Advance M8-M11 parity workflows

tools/web/generate-sequencer-codec-fixture.sh

@@ -0,0 +1,19 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+if [[ $# -ne 1 ]]; then
+  echo "usage: $0 OUTPUT.mp4" >&2
+  exit 2
+fi
+
+output=$1
+ffmpeg_bin=${FFMPEG_BIN:-ffmpeg}
+mkdir -p "$(dirname "$output")"
+
+"$ffmpeg_bin" -v error \
+  -f lavfi -i "color=c=red:s=16x16:r=2:d=1" \
+  -an -c:v libx264 -profile:v baseline -level 3.0 -pix_fmt yuv420p \
+  -movflags +faststart -map_metadata -1 -fflags +bitexact -flags:v +bitexact \
+  -metadata creation_time=1970-01-01T00:00:00Z -y "$output"
+
+printf 'sequencer-codec-fixture path=%s bytes=%s\n' "$output" "$(wc -c < "$output")"