揭秘虚拟制作中压缩技术的应用
Demystifying the use of Compression in Virtual Production
AI总结：
针对虚拟制作中无损压缩素材存储带宽需求高、缺乏有损压缩质量评估方法的问题，提出对比不同压缩标准、比特率和GOP大小的机内录制质量评估方法，发现混合编解码器能以低得多的资源需求达到同等质量。
摘要：
虚拟制作（Virtual Production，VP）技术持续提升了片场拍摄的灵活性，也增强了现场演唱会的体验。VP的核心技术依赖高分辨率、高亮度的LED面板来回放/渲染视频内容。其有效部署存在诸多技术挑战，例如面板间的图像拼接同步、跨面板色彩平衡，以及补偿因拍摄角度变化导致的色彩波动。考虑到复杂性和潜在的质量下降，行业更倾向于使用“原始”或无损压缩的显示源素材，这需要大量的存储和带宽。现代有损压缩标准（如AV1或H.265）能够以低得多的比特率和资源需求维持相同的质量。目前尚无公认的方法来评估当VP场景通过机内录制时，这些标准对质量的影响。我们提出了一种评估这种影响的方法，通过对比经VP屏幕显示并机内录制的无损和有损压缩素材来实现。我们评估了HAP/NotchLC/Daniel2以及AV1/HEVC/H.264压缩在2 Mb/s到2000 Mb/s比特率、不同GOP（图像组）大小下的质量影响。随后使用多种感知质量指标自动评估机内图像质量，以通过LED墙显示的原始未压缩源内容作为参考。我们的结果表明，使用混合编解码器可达到与中间编码器相同的质量，而比特率和存储需求低几个数量级。
英文摘要：
Virtual Production (VP) technologies have continued to improve the flexibility of on-set filming and enhance the live concert experience. The core technology of VP relies on high-resolution, high-brightness LED panels to playback/render video content. There are a number of technical challenges to effective deployment e.g. image tile synchronisation across the panels, cross panel colour balancing and compensating for colour fluctuations due to changes in camera angles. Given the complexity and potential quality degradation, the industry prefers "pristine" or lossless compressed source material for displays, which requires significant storage and bandwidth. Modern lossy compression standards like AV1 or H.265 could maintain the same quality at significantly lower bitrates and resource demands. There is yet no agreed methodology for assessing the impact of these standards on quality when the VP scene is recorded in-camera. We present a methodology to assess this impact by comparing lossless and lossy compressed footage displayed through VP screens and recorded in-camera. We assess the quality impact of HAP/NotchLC/Daniel2 and AV1/HEVC/H.264 compression bitrates from 2 Mb/s to 2000 Mb/s with various GOP sizes. Several perceptual quality metrics are then used to automatically evaluate in-camera picture quality, referencing the original uncompressed source content through the LED wall. Our results show that we can achieve the same quality with hybrid codecs as with intermediate encoders at orders of magnitude less bitrate and storage requirements.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
