diff --git a/libraries/transformer/src/main/java/androidx/media3/transformer/CompositeAssetLoader.java b/libraries/transformer/src/main/java/androidx/media3/transformer/CompositeAssetLoader.java
index ffed659c65..5eb1a5ea17 100644
--- a/libraries/transformer/src/main/java/androidx/media3/transformer/CompositeAssetLoader.java
+++ b/libraries/transformer/src/main/java/androidx/media3/transformer/CompositeAssetLoader.java
@@ -21,6 +21,7 @@ import static androidx.media3.common.util.Assertions.checkState;
 import static androidx.media3.common.util.Assertions.checkStateNotNull;
 import static androidx.media3.transformer.Transformer.PROGRESS_STATE_AVAILABLE;
 import static androidx.media3.transformer.Transformer.PROGRESS_STATE_NOT_STARTED;
+import static androidx.media3.transformer.TransformerUtil.getProcessedTrackType;
 
 import android.graphics.Bitmap;
 import android.os.Looper;
@@ -191,9 +192,7 @@ import java.util.concurrent.atomic.AtomicInteger;
       long streamStartPositionUs,
       long streamOffsetUs)
       throws ExportException {
-    // Consider image as video because image inputs are fed to the VideoSamplePipeline.
-    int trackType =
-        MimeTypes.isAudio(format.sampleMimeType) ? C.TRACK_TYPE_AUDIO : C.TRACK_TYPE_VIDEO;
+    @C.TrackType int trackType = getProcessedTrackType(format.sampleMimeType);
     SampleConsumer sampleConsumer;
     if (currentMediaItemIndex.get() == 0) {
       boolean addForcedAudioTrack =
diff --git a/libraries/transformer/src/main/java/androidx/media3/transformer/SamplePipeline.java b/libraries/transformer/src/main/java/androidx/media3/transformer/SamplePipeline.java
index 89e0ba8edd..906914e856 100644
--- a/libraries/transformer/src/main/java/androidx/media3/transformer/SamplePipeline.java
+++ b/libraries/transformer/src/main/java/androidx/media3/transformer/SamplePipeline.java
@@ -21,6 +21,7 @@ import static androidx.media3.common.util.Assertions.checkNotNull;
 import static androidx.media3.common.util.Assertions.checkStateNotNull;
 import static androidx.media3.transformer.EncoderUtil.getSupportedEncoders;
 import static androidx.media3.transformer.EncoderUtil.getSupportedEncodersForHdrEditing;
+import static androidx.media3.transformer.TransformerUtil.getProcessedTrackType;
 
 import androidx.annotation.Nullable;
 import androidx.media3.common.C;
@@ -55,10 +56,7 @@ import java.util.List;
       Format firstInputFormat, long streamStartPositionUs, MuxerWrapper muxerWrapper) {
     this.streamStartPositionUs = streamStartPositionUs;
     this.muxerWrapper = muxerWrapper;
-    outputTrackType =
-        MimeTypes.isImage(firstInputFormat.sampleMimeType)
-            ? C.TRACK_TYPE_VIDEO
-            : MimeTypes.getTrackType(firstInputFormat.sampleMimeType);
+    this.outputTrackType = getProcessedTrackType(firstInputFormat.sampleMimeType);
   }
 
   @Override
diff --git a/libraries/transformer/src/main/java/androidx/media3/transformer/TransformerInternal.java b/libraries/transformer/src/main/java/androidx/media3/transformer/TransformerInternal.java
index 7085894267..89a781b9f5 100644
--- a/libraries/transformer/src/main/java/androidx/media3/transformer/TransformerInternal.java
+++ b/libraries/transformer/src/main/java/androidx/media3/transformer/TransformerInternal.java
@@ -24,6 +24,7 @@ import static androidx.media3.transformer.ExportException.ERROR_CODE_FAILED_RUNT
 import static androidx.media3.transformer.ExportException.ERROR_CODE_MUXING_FAILED;
 import static androidx.media3.transformer.Transformer.PROGRESS_STATE_AVAILABLE;
 import static androidx.media3.transformer.Transformer.PROGRESS_STATE_NOT_STARTED;
+import static androidx.media3.transformer.TransformerUtil.getProcessedTrackType;
 import static java.lang.annotation.ElementType.TYPE_USE;
 
 import android.content.Context;
@@ -452,11 +453,7 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
                   firstInputFormat, supportedOutputTypes, streamStartPositionUs, streamOffsetUs),
               streamStartPositionUs,
               streamOffsetUs);
-      // Consider image as video because image inputs are fed to the VideoSamplePipeline.
-      int trackType =
-          MimeTypes.isAudio(firstInputFormat.sampleMimeType)
-              ? C.TRACK_TYPE_AUDIO
-              : C.TRACK_TYPE_VIDEO;
+      @C.TrackType int trackType = getProcessedTrackType(firstInputFormat.sampleMimeType);
       compositeAssetLoaders
           .get(sequenceIndex)
           .addOnMediaItemChangedListener(samplePipeline, trackType);
@@ -531,12 +528,14 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
           (supportedOutputTypes & SUPPORTED_OUTPUT_TYPE_ENCODED) != 0;
       checkArgument(assetLoaderCanOutputDecoded || assetLoaderCanOutputEncoded);
 
+      @C.TrackType int trackType = getProcessedTrackType(inputFormat.sampleMimeType);
+
       boolean shouldTranscode = false;
       if (!assetLoaderCanOutputEncoded) {
         shouldTranscode = true;
-      } else if (MimeTypes.isAudio(inputFormat.sampleMimeType)) {
+      } else if (trackType == C.TRACK_TYPE_AUDIO) {
         shouldTranscode = shouldTranscodeAudio(inputFormat);
-      } else if (MimeTypes.isVideo(inputFormat.sampleMimeType)) {
+      } else if (trackType == C.TRACK_TYPE_VIDEO) {
         shouldTranscode = shouldTranscodeVideo(inputFormat, streamStartPositionUs, streamOffsetUs);
       }
 
diff --git a/libraries/transformer/src/main/java/androidx/media3/transformer/TransformerUtil.java b/libraries/transformer/src/main/java/androidx/media3/transformer/TransformerUtil.java
new file mode 100644
index 0000000000..d4092b5f87
--- /dev/null
+++ b/libraries/transformer/src/main/java/androidx/media3/transformer/TransformerUtil.java
@@ -0,0 +1,40 @@
+/*
+ * Copyright 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package androidx.media3.transformer;
+
+import androidx.annotation.Nullable;
+import androidx.media3.common.C;
+import androidx.media3.common.MimeTypes;
+
+/** Utility methods for Transformer. */
+/* package */ final class TransformerUtil {
+
+  private TransformerUtil() {}
+
+  /**
+   * Returns the {@link C.TrackType track type} constant corresponding to how a specified MIME type
+   * should be processed, which may be {@link C#TRACK_TYPE_UNKNOWN} if it could not be determined.
+   *
+   * <p>{@linkplain MimeTypes#isImage image} mime types are processed as {@link C#TRACK_TYPE_VIDEO}.
+   *
+   * <p>See {@link MimeTypes#getTrackType} for more details.
+   */
+  public static @C.TrackType int getProcessedTrackType(@Nullable String mimeType) {
+    @C.TrackType int trackType = MimeTypes.getTrackType(mimeType);
+    return trackType == C.TRACK_TYPE_IMAGE ? C.TRACK_TYPE_VIDEO : trackType;
+  }
+}