14 Free Trailer Loudness Measurement Chain Agreement Tools (2026)
Trend-timed <span style="font-weight: 600;">June 2026</span> <span style="font-style: italic;">measurement-chain</span> bookmark list—one <span style="font-weight: 600;">WAV master</span>, one <span style="font-weight: 600;">authority meter</span> (Youlean), <span style="font-style: italic;">ffmpeg</span> CI cross-check, <span style="font-style: italic;">±0.5 LU</span> agreement. Log <span style="font-style: italic;">loudness_receipt</span> on <a href="https://gamineai.com/resources/20-free-build-validation-and-release-checklist-resources-for-indie-games-2026-edition">build validation checklist</a>. Distinct from <a href="https://gamineai.com/resources/14-free-fest-trailer-demo-lufs-loudness-meter-normalization-tools-2026-q3">fourteen-tool meter roundup</a>; pairs <a href="https://gamineai.com/help/audacity-lufs-export-disagrees-youlean-sample-rate-mid-chain-fix">Audacity vs Youlean drift fix</a>.
Tool picker spine—Youlean, ffmpeg, Audacity, middleware meters; this list is the chain-of-custody lane when meters disagree.
Start here: pick tools, then lock chain below
Drift troubleshooting—48 kHz project vs 44.1 kHz export and MP3 measurement mistakes; measurement_chain receipt rows.
Use when: 3+ LU gap
Layout lane—stereo tagged as mono breaks loudnorm and Youlean agreement; fix before authority pass.
Pair with: two-pass JSON cross-check
Recommended authority meter—integrated LUFS + true peak on trailer_master.wav before any lossy encode.
Pro tip: log as authority_meter in receipt
ffmpeg — ffprobe
Official DocsPre-flight gate—sample_rate, channel_layout, duration before meters run.
Use for: CI fail-closed on bad masters
ffmpeg — loudnorm filter
Open SourceCI cross-check only—two-pass print_format=json summary; must agree within ±0.5 LU of Youlean on same WAV.
Not a second mastering pass after Youlean
Audacity
ToolEdit lane—cuts, fades, noise reduction; avoid competing Normalize if Youlean is authority.
Export: 32-bit float WAV at locked project rate
ITU-R BS.1770 (EBU R128 reference)
ReferenceVocabulary anchor—integrated loudness definition for contractor reports and LOUDNESS_TARGETS.md bands.
Use for: contract language
JSON Schema
ReferenceReceipt validation—require measurement_chain[], agreement_lu, measurement_file ending in .wav.
Pro tip: fail promotion if agreement_lu > 0.5
LOUDNESS_TARGETS.md + beginner/dev paths—defines −16 to −14 trailer band; this resource owns meter agreement.
Workflow depth: listicle
Picture + audio gate—pair loudness receipt with trailer scope audit before October fest locks.
Use for: store-truth week
BUILD_RECEIPT column—attach loudness_receipt_v1.json beside binary smoke before branch promotion.
Pro tip: WAV numbers only on gate
Receipt home—store audio_integrated_lufs + measurement-chain hash with upload log.
Use for: cert + partner packets
Idle-trust context—menu audio loudness + FPS discipline are separate gates; do not mask hot trailers with loud menus.
Pair with: menu FPS resource list