad number format for value: $value")
+  }
+  return -1L
+}
+
+/**
+ * Parses manifest tags representing a named numerical value, returning the value as a string
+ */
+@OptIn(UnstableApi::class)
+@JvmSynthetic
+internal fun parseManifestTag(currentWindow: Timeline.Window, tagName: String): String {
+  if (!isHlsExtensionAvailable()) {
+    return "-1"
+  }
+
+  if (currentWindow.manifest != null && tagName.isNotEmpty()) {
+    if (currentWindow.manifest is HlsManifest) {
+      val manifest = currentWindow.manifest as HlsManifest
+      for (tag in manifest.mediaPlaylist.tags) {
+        if (tag.contains(tagName)) {
+          var value = tag.split(tagName).toTypedArray()[1]
+          if (value.contains(",")) {
+            value = value.split(",").toTypedArray()[0]
+          }
+          if (value.startsWith("=") || value.startsWith(":")) {
+            value = value.substring(1, value.length)
+          }
+          return value
+        }
+      }
+    }
+  }
+  return "-1"
+}