HLS just got really complicated. On September 9, 2017, Apple updated their HLS authoring requirements to include HDR and 4K recommendations. The updated ladder is shown below. Here are some of the new/updated requirements for HEVC and HDR. There are more in the spec, but these are the ones I wanted to comment on. 1.6. Profile, Level,…
VMAF stands for Video Multimethod Assessment Fusion, but all you really need to know is that it’s the video quality metric co-invented by Netflix to replace the Peak Signal to Noise Ratio (PSNR) that used to fuel the company’s per-title encoding function. In the image above, which is courtesy of Netflix, you see how VMAF scores on…
Apple’s HLS Authoring Specifications for Apple Devices approves up to 200% constrained VBR but Apple’s actual encodes are more like 110-120% constrained. What Apple Says As you probably know, Apple recently made sweeping changes to their HLS recommendations, including changing from 110% constrained VBR for VOD in TN2224, to 200% constrained VBR in the HLS…
As quality metrics go, PSNR is considered a blunt tool obsoleted by higher end metrics like Netflix’s VMAF or SSIMwave’s SSIMplus. That said, it’s accessible and understood, and has been used for years. Of course, none of that matters if it delivers misleading results. So that’s what I decided to test in a round of two…
I recently finished a white paper comparing the pricing for a new cloud encoding service named Hybrik with multiple cloud providers, including Amazon Elastic Transcoder, Microsoft Azure, Bitmovin, encoding.com, Telestream Cloud, and Zencoder. The white-paper was sponsored by Hybrik, and you can download it below. By way of background, I ran all calculations by the respective services…
I recently finished evaluating Beamr Video. The evaluation included analyzing the quality of the resulting clips using objective measures such as PSNR, SSIM and VQM, and conducting extensive viewing of the optimized clips, assessing their subjective quality compared to the original clips. Following this evaluation, I concluded that “for 99.99% of the expert and average…