playback: use isactive in replaygain [#174]

Override isActive to control when the ReplayGain engine should
manipulate audio.

This makes the system much more efficient, as we can side-step a
useless copy when ReplayGain shouldn't be applied.

CHANGELOG.md

@@ -8,6 +8,7 @@
 
 #### What's Improved
 - Made "timeline" elements (like playback controls) always left-to-right
+- Improved performance when ReplayGain is not enabled
 
 #### What's Fixed
 - Fixed broken tablet layouts
@@ -16,6 +17,7 @@
 - Fixed miscellanious startup issues
 - Fixed crash if settings was navigated away before playback state
 finished saving
+- Fixed broken album menu
 
 #### What's Changed
 - Reworked typography and iconography to be more aligned with material

app/src/main/java/org/oxycblt/auxio/playback/replaygain/ReplayGainAudioProcessor.kt

@@ -218,29 +218,26 @@ class ReplayGainAudioProcessor(context: Context) : BaseAudioProcessor() {
         throw AudioProcessor.UnhandledAudioFormatException(inputAudioFormat)
     }
 
+    override fun isActive() = super.isActive() && volume != 1f
+
     override fun queueInput(inputBuffer: ByteBuffer) {
         val position = inputBuffer.position()
         val limit = inputBuffer.limit()
         val size = limit - position
         val buffer = replaceOutputBuffer(size)
 
-        if (volume == 1f) {
-            // No need to apply ReplayGain.
-            buffer.put(inputBuffer.slice())
-        } else {
-            for (i in position until limit step 2) {
-                // Ensure we clamp the values to the minimum and maximum values possible
-                // for the encoding. This prevents issues where samples amplified beyond
-                // 1 << 16 will end up becoming truncated during the conversion to a short,
-                // resulting in popping.
-                var sample = inputBuffer.getLeShort(i)
-                sample =
-                    (sample * volume)
-                        .toInt()
-                        .clamp(Short.MIN_VALUE.toInt(), Short.MAX_VALUE.toInt())
-                        .toShort()
-                buffer.putLeShort(sample)
-            }
+        for (i in position until limit step 2) {
+            // Ensure we clamp the values to the minimum and maximum values possible
+            // for the encoding. This prevents issues where samples amplified beyond
+            // 1 << 16 will end up becoming truncated during the conversion to a short,
+            // resulting in popping.
+            var sample = inputBuffer.getLeShort(i)
+            sample =
+                (sample * volume)
+                    .toInt()
+                    .clamp(Short.MIN_VALUE.toInt(), Short.MAX_VALUE.toInt())
+                    .toShort()
+            buffer.putLeShort(sample)
         }
 
         inputBuffer.position(limit)

app/src/main/res/layout-sw600dp/fragment_playback_panel.xml

@@ -66,8 +66,8 @@
         android:id="@+id/playback_seek_bar"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
-        android:layout_marginStart="@dimen/spacing_medium"
-        android:layout_marginEnd="@dimen/spacing_medium"
+        android:layout_marginStart="@dimen/spacing_small"
+        android:layout_marginEnd="@dimen/spacing_small"
         app:layout_constraintBottom_toTopOf="@+id/playback_controls_container"
         app:layout_constraintEnd_toEndOf="parent"
         app:layout_constraintHorizontal_bias="0.0"