private void PopulateFrames()
    {
        Frames = new Texture2D[_sampleManager.GetDataLength()];

        _framesDownloaded = 0;

        for (int i = 0; i < Frames.Length; i++)
        {
            // First check cache
            if (File.Exists(Path.Combine(_sampleManager.CacheDirectory, "Image_" + i + ".jpg")))
            {
                StartCoroutine(DownloadFrameFromCache(i));
            }
            else    // Download from AWS
            {
                StartCoroutine(DownloadFrame(i));
            }
        }
    }