feat: add encoder tuning harness for 4K60 fractal videos

make_clips.sh renders lossless FFV1 4K60 test clips through the Makefile's colour conversion; sweep.sh encodes them with a list of ffmpeg configs and scores each with VMAF 4K (mean/p1/min), VMAF-NEG, CAMBI banding and PSNR-Y. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-09-29 17:59:14 +02:00
parent 49130f5ecf
commit da992c139a
4 changed files with 164 additions and 0 deletions
@@ -0,0 +1,66 @@
+#!/usr/bin/env bash
+# Render the lossless 4K60 test clips that sweep.sh encodes.
+#
+# Each clip goes through the same RGBA -> bt709 tv-range 10-bit conversion as
+# the Makefile, then into lossless FFV1. The clips are therefore exactly what the
+# encoders see, so VMAF against them measures the encoder alone.
+#
+#   tools/encode/make_clips.sh [--size WxH] [--seconds S] [--force] [clip...]
+set -euo pipefail
+
+here=$(cd "$(dirname "$0")" && pwd)
+root=$(cd "$here/../.." && pwd)
+out="$here/clips"
+size=3840x2160
+seconds=4
+fps=60
+force=0
+only=()
+
+while [[ $# -gt 0 ]]; do
+    case $1 in
+        --size) size=$2; shift 2 ;;
+        --seconds) seconds=$2; shift 2 ;;
+        --force) force=1; shift ;;
+        -h|--help) sed -n '2,9p' "$0"; exit 0 ;;
+        *) only+=("$1"); shift ;;
+    esac
+done
+
+# Seahorse valley, minibrot at 3.7e-41 (tools/deep-zoom/LOCATIONS.md).
+SH_RE=-0.77568376800905379745347652613832924487504096622022
+SH_IM=0.13646736829469012473375311880735014411233827361594
+
+# name | mandelbrot flags. Zoom speeds bracket a typical 60 s dive (~0.7 decade/s).
+clips=(
+    # Worst case: dense filaments, 1.5 decades/s of scaling motion.
+    "filaments|--view=$SH_RE,$SH_IM,1e-8 --to-view=$SH_RE,$SH_IM,3e-15 --linear"
+    # Smooth concentric bands closing in on the minibrot: banding/blocking risk.
+    "bands|--view=$SH_RE,$SH_IM,1e-38 --to-view=$SH_RE,$SH_IM,1.1e-40 --linear"
+    # Embedded Julia set, slow drift: fine static texture, psy/detail retention.
+    "julia|--view=$SH_RE,$SH_IM,2e-30 --to-view=$SH_RE,$SH_IM,1e-30 --linear"
+)
+
+[[ -x $root/target/release/mandelbrot ]] || cargo build --release --manifest-path "$root/Cargo.toml"
+mkdir -p "$out"
+w=${size%x*}
+h=${size#*x}
+
+for entry in "${clips[@]}"; do
+    name=${entry%%|*}
+    flags=${entry#*|}
+    if [[ ${#only[@]} -gt 0 && ! " ${only[*]} " =~ " $name " ]]; then continue; fi
+    dst="$out/$name.mkv"
+    if [[ -f $dst && $force = 0 ]]; then echo "skip $name (exists, --force to redo)"; continue; fi
+    echo "render $name ($size, ${seconds}s @ ${fps}fps)"
+    # shellcheck disable=SC2086
+    "$root/target/release/mandelbrot" --headless --antialias $flags \
+        --width "$w" --height "$h" --fps "$fps" --duration "$seconds" --export-path - |
+        ffmpeg -hide_banner -loglevel error -y \
+            -f rawvideo -pix_fmt rgba -s "$size" -framerate "$fps" -i - \
+            -vf "scale=out_color_matrix=bt709:out_range=tv:flags=accurate_rnd+full_chroma_int+bitexact,format=yuv420p10le" \
+            -c:v ffv1 -level 3 -slices 16 -g 1 \
+            -colorspace bt709 -color_primaries bt709 -color_trc bt709 -color_range tv \
+            "$dst.tmp.mkv"
+    mv "$dst.tmp.mkv" "$dst"
+done