The efficiency of a video-codec is closely linked to the spatial and temporal redundancy of the input video. A video that contains lots of movement and scene changes (e.g sports and action movies) is much “harder” to encode, than a video in which most parts are redundant or slowly changing over time (e.g animated movies). Hence, different types of content require different bitrate settings to achieve a certain quality. As a result, applying a title-based encoding-ladder introduces major advantages compared to the classic approach of a “one-fits-all” encoding ladder.
Standard per-title encoding solutions identify the optimal encoding settings for a single asset in a complexity analysis step, prior to the actual production encodes. The most common approach to determine this complexity is by performing multiple test encodes. Based on the resulting bitrate/quality (PSNR, SSIM,VMAF) value pairs, content specific bitrate/resolution ladders are derived and applied. The major downside of such a solution comes with the fact that the test encodes are very computational heavy and not applicable in a live video streaming scenario.