OutputConvolver re-assigns .buffer on every update, restarting the convolution on each level switch; bufferSize from storage is unvalidated #198

Severity: medium

Where: chrome/player/ui/audio/OutputConvolver.mjs (updateNodes: ch.convolverNode.normalize = channelConfig.normalize; ch.convolverNode.buffer = ch.impulseBuffer; unconditionally per active channel), config/AudioConvolverControl.mjs (fromObj takes obj.bufferSize as is)

What happens

AudioConfigManager.updateChannelCount() calls updateNodes() at LOADEDDATA and on every audio/video level change, and every checkbox/toggle calls it too. Each assignment makes Gecko rebuild the reverb for each channel: the tail is cut and restarts (an audible dropout or click per ABR switch); for a 16384-tap impulse response the FFT partitions are rebuilt each time. A NaN bufferSize from localStorage makes channelData.length > IMPULSE_LENGTH false, so a multi-minute file is used whole as the impulse response.

Suggested fix

Assign buffer/normalize only when they changed (keep the last applied pair on ch); clamp bufferSize to [128, 16384] in fromObj as the input handler does.

Confidence: high.

From a line-by-line code review of the tree at 41363fd (2026-10-02). Each claim above was checked against the source before filing; the reproduction steps and line references are as of that commit.

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