IMF Source Reader leaking/consuming memory

I don't know if it's not source reader basic behavior, but even thoug I am releasing every sample it keeps consuming memory up to size of file that is being red.

Source reader:

    hr = pAttributes->SetUINT32(MF_SOURCE_READER_ENABLE_VIDEO_PROCESSING, TRUE);
    hr = MFCreateSourceReaderFromURL(wszFileName, pAttributes, &m_pReader);

Code:

    /*in loop*/
    hr = m_pReader->ReadSample(
            (DWORD)MF_SOURCE_READER_FIRST_VIDEO_STREAM,
            0,
            NULL,&dwFlagss,&time,&pSampleTmp
            );

    SafeRelease(&pSampleTmp); 

Is there some attribute to set or there is nothing I can do about this and have to use MediaSession or MFPlayer? If so could you propose how to get individual samples from them? (with DXVA would be best but I think I can solve this)