Implement audio speed

Author: Zubii12

android/src/main/kotlin/com/simform/audio_waveforms/AudioPlayer.kt

@@ -169,6 +169,19 @@ class AudioPlayer(
         }
     }
 
+    fun setRate(rate: Float?, result: MethodChannel.Result) {
+        try {
+            if (rate != null) {
+                player?.setPlaybackSpeed(rate)
+                result.success(true)
+            } else {
+                result.success(false)
+            }
+        } catch (e: Exception) {
+            result.success(false)
+        }
+    }
+
     private fun startListening(result: MethodChannel.Result) {
         runnable = object : Runnable {
             override fun run() {

android/src/main/kotlin/com/simform/audio_waveforms/AudioWaveformsPlugin.kt

@@ -144,6 +144,15 @@ class AudioWaveformsPlugin : FlutterPlugin, MethodCallHandler, ActivityAware {
                     result.error(Constants.LOG_TAG, "Player key can't be null", "")
                 }
             }
+            Constants.setRate -> {
+                val rate = call.argument(Constants.rate) as Double?
+                val key = call.argument(Constants.playerKey) as String?
+                if (key != null) {
+                    audioPlayers[key]?.setRate(rate?.toFloat(), result)
+                } else {
+                    result.error(Constants.LOG_TAG, "Player key can't be null", "")
+                }
+            }
             Constants.getDuration -> {
                 val type =
                     if ((call.argument(Constants.durationType) as Int?) == 0) DurationType.Current else DurationType.Max

android/src/main/kotlin/com/simform/audio_waveforms/Utils.kt

@@ -49,6 +49,8 @@ object Constants {
     const val progress = "progress"
     const val setVolume = "setVolume"
     const val volume = "volume"
+    const val setRate = "setRate"
+    const val rate = "rate"
     const val getDuration = "getDuration"
     const val durationType = "durationType"
     const val playerKey = "playerKey"

ios/Classes/AudioPlayer.swift

@@ -33,6 +33,8 @@ class AudioPlayer: NSObject, AVAudioPlayerDelegate {
             } catch {
                 result(FlutterError(code: Constants.audioWaveforms, message: "Failed to prepare player", details: error.localizedDescription))
             }
+            player?.enableRate = true
+            player?.rate = 1.0
             player?.prepareToPlay()
             player?.volume = Float(volume ?? 1.0)
             result(true)
@@ -110,6 +112,11 @@ class AudioPlayer: NSObject, AVAudioPlayerDelegate {
         result(true)
     }
 
+    func setRate(_ rate: Double?, _ result: @escaping FlutterResult) {
+        player?.rate = Float(rate ?? 1.0);
+        result(true)
+    }
+    
     func seekTo(_ time: Int?, _ result: @escaping FlutterResult) {
         if(time != nil) {
             player?.currentTime = Double(time! / 1000)

ios/Classes/SwiftAudioWaveformsPlugin.swift

@@ -101,6 +101,13 @@ public class SwiftAudioWaveformsPlugin: NSObject, FlutterPlugin {
             } else {
                 result(FlutterError(code: Constants.audioWaveforms, message: "Can not set volume", details: "Player key is null"))
             }
+        case Constants.setRate:
+            let key = args?[Constants.playerKey] as? String
+            if(key != nil){
+                audioPlayers[key!]?.setRate(args?[Constants.rate] as? Double,result)
+            } else {
+                result(FlutterError(code: Constants.audioWaveforms, message: "Can not set rate", details: "Player key is null"))
+            }
         case Constants.getDuration:
             let type = args?[Constants.durationType] as? Int
             let key = args?[Constants.playerKey] as? String

ios/Classes/Utils.swift

@@ -40,6 +40,8 @@ struct Constants {
     static let seekTo = "seekTo"
     static let progress = "progress"
     static let setVolume = "setVolume"
+    static let setRate = "setRate"
+    static let rate = "rate"
     static let volume = "volume"
     static let getDuration = "getDuration"
     static let durationType = "durationType"

lib/src/base/audio_waveforms_interface.dart

@@ -156,6 +156,15 @@ class AudioWaveformsInterface {
     });
     return result ?? false;
   }
+  
+  ///platform call to set rate
+  Future<bool> setRate(double rate, String key) async {
+    var result = await _methodChannel.invokeMethod(Constants.setRate, {
+      Constants.rate: rate,
+      Constants.playerKey: key,
+    });
+    return result ?? false;
+  }
 
   ///platform call to seek audio at provided position
   Future<bool> seekTo(String key, int progress) async {

lib/src/base/constants.dart

@@ -26,6 +26,8 @@ class Constants {
   static const String progress = "progress";
   static const String setVolume = "setVolume";
   static const String volume = "volume";
+  static const String setRate = "setRate";
+  static const String rate = "rate";
   static const String rightVolume = "rightVolume";
   static const String getDuration = "getDuration";
   static const String durationType = "durationType";

lib/src/controllers/player_controller.dart

@@ -237,6 +237,17 @@ class PlayerController extends ChangeNotifier {
     return result;
   }
 
+  /// Sets rate for this player. Doesn't throw Exception.
+  /// Returns false if it couldn't set the rate.
+  ///
+  /// Default to 1.0
+
+  Future<bool> setRate(double rate) async {
+    final result =
+        await AudioWaveformsInterface.instance.setRate(rate, playerKey);
+    return result;
+  }
+
   /// Returns maximum duration for [DurationType.max] and
   /// current duration for [DurationType.current] for playing media.
   /// The duration is in milliseconds, if no duration is available