FFmpeg HDR to SDR tone mapping that doesn't look washed out (2026)
TL;DR Converting HDR10 to SDR with a naive FFmpeg command gives you grey, washed-out video. The fix is tone mapping. We will detect HDR with ffprobe , run two working tone-map chains ( zscale on CPU, libplacebo on GPU) in FFmpeg 8.0, compare operators, and batch it. Test the commands on your own build before shipping. 📦 Code: github.com/USER/hdr-to-sdr, replace before publishing If you have ever run an HDR clip through your normal pipeline and gotten back something flat and foggy, this post is for you. The bug is that HDR and SDR are different color systems, and "just converting" reinterprets one as the other. We will use FFmpeg 8.0 "Huffman" (8.0.2 is current as of May 2026). Why naive conversion fails HDR10 SDR Transfer function PQ (SMPTE ST 2084) gamma 2.4 / BT.1886 Color primaries Rec.2020 (wide) BT.709 (narrow) Peak luminance ~1,000 to 4,000 nits ~100 nits A command that ends in -pix_fmt yuv420p with no tone mapping reads PQ-encoded, Rec.2020 values as if they were SDR. The gamut gets crushed with no intelligence and the brightness curve is misread. Hence the fog. 1. Detect whether a file is even HDR 🔍 Do not tone-map SDR files. Check first: # detect transfer characteristics and primaries ffprobe -v error -select_streams v:0 \ -show_entries stream = color_transfer,color_primaries,color_space \ -of default = noprint_wrappers = 1 input.mkv HDR10 content reports something like: color_space = bt2020nc color_transfer = smpte2084 color_primaries = bt2020 If color_transfer is smpte2084 (PQ) or arib-std-b67 (HLG), you have HDR and you need to tone-map. If it says bt709 , leave it alone. 2. The libplacebo path (GPU, my default) 🚀 libplacebo is the Vulkan-accelerated filter in FFmpeg 8.0. It follows the ITU tone-mapping recommendations and handles the color conversions internally, so the command is short: ffmpeg -i input.mkv \ -vf "libplacebo=tonemapping=bt.2390:colorspace=bt709:color_primaries=bt709:color_trc=bt709:format=yuv420p" \ -c :v libx264 -crf 20 -c :a copy \ ou