## 4 Experimental Results
Even better results were achieved while testing on real drone footage, but it is worth noticing that real drone footage was filmed using only basic movements. No complex movements, such as combined forward motion and left-right rotation, were used. In real drone footage, MDIS was up to 4.25 times faster than the DS while preserving video quality and compression rate. This version of MDIS excluded the extra corner search locations that were added in one of the MDIS versions (Figure 9). Including the corners resulted in a slightly smaller video file size, but at the cost of a longer encoding time. The reduction in file size was minimal (around 1 MB), while the MDIS execution time increased by approximately 15%. Therefore, the disadvantages of using the corner search locations outweigh the benefits, at least in this case of encoding the simulator footage. The search range weight factor used in \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Algorithm** & **Sequence Number** & **Encoded Video File Size [MB]** & \
\begin{tabular}{c} **Search Time [CPU s] (Less** \\ **Is Better)** \\ \end{tabular} &
\begin{tabular}{c} **PSNR [dB] (More Is Better)** \\ \end{tabular} \\ \hline \multirow{3}{*}{**DS**} & 1 & 10.2 & 1.53 & 45.36 \\  & 2 & 38.1 & 38.70 & 43.08 \\  & 3 & 19.7 & 1.11 & 43.68 \\  & 4 & 9.87 & 12.37 & 44.92 \\ \hline \multirow{3}{*}{**MDIS**} & 1 & 10.2 & 0.36 & 45.44 \\  & 2 & 37.9 & 11.02 & 43.08 \\ \cline{1-1}  & 3 & 19.7 & 0.35 & 43.69 \\ \cline{1-1}  & 4 & 9.80 & 3.07 & 44.85 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Comparison of encoded file size, encoding time, and encoding quality for DS and MDIS in case of encoding 4 different real drone sequences. Figure 15: Chart showing CPU time consumption per functions for the entire simulator sequence encoding via MDIS and DS algorithms. this version was 2. This refers to the search range that is modified based on the calculated search probabilities. This would mean that a block that had a search probability of 1.0 had the search range doubled. It is worth noting that the process of calculating the search probabilities has a negligible impact on the encoding time. We found it very interesting how MDIS resulted in smaller video file sizes. Hence, a detailed inspection was performed using VQAnalyzer software version 7.2.0.73697 [27]. Oftentimes, MDIS guides the ME process in the right direction. In DS, there can be cases where blocks 'accidentally' find the most similar blocks on search locations that do not align with the drone's movement. For instance, during the first iteration of DS, the center might shift to the left search location even though the drone is moving right. While the left search location may indeed be the best match in the first iteration, DS might not find better blocks in subsequent iterations. In contrast, MDIS, which might not find the best match in the first iteration, often identifies much better blocks in later iterations. This discrepancy can also impact neighboring blocks due to the process of selecting the initial MV. At times, DS might conclude that the best match is in the left search location, causing neighboring blocks to start their search from that point, which can lead to 'dead-ends'. Although this can also occur with MDIS, it happens less frequently due to the enforced search direction, which is grounded in theoretical principles. Figures 16 and 17 show this effect--they are snippets of the same video frame, but one is from the video encoded with DS, and one is from the video encoded with MDIS. There are much fewer MVs in the case of DS, which makes the DS frame much bigger. In this case, the frame encoded with DS takes 2.27 MB, while the frame encoded with MDIS takes 1.95 MB. Figure 16: Frame snippet encoded using the DS algorithm, illustrating an area where no MVs were found in the ME process. Figure 17: Identical frame snippet as depicted in Figure 16, highlighting numerous MVs (in orange color) detected during the ME process.