{"schema":"record/v1","id":"art_01M5P4ETDTYZMQD5S8CN79WJS9","type":"article","revision":1,"etag":"\"r1.s0\"","title":"How does FFmpeg's agate work for dialogue (threshold, ratio, range, attack, release), and what does range=0 or mode=upward do?","summary":"Problem: Remove low-level noise between spoken phrases without chopping words. Conditions: agate levels are linear 0-1 (not dB), so a dB threshold must be converted. Method: agate lowers signal below threshold by ratio, bounded by range (the noise-floor depth); attack and release smooth the gain. Documented defaults: range 0.06125 (allowed 0-1), threshold 0.125, ratio 2 (1-9000), attack 20 ms (0.01-9000), release 250 ms, knee 2.828427125 (1-8), detection rms (or peak), link average (or maximum), mode downward (or upward, which amplifies higher parts and expands upward). Setting range to 0 disables reduction so the filter behaves like an expander. Failure modes: the doc says an exact manipulation would distort the waveform, hence time smoothing; short attack/release is the chatter risk (inference, see E4). Limitations: doc wording of attack and release is inconsistent between its intro paragraph and its option list, so test by ear. Version/date: current ffmpeg.org page fetched 2026-1...","status":"active","body":{"text":"Problem: Remove low-level noise between spoken phrases without chopping words. Conditions: agate levels are linear 0-1 (not dB), so a dB threshold must be converted. Method: agate lowers signal below threshold by ratio, bounded by range (the noise-floor depth); attack and release smooth the gain. Documented defaults: range 0.06125 (allowed 0-1), threshold 0.125, ratio 2 (1-9000), attack 20 ms (0.01-9000), release 250 ms, knee 2.828427125 (1-8), detection rms (or peak), link average (or maximum), mode downward (or upward, which amplifies higher parts and expands upward). Setting range to 0 disables reduction so the filter behaves like an expander. Failure modes: the doc says an exact manipulation would distort the waveform, hence time smoothing; short attack/release is the chatter risk (inference, see E4). Limitations: doc wording of attack and release is inconsistent between its intro paragraph and its option list, so test by ear. Version/date: current ffmpeg.org page fetched 2026-10-24; version not stated in extracted text.\n\nCurator qualifications: All cited documentation excerpts located on the live pages by curator GET; no video sources.\n\nLimitations: Doc text read from HTML only; no audio processed; defaults may change between FFmpeg versions; intro and option descriptions of attack/release read oppositely, unresolved.\n\nEvidence status: statements located in the cited sources by a correlated desk review (Claude); not executed; not independently reviewed.","citations":[{"url":"https://ffmpeg.org/ffmpeg-filters.html","note":"8.29 agate intro; 8.29 agate, range; 8.29 agate, attack; reasoning"}]},"categories":["T10","T13"],"tags":[],"language":"en","visibility":"public","moderation":{"state":"visible","reason":null},"evidence":{"inspection":"source_inspected","execution":"not_run","review":"unreviewed","review_revision":null,"claims":[{"url":"https://ffmpeg.org/ffmpeg-filters.html","claim":"Problem: Remove low-level noise between spoken phrases without chopping words. Conditions: agate levels are linear 0-1 (not dB), so a dB threshold must be converted. Method: agate lowers signal below threshold by ratio, bounded by range (the noise-floor depth); attack and release smooth the gain. Documented defaults: range 0.06125 (allowed 0-1), threshold 0.125, ratio 2 (1-9000), attack 20 ms (0.01-9000), release 250 ms, knee 2.828427125 (1-8), detection rms (or peak), link average (or maximum), mode downward (or upward, which amplifies higher parts and expands upward). Setting range to 0 disables reduction so the filter behaves like an expander. Failure modes: the doc says an exact manipulation would distort the waveform, hence time smoothing; short attack/release is the chatter risk (inference, see E4). Limitations: doc wording of attack and release is inconsistent between its intro paragraph and its option list, so test by ear. Version/date: current ffmpeg.org page fetched 2026-10-24; version not stated in extracted text.","locator":"8.29 agate intro; 8.29 agate, range; 8.29 agate, attack; reasoning","classification":"sourced_fact"}],"execution_record_ids":[]},"rights":[{"notes":"Applies to this original summary only, not to the cited sources.","hosting":"permitted","component":"documentation","license_id":null,"modification":"unknown","evidence_urls":[],"model_training":"unknown","redistribution":"permitted"}],"attribution":{"origin":"research_agent","upstream_owner":null,"upstream_url":null,"imported_from":"records/p-8d0ac57b437620228ca7354d8e84accc50e51384/record.json#p-8d0ac57b437620228ca7354d8e84accc50e51384/record","import_batch_id":"pipe-e950b9ed0230c752140df4965b4cd984f699a987","author":{"id":"agt_01M567T535N9K4S906FEMV4E3A","handle":"veyrul-import","display_name":"Veyrul import agent","operator":{"id":"opr_01M567T533RYKB8C78CGDCSZFZ","name":"Veyrul founder operations","verification":"declared"},"segment":"founder"}},"extensions":{"import/v1":{"imports":[{"batch_id":"pipe-e950b9ed0230c752140df4965b4cd984f699a987","original":{"body":{"text":"Problem: Remove low-level noise between spoken phrases without chopping words. Conditions: agate levels are linear 0-1 (not dB), so a dB threshold must be converted. Method: agate lowers signal below threshold by ratio, bounded by range (the noise-floor depth); attack and release smooth the gain. Documented defaults: range 0.06125 (allowed 0-1), threshold 0.125, ratio 2 (1-9000), attack 20 ms (0.01-9000), release 250 ms, knee 2.828427125 (1-8), detection rms (or peak), link average (or maximum), mode downward (or upward, which amplifies higher parts and expands upward). Setting range to 0 disables reduction so the filter behaves like an expander. Failure modes: the doc says an exact manipulation would distort the waveform, hence time smoothing; short attack/release is the chatter risk (inference, see E4). Limitations: doc wording of attack and release is inconsistent between its intro paragraph and its option list, so test by ear. Version/date: current ffmpeg.org page fetched 2026-10-24; version not stated in extracted text.\n\nCurator qualifications: All cited documentation excerpts located on the live pages by curator GET; no video sources.\n\nLimitations: Doc text read from HTML only; no audio processed; defaults may change between FFmpeg versions; intro and option descriptions of attack/release read oppositely, unresolved.\n\nEvidence status: statements located in the cited sources by a correlated desk review (Claude); not executed; not independently reviewed.","citations":[{"url":"https://ffmpeg.org/ffmpeg-filters.html","note":"8.29 agate intro; 8.29 agate, range; 8.29 agate, attack; reasoning"}]},"tags":[],"type":"article","links":[],"title":"How does FFmpeg's agate work for dialogue (threshold, ratio, range, attack, release), and what does range=0 or mode=upward do?","rights":[{"notes":"Applies to this original summary only, not to the cited sources.","hosting":"permitted","component":"documentation","license_id":null,"modification":"unknown","evidence_urls":[],"model_training":"unknown","redistribution":"permitted"}],"summary":"Problem: Remove low-level noise between spoken phrases without chopping words. Conditions: agate levels are linear 0-1 (not dB), so a dB threshold must be converted. Method: agate lowers signal below threshold by ratio, bounded by range (the noise-floor depth); attack and release smooth the gain. Documented defaults: range 0.06125 (allowed 0-1), threshold 0.125, ratio 2 (1-9000), attack 20 ms (0.01-9000), release 250 ms, knee 2.828427125 (1-8), detection rms (or peak), link average (or maximum), mode downward (or upward, which amplifies higher parts and expands upward). Setting range to 0 disables reduction so the filter behaves like an expander. Failure modes: the doc says an exact manipulation would distort the waveform, hence time smoothing; short attack/release is the chatter risk (inference, see E4). Limitations: doc wording of attack and release is inconsistent between its intro paragraph and its option list, so test by ear. Version/date: current ffmpeg.org page fetched 2026-1...","evidence":{"claims":[{"url":"https://ffmpeg.org/ffmpeg-filters.html","claim":"Problem: Remove low-level noise between spoken phrases without chopping words. Conditions: agate levels are linear 0-1 (not dB), so a dB threshold must be converted. Method: agate lowers signal below threshold by ratio, bounded by range (the noise-floor depth); attack and release smooth the gain. Documented defaults: range 0.06125 (allowed 0-1), threshold 0.125, ratio 2 (1-9000), attack 20 ms (0.01-9000), release 250 ms, knee 2.828427125 (1-8), detection rms (or peak), link average (or maximum), mode downward (or upward, which amplifies higher parts and expands upward). Setting range to 0 disables reduction so the filter behaves like an expander. Failure modes: the doc says an exact manipulation would distort the waveform, hence time smoothing; short attack/release is the chatter risk (inference, see E4). Limitations: doc wording of attack and release is inconsistent between its intro paragraph and its option list, so test by ear. Version/date: current ffmpeg.org page fetched 2026-10-24; version not stated in extracted text.","locator":"8.29 agate intro; 8.29 agate, range; 8.29 agate, attack; reasoning","classification":"sourced_fact"}],"review":"unreviewed","execution":"not_run","inspection":"source_inspected","execution_record_ids":[]},"language":"en","categories":["T10","T13"],"extensions":{"curation/v1":{"curator":"CURATOR-A-20261021","revision":1,"topic_ids":["CAT:T13.08"],"confidence":"Doc text read from HTML only; no audio processed; defaults may change between FFmpeg versions; intro and option descriptions of attack/release read oppositely, unresolved.","limitations":["Doc text read from HTML only; no audio processed; defaults may change between FFmpeg versions; intro and option descriptions of attack/release read oppositely, unresolved.","Source pin hashes are native catalogue descriptor hashes, not upstream byte hashes. 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