diff --git a/media/libmediatranscoding/transcoder/MediaSampleWriter.cpp b/media/libmediatranscoding/transcoder/MediaSampleWriter.cpp
index 0e800bc..e931cc1 100644
--- a/media/libmediatranscoding/transcoder/MediaSampleWriter.cpp
+++ b/media/libmediatranscoding/transcoder/MediaSampleWriter.cpp
@@ -19,6 +19,7 @@
 
 #include <android-base/logging.h>
 #include <media/MediaSampleWriter.h>
+#include <media/NdkCommon.h>
 #include <media/NdkMediaMuxer.h>
 #include <sys/prctl.h>
 #include <utils/AndroidThreads.h>
@@ -126,7 +127,15 @@
         LOG(ERROR) << "Muxer needs to be initialized when adding tracks.";
         return nullptr;
     }
-    ssize_t trackIndexOrError = mMuxer->addTrack(trackFormat.get());
+
+    AMediaFormat* trackFormatCopy = AMediaFormat_new();
+    AMediaFormat_copy(trackFormatCopy, trackFormat.get());
+    // Request muxer to use background priorities by default.
+    AMediaFormatUtils::SetDefaultFormatValueInt32(TBD_AMEDIACODEC_PARAMETER_KEY_BACKGROUND_MODE,
+                                                  trackFormatCopy, 1 /* true */);
+
+    ssize_t trackIndexOrError = mMuxer->addTrack(trackFormatCopy);
+    AMediaFormat_delete(trackFormatCopy);
     if (trackIndexOrError < 0) {
         LOG(ERROR) << "Failed to add media track to muxer: " << trackIndexOrError;
         return nullptr;
diff --git a/media/libmediatranscoding/transcoder/NdkCommon.cpp b/media/libmediatranscoding/transcoder/NdkCommon.cpp
index 2d85df7..e133cd6 100644
--- a/media/libmediatranscoding/transcoder/NdkCommon.cpp
+++ b/media/libmediatranscoding/transcoder/NdkCommon.cpp
@@ -42,6 +42,7 @@
 
 /* TODO(lnilsson): Finalize value or adopt AMediaFormat key once available. */
 const char* TBD_AMEDIACODEC_PARAMETER_KEY_COLOR_TRANSFER_REQUEST = "color-transfer-request";
+const char* TBD_AMEDIACODEC_PARAMETER_KEY_BACKGROUND_MODE = "android._background-mode";
 
 namespace AMediaFormatUtils {
 
diff --git a/media/libmediatranscoding/transcoder/VideoTrackTranscoder.cpp b/media/libmediatranscoding/transcoder/VideoTrackTranscoder.cpp
index 6ed45ed..6c51907 100644
--- a/media/libmediatranscoding/transcoder/VideoTrackTranscoder.cpp
+++ b/media/libmediatranscoding/transcoder/VideoTrackTranscoder.cpp
@@ -254,6 +254,10 @@
     // MediaSampleWriter track format, and MediaSampleWriter will call AMediaMuxer_setOrientationHint.
     AMediaFormat_setInt32(encoderFormat, AMEDIAFORMAT_KEY_ROTATION, 0);
 
+    // Request encoder to use background priorities by default.
+    SetDefaultFormatValueInt32(TBD_AMEDIACODEC_PARAMETER_KEY_BACKGROUND_MODE, encoderFormat,
+                               1 /* true */);
+
     mDestinationFormat = std::shared_ptr<AMediaFormat>(encoderFormat, &AMediaFormat_delete);
 
     // Create and configure the encoder.
@@ -335,6 +339,7 @@
     static const std::vector<EntryCopier> kEncoderEntriesToCopy{
             ENTRY_COPIER2(AMEDIAFORMAT_KEY_OPERATING_RATE, Float, Int32),
             ENTRY_COPIER(AMEDIAFORMAT_KEY_PRIORITY, Int32),
+            ENTRY_COPIER(TBD_AMEDIACODEC_PARAMETER_KEY_BACKGROUND_MODE, Int32),
     };
     CopyFormatEntries(mDestinationFormat.get(), decoderFormat.get(), kEncoderEntriesToCopy);
 
diff --git a/media/libmediatranscoding/transcoder/include/media/NdkCommon.h b/media/libmediatranscoding/transcoder/include/media/NdkCommon.h
index c5547c6..2441922 100644
--- a/media/libmediatranscoding/transcoder/include/media/NdkCommon.h
+++ b/media/libmediatranscoding/transcoder/include/media/NdkCommon.h
@@ -59,6 +59,7 @@
 extern const char* TBD_AMEDIACODEC_PARAMETER_KEY_VIDEO_BITRATE;
 extern const char* TBD_AMEDIACODEC_PARAMETER_KEY_MAX_B_FRAMES;
 extern const char* TBD_AMEDIACODEC_PARAMETER_KEY_COLOR_TRANSFER_REQUEST;
+extern const char* TBD_AMEDIACODEC_PARAMETER_KEY_BACKGROUND_MODE;
 static constexpr int TBD_AMEDIACODEC_BUFFER_FLAG_KEY_FRAME = 0x1;
 
 static constexpr int kBitrateModeConstant = 2;
diff --git a/media/libmediatranscoding/transcoder/tests/MediaSampleWriterTests.cpp b/media/libmediatranscoding/transcoder/tests/MediaSampleWriterTests.cpp
index 8b3905c..0a8a06e 100644
--- a/media/libmediatranscoding/transcoder/tests/MediaSampleWriterTests.cpp
+++ b/media/libmediatranscoding/transcoder/tests/MediaSampleWriterTests.cpp
@@ -117,8 +117,9 @@
 }
 
 bool operator==(const TestMuxer::Event& lhs, const TestMuxer::Event& rhs) {
-    return lhs.type == rhs.type && lhs.format == rhs.format && lhs.trackIndex == rhs.trackIndex &&
-           lhs.data == rhs.data && lhs.info == rhs.info;
+    // Don't test format pointer equality since the writer can make a copy.
+    return lhs.type == rhs.type /*&& lhs.format == rhs.format*/ &&
+           lhs.trackIndex == rhs.trackIndex && lhs.data == rhs.data && lhs.info == rhs.info;
 }
 
 /** Represents a media source file. */