Take format for `SilentAudioGenerator`

This simplifies the caller slightly.

PiperOrigin-RevId: 495234339

library/transformer/src/main/java/com/google/android/exoplayer2/transformer/AudioTranscodingSamplePipeline.java

@@ -69,11 +69,7 @@ import org.checkerframework.dataflow.qual.Pure;
     super(inputFormat, streamStartPositionUs, muxerWrapper);
 
     if (forceSilentAudioDurationUs != C.TIME_UNSET) {
-      silentAudioGenerator =
-          new SilentAudioGenerator(
-              forceSilentAudioDurationUs,
-              inputFormat.sampleRate,
-              Util.getPcmFrameSize(C.ENCODING_PCM_16BIT, inputFormat.channelCount));
+      silentAudioGenerator = new SilentAudioGenerator(inputFormat, forceSilentAudioDurationUs);
     } else {
       silentAudioGenerator = null;
     }

library/transformer/src/main/java/com/google/android/exoplayer2/transformer/SilentAudioGenerator.java

@@ -17,6 +17,8 @@
 package com.google.android.exoplayer2.transformer;
 
 import com.google.android.exoplayer2.C;
+import com.google.android.exoplayer2.Format;
+import com.google.android.exoplayer2.util.Util;
 import java.nio.ByteBuffer;
 import java.nio.ByteOrder;
 
@@ -27,8 +29,13 @@ import java.nio.ByteOrder;
 
   private long remainingBytesToOutput;
 
-  public SilentAudioGenerator(long totalDurationUs, long sampleRate, int frameSize) {
-    remainingBytesToOutput = frameSize * ((sampleRate * totalDurationUs) / C.MICROS_PER_SECOND);
+  public SilentAudioGenerator(Format format, long totalDurationUs) {
+    int frameSize =
+        Util.getPcmFrameSize(
+            format.pcmEncoding == Format.NO_VALUE ? C.ENCODING_PCM_16BIT : format.pcmEncoding,
+            format.channelCount);
+    long outputFrameCount = (format.sampleRate * totalDurationUs) / C.MICROS_PER_SECOND;
+    remainingBytesToOutput = frameSize * outputFrameCount;
     internalBuffer =
         ByteBuffer.allocate(DEFAULT_BUFFER_SIZE_FRAMES * frameSize).order(ByteOrder.nativeOrder());
     internalBuffer.flip();

library/transformer/src/test/java/com/google/android/exoplayer2/transformer/SilentAudioGeneratorTest.java

@@ -18,6 +18,8 @@ package com.google.android.exoplayer2.transformer;
 import static com.google.common.truth.Truth.assertThat;
 
 import androidx.test.ext.junit.runners.AndroidJUnit4;
+import com.google.android.exoplayer2.C;
+import com.google.android.exoplayer2.Format;
 import java.nio.ByteBuffer;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -30,7 +32,12 @@ public class SilentAudioGeneratorTest {
   public void numberOfBytesProduced_isCorrect() {
     SilentAudioGenerator generator =
         new SilentAudioGenerator(
-            /* totalDurationUs= */ 3_000_000, /* sampleRate= */ 88_200, /* frameSize= */ 12);
+            new Format.Builder()
+                .setSampleRate(88_200)
+                .setPcmEncoding(C.ENCODING_PCM_16BIT)
+                .setChannelCount(6)
+                .build(),
+            /* totalDurationUs= */ 3_000_000);
     int bytesOutput = 0;
     while (!generator.isEnded()) {
       ByteBuffer output = generator.getBuffer();
@@ -47,7 +54,12 @@ public class SilentAudioGeneratorTest {
   public void lastBufferProduced_isCorrectSize() {
     SilentAudioGenerator generator =
         new SilentAudioGenerator(
-            /* totalDurationUs= */ 1_000_000, /* sampleRate= */ 44_100, /* frameSize= */ 4);
+            new Format.Builder()
+                .setSampleRate(44_100)
+                .setPcmEncoding(C.ENCODING_PCM_16BIT)
+                .setChannelCount(2)
+                .build(),
+            /* totalDurationUs= */ 1_000_000);
 
     int currentBufferSize = 0;
     while (!generator.isEnded()) {
@@ -66,7 +78,12 @@ public class SilentAudioGeneratorTest {
   public void totalBytesLowerThanDefaultBufferSize_smallBufferProduced() {
     SilentAudioGenerator generator =
         new SilentAudioGenerator(
-            /* totalDurationUs= */ 5_000, /* sampleRate= */ 48_000, /* frameSize= */ 4);
+            new Format.Builder()
+                .setSampleRate(48_000)
+                .setPcmEncoding(C.ENCODING_PCM_16BIT)
+                .setChannelCount(2)
+                .build(),
+            /* totalDurationUs= */ 5_000);
     // 5_000 * 48_000 * 4 / 1_000_000 = 960
     assertThat(generator.getBuffer().remaining()).isEqualTo(960);
   }