diff --git a/sdk/android/BUILD.gn b/sdk/android/BUILD.gn
index f666c3d..0e603e4 100644
--- a/sdk/android/BUILD.gn
+++ b/sdk/android/BUILD.gn
@@ -327,6 +327,7 @@
       "api/org/webrtc/VideoTrack.java",
       "src/java/org/webrtc/NativeLibrary.java",
       "src/java/org/webrtc/NativeCapturerObserver.java",
+      "src/java/org/webrtc/NativeAndroidVideoTrackSource.java",
     ]
 
     deps = [
@@ -662,7 +663,6 @@
       "src/jni/video_encoder_wrapper.h",
       "src/jni/video_sink.cc",
       "src/jni/video_sink.h",
-      "src/jni/video_source.cc",
       "src/jni/video_track.cc",
       "src/jni/yuv_helper.cc",
     ]
@@ -1256,12 +1256,12 @@
       "api/org/webrtc/VideoEncoderFallback.java",
       "api/org/webrtc/VideoFrame.java",
       "api/org/webrtc/VideoSink.java",
-      "api/org/webrtc/VideoSource.java",
       "api/org/webrtc/VideoTrack.java",
       "api/org/webrtc/YuvHelper.java",
       "src/java/org/webrtc/H264Utils.java",
       "src/java/org/webrtc/NV12Buffer.java",
       "src/java/org/webrtc/NV21Buffer.java",
+      "src/java/org/webrtc/NativeAndroidVideoTrackSource.java",
       "src/java/org/webrtc/NativeCapturerObserver.java",
       "src/java/org/webrtc/VideoDecoderWrapper.java",
       "src/java/org/webrtc/VideoEncoderWrapper.java",
diff --git a/sdk/android/api/org/webrtc/VideoSource.java b/sdk/android/api/org/webrtc/VideoSource.java
index 995304e..f783a57 100644
--- a/sdk/android/api/org/webrtc/VideoSource.java
+++ b/sdk/android/api/org/webrtc/VideoSource.java
@@ -16,11 +16,40 @@
  * Java wrapper of native AndroidVideoTrackSource.
  */
 public class VideoSource extends MediaSource {
-  private final NativeCapturerObserver capturerObserver;
+  /** Simple aspect ratio clas for use in constraining output format. */
+  public static class AspectRatio {
+    public static final AspectRatio UNDEFINED = new AspectRatio(/* width= */ 0, /* height= */ 0);
+
+    public final int width;
+    public final int height;
+
+    public AspectRatio(int width, int height) {
+      this.width = width;
+      this.height = height;
+    }
+  }
+
+  private final NativeAndroidVideoTrackSource nativeAndroidVideoTrackSource;
+  private final CapturerObserver capturerObserver = new CapturerObserver() {
+    @Override
+    public void onCapturerStarted(boolean success) {
+      nativeAndroidVideoTrackSource.setState(success);
+    }
+
+    @Override
+    public void onCapturerStopped() {
+      nativeAndroidVideoTrackSource.setState(/* isLive= */ false);
+    }
+
+    @Override
+    public void onFrameCaptured(VideoFrame frame) {
+      nativeAndroidVideoTrackSource.onFrameCaptured(frame);
+    }
+  };
 
   public VideoSource(long nativeSource) {
     super(nativeSource);
-    this.capturerObserver = new NativeCapturerObserver(nativeSource);
+    this.nativeAndroidVideoTrackSource = new NativeAndroidVideoTrackSource(nativeSource);
   }
 
   /**
@@ -42,8 +71,18 @@
    */
   public void adaptOutputFormat(
       int landscapeWidth, int landscapeHeight, int portraitWidth, int portraitHeight, int fps) {
-    nativeAdaptOutputFormat(getNativeVideoTrackSource(), landscapeWidth, landscapeHeight,
-        portraitWidth, portraitHeight, fps);
+    adaptOutputFormat(new AspectRatio(landscapeWidth, landscapeHeight),
+        /* maxLandscapePixelCount= */ landscapeWidth * landscapeHeight,
+        new AspectRatio(portraitWidth, portraitHeight),
+        /* maxPortraitPixelCount= */ portraitWidth * portraitHeight, fps);
+  }
+
+  /** Same as above, with even more control as each constraint is optional. */
+  public void adaptOutputFormat(AspectRatio targetLandscapeAspectRatio,
+      @Nullable Integer maxLandscapePixelCount, AspectRatio targetPortraitAspectRatio,
+      @Nullable Integer maxPortraitPixelCount, @Nullable Integer maxFps) {
+    nativeAndroidVideoTrackSource.adaptOutputFormat(targetLandscapeAspectRatio,
+        maxLandscapePixelCount, targetPortraitAspectRatio, maxPortraitPixelCount, maxFps);
   }
 
   public CapturerObserver getCapturerObserver() {
@@ -54,7 +93,4 @@
   long getNativeVideoTrackSource() {
     return getNativeMediaSource();
   }
-
-  private static native void nativeAdaptOutputFormat(long source, int landscapeWidth,
-      int landscapeHeight, int portraitWidth, int portraitHeight, int fps);
 }
diff --git a/sdk/android/src/java/org/webrtc/NativeAndroidVideoTrackSource.java b/sdk/android/src/java/org/webrtc/NativeAndroidVideoTrackSource.java
new file mode 100644
index 0000000..da963a8
--- /dev/null
+++ b/sdk/android/src/java/org/webrtc/NativeAndroidVideoTrackSource.java
@@ -0,0 +1,64 @@
+/*
+ *  Copyright (c) 2019 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+package org.webrtc;
+
+import android.support.annotation.Nullable;
+import org.webrtc.VideoFrame;
+
+/**
+ * This class is meant to be a simple layer that only handles the JNI wrapping of a C++
+ * AndroidVideoTrackSource, that can easily be mocked out in Java unit tests. Refrain from adding
+ * any unnecessary logic to this class.
+ */
+class NativeAndroidVideoTrackSource {
+  // Pointer to webrtc::jni::AndroidVideoTrackSource.
+  private final long nativeAndroidVideoTrackSource;
+
+  public NativeAndroidVideoTrackSource(long nativeAndroidVideoTrackSource) {
+    this.nativeAndroidVideoTrackSource = nativeAndroidVideoTrackSource;
+  }
+
+  /**
+   * Set the state for the native MediaSourceInterface. Maps boolean to either
+   * SourceState::kLive or SourceState::kEnded.
+   */
+  public void setState(boolean isLive) {
+    nativeSetState(nativeAndroidVideoTrackSource, isLive);
+  }
+
+  /** Pass a frame to the native AndroidVideoTrackSource. */
+  public void onFrameCaptured(VideoFrame frame) {
+    nativeOnFrameCaptured(nativeAndroidVideoTrackSource, frame.getBuffer().getWidth(),
+        frame.getBuffer().getHeight(), frame.getRotation(), frame.getTimestampNs(),
+        frame.getBuffer());
+  }
+
+  /**
+   * Calling this function will cause frames to be scaled down to the requested resolution. Also,
+   * frames will be cropped to match the requested aspect ratio, and frames will be dropped to match
+   * the requested fps.
+   */
+  public void adaptOutputFormat(VideoSource.AspectRatio targetLandscapeAspectRatio,
+      @Nullable Integer maxLandscapePixelCount, VideoSource.AspectRatio targetPortraitAspectRatio,
+      @Nullable Integer maxPortraitPixelCount, @Nullable Integer maxFps) {
+    nativeAdaptOutputFormat(nativeAndroidVideoTrackSource, targetLandscapeAspectRatio.width,
+        targetLandscapeAspectRatio.height, maxLandscapePixelCount, targetPortraitAspectRatio.width,
+        targetPortraitAspectRatio.height, maxPortraitPixelCount, maxFps);
+  }
+
+  private static native void nativeSetState(long nativeAndroidVideoTrackSource, boolean isLive);
+  private static native void nativeAdaptOutputFormat(long nativeAndroidVideoTrackSource,
+      int landscapeWidth, int landscapeHeight, @Nullable Integer maxLandscapePixelCount,
+      int portraitWidth, int portraitHeight, @Nullable Integer maxPortraitPixelCount,
+      @Nullable Integer maxFps);
+  private static native void nativeOnFrameCaptured(long nativeAndroidVideoTrackSource, int width,
+      int height, int rotation, long timestampNs, VideoFrame.Buffer buffer);
+}
diff --git a/sdk/android/src/java/org/webrtc/NativeCapturerObserver.java b/sdk/android/src/java/org/webrtc/NativeCapturerObserver.java
index b5f8ae4..69a0d54 100644
--- a/sdk/android/src/java/org/webrtc/NativeCapturerObserver.java
+++ b/sdk/android/src/java/org/webrtc/NativeCapturerObserver.java
@@ -10,40 +10,32 @@
 
 package org.webrtc;
 
-import android.support.annotation.Nullable;
 import org.webrtc.VideoFrame;
 
 /**
- * Implements VideoCapturer.CapturerObserver and feeds frames to
- * webrtc::jni::AndroidVideoTrackSource.
+ * Used from native api and implements a simple VideoCapturer.CapturerObserver that feeds frames to
+ * a webrtc::jni::AndroidVideoTrackSource.
  */
 class NativeCapturerObserver implements CapturerObserver {
-  // Pointer to webrtc::jni::AndroidVideoTrackSource.
-  private final long nativeSource;
+  private final NativeAndroidVideoTrackSource nativeAndroidVideoTrackSource;
 
   @CalledByNative
   public NativeCapturerObserver(long nativeSource) {
-    this.nativeSource = nativeSource;
+    this.nativeAndroidVideoTrackSource = new NativeAndroidVideoTrackSource(nativeSource);
   }
 
   @Override
   public void onCapturerStarted(boolean success) {
-    nativeCapturerStarted(nativeSource, success);
+    nativeAndroidVideoTrackSource.setState(success);
   }
 
   @Override
   public void onCapturerStopped() {
-    nativeCapturerStopped(nativeSource);
+    nativeAndroidVideoTrackSource.setState(/* isLive= */ false);
   }
 
   @Override
   public void onFrameCaptured(VideoFrame frame) {
-    nativeOnFrameCaptured(nativeSource, frame.getBuffer().getWidth(), frame.getBuffer().getHeight(),
-        frame.getRotation(), frame.getTimestampNs(), frame.getBuffer());
+    nativeAndroidVideoTrackSource.onFrameCaptured(frame);
   }
-
-  private static native void nativeCapturerStarted(long source, boolean success);
-  private static native void nativeCapturerStopped(long source);
-  private static native void nativeOnFrameCaptured(
-      long source, int width, int height, int rotation, long timestampNs, VideoFrame.Buffer frame);
 }
diff --git a/sdk/android/src/jni/android_video_track_source.cc b/sdk/android/src/jni/android_video_track_source.cc
index 65b2bef..a9fb10d 100644
--- a/sdk/android/src/jni/android_video_track_source.cc
+++ b/sdk/android/src/jni/android_video_track_source.cc
@@ -10,6 +10,8 @@
 
 #include "sdk/android/src/jni/android_video_track_source.h"
 
+#include "sdk/android/generated_video_jni/jni/NativeAndroidVideoTrackSource_jni.h"
+
 #include <utility>
 
 #include "rtc_base/logging.h"
@@ -20,6 +22,20 @@
 namespace {
 // MediaCodec wants resolution to be divisible by 2.
 const int kRequiredResolutionAlignment = 2;
+
+VideoRotation jintToVideoRotation(jint rotation) {
+  RTC_DCHECK(rotation == 0 || rotation == 90 || rotation == 180 ||
+             rotation == 270);
+  return static_cast<VideoRotation>(rotation);
+}
+
+absl::optional<std::pair<int, int>> OptionalAspectRatio(jint j_width,
+                                                        jint j_height) {
+  if (j_width > 0 && j_height > 0)
+    return std::pair<int, int>(j_width, j_height);
+  return absl::nullopt;
+}
+
 }  // namespace
 
 AndroidVideoTrackSource::AndroidVideoTrackSource(rtc::Thread* signaling_thread,
@@ -42,11 +58,17 @@
   return false;
 }
 
-void AndroidVideoTrackSource::SetState(SourceState state) {
+void AndroidVideoTrackSource::SetState(JNIEnv* env,
+                                       const JavaRef<jobject>& j_caller,
+                                       jboolean j_is_live) {
+  InternalSetState(j_is_live ? kLive : kEnded);
+}
+
+void AndroidVideoTrackSource::InternalSetState(SourceState state) {
   if (rtc::Thread::Current() != signaling_thread_) {
     invoker_.AsyncInvoke<void>(
         RTC_FROM_HERE, signaling_thread_,
-        rtc::Bind(&AndroidVideoTrackSource::SetState, this, state));
+        rtc::Bind(&AndroidVideoTrackSource::InternalSetState, this, state));
     return;
   }
 
@@ -65,13 +87,16 @@
 }
 
 void AndroidVideoTrackSource::OnFrameCaptured(
-    JNIEnv* jni,
-    int width,
-    int height,
-    int64_t timestamp_ns,
-    VideoRotation rotation,
+    JNIEnv* env,
+    const JavaRef<jobject>& j_caller,
+    jint j_width,
+    jint j_height,
+    jint j_rotation,
+    jlong j_timestamp_ns,
     const JavaRef<jobject>& j_video_frame_buffer) {
-  int64_t camera_time_us = timestamp_ns / rtc::kNumNanosecsPerMicrosec;
+  const VideoRotation rotation = jintToVideoRotation(j_rotation);
+
+  int64_t camera_time_us = j_timestamp_ns / rtc::kNumNanosecsPerMicrosec;
   int64_t translated_camera_time_us =
       align_timestamps_ ? timestamp_aligner_.TranslateTimestamp(
                               camera_time_us, rtc::TimeMicros())
@@ -85,14 +110,14 @@
   int crop_y;
 
   if (rotation % 180 == 0) {
-    if (!AdaptFrame(width, height, camera_time_us, &adapted_width,
+    if (!AdaptFrame(j_width, j_height, camera_time_us, &adapted_width,
                     &adapted_height, &crop_width, &crop_height, &crop_x,
                     &crop_y)) {
       return;
     }
   } else {
     // Swap all width/height and x/y.
-    if (!AdaptFrame(height, width, camera_time_us, &adapted_height,
+    if (!AdaptFrame(j_height, j_width, camera_time_us, &adapted_height,
                     &adapted_width, &crop_height, &crop_width, &crop_y,
                     &crop_x)) {
       return;
@@ -100,8 +125,8 @@
   }
 
   rtc::scoped_refptr<VideoFrameBuffer> buffer =
-      AndroidVideoBuffer::Create(jni, j_video_frame_buffer)
-          ->CropAndScale(jni, crop_x, crop_y, crop_width, crop_height,
+      AndroidVideoBuffer::Create(env, j_video_frame_buffer)
+          ->CropAndScale(env, crop_x, crop_y, crop_width, crop_height,
                          adapted_width, adapted_height);
 
   // AdaptedVideoTrackSource handles applying rotation for I420 frames.
@@ -116,16 +141,22 @@
               .build());
 }
 
-void AndroidVideoTrackSource::OnOutputFormatRequest(int landscape_width,
-                                                    int landscape_height,
-                                                    int portrait_width,
-                                                    int portrait_height,
-                                                    int fps) {
+void AndroidVideoTrackSource::AdaptOutputFormat(
+    JNIEnv* env,
+    const JavaRef<jobject>& j_caller,
+    jint j_landscape_width,
+    jint j_landscape_height,
+    const JavaRef<jobject>& j_max_landscape_pixel_count,
+    jint j_portrait_width,
+    jint j_portrait_height,
+    const JavaRef<jobject>& j_max_portrait_pixel_count,
+    const JavaRef<jobject>& j_max_fps) {
   video_adapter()->OnOutputFormatRequest(
-      std::make_pair(landscape_width, landscape_height),
-      landscape_width * landscape_height,
-      std::make_pair(portrait_width, portrait_height),
-      portrait_width * portrait_height, fps);
+      OptionalAspectRatio(j_landscape_width, j_landscape_height),
+      JavaToNativeOptionalInt(env, j_max_landscape_pixel_count),
+      OptionalAspectRatio(j_portrait_width, j_portrait_height),
+      JavaToNativeOptionalInt(env, j_max_portrait_pixel_count),
+      JavaToNativeOptionalInt(env, j_max_fps));
 }
 
 }  // namespace jni
diff --git a/sdk/android/src/jni/android_video_track_source.h b/sdk/android/src/jni/android_video_track_source.h
index 337a93d..5640c1d 100644
--- a/sdk/android/src/jni/android_video_track_source.h
+++ b/sdk/android/src/jni/android_video_track_source.h
@@ -39,27 +39,37 @@
   // depending on video codec.
   absl::optional<bool> needs_denoising() const override;
 
-  // Called by the native capture observer
   void SetState(SourceState state);
 
   SourceState state() const override;
 
   bool remote() const override;
 
-  void OnFrameCaptured(JNIEnv* jni,
-                       int width,
-                       int height,
-                       int64_t timestamp_ns,
-                       VideoRotation rotation,
+  void OnFrameCaptured(JNIEnv* env,
+                       const JavaRef<jobject>& j_caller,
+                       jint j_width,
+                       jint j_height,
+                       jint j_rotation,
+                       jlong j_timestamp_ns,
                        const JavaRef<jobject>& j_video_frame_buffer);
 
-  void OnOutputFormatRequest(int landscape_width,
-                             int landscape_height,
-                             int portrait_width,
-                             int portrait_height,
-                             int fps);
+  void SetState(JNIEnv* env,
+                const JavaRef<jobject>& j_caller,
+                jboolean j_is_live);
+
+  void AdaptOutputFormat(JNIEnv* env,
+                         const JavaRef<jobject>& j_caller,
+                         jint j_landscape_width,
+                         jint j_landscape_height,
+                         const JavaRef<jobject>& j_max_landscape_pixel_count,
+                         jint j_portrait_width,
+                         jint j_portrait_height,
+                         const JavaRef<jobject>& j_max_portrait_pixel_count,
+                         const JavaRef<jobject>& j_max_fps);
 
  private:
+  void InternalSetState(SourceState state);
+
   rtc::Thread* signaling_thread_;
   rtc::AsyncInvoker invoker_;
   SourceState state_;
diff --git a/sdk/android/src/jni/native_capturer_observer.cc b/sdk/android/src/jni/native_capturer_observer.cc
index 961f5bf..1babf68 100644
--- a/sdk/android/src/jni/native_capturer_observer.cc
+++ b/sdk/android/src/jni/native_capturer_observer.cc
@@ -18,14 +18,6 @@
 namespace webrtc {
 namespace jni {
 
-namespace {
-VideoRotation jintToVideoRotation(jint rotation) {
-  RTC_DCHECK(rotation == 0 || rotation == 90 || rotation == 180 ||
-             rotation == 270);
-  return static_cast<VideoRotation>(rotation);
-}
-}  // namespace
-
 ScopedJavaLocalRef<jobject> CreateJavaNativeCapturerObserver(
     JNIEnv* env,
     rtc::scoped_refptr<AndroidVideoTrackSource> native_source) {
@@ -33,40 +25,5 @@
       env, NativeToJavaPointer(native_source.release()));
 }
 
-static void JNI_NativeCapturerObserver_OnFrameCaptured(
-    JNIEnv* jni,
-    jlong j_source,
-    jint j_width,
-    jint j_height,
-    jint j_rotation,
-    jlong j_timestamp_ns,
-    const JavaParamRef<jobject>& j_video_frame_buffer) {
-  AndroidVideoTrackSource* source =
-      reinterpret_cast<AndroidVideoTrackSource*>(j_source);
-  source->OnFrameCaptured(jni, j_width, j_height, j_timestamp_ns,
-                          jintToVideoRotation(j_rotation),
-                          j_video_frame_buffer);
-}
-
-static void JNI_NativeCapturerObserver_CapturerStarted(
-    JNIEnv* jni,
-    jlong j_source,
-    jboolean j_success) {
-  RTC_LOG(LS_INFO) << "NativeCapturerObserver_nativeCapturerStarted";
-  AndroidVideoTrackSource* source =
-      reinterpret_cast<AndroidVideoTrackSource*>(j_source);
-  source->SetState(j_success ? AndroidVideoTrackSource::SourceState::kLive
-                             : AndroidVideoTrackSource::SourceState::kEnded);
-}
-
-static void JNI_NativeCapturerObserver_CapturerStopped(
-    JNIEnv* jni,
-    jlong j_source) {
-  RTC_LOG(LS_INFO) << "NativeCapturerObserver_nativeCapturerStopped";
-  AndroidVideoTrackSource* source =
-      reinterpret_cast<AndroidVideoTrackSource*>(j_source);
-  source->SetState(AndroidVideoTrackSource::SourceState::kEnded);
-}
-
 }  // namespace jni
 }  // namespace webrtc
diff --git a/sdk/android/src/jni/video_source.cc b/sdk/android/src/jni/video_source.cc
deleted file mode 100644
index 0c41fd8..0000000
--- a/sdk/android/src/jni/video_source.cc
+++ /dev/null
@@ -1,33 +0,0 @@
-/*
- *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
- *
- *  Use of this source code is governed by a BSD-style license
- *  that can be found in the LICENSE file in the root of the source
- *  tree. An additional intellectual property rights grant can be found
- *  in the file PATENTS.  All contributing project authors may
- *  be found in the AUTHORS file in the root of the source tree.
- */
-
-#include "rtc_base/logging.h"
-#include "sdk/android/generated_video_jni/jni/VideoSource_jni.h"
-#include "sdk/android/native_api/jni/java_types.h"
-#include "sdk/android/src/jni/android_video_track_source.h"
-
-namespace webrtc {
-namespace jni {
-
-static void JNI_VideoSource_AdaptOutputFormat(JNIEnv* jni,
-                                              jlong j_source,
-                                              jint j_landscape_width,
-                                              jint j_landscape_height,
-                                              jint j_portrait_width,
-                                              jint j_portrait_height,
-                                              jint j_fps) {
-  RTC_LOG(LS_INFO) << "VideoSource_nativeAdaptOutputFormat";
-  reinterpret_cast<AndroidVideoTrackSource*>(j_source)->OnOutputFormatRequest(
-      j_landscape_width, j_landscape_height, j_portrait_width,
-      j_portrait_height, j_fps);
-}
-
-}  // namespace jni
-}  // namespace webrtc