656 lines
23 KiB
Rust

use serde::Serialize;
const DEFAULT_AUDIO_WINDOW_MS: u32 = 5;
const DEFAULT_MAX_PAIR_GAP_S: f64 = 0.5;
const DEFAULT_PULSE_PERIOD_S: f64 = 1.0;
const DEFAULT_PULSE_WIDTH_S: f64 = 0.12;
const DEFAULT_MARKER_TICK_PERIOD: u32 = 5;
const CALIBRATION_MIN_PAIRED_EVENTS: usize = 13;
const CALIBRATION_MAX_DRIFT_MS: f64 = 40.0;
const CALIBRATION_MAX_START_MEDIAN_DISAGREEMENT_MS: f64 = 250.0;
const CALIBRATION_SETTLED_SKEW_MS: f64 = 5.0;
const RAW_ACTIVITY_CONFIRMS_PAIR_MAX_DISAGREEMENT_MS: f64 = 250.0;
const VERDICT_MIN_PAIRED_EVENTS: usize = 3;
const VERDICT_PREFERRED_P95_ABS_SKEW_MS: f64 = 35.0;
const VERDICT_ACCEPTABLE_P95_ABS_SKEW_MS: f64 = 80.0;
const VERDICT_GROSS_FAILURE_P95_ABS_SKEW_MS: f64 = 250.0;
const VERDICT_CATASTROPHIC_MAX_ABS_SKEW_MS: f64 = 1_000.0;
#[derive(Clone, Debug, PartialEq, Serialize)]
pub struct SyncAnalysisReport {
pub video_event_count: usize,
pub audio_event_count: usize,
pub paired_event_count: usize,
pub coded_events: bool,
pub activity_start_delta_ms: f64,
pub raw_first_video_activity_s: f64,
pub raw_first_audio_activity_s: f64,
pub first_skew_ms: f64,
pub last_skew_ms: f64,
pub mean_skew_ms: f64,
pub median_skew_ms: f64,
pub max_abs_skew_ms: f64,
pub drift_ms: f64,
pub skews_ms: Vec<f64>,
pub video_onsets_s: Vec<f64>,
pub audio_onsets_s: Vec<f64>,
pub paired_events: Vec<SyncEventPair>,
}
#[derive(Clone, Debug, PartialEq, Serialize)]
pub struct SyncEventPair {
pub event_id: usize,
#[serde(skip_serializing_if = "Option::is_none")]
pub server_event_id: Option<usize>,
#[serde(skip_serializing_if = "Option::is_none")]
pub event_code: Option<u32>,
pub video_time_s: f64,
pub audio_time_s: f64,
pub skew_ms: f64,
pub confidence: f64,
}
#[derive(Clone, Debug, PartialEq, Serialize)]
pub struct SyncAnalysisVerdict {
pub status: String,
pub passed: bool,
pub p95_abs_skew_ms: f64,
pub max_abs_skew_ms: f64,
pub preferred_p95_abs_skew_ms: f64,
pub acceptable_p95_abs_skew_ms: f64,
pub gross_failure_p95_abs_skew_ms: f64,
pub catastrophic_max_abs_skew_ms: f64,
pub reason: String,
}
#[derive(Clone, Debug, PartialEq, Eq, Serialize)]
pub struct SyncCalibrationRecommendation {
pub ready: bool,
pub recommended_audio_offset_adjust_us: i64,
pub recommended_video_offset_adjust_us: i64,
pub note: String,
}
impl SyncAnalysisReport {
#[must_use]
pub fn verdict(&self) -> SyncAnalysisVerdict {
let p95_abs_skew_ms = percentile_abs(&self.skews_ms, 0.95);
let base = SyncAnalysisVerdict {
status: String::new(),
passed: false,
p95_abs_skew_ms,
max_abs_skew_ms: self.max_abs_skew_ms,
preferred_p95_abs_skew_ms: VERDICT_PREFERRED_P95_ABS_SKEW_MS,
acceptable_p95_abs_skew_ms: VERDICT_ACCEPTABLE_P95_ABS_SKEW_MS,
gross_failure_p95_abs_skew_ms: VERDICT_GROSS_FAILURE_P95_ABS_SKEW_MS,
catastrophic_max_abs_skew_ms: VERDICT_CATASTROPHIC_MAX_ABS_SKEW_MS,
reason: String::new(),
};
if self.paired_event_count < VERDICT_MIN_PAIRED_EVENTS {
return SyncAnalysisVerdict {
status: "insufficient_data".to_string(),
reason: format!(
"need at least {VERDICT_MIN_PAIRED_EVENTS} paired events; saw {}",
self.paired_event_count
),
..base
};
}
if self.max_abs_skew_ms >= VERDICT_CATASTROPHIC_MAX_ABS_SKEW_MS {
return SyncAnalysisVerdict {
status: "catastrophic_failure".to_string(),
reason: format!(
"max skew {:.1} ms is at or above the {:.1} ms catastrophic boundary",
self.max_abs_skew_ms, VERDICT_CATASTROPHIC_MAX_ABS_SKEW_MS
),
..base
};
}
if self.activity_start_delta_ms.abs() >= VERDICT_CATASTROPHIC_MAX_ABS_SKEW_MS
&& self.raw_activity_start_is_verdict_relevant()
{
return SyncAnalysisVerdict {
status: "catastrophic_failure".to_string(),
reason: format!(
"audio/video activity starts are separated by {:+.1} ms, at or above the {:.1} ms catastrophic boundary",
self.activity_start_delta_ms, VERDICT_CATASTROPHIC_MAX_ABS_SKEW_MS
),
..base
};
}
if p95_abs_skew_ms > VERDICT_GROSS_FAILURE_P95_ABS_SKEW_MS {
return SyncAnalysisVerdict {
status: "gross_failure".to_string(),
reason: format!(
"p95 skew {:.1} ms exceeds the {:.1} ms gross-failure boundary",
p95_abs_skew_ms, VERDICT_GROSS_FAILURE_P95_ABS_SKEW_MS
),
..base
};
}
let raw_activity_note = self.raw_activity_note();
if p95_abs_skew_ms <= VERDICT_PREFERRED_P95_ABS_SKEW_MS {
return SyncAnalysisVerdict {
status: "preferred".to_string(),
passed: true,
reason: format!(
"p95 skew {:.1} ms is inside the preferred {:.1} ms band{}",
p95_abs_skew_ms, VERDICT_PREFERRED_P95_ABS_SKEW_MS, raw_activity_note
),
..base
};
}
if p95_abs_skew_ms <= VERDICT_ACCEPTABLE_P95_ABS_SKEW_MS {
return SyncAnalysisVerdict {
status: "acceptable".to_string(),
passed: true,
reason: format!(
"p95 skew {:.1} ms is inside the acceptable {:.1} ms band{}",
p95_abs_skew_ms, VERDICT_ACCEPTABLE_P95_ABS_SKEW_MS, raw_activity_note
),
..base
};
}
SyncAnalysisVerdict {
status: "gross_failure".to_string(),
reason: format!(
"p95 skew {:.1} ms exceeds the {:.1} ms acceptable band",
p95_abs_skew_ms, VERDICT_ACCEPTABLE_P95_ABS_SKEW_MS
),
..base
}
}
#[must_use]
pub fn calibration_recommendation(&self) -> SyncCalibrationRecommendation {
if self.paired_event_count < CALIBRATION_MIN_PAIRED_EVENTS {
return SyncCalibrationRecommendation {
ready: false,
recommended_audio_offset_adjust_us: 0,
recommended_video_offset_adjust_us: 0,
note: format!(
"need at least {CALIBRATION_MIN_PAIRED_EVENTS} paired pulses; saw {}",
self.paired_event_count
),
};
}
if self.drift_ms.abs() > CALIBRATION_MAX_DRIFT_MS {
return SyncCalibrationRecommendation {
ready: false,
recommended_audio_offset_adjust_us: 0,
recommended_video_offset_adjust_us: 0,
note: format!(
"drift {:.1} ms exceeds the {:.1} ms calibration limit",
self.drift_ms, CALIBRATION_MAX_DRIFT_MS
),
};
}
let start_median_disagreement_ms = self.activity_start_pair_disagreement_ms();
if self.raw_activity_start_is_verdict_relevant()
&& start_median_disagreement_ms.abs() > CALIBRATION_MAX_START_MEDIAN_DISAGREEMENT_MS
{
return SyncCalibrationRecommendation {
ready: false,
recommended_audio_offset_adjust_us: 0,
recommended_video_offset_adjust_us: 0,
note: format!(
"activity start delta {:+.1} ms disagrees with median skew {:+.1} ms by {:.1} ms, above the {:.1} ms calibration-safe band",
self.activity_start_delta_ms,
self.median_skew_ms,
start_median_disagreement_ms.abs(),
CALIBRATION_MAX_START_MEDIAN_DISAGREEMENT_MS
),
};
}
let recommended_audio_offset_adjust_us = (-(self.median_skew_ms * 1_000.0)).round() as i64;
let recommended_video_offset_adjust_us = -recommended_audio_offset_adjust_us;
let raw_activity_note = self.raw_activity_calibration_note();
let note = if self.median_skew_ms.abs() <= CALIBRATION_SETTLED_SKEW_MS {
format!(
"median skew {:.1} ms is already within the settled {:.1} ms band{}",
self.median_skew_ms, CALIBRATION_SETTLED_SKEW_MS, raw_activity_note
)
} else {
format!(
"apply the audio offset adjustment to move median skew from {:+.1} ms toward 0.0 ms{}",
self.median_skew_ms, raw_activity_note
)
};
SyncCalibrationRecommendation {
ready: true,
recommended_audio_offset_adjust_us,
recommended_video_offset_adjust_us,
note,
}
}
#[must_use]
pub fn activity_start_pair_disagreement_ms(&self) -> f64 {
self.activity_start_delta_ms - self.median_skew_ms
}
#[must_use]
pub fn raw_activity_start_confirms_pairs(&self) -> bool {
self.activity_start_pair_disagreement_ms().abs()
<= RAW_ACTIVITY_CONFIRMS_PAIR_MAX_DISAGREEMENT_MS
}
pub fn raw_activity_start_is_verdict_relevant(&self) -> bool {
if self.raw_activity_start_confirms_pairs() {
return true;
}
if self.coded_events || self.paired_event_count < VERDICT_MIN_PAIRED_EVENTS {
return false;
}
// Cadence-only pairing can alias by a whole pulse period and look
// deceptively good. Use raw activity as a guard only when paired
// evidence otherwise appears passable; if paired pulses already fail,
// report that direct failure instead of promoting a noisy raw edge.
percentile_abs(&self.skews_ms, 0.95) <= VERDICT_ACCEPTABLE_P95_ABS_SKEW_MS
}
fn raw_activity_note(&self) -> String {
if self.activity_start_delta_ms.abs() < VERDICT_CATASTROPHIC_MAX_ABS_SKEW_MS
|| self.raw_activity_start_is_verdict_relevant()
{
String::new()
} else {
format!(
"; raw activity start delta {:+.1} ms is reported separately because it disagrees with paired pulses by {:.1} ms",
self.activity_start_delta_ms,
self.activity_start_pair_disagreement_ms().abs()
)
}
}
fn raw_activity_calibration_note(&self) -> String {
if self.raw_activity_start_is_verdict_relevant() {
String::new()
} else {
format!(
"; raw activity start delta {:+.1} ms is not used for calibration because paired pulses disagree by {:.1} ms",
self.activity_start_delta_ms,
self.activity_start_pair_disagreement_ms().abs()
)
}
}
}
fn percentile_abs(values: &[f64], percentile: f64) -> f64 {
if values.is_empty() {
return 0.0;
}
let mut sorted = values.iter().copied().map(f64::abs).collect::<Vec<_>>();
sorted.sort_by(|left, right| left.total_cmp(right));
let index = ((sorted.len() as f64 * percentile).ceil() as usize)
.saturating_sub(1)
.min(sorted.len() - 1);
sorted[index]
}
#[derive(Clone, Debug, PartialEq)]
pub struct SyncAnalysisOptions {
pub audio_window_ms: u32,
pub max_pair_gap_s: f64,
pub pulse_period_s: f64,
pub pulse_width_s: f64,
pub marker_tick_period: u32,
pub event_width_codes: Vec<u32>,
pub analysis_start_s: Option<f64>,
pub analysis_end_s: Option<f64>,
}
impl Default for SyncAnalysisOptions {
fn default() -> Self {
Self {
audio_window_ms: DEFAULT_AUDIO_WINDOW_MS,
max_pair_gap_s: DEFAULT_MAX_PAIR_GAP_S,
pulse_period_s: DEFAULT_PULSE_PERIOD_S,
pulse_width_s: DEFAULT_PULSE_WIDTH_S,
marker_tick_period: DEFAULT_MARKER_TICK_PERIOD,
event_width_codes: Vec::new(),
analysis_start_s: None,
analysis_end_s: None,
}
}
}
#[cfg(test)]
mod tests {
use super::{SyncAnalysisOptions, SyncAnalysisReport};
#[test]
fn default_options_match_live_probe_expectations() {
let options = SyncAnalysisOptions::default();
assert_eq!(options.audio_window_ms, 5);
assert!((options.max_pair_gap_s - 0.5).abs() < f64::EPSILON);
assert!((options.pulse_period_s - 1.0).abs() < f64::EPSILON);
assert!((options.pulse_width_s - 0.12).abs() < f64::EPSILON);
assert_eq!(options.marker_tick_period, 5);
assert!(options.event_width_codes.is_empty());
}
#[test]
fn calibration_recommendation_requires_enough_pairs() {
let report = SyncAnalysisReport {
video_event_count: 4,
audio_event_count: 4,
paired_event_count: 4,
coded_events: false,
activity_start_delta_ms: 0.0,
raw_first_video_activity_s: 0.0,
raw_first_audio_activity_s: 0.0,
first_skew_ms: 20.0,
last_skew_ms: 20.0,
mean_skew_ms: 20.0,
median_skew_ms: 20.0,
max_abs_skew_ms: 20.0,
drift_ms: 0.0,
skews_ms: vec![20.0; 4],
video_onsets_s: vec![],
audio_onsets_s: vec![],
paired_events: vec![],
};
let recommendation = report.calibration_recommendation();
assert!(!recommendation.ready);
assert_eq!(recommendation.recommended_audio_offset_adjust_us, 0);
assert!(
recommendation
.note
.contains("need at least 13 paired pulses")
);
}
#[test]
fn calibration_recommendation_rejects_unstable_drift() {
let report = SyncAnalysisReport {
video_event_count: 12,
audio_event_count: 12,
paired_event_count: 14,
coded_events: false,
activity_start_delta_ms: 0.0,
raw_first_video_activity_s: 0.0,
raw_first_audio_activity_s: 0.0,
first_skew_ms: 10.0,
last_skew_ms: 70.0,
mean_skew_ms: 40.0,
median_skew_ms: 35.0,
max_abs_skew_ms: 70.0,
drift_ms: 60.0,
skews_ms: vec![10.0, 20.0, 30.0, 40.0, 50.0, 60.0, 70.0],
video_onsets_s: vec![],
audio_onsets_s: vec![],
paired_events: vec![],
};
let recommendation = report.calibration_recommendation();
assert!(!recommendation.ready);
assert_eq!(recommendation.recommended_audio_offset_adjust_us, 0);
assert!(recommendation.note.contains("drift 60.0 ms exceeds"));
}
#[test]
fn calibration_recommendation_maps_median_skew_to_audio_and_video_offsets() {
let report = SyncAnalysisReport {
video_event_count: 14,
audio_event_count: 14,
paired_event_count: 14,
coded_events: false,
activity_start_delta_ms: 0.0,
raw_first_video_activity_s: 0.0,
raw_first_audio_activity_s: 0.0,
first_skew_ms: 28.0,
last_skew_ms: 32.0,
mean_skew_ms: 30.0,
median_skew_ms: 30.0,
max_abs_skew_ms: 32.0,
drift_ms: 4.0,
skews_ms: vec![28.0, 30.0, 32.0],
video_onsets_s: vec![],
audio_onsets_s: vec![],
paired_events: vec![],
};
let recommendation = report.calibration_recommendation();
assert!(recommendation.ready);
assert_eq!(recommendation.recommended_audio_offset_adjust_us, -30_000);
assert_eq!(recommendation.recommended_video_offset_adjust_us, 30_000);
assert!(recommendation.note.contains("move median skew"));
}
#[test]
fn calibration_recommendation_accepts_large_stable_measured_offsets() {
let report = SyncAnalysisReport {
video_event_count: 16,
audio_event_count: 16,
paired_event_count: 16,
coded_events: false,
activity_start_delta_ms: -766.4,
raw_first_video_activity_s: 7.491,
raw_first_audio_activity_s: 6.725,
first_skew_ms: -766.4,
last_skew_ms: -769.2,
mean_skew_ms: -756.0,
median_skew_ms: -766.4,
max_abs_skew_ms: 775.7,
drift_ms: -2.8,
skews_ms: vec![-766.4; 16],
video_onsets_s: vec![],
audio_onsets_s: vec![],
paired_events: vec![],
};
let recommendation = report.calibration_recommendation();
assert!(recommendation.ready);
assert_eq!(recommendation.recommended_audio_offset_adjust_us, 766_400);
assert!(recommendation.note.contains("move median skew"));
}
#[test]
fn calibration_recommendation_uses_pairs_when_raw_activity_disagrees() {
let report = SyncAnalysisReport {
video_event_count: 16,
audio_event_count: 16,
paired_event_count: 16,
coded_events: false,
activity_start_delta_ms: 6_735.0,
raw_first_video_activity_s: 0.0,
raw_first_audio_activity_s: 6.735,
first_skew_ms: -90.0,
last_skew_ms: -100.0,
mean_skew_ms: -95.0,
median_skew_ms: -99.0,
max_abs_skew_ms: 120.0,
drift_ms: -10.0,
skews_ms: vec![-99.0; 16],
video_onsets_s: vec![],
audio_onsets_s: vec![],
paired_events: vec![],
};
let recommendation = report.calibration_recommendation();
assert!(recommendation.ready);
assert_eq!(recommendation.recommended_audio_offset_adjust_us, 99_000);
assert!(recommendation.note.contains("paired pulses disagree"));
}
#[test]
fn calibration_recommendation_uses_coded_pairs_when_raw_activity_disagrees() {
let report = SyncAnalysisReport {
video_event_count: 14,
audio_event_count: 14,
paired_event_count: 13,
coded_events: true,
activity_start_delta_ms: -3_620.7,
raw_first_video_activity_s: 9.361,
raw_first_audio_activity_s: 5.740,
first_skew_ms: -270.0,
last_skew_ms: -230.0,
mean_skew_ms: -205.0,
median_skew_ms: -188.4,
max_abs_skew_ms: 273.8,
drift_ms: 40.0,
skews_ms: vec![-270.0, -240.0, -188.4, -175.0, -130.0],
video_onsets_s: vec![],
audio_onsets_s: vec![],
paired_events: vec![],
};
let recommendation = report.calibration_recommendation();
assert!(recommendation.ready);
assert_eq!(recommendation.recommended_audio_offset_adjust_us, 188_400);
assert!(recommendation.note.contains("paired pulses disagree"));
}
#[test]
fn calibration_recommendation_reports_when_skew_is_already_settled() {
let report = SyncAnalysisReport {
video_event_count: 14,
audio_event_count: 14,
paired_event_count: 14,
coded_events: false,
activity_start_delta_ms: 0.0,
raw_first_video_activity_s: 0.0,
raw_first_audio_activity_s: 0.0,
first_skew_ms: 3.0,
last_skew_ms: 4.0,
mean_skew_ms: 3.5,
median_skew_ms: 4.0,
max_abs_skew_ms: 4.0,
drift_ms: 1.0,
skews_ms: vec![3.0, 4.0],
video_onsets_s: vec![],
audio_onsets_s: vec![],
paired_events: vec![],
};
let recommendation = report.calibration_recommendation();
assert!(recommendation.ready);
assert_eq!(recommendation.recommended_audio_offset_adjust_us, -4_000);
assert!(recommendation.note.contains("already within the settled"));
}
#[test]
fn verdict_passes_preferred_skew_band() {
let report = SyncAnalysisReport {
video_event_count: 5,
audio_event_count: 5,
paired_event_count: 5,
coded_events: false,
activity_start_delta_ms: 0.0,
raw_first_video_activity_s: 0.0,
raw_first_audio_activity_s: 0.0,
first_skew_ms: 10.0,
last_skew_ms: 20.0,
mean_skew_ms: 15.0,
median_skew_ms: 15.0,
max_abs_skew_ms: 20.0,
drift_ms: 10.0,
skews_ms: vec![10.0, 12.0, 15.0, 18.0, 20.0],
video_onsets_s: vec![],
audio_onsets_s: vec![],
paired_events: vec![],
};
let verdict = report.verdict();
assert!(verdict.passed);
assert_eq!(verdict.status, "preferred");
}
#[test]
fn verdict_flags_catastrophic_desync() {
let report = SyncAnalysisReport {
video_event_count: 5,
audio_event_count: 5,
paired_event_count: 5,
coded_events: false,
activity_start_delta_ms: 0.0,
raw_first_video_activity_s: 0.0,
raw_first_audio_activity_s: 0.0,
first_skew_ms: 8_000.0,
last_skew_ms: 8_000.0,
mean_skew_ms: 8_000.0,
median_skew_ms: 8_000.0,
max_abs_skew_ms: 8_000.0,
drift_ms: 0.0,
skews_ms: vec![8_000.0; 5],
video_onsets_s: vec![],
audio_onsets_s: vec![],
paired_events: vec![],
};
let verdict = report.verdict();
assert!(!verdict.passed);
assert_eq!(verdict.status, "catastrophic_failure");
}
#[test]
fn verdict_flags_catastrophic_activity_start_delta() {
let report = SyncAnalysisReport {
video_event_count: 20,
audio_event_count: 20,
paired_event_count: 20,
coded_events: false,
activity_start_delta_ms: 20_000.0,
raw_first_video_activity_s: 0.0,
raw_first_audio_activity_s: 0.0,
first_skew_ms: 900.0,
last_skew_ms: 900.0,
mean_skew_ms: 19_900.0,
median_skew_ms: 19_900.0,
max_abs_skew_ms: 900.0,
drift_ms: 0.0,
skews_ms: vec![900.0; 20],
video_onsets_s: vec![],
audio_onsets_s: vec![],
paired_events: vec![],
};
let verdict = report.verdict();
assert!(!verdict.passed);
assert_eq!(verdict.status, "catastrophic_failure");
assert!(verdict.reason.contains("activity starts"));
}
#[test]
fn verdict_ignores_uncorroborated_raw_activity_for_coded_runs() {
let report = SyncAnalysisReport {
video_event_count: 20,
audio_event_count: 20,
paired_event_count: 20,
coded_events: true,
activity_start_delta_ms: -3_620.7,
raw_first_video_activity_s: 9.361,
raw_first_audio_activity_s: 5.740,
first_skew_ms: -20.0,
last_skew_ms: -18.0,
mean_skew_ms: -19.0,
median_skew_ms: -19.0,
max_abs_skew_ms: 20.0,
drift_ms: 2.0,
skews_ms: vec![-20.0; 20],
video_onsets_s: vec![],
audio_onsets_s: vec![],
paired_events: vec![],
};
let verdict = report.verdict();
assert!(verdict.passed);
assert_eq!(verdict.status, "preferred");
assert!(verdict.reason.contains("raw activity start delta"));
}
}