diff --git a/app/build.gradle b/app/build.gradle
index d9a911a..7e2583b 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -8,8 +8,8 @@ android {
         applicationId "com.github.axet.audiorecorder"
         minSdkVersion 16
         targetSdkVersion 23
-        versionCode 77
-        versionName "1.1.55"
+        versionCode 78
+        versionName "1.1.56"
     }
     signingConfigs {
         release {
diff --git a/app/src/main/java/com/github/axet/audiorecorder/encoders/FormatM4A.java b/app/src/main/java/com/github/axet/audiorecorder/encoders/FormatM4A.java
index ca83638..58fc555 100755
--- a/app/src/main/java/com/github/axet/audiorecorder/encoders/FormatM4A.java
+++ b/app/src/main/java/com/github/axet/audiorecorder/encoders/FormatM4A.java
@@ -14,9 +14,7 @@ public class FormatM4A extends MuxerMP4 {
         Map<String, MediaCodecInfo> map = findEncoder("audio/mp4");
         if (map.isEmpty())
             throw new RuntimeException("mp4 not supported");
-        MediaFormat format = new MediaFormat();
-        format.setString(MediaFormat.KEY_MIME, prefered("audio/mp4a-latm", map));
-        format.setInteger(MediaFormat.KEY_AAC_PROFILE, MediaCodecInfo.CodecProfileLevel.AACObjectHE);
+        MediaFormat format = MuxerMP4.getDefault("audio/mp4a-latm", map);
         format.setInteger(MediaFormat.KEY_SAMPLE_RATE, info.sampleRate);
         format.setInteger(MediaFormat.KEY_CHANNEL_COUNT, info.channels);
         format.setInteger(MediaFormat.KEY_BIT_RATE, 64000);
diff --git a/app/src/main/java/com/github/axet/audiorecorder/encoders/MuxerMP4.java b/app/src/main/java/com/github/axet/audiorecorder/encoders/MuxerMP4.java
index 9aa97f6..4ee61b1 100755
--- a/app/src/main/java/com/github/axet/audiorecorder/encoders/MuxerMP4.java
+++ b/app/src/main/java/com/github/axet/audiorecorder/encoders/MuxerMP4.java
@@ -64,6 +64,12 @@ public class MuxerMP4 implements Encoder {
         return null;
     }
 
+    public static MediaFormat getDefault(String pref, Map<String, MediaCodecInfo> map) {
+        String p = prefered(pref, map);
+        MediaFormat format = map.get(p).getCapabilitiesForType(p).getDefaultFormat();
+        return format;
+    }
+
     public void create(EncoderInfo info, MediaFormat format, File out) {
         this.info = info;