Image Sequence GPU Memory Leak? How can I clean up this from memory / gpu as it goes?

I’ve been posting several separate posts all relating to the same project. I got pretty far but now am stuck on something. Memory Leaks!

Here’s a screen capture of where I’m at:

Functionality wise this is working! There are 4 image sequences on my desktop (so EXTERNAL to packaged game). This game is currently randomly setting in/out points on each of those clips, playing it, and then switching to the next clip and repeating that action over and over.

So for about a minute straight its working GREAT. Then at about 54 seconds, it freezes and then frame glitches like crazy! This coincides with my gpu usage hitting 30%ish each time it does that. I see the GPU % climb climb climb, hit 30% SCRAMBLE… then it drops way down to like 12%. then it slowly builds back up up up, hits 30% and SCRAMBLE.

So obviously how I’m doing this is bloating up the memory (computer gets HOT) and then it dies but recovers (maybe some automatic garbage collection repairs it?)

I figured this would be the case until I figured out how to have this stuff EXIT the memory.

Here’s the header file:

// Fill out your copyright notice in the Description page of Project Settings.

#pragma once

#include "CoreMinimal.h"
#include "GameFramework/Actor.h"
#include <Runtime\Core\Public\Misc\FileHelper.h>
#include <Runtime\ImageWrapper\Public\IImageWrapper.h>
#include <Runtime\ImageWrapper\Public\IImageWrapperModule.h>
#include "TEST_VideoStreamDisplay.generated.h"

class IMAGETEXTURECPP_API ATEST_VideoStreamDisplay : public AActor

// Sets default values for this actor's properties
FString ZeroFillInt32ToFString(int32 Value, int32 ZeroFillCount);

void OnPlayNextFrame();

// Called when the game starts or when spawned
virtual void BeginPlay() override;

// Called every frame
virtual void Tick(float DeltaTime) override;

UStaticMeshComponent* SampleMesh;

UMaterialInstanceDynamic* MyMaterial;
UMaterialInterface* LoadedMaterial;

IImageWrapperModule& ImageWrapperModule = FModuleManager::LoadModuleChecked<IImageWrapperModule>(FName("ImageWrapper"));
TSharedPtr<IImageWrapper> PNGImageWrapper = ImageWrapperModule.CreateImageWrapper(EImageFormat::PNG);
//TArray<uint8> BinaryArray;
//TArray<uint8> RawData;
UTexture2D* myTexture;

int32 TEST_CurrentFrame = 0;
FString TEST_CurrentClipName = "earth";
int32 TEST_CurrentClipDuration = 707;
int32 TEST_CurrentOutPoint = 20;

and the implementation file

// Fill out your copyright notice in the Description page of Project Settings.

#include "TEST_VideoStreamDisplay.h"
#include <Runtime\Core\Public\Misc\Paths.h>
#include <Runtime\Core\Public\HAL\PlatformFilemanager.h>
#include <Runtime\ImageWrapper\Public\IImageWrapper.h>
#include <Runtime\ImageWrapper\Public\IImageWrapperModule.h>

// Sets default values
    // Set this actor to call Tick() every frame. You can turn this off to improve performance if you don't need it.
   PrimaryActorTick.bCanEverTick = true;

   SampleMesh = CreateDefaultSubobject<UStaticMeshComponent>(TEXT("SampleMesh"));

FString ATEST_VideoStreamDisplay::ZeroFillInt32ToFString(int32 Value, int32 ZeroFillCount)
   FString InputValueStr = "";

   FString BuildReturnValue = "";

   for (int32 i = InputValueStr.Len(); i < ZeroFillCount; i++)
      BuildReturnValue += "0";

   BuildReturnValue += InputValueStr;
   return BuildReturnValue;

void ATEST_VideoStreamDisplay::OnPlayNextFrame()
   FString ZeroFillString = ZeroFillInt32ToFString(TEST_CurrentFrame, 3);

   //UE_LOG(LogTemp, Log, TEXT("ZeroFillString %s]"), *ZeroFillString);

   FString PngFile = "C:/Users/dev/Desktop/BRYAN_TEST/"+TEST_CurrentClipName+"/"+TEST_CurrentClipName+"_";
   PngFile += ZeroFillString;
   PngFile += ".png";
   //UE_LOG(LogTemp, Log, TEXT("PNG FILE %s]"), *PngFile);

   //IImageWrapperModule& ImageWrapperModule = FModuleManager::LoadModuleChecked<IImageWrapperModule>(FName("ImageWrapper"));
   //TSharedPtr<IImageWrapper> PNGImageWrapper = ImageWrapperModule.CreateImageWrapper(EImageFormat::PNG);
   TArray<uint8> BinaryArray;

   if (FFileHelper::LoadFileToArray(BinaryArray, *PngFile))
   //UE_LOG(LogTemp, Log, TEXT("LoadFileToArray() success"));

   if (PNGImageWrapper.IsValid() && PNGImageWrapper->SetCompressed(BinaryArray.GetData(), BinaryArray.Num()))
      //UE_LOG(LogTemp, Log, TEXT("its valid, keep going"));
      TArray<uint8> RawData;

      if (PNGImageWrapper->GetRaw(ERGBFormat::BGRA, 8, RawData))
         //UE_LOG(LogTemp, Log, TEXT("GetRaw success keep going"));

         //UTexture2D* myTexture = UTexture2D::CreateTransient(600, 338, PF_B8G8R8A8);
         myTexture = UTexture2D::CreateTransient(600, 338, PF_B8G8R8A8);

         //UE_LOG(LogTemp, Log, TEXT("Now try to make a material instance of the video stream material"));
         //UMaterialInterface* LoadedMaterial = LoadObject<UMaterialInterface>(nullptr, TEXT("/Game/Foo.Foo"), nullptr, LOAD_None, nullptr);
         // PUT_BACK if its not working!

         if (LoadedMaterial)
            //UE_LOG(LogTemp, Log, TEXT("LoadedMaterial true"));
            //MyMaterial = UMaterialInstanceDynamic::Create(LoadedMaterial, NULL);

            if (MyMaterial)
               //UE_LOG(LogTemp, Log, TEXT("MyMaterial true"));
               MyMaterial->SetTextureParameterValue(TEXT("TextureInput"), myTexture);

               //Finally, apply the material to your mesh component
               SampleMesh->SetMaterial(0, MyMaterial);

   //up the current frame and run logic to switch to next clip

   if (TEST_CurrentFrame > TEST_CurrentOutPoint) TEST_CurrentFrame = 9999;

   if (TEST_CurrentFrame > TEST_CurrentClipDuration)
      UE_LOG(LogTemp, Log, TEXT("time to change clips"));
      TEST_CurrentFrame = 0;
      if(TEST_CurrentClipName == "earth")
         TEST_CurrentClipName = "fire";
         TEST_CurrentClipDuration = 647;
      else if (TEST_CurrentClipName == "fire")
         TEST_CurrentClipName = "water";
         TEST_CurrentClipDuration = 738;
      else if (TEST_CurrentClipName == "water")
         TEST_CurrentClipName = "wind";
         TEST_CurrentClipDuration = 198;
      else if (TEST_CurrentClipName == "wind")
         TEST_CurrentClipName = "earth";
         TEST_CurrentClipDuration = 707;

      TEST_CurrentFrame = FMath::RandRange(int32(0), TEST_CurrentClipDuration);
      //make the shot last up to 6 seconds
      TEST_CurrentOutPoint = FMath::RandRange(TEST_CurrentFrame + 1, TEST_CurrentFrame+144);

      //UE_LOG(LogTemp, Log, TEXT("Random Number: %d"), inPointFrame);


// Called when the game starts or when spawned
void ATEST_VideoStreamDisplay::BeginPlay()

   //Setup the SampleMesh position and scale for this video playback to display on
   FRotator InitPlaneRotation = FRotator(0, 0, 0);
   InitPlaneRotation.Pitch = 0;
   InitPlaneRotation.Yaw = 90;
   InitPlaneRotation.Roll = 90;
   SampleMesh->SetRelativeScale3D(FVector(3.2, 1.8, 1));

   //setup material stuff
   LoadedMaterial = LoadObject<UMaterialInterface>(nullptr, TEXT("/Game/Foo.Foo"), nullptr, LOAD_None, nullptr);
   MyMaterial = UMaterialInstanceDynamic::Create(LoadedMaterial, NULL);

   //Setup the 24 FPS timer for video playback to run on, 0.0416666666666667 = 24 FPS time (approx)
   //need to set up a delta time and make corrections for the incorrect timing of each function call.
   FTimerHandle TimerHandle;
   FTimerDelegate TimerDel;
   TimerDel.BindUFunction(this, FName("OnPlayNextFrame"));
   GetWorld()->GetTimerManager().SetTimer(TimerHandle, TimerDel, 0.0416666666666667, true);

// Called every frame
void ATEST_VideoStreamDisplay::Tick(float DeltaTime)

Note: I know there are media textures that can load image sequences but i don’t think that route will work as I need very accurate start / stop, and to be abel to with custom code control the playback speed/rate at a greater degree than I found with the media texture route. Plus these are external not packaged.

Any tips/feedback would be greatly appreciated! Also the route of loading in a new texture onto that material instance 24 times a second I figure I’m doing wrong and that it’s just bloating memory or somehow creating a BUNCH of texture instances that bloat gpu memory somewhere.

If someone knows a better route to rapidly update the texture based on this attempt at radpily loading new video frames into the material I’m all ears!

^^ Also by using this route I can control how many frames get loaded at once for a custom buffer as I continue with this. Probably more control than I can get with Media texture… Especially if I load huge files into it… need to be able to control how much is loaded in at once.

Oh wow. So, you’re calling OnPlayNextFrame() on a timer that executes every 0.0416666666666667 seconds, and in that function you’re:

  1. Loading the particular image file
  2. Creating the Texture2D from the file data
  3. Loading the material, setting its texture, and applying it to the mesh
  4. Deciding what the next frame is going to be
    Is this correct?

That’s a lot of loading to do in a short period of time. I would suggest loading all of your textures/creating Texture2Ds upfront and then just apply them in OnPlayNextFrame(). You also don’t need to load your base material and create your dynamic material over and over again. Just do it once, then change the texture parameter to change from image to image.

Now, I’m not going to argue the merits of using the UE4 image sequence and player functionality, since you’re set in your frame accuracy wants. I’ll keep my suggestions in the bounds of how you’ve set things up for yourself. So, yeah, this is how you might want to approach it:

  1. Load each image and create Texture2D’s up front, holding them all in a TArray. If you want to separate them out to your image categories (fire, water, wind, etc), that’s fine too. You’ll just need to put code in to use the proper array when you need to.
  2. Create your dynamic material just once up front and apply it to your mesh
  3. OnPlayNextFrame() should pretty much do one thing: SetTextureParameterValue to whichever frame should be displayed next.

Give that a try and see if it improves your playback.

Sorry, I just saw your comment about how many frames get loaded at once for a custom buffer. If you move toward the HUGE files bit, as you said, that load time isn’t going to get faster in that short frame period. So, consider doing the same thing I said above, but make it load the images in batches – maybe on a separate thread while the current batch of frames are being displayed.

Gotcha. So yeah I got to start coding a custom buffer thats on its own timer doing batches of loads. If they’re all in a managed TArray doing my own forced garbage collection and deleting instances from memory might be easier. Before I move onto the next step I need to beat this part into shape and stress test it. It needs to be able to play for an hour straight without hitting any bumps / hiccups in memory. Not only that, but well enough to do the same for 30 fps and 60 fps. In those cases, definitely will need the custom buffer to be working properly… thanks for the tips again! Its also getting to that point where I need to diagram the idea and start getting more OOP with some classes to organize this more.