Unreal FFMpeg decoder

FFMpegSoundWave.cpp

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

#include "RIVR.h"
#include "FFMpegSoundWave.h"

UFFMpegSoundWave::UFFMpegSoundWave(const FObjectInitializer &ObjectInitializer)
{
    bProcedural = true;
    bCanProcessAsync = true;
    bStreaming = true;
    DecompressionType = DTYPE_Procedural;

    //TODO Move to safer zone
    av_register_all();

    avformat_open_input(&container, "/Users/drouar_b/Antidote.mp3", NULL, NULL);

    avformat_find_stream_info(container, NULL);
    for (int i = 0; i < container->nb_streams; i++) {
        if (container->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_AUDIO) {
            stream_id = i;
            break;
        }
    }

    codec_parameter = container->streams[stream_id]->codecpar;
    codec = avcodec_find_decoder(codec_parameter->codec_id);
    codec_context = avcodec_alloc_context3(codec);
    avcodec_parameters_to_context(codec_context, codec_parameter);
    avcodec_open2(codec_context, codec, NULL);

}

int32 UFFMpegSoundWave::GeneratePCMData(uint8* PCMData, const int32 SamplesNeeded) {
    AVPacket *packet = av_packet_alloc();
    AVFrame *frame = av_frame_alloc();

    if (av_read_frame(container, packet) == 0) {
        avcodec_send_packet(codec_context, packet);
        avcodec_receive_frame(codec_context, frame);
        GEngine->AddOnScreenDebugMessage(-1, 15, FColor::Red, FString::FromInt(frame->linesize[0]));
        GEngine->AddOnScreenDebugMessage(-1, 15, FColor::Red, FString::FromInt(SamplesNeeded));
        memcpy(PCMData, frame->data[0], frame->linesize[0]);
        return frame->linesize[0];
    }
    return 0;
}

FFMpegSoundWave.h

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

#pragma once

#include "RIVR.h"
#include "Sound/SoundWaveProcedural.h"
extern "C" {
#include "libavformat/avformat.h"
#include "libavcodec/avcodec.h"
}
#include "FFMpegSoundWave.generated.h"

/**
 *
 */
UCLASS()
class RIVR_API UFFMpegSoundWave : public USoundWaveProcedural
{
    GENERATED_BODY()

public:
    UFFMpegSoundWave(const FObjectInitializer &ObjectInitializer);

    virtual int32 GeneratePCMData(uint8* PCMData, const int32 SamplesNeeded) override;

private:
    int stream_id;
    AVFormatContext* container;
    AVCodecParameters* codec_parameter;
    AVCodec* codec;
    AVCodecContext *codec_context;
};

MyActor.cpp

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

#include "RIVR.h"
#include "MyActor.h"


// Sets default values
AMyActor::AMyActor(const FObjectInitializer &ObjectInitializer)
{
    ac = ObjectInitializer.CreateDefaultSubobject<UAudioComponent>(this, TEXT("audio component"));
    ac->bAutoActivate = false;
    ac->bStopWhenOwnerDestroyed = false;
}

// Called when the game starts or when spawned
void AMyActor::BeginPlay()
{
	Super::BeginPlay();
    sw = NewObject<UFFMpegSoundWave>(this);
    sw->SampleRate = 44100;
    sw->NumChannels = 1;
    sw->Duration = INDEFINITELY_LOOPING_DURATION;
    sw->bLooping = true;

    TArray<uint8> data;
    data.Init(0, 512);
    int lol = sw->GeneratePCMData(data.GetData(), 512);
    GEngine->AddOnScreenDebugMessage(-1, 1, FColor::Red, FString::FromInt(lol));

    ac->SetVolumeMultiplier(100);
    ac->Activate(true);
    ac->SetSound(sw);
    ac->Play(0);
}

// Called every frame
void AMyActor::Tick( float DeltaTime )
{
	Super::Tick( DeltaTime );

}

void AMyActor::Debug(FString msg){
    if (GEngine){
        GEngine->AddOnScreenDebugMessage(-1, 1, FColor::Red, msg);
    }
}

MyActor.h

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

#pragma once

#include "GameFramework/Actor.h"
#include "Sound/SoundCue.h"
#include "Sound/SoundWaveProcedural.h"
#include "FFMpegSoundWave.h"
#include "MyActor.generated.h"


UCLASS()
class RIVR_API AMyActor : public AActor
{
	GENERATED_BODY()
	
public:	
	// Sets default values for this actor's properties
	AMyActor(const FObjectInitializer &ObjectInitializer);


	// Called when the game starts or when spawned
	virtual void BeginPlay() override;
	
	// Called every frame
	virtual void Tick( float DeltaSeconds ) override;

    void Debug(FString msg);

private:
    UAudioComponent *ac;
    USoundWave *sw;
    TArray < uint8 > rawFile;
    bool loaded;
};

Thank you for providing example!