[Encoder] Colors got inverted

[abdullahsultan]

Original Image

Encoded Image

I am trying to Encode frames in Unreal Engine to create a video later, I saved fames in yuv and converted to mp4 via Ffmpeg and colors are fine but if I encode via PopH264 (save as .h264) and convert .h264 to mp4 via ffmpeg colors get inverted as shown in Images.
Following is the code I am using:
Creating Encoder

EncoderWrapper::CreateEncoder(int32 InViewportWidth, int32 InViewportHeight, int32 InBitRate)
{
    ViewportWidth = InViewportWidth;
    ViewportHeight = InViewportHeight;
    BitRate = InBitRate;
    EncodedFrames.Empty();
    const FString Options = FString::Printf(
        TEXT("{\"Width\":%d,\"Height\":%d,\"AverageKbps\":%d,\"Realtime\":true}"),
        InViewportWidth,
        InViewportHeight,
        InBitRate
    );

    char Error[1024] = { 0 };

    PopH264Encoder = PopH264_CreateEncoder(TCHAR_TO_UTF8(*Options), Error, sizeof(Error));

    if (PopH264Encoder <= 0)
    {
        UE_LOG(LogEncoderWrapper, Error, TEXT("PopH264 create failed: %s"), UTF8_TO_TCHAR(Error));
    }
}

Pushing Frames:

bool EncoderWrapper::PushFrameToPopH264(
    int32 Encoder,
    int Width,
    int Height,
    const uint8* YPlane,
    const uint8* UPlane,
    const uint8* VPlane,
    TArray<TArray<uint8>>& OutPackets
)
{
    if (Encoder <= 0 || !YPlane || !UPlane || !VPlane)
    {
        return false;
    }

    const int32 LumaSize = Width * Height;
    const int32 ChromaSize = (Width / 2) * (Height / 2);

    FString Meta = FString::Printf(
        TEXT("{\"Width\":%d,\"Height\":%d,\"Format\":\"Yuv_8_8_8\",\"LumaSize\":%d,\"ChromaUSize\":%d,\"ChromaVSize\":%d}"),
        Width,
        Height,
        LumaSize,
        ChromaSize,
        ChromaSize
    );

    char ErrorBuffer[1024] = { 0 };

    PopH264_EncoderPushFrame(
        Encoder,
        TCHAR_TO_UTF8(*Meta),
        YPlane,
        UPlane,
        VPlane,
        ErrorBuffer,
        sizeof(ErrorBuffer)
    );

    if (ErrorBuffer[0] != 0)
    {
        UE_LOG(LogEncoderWrapper, Error, TEXT("PopH264 Encode Error: %s"), UTF8_TO_TCHAR(ErrorBuffer));
        return false;
    }

    // Drain all available encoded packets
    while (true)
    {
        uint8 TempBuffer[1024 * 1024];

        int32 PacketSize = PopH264_EncoderPopData(
            Encoder,
            TempBuffer,
            sizeof(TempBuffer)
        );

        if (PacketSize <= 0)
        {
            break;
        }

        TArray<uint8> Packet;
        Packet.Append(TempBuffer, PacketSize);

        OutPackets.Add(MoveTemp(Packet));
    }

    return true;
}

[SoylentGraham]

hmm looks like RGB vs BGR to me, but if your UV planes are correct (via ffmpeg encoding) then I wonder if the format is expecting chroma as VU (so swap the planes)

I'm pretty sure I included something that would tell you what format the encoder expected - but I think you can also specify the format, (and then if neccessary it'll do [slow]colour conversions)

The default formats for encoding/decoding on all platforms were always the most efficient for the platform (and android/win/mac/ios/etc are all totally different)

[abdullahsultan]

Regarding the format I am now sure it is using YUV420:

And if I swap UV planes, .H264 to mp4 via ffmpeg throws error: