TY - GEN A1 - Herglotz, Christian A1 - Och, Hannah A1 - Meyer, Anna A1 - Ramasubbu, Geetha A1 - Eichermüller, Lena A1 - Kränzler, Matthias A1 - Brand, Fabian A1 - Fischer, Kristian A1 - Nguyen, Dat Thanh A1 - Regensky, Andy A1 - Kaup, André T1 - The Bjøntegaard Bible Why Your Way of Comparing Video Codecs May Be Wrong T2 - IEEE Transactions on Image Processing N2 - In this paper, we provide an in-depth assessment on the Bjøntegaard Delta. We construct a large data set of video compression performance comparisons using a diverse set of metrics including PSNR, VMAF, bitrate, and processing energies. These metrics are evaluated for visual data types such as classic perspective video, 360° video, point clouds, and screen content. As compression technology, we consider multiple hybrid video codecs as well as state-of-the-art neural network based compression methods. Using additional supporting points in-between standard points defined by parameters such as the quantization parameter, we assess the interpolation error of the Bjøntegaard-Delta (BD) calculus and its impact on the final BD value. From the analysis, we find that the BD calculus is most accurate in the standard application of rate-distortion comparisons with mean errors below 0.5 percentage points. For other applications and special cases, e.g., VMAF quality, energy considerations, or inter-codec comparisons, the errors are higher (up to 5 percentage points), but can be halved by using a higher number of supporting points. We finally come up with recommendations on how to use the BD calculus such that the validity of the resulting BD-values is maximized. Main recommendations are as follows: First, relative curve differences should be plotted and analyzed. Second, the logarithmic domain should be used for saturating metrics such as SSIM and VMAF. Third, BD values below a certain threshold indicated by the subset error should not be used to draw recommendations. Fourth, using two supporting points is sufficient to obtain rough performance estimates. KW - Measurement KW - Calculus KW - Codecs KW - Interpolation KW - Image coding KW - Distortion KW - Visualization Y1 - 2024 U6 - https://doi.org/10.1109/TIP.2023.3346695 SN - 1057-7149 SN - 1941-0042 IS - Volume 33 SP - 987 EP - 1001 ER - TY - GEN A1 - Ramasubbu, Geetha A1 - Kaup, André A1 - Herglotz, Christian T1 - Modeling the Energy Consumption of the HEVC Software Encoding Process using Processor events T2 - IEEE 26th International Workshop on Multimedia Signal Processing (MMSP) N2 - Developing energy-efficient video encoding algorithms is highly important due to the high processing complexities and, consequently, the high energy demand of the encoding process. To accomplish this, the energy consumption of the video encoders must be studied, which is only possible with a complex and dedicated energy measurement setup. This emphasizes the need for simple energy estimation models, which estimate the energy required for the encoding. Our paper investigates the possibility of estimating the energy demand of a HEVC software CPU-encoding process using processor events. First, we perform energy measurements and obtain processor events using dedicated profiling software. Then, by using the measured energy demand of the encoding process and profiling data, we build an encoding energy estimation model that uses the processor events of the ultrafast encoding preset to obtain the energy estimate for complex encoding presets with a mean absolute percentage error of 5.36% when averaged over all the presets. Additionally, we present an energy model that offers the possibility of obtaining energy distribution among various encoding sub-processes. energy models from literature. By using a unified evaluation framework we show how accurately the required decoding energy for different decoding systems can be approximated. We give thorough explanations on the model parameters and explain how the model variables are derived. To show the modeling capabilities in general, we test the estimation performance for different decoding software and hardware solutions, where we find that the proposed model outperforms the models from literature by reaching frame-wise mean estimation errors of less than 7% for software and less than 15% for hardware based systems. KW - Energy consumption KW - Analytical models KW - Software algorithms KW - Estimation KW - Energy measurement KW - Signal processing algorithms KW - Streaming media KW - Encoding KW - Software KW - Energy efficiency Y1 - 2024 SN - 979-8-3503-8725-4 SN - 979-8-3503-8726-1 U6 - https://doi.org/10.1109/MMSP61759.2024.10743858 SN - 2473-3628 SN - 2163-3517 PB - IEEE ER - TY - GEN A1 - Ramasubbu, Geetha A1 - Kaup, André A1 - Herglotz, Christian T1 - Towards Video Codec Performance Evaluation: A Rate-Energy-Distortion Perspective T2 - 16th International Conference on Quality of Multimedia Experience (QoMEX) N2 - The Bjøntegaard Delta rate (BD-rate) objectively assesses the coding efficiency of video codecs using the rate-distortion (R-D) performance but overlooks encoding energy, which is crucial in practical applications, especially for those on handheld devices. Although R-D analysis can be extended to incorporate encoding energy as energy-distortion (E-D), it fails to integrate all three parameters seamlessly. This work proposes a novel approach to address this limitation by introducing a 3D representation of rate, encoding energy, and distortion through surface fitting. In addition, we evaluate various surface fitting techniques based on their accuracy and investigate the proposed 3D representation and its projections. The overlapping areas in projections help in encoder selection and recommend avoiding the slow presets of the older encoders (x264, x265), as the recent encoders (x265, VVenC) offer higher quality for the same bitrate-energy performance and provide a lower rate for the same energy-distortion performance. KW - Performance evaluation KW - Video coding KW - Three-dimensional displays KW - Fitting KW - Rate-distortion KW - Rate distortion theory KW - Distortion Y1 - 2024 U6 - https://doi.org/10.1109/QoMEX61742.2024.10598269 SN - 2472-7814 SN - 2372-7179 SP - 96 EP - 99 ER -