From 38ead8c1e9667afa981b7c5a43eb5646c04bf769 Mon Sep 17 00:00:00 2001
From: Brad Stein <Brad.Stein@gmail.com>
Date: Sun, 26 Apr 2026 13:22:52 -0300
Subject: [PATCH] fix(sync): pace webcam timestamps by frame duration

---
 Cargo.lock                                  |  6 +++---
 client/Cargo.toml                           |  2 +-
 client/src/input/camera.rs                  |  3 ++-
 client/src/input/camera/capture_pipeline.rs | 14 ++++++++++++--
 client/src/input/camera/device_selection.rs |  3 ++-
 common/Cargo.toml                           |  2 +-
 server/Cargo.toml                           |  2 +-
 7 files changed, 22 insertions(+), 10 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 5d4b999..36194ca 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1642,7 +1642,7 @@ checksum = "09edd9e8b54e49e587e4f6295a7d29c3ea94d469cb40ab8ca70b288248a81db2"
 
 [[package]]
 name = "lesavka_client"
-version = "0.14.2"
+version = "0.14.3"
 dependencies = [
  "anyhow",
  "async-stream",
@@ -1676,7 +1676,7 @@ dependencies = [
 
 [[package]]
 name = "lesavka_common"
-version = "0.14.2"
+version = "0.14.3"
 dependencies = [
  "anyhow",
  "base64",
@@ -1688,7 +1688,7 @@ dependencies = [
 
 [[package]]
 name = "lesavka_server"
-version = "0.14.2"
+version = "0.14.3"
 dependencies = [
  "anyhow",
  "base64",
diff --git a/client/Cargo.toml b/client/Cargo.toml
index 53f79cb..d179765 100644
--- a/client/Cargo.toml
+++ b/client/Cargo.toml
@@ -4,7 +4,7 @@ path                    = "src/main.rs"
 
 [package]
 name                    = "lesavka_client"
-version                 = "0.14.2"
+version                 = "0.14.3"
 edition                 = "2024"
 
 [dependencies]
diff --git a/client/src/input/camera.rs b/client/src/input/camera.rs
index 8c75911..657db91 100644
--- a/client/src/input/camera.rs
+++ b/client/src/input/camera.rs
@@ -50,7 +50,8 @@ pub struct CameraCapture {
     pipeline: gst::Pipeline,
     sink: gst_app::AppSink,
     preview_tap_running: Option<Arc<AtomicBool>>,
-    pts_rebaser: crate::live_capture_clock::SourcePtsRebaser,
+    pts_rebaser: crate::live_capture_clock::DurationPacedSourcePtsRebaser,
+    frame_duration_us: u64,
 }
 
 include!("camera/capture_pipeline.rs");
diff --git a/client/src/input/camera/capture_pipeline.rs b/client/src/input/camera/capture_pipeline.rs
index 3185b73..d5ee5ba 100644
--- a/client/src/input/camera/capture_pipeline.rs
+++ b/client/src/input/camera/capture_pipeline.rs
@@ -227,7 +227,8 @@ impl CameraCapture {
             pipeline,
             sink,
             preview_tap_running,
-            pts_rebaser: crate::live_capture_clock::SourcePtsRebaser::default(),
+            pts_rebaser: crate::live_capture_clock::DurationPacedSourcePtsRebaser::default(),
+            frame_duration_us: (1_000_000u64 / u64::from(fps.max(1))).max(1),
         })
     }
 
@@ -236,7 +237,15 @@ impl CameraCapture {
         let buf = sample.buffer()?;
         let map = buf.map_readable().ok()?;
         let source_pts_us = buf.pts().map(|ts| ts.nseconds() / 1_000);
-        let timing = self.pts_rebaser.rebase_or_now(source_pts_us, 1);
+        let packet_duration_us = buf
+            .duration()
+            .map(|ts| (ts.nseconds() / 1_000).max(1))
+            .unwrap_or(self.frame_duration_us);
+        let timing = self.pts_rebaser.rebase_with_packet_duration(
+            source_pts_us,
+            packet_duration_us,
+            crate::live_capture_clock::upstream_source_lag_cap(),
+        );
         let pts = timing.packet_pts_us;
         static CAMERA_PACKET_COUNT: std::sync::atomic::AtomicU64 =
             std::sync::atomic::AtomicU64::new(0);
@@ -278,6 +287,7 @@ fn log_camera_timing_sample(
             packet_pts_us = timing.packet_pts_us,
             pull_path_delay_us = timing.capture_now_us as i128 - timing.packet_pts_us as i128,
             used_source_pts = timing.used_source_pts,
+            lag_clamped = timing.lag_clamped,
             bytes,
             "📸 upstream webcam timing sample"
         );
diff --git a/client/src/input/camera/device_selection.rs b/client/src/input/camera/device_selection.rs
index c407239..1c95c05 100644
--- a/client/src/input/camera/device_selection.rs
+++ b/client/src/input/camera/device_selection.rs
@@ -94,7 +94,8 @@ impl CameraCapture {
             pipeline,
             sink,
             preview_tap_running: None,
-            pts_rebaser: crate::live_capture_clock::SourcePtsRebaser::default(),
+            pts_rebaser: crate::live_capture_clock::DurationPacedSourcePtsRebaser::default(),
+            frame_duration_us: 1,
         }
     }
 
diff --git a/common/Cargo.toml b/common/Cargo.toml
index 2a2473e..5a8e6eb 100644
--- a/common/Cargo.toml
+++ b/common/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name                    = "lesavka_common"
-version                 = "0.14.2"
+version                 = "0.14.3"
 edition                 = "2024"
 build                   = "build.rs"
 
diff --git a/server/Cargo.toml b/server/Cargo.toml
index c57ee84..5adff37 100644
--- a/server/Cargo.toml
+++ b/server/Cargo.toml
@@ -10,7 +10,7 @@ bench                   = false
 
 [package]
 name                    = "lesavka_server"
-version                 = "0.14.2"
+version                 = "0.14.3"
 edition                 = "2024"
 autobins                = false