Scale waveform bars from stored amplitudes to the renderer's range - #5815
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Scale waveform bars from stored amplitudes to the renderer's range#5815lukemelia wants to merge 1 commit into
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Every envelope producer persists bars as 0..1 amplitudes — decoded RMS of float samples, MP3's peak-normalized side-info envelope, the WAV streaming envelope — while AudioPreview draws bar heights from 0-100 percentages with a minimum sliver height. The projection clamped values into [0, 100] but never rescaled, so a full-scale 1.0 bar computed a height below the sliver minimum and every waveform rendered as an identical flat dashed line, indistinguishable from silence. waveformBarsFor now scales by 100 before clamping. No stored data ever used the 0-100 scale the clamp implied, so there is no compatibility concern. Tests pin the contract: a full-scale bar projects to 100, out-of-range values clamp, and resampling operates on the projected scale. Fixes CS-12556. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
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What this does
Every audio waveform rendered as a flat dashed line of identical minimum-height slivers — indistinguishable from silence — regardless of the track's dynamics. The cause is a scale mismatch across the projection seam:
AudioPreviewdraws bar heights from 0–100 percentages ((v / 100) * 96) with a 1.5 minimum sliver, so a full-scale 1.0 bar computes a 0.96 height — below the minimum — and every bar clamps to the identical sliver.waveformBarsForinfile-view-model.ts, whose contract (perAudioPreview's own comment) is to deliver bars "already normalized to 0–100". It clamped into [0, 100] but never rescaled.waveformBarsFornow scales by 100 before clamping. There is no compatibility concern: no producer ever emitted the 0–100 scale the clamp implied, so every persisted envelope is 0..1.Test plan
packages/host/tests/unit/file-view-model-test.ts: new contract test — a full-scale 1.0 bar projects to 100 (full height rather than the minimum sliver), out-of-range values clamp to [0, 100]; the existing resample and under-budget tests now feed 0..1 amplitudes and assert the projected scale. FullUnit | file-formatsmodule: 23 tests, 58 assertions, passing locally against a full dev stack.Fixes CS-12556.
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