From b69f93fca60a06d7117670530eb6f526bb1df9be Mon Sep 17 00:00:00 2001
From: MediaPipe Team <mediapipe-team@google.com>
Date: Fri, 2 Jun 2023 12:29:29 -0700
Subject: [PATCH] Internal change

PiperOrigin-RevId: 537381138
---
 mediapipe/gpu/gl_calculator_helper.cc            |  8 ++++++++
 mediapipe/gpu/gl_calculator_helper.h             | 16 +++++++++++++++-
 .../gpu/image_frame_to_gpu_buffer_calculator.cc  |  7 +++----
 3 files changed, 26 insertions(+), 5 deletions(-)

diff --git a/mediapipe/gpu/gl_calculator_helper.cc b/mediapipe/gpu/gl_calculator_helper.cc
index 9b217ddfd..974525a91 100644
--- a/mediapipe/gpu/gl_calculator_helper.cc
+++ b/mediapipe/gpu/gl_calculator_helper.cc
@@ -211,6 +211,14 @@ GlTexture GlCalculatorHelper::CreateDestinationTexture(int width, int height,
   return MapGpuBuffer(gpu_buffer, gpu_buffer.GetWriteView<GlTextureView>(0));
 }
 
+GlTexture GlCalculatorHelper::CreateDestinationTexture(
+    const ImageFrame& image_frame) {
+  // TODO: ensure buffer pool is used when creating textures out of
+  // ImageFrame.
+  GpuBuffer gpu_buffer = GpuBufferCopyingImageFrame(image_frame);
+  return MapGpuBuffer(gpu_buffer, gpu_buffer.GetWriteView<GlTextureView>(0));
+}
+
 GlTexture GlCalculatorHelper::CreateSourceTexture(
     const mediapipe::Image& image) {
   return CreateSourceTexture(image.GetGpuBuffer());
diff --git a/mediapipe/gpu/gl_calculator_helper.h b/mediapipe/gpu/gl_calculator_helper.h
index af897bbe9..c1b94fa82 100644
--- a/mediapipe/gpu/gl_calculator_helper.h
+++ b/mediapipe/gpu/gl_calculator_helper.h
@@ -135,6 +135,12 @@ class GlCalculatorHelper {
   // This is deprecated because: 1) it encourages the use of GlTexture as a
   // long-lived object; 2) it requires copying the ImageFrame's contents,
   // which may not always be necessary.
+  //
+  // WARNING: do NOT use as a destination texture which will be sent to
+  // downstream calculators as it may lead to synchronization issues. The result
+  // is meant to be a short-lived object, local to a single calculator and
+  // single GL thread. Use `CreateDestinationTexture` instead, if you need a
+  // destination texture.
   ABSL_DEPRECATED("Use `GpuBufferWithImageFrame`.")
   GlTexture CreateSourceTexture(const ImageFrame& image_frame);
 
@@ -156,6 +162,14 @@ class GlCalculatorHelper {
       int output_width, int output_height,
       GpuBufferFormat format = GpuBufferFormat::kBGRA32);
 
+  // Creates a destination texture copying and uploading passed image frame.
+  //
+  // WARNING: mind that this functions creates a new texture every time and
+  // doesn't use MediaPipe's gpu buffer pool.
+  // TODO: ensure buffer pool is used when creating textures out of
+  // ImageFrame.
+  GlTexture CreateDestinationTexture(const ImageFrame& image_frame);
+
   // The OpenGL name of the output framebuffer.
   GLuint framebuffer() const;
 
@@ -196,7 +210,7 @@ class GlCalculatorHelper {
 // This class should be the main way to interface with GL memory within a single
 // calculator. This is the preferred way to utilize the memory pool inside of
 // the helper, because GlTexture manages efficiently releasing memory back into
-// the pool. A GPU backed Image can be extracted from the unerlying
+// the pool. A GPU backed Image can be extracted from the underlying
 // memory.
 class GlTexture {
  public:
diff --git a/mediapipe/gpu/image_frame_to_gpu_buffer_calculator.cc b/mediapipe/gpu/image_frame_to_gpu_buffer_calculator.cc
index 2a8331db8..a741e42a7 100644
--- a/mediapipe/gpu/image_frame_to_gpu_buffer_calculator.cc
+++ b/mediapipe/gpu/image_frame_to_gpu_buffer_calculator.cc
@@ -71,11 +71,10 @@ absl::Status ImageFrameToGpuBufferCalculator::Process(CalculatorContext* cc) {
 #else
   const auto& input = cc->Inputs().Index(0).Get<ImageFrame>();
   helper_.RunInGlContext([this, &input, &cc]() {
-    auto src = helper_.CreateSourceTexture(input);
-    auto output = src.GetFrame<GpuBuffer>();
-    glFlush();
+    GlTexture dst = helper_.CreateDestinationTexture(input);
+    std::unique_ptr<GpuBuffer> output = dst.GetFrame<GpuBuffer>();
     cc->Outputs().Index(0).Add(output.release(), cc->InputTimestamp());
-    src.Release();
+    dst.Release();
   });
 #endif  // MEDIAPIPE_GPU_BUFFER_USE_CV_PIXEL_BUFFER
   return absl::OkStatus();