diff --git a/api/test/frame_generator_interface.h b/api/test/frame_generator_interface.h
index 90e60debac..84aa1dcafb 100644
--- a/api/test/frame_generator_interface.h
+++ b/api/test/frame_generator_interface.h
@@ -23,6 +23,10 @@ namespace test {
 
 class FrameGeneratorInterface {
  public:
+  struct Resolution {
+    size_t width;
+    size_t height;
+  };
   struct VideoFrameData {
     VideoFrameData(rtc::scoped_refptr<VideoFrameBuffer> buffer,
                    absl::optional<VideoFrame::UpdateRect> update_rect)
@@ -43,6 +47,11 @@ class FrameGeneratorInterface {
 
   // Change the capture resolution.
   virtual void ChangeResolution(size_t width, size_t height) = 0;
+
+  virtual Resolution GetResolution() const {
+    // TODO(mbonadei): Remove and make it pure virtual.
+    return {.width = 0, .height = 0};
+  }
 };
 
 }  // namespace test
diff --git a/test/frame_generator.cc b/test/frame_generator.cc
index b6f16a573d..d2fa95352d 100644
--- a/test/frame_generator.cc
+++ b/test/frame_generator.cc
@@ -45,6 +45,12 @@ void SquareGenerator::ChangeResolution(size_t width, size_t height) {
   RTC_CHECK(height_ > 0);
 }
 
+FrameGeneratorInterface::Resolution SquareGenerator::GetResolution() const {
+  MutexLock lock(&mutex_);
+  return {.width = static_cast<size_t>(width_),
+          .height = static_cast<size_t>(height_)};
+}
+
 rtc::scoped_refptr<I420Buffer> SquareGenerator::CreateI420Buffer(int width,
                                                                  int height) {
   rtc::scoped_refptr<I420Buffer> buffer(I420Buffer::Create(width, height));
@@ -205,6 +211,10 @@ bool YuvFileGenerator::ReadNextFrame() {
   return frame_index_ != prev_frame_index || file_index_ != prev_file_index;
 }
 
+FrameGeneratorInterface::Resolution YuvFileGenerator::GetResolution() const {
+  return {.width = width_, .height = height_};
+}
+
 NV12FileGenerator::NV12FileGenerator(std::vector<FILE*> files,
                                      size_t width,
                                      size_t height,
@@ -247,6 +257,10 @@ FrameGeneratorInterface::VideoFrameData NV12FileGenerator::NextFrame() {
   return VideoFrameData(last_read_buffer_, update_rect);
 }
 
+FrameGeneratorInterface::Resolution NV12FileGenerator::GetResolution() const {
+  return {.width = width_, .height = height_};
+}
+
 bool NV12FileGenerator::ReadNextFrame() {
   size_t prev_frame_index = frame_index_;
   size_t prev_file_index = file_index_;
@@ -287,6 +301,11 @@ FrameGeneratorInterface::VideoFrameData SlideGenerator::NextFrame() {
   return VideoFrameData(buffer_, absl::nullopt);
 }
 
+FrameGeneratorInterface::Resolution SlideGenerator::GetResolution() const {
+  return {.width = static_cast<size_t>(width_),
+          .height = static_cast<size_t>(height_)};
+}
+
 void SlideGenerator::GenerateNewFrame() {
   // The squares should have a varying order of magnitude in order
   // to simulate variation in the slides' complexity.
@@ -390,6 +409,12 @@ ScrollingImageFrameGenerator::NextFrame() {
   return current_frame_;
 }
 
+FrameGeneratorInterface::Resolution
+ScrollingImageFrameGenerator::GetResolution() const {
+  return {.width = static_cast<size_t>(target_width_),
+          .height = static_cast<size_t>(target_height_)};
+}
+
 void ScrollingImageFrameGenerator::UpdateSourceFrame(size_t frame_num) {
   VideoFrame::UpdateRect acc_update{0, 0, 0, 0};
   while (current_frame_num_ != frame_num) {
diff --git a/test/frame_generator.h b/test/frame_generator.h
index 9a8f08cea6..6eb6bf77cd 100644
--- a/test/frame_generator.h
+++ b/test/frame_generator.h
@@ -38,6 +38,7 @@ class SquareGenerator : public FrameGeneratorInterface {
 
   void ChangeResolution(size_t width, size_t height) override;
   VideoFrameData NextFrame() override;
+  Resolution GetResolution() const override;
 
  private:
   rtc::scoped_refptr<I420Buffer> CreateI420Buffer(int width, int height);
@@ -59,7 +60,7 @@ class SquareGenerator : public FrameGeneratorInterface {
     const uint8_t yuv_a_;
   };
 
-  Mutex mutex_;
+  mutable Mutex mutex_;
   const OutputType type_;
   int width_ RTC_GUARDED_BY(&mutex_);
   int height_ RTC_GUARDED_BY(&mutex_);
@@ -79,6 +80,7 @@ class YuvFileGenerator : public FrameGeneratorInterface {
   void ChangeResolution(size_t width, size_t height) override {
     RTC_LOG(LS_WARNING) << "YuvFileGenerator::ChangeResolution not implemented";
   }
+  Resolution GetResolution() const override;
 
  private:
   // Returns true if the new frame was loaded.
@@ -111,6 +113,7 @@ class NV12FileGenerator : public FrameGeneratorInterface {
     RTC_LOG(LS_WARNING)
         << "NV12FileGenerator::ChangeResolution not implemented";
   }
+  Resolution GetResolution() const override;
 
  private:
   // Returns true if the new frame was loaded.
@@ -140,6 +143,7 @@ class SlideGenerator : public FrameGeneratorInterface {
   void ChangeResolution(size_t width, size_t height) override {
     RTC_LOG(LS_WARNING) << "SlideGenerator::ChangeResolution not implemented";
   }
+  Resolution GetResolution() const override;
 
  private:
   // Generates some randomly sized and colored squares scattered
@@ -171,6 +175,7 @@ class ScrollingImageFrameGenerator : public FrameGeneratorInterface {
     RTC_LOG(LS_WARNING)
         << "ScrollingImageFrameGenerator::ChangeResolution not implemented";
   }
+  Resolution GetResolution() const override;
 
  private:
   void UpdateSourceFrame(size_t frame_num);
diff --git a/test/testsupport/ivf_video_frame_generator.cc b/test/testsupport/ivf_video_frame_generator.cc
index 92700e192f..ae87fb8b04 100644
--- a/test/testsupport/ivf_video_frame_generator.cc
+++ b/test/testsupport/ivf_video_frame_generator.cc
@@ -105,6 +105,11 @@ void IvfVideoFrameGenerator::ChangeResolution(size_t width, size_t height) {
   height_ = height;
 }
 
+FrameGeneratorInterface::Resolution IvfVideoFrameGenerator::GetResolution()
+    const {
+  return {.width = width_, .height = height_};
+}
+
 int32_t IvfVideoFrameGenerator::DecodedCallback::Decoded(
     VideoFrame& decoded_image) {
   Decoded(decoded_image, 0, 0);
diff --git a/test/testsupport/ivf_video_frame_generator.h b/test/testsupport/ivf_video_frame_generator.h
index 4b6d116383..9a4c1e2858 100644
--- a/test/testsupport/ivf_video_frame_generator.h
+++ b/test/testsupport/ivf_video_frame_generator.h
@@ -35,6 +35,7 @@ class IvfVideoFrameGenerator : public FrameGeneratorInterface {
 
   VideoFrameData NextFrame() override;
   void ChangeResolution(size_t width, size_t height) override;
+  Resolution GetResolution() const override;
 
  private:
   class DecodedCallback : public DecodedImageCallback {