For the purposes of this comparison, I compared libvpx (VP9), x264 (H.264) and x265 (HEVC), each using 2-pass encodes to a set of target bitrates (x264/x265: –bitrate=250-16000 libvpx: –target-bitrate=250-16000) with SSIM tuning ( –tune=ssim) at the slowest (i.e.

Now, when I say “codecs”, I really mean “encoders”. By drawing these bitrate/quality value pairs in a graph, we can compare video codecs. The recommended objective metric for video quality is SSIM. Scientifically, we typically encode one or more video clips using standard codec settings at various target bitrates, and then measure the objective quality of each output clip. The most important question for video codecs is quality. Fortunately, that concern has been addressed! So here, I will compare encoding (quality+speed) and decoding (speed) performance of VP9 vs. The elephant-in-the-room question since then has always been: what about HEVC? I couldn’t address this question back then, because the blog post was primarily about decoders, and FFmpeg’s decoder for HEVC was immature (from a performance perspective). We also talked about encoding performance (quality, mainly), and showed VP9 significantly outperformed H.264, although it was much slower. A while ago, I posted about ffvp9, FFmpeg‘s native decoder for the VP9 video codec, which significantly outperforms Google’s decoder (part of libvpx).

Ffmpeg hevc to h264