feat: add support to change playback speed (#619)

support to change playback speed!

@todo: #619 (review)

android/src/main/java/com/dooboolab.audiorecorderplayer/RNAudioRecorderPlayerModule.kt

@@ -194,6 +194,16 @@ class RNAudioRecorderPlayerModule(private val reactContext: ReactApplicationCont
         promise.resolve("set volume")
     }
 
+    @ReactMethod
+    fun setPlaybackSpeed(playbackSpeed: Float, promise: Promise) {
+        if (mediaPlayer == null) {
+            promise.reject("setPlaybackSpeed", "player is null.")
+            return
+        }
+        mediaPlayer!!.playbackParams = mediaPlayer!!.playbackParams.setSpeed(playbackSpeed)
+        promise.resolve("setPlaybackSpeed")
+    }
+
     @ReactMethod
     fun startPlayer(path: String, httpHeaders: ReadableMap?, promise: Promise) {
         if (mediaPlayer != null) {

index.ts

@@ -420,6 +420,15 @@ class AudioRecorderPlayer {
     return RNAudioRecorderPlayer.setVolume(volume);
   };
 
+  /**
+   * Set playback speed.
+   * @param {number} setPlaybackSpeed set playback speed.
+   * @returns {Promise<string>}
+   */
+  setPlaybackSpeed = async (playbackSpeed: number): Promise<string> => {
+    return RNAudioRecorderPlayer.setPlaybackSpeed(playbackSpeed);
+  };
+
   /**
    * Set subscription duration. Default is 0.5.
    * @param {number} sec subscription callback duration in seconds.

ios/RNAudioRecorderPlayer.m

@@ -30,6 +30,10 @@ @interface RCT_EXTERN_MODULE(RNAudioRecorderPlayer, RCTEventEmitter)
                   resolve:(RCTPromiseResolveBlock) resolve
                   rejecter:(RCTPromiseRejectBlock) reject);
 
+RCT_EXTERN_METHOD(setPlaybackSpeed:(float)playbackSpeed
+                  resolve:(RCTPromiseResolveBlock) resolve
+                  rejecter:(RCTPromiseRejectBlock) reject);
+
 RCT_EXTERN_METHOD(startPlayer:(NSString*)path
                   httpHeaders:(NSDictionary*)httpHeaders
                   resolve:(RCTPromiseResolveBlock)resolve

ios/RNAudioRecorderPlayer.swift

@@ -464,6 +464,21 @@ class RNAudioRecorderPlayer: RCTEventEmitter, AVAudioRecorderDelegate {
         audioPlayer.volume = volume
         resolve(volume)
     }
+
+    @objc(setPlaybackSpeed:resolve:rejecter:)
+    public func setPlaybackSpeed(
+        playbackSpeed: Float,
+        resolve: @escaping RCTPromiseResolveBlock,
+        rejecter reject: @escaping RCTPromiseRejectBlock
+    ) -> Void {
+        if (audioPlayer == nil) {
+            return reject("RNAudioPlayerRecorder", "Player is null", nil)
+        }
+
+        audioPlayer.rate = playbackSpeed
+        resolve("setPlaybackSpeed")
+    }
+
     private func avFormat(fromString encoding: String?) -> AudioFormatID? {
         if (encoding == nil) {
             return kAudioFormatAppleLossless