android scale and rotate animations are not smooth

Question

I am working on a new application, and in the main window I present some animations. The problem is that the animations are not smooth.(The newer android version it is the animations get less smooth) Here is the xml code:

<scale android:pivotX="50%"
    android:pivotY="50%"
    android:fromXScale="1"
    android:fromYScale="1"
    android:repeatCount="infinite"
    android:repeatMode="reverse"
    android:duration="1000"
    android:interpolator="@android:anim/linear_interpolator"
    android:toXScale="0.75" android:toYScale="0.75"
    xmlns:android="http://schemas.android.com/apk/res/android">
</scale>


<?xml version="1.0" encoding="utf-8"?>
<rotate android:fromDegrees="0"
    android:toDegrees="90"
    xmlns:android="http://schemas.android.com/apk/res/android" 
    android:duration="1000"
    android:repeatCount="infinite"
    android:interpolator="@android:anim/linear_interpolator"
    android:repeatMode="reverse"
    android:pivotX="50%" android:pivotY="50%">
    <!--
    android:fillAfter="false"
    android:startOffset="0"
    -->
</rotate>