superuser404notfound · orut34iop · Sep 7, 2026
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
@@ -40,6 +40,12 @@ jobs:
       - name: swift test
         run: swift test
 
+      - name: Timestamp policy and generated media regressions
+        run: |
+          brew list ffmpeg >/dev/null 2>&1 || brew install ffmpeg
+          bash Scripts/test-h264-matroska-timestamps.sh
+          bash Scripts/test-h264-timestamp-controls.sh
+
       # The transport probe is a device harness and runs nowhere in CI, so nothing else would keep
       # it compiling. A harness that stopped building is discovered by the person who needed it.
       - name: build the transport probe (AE#377)

diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -10,7 +10,14 @@ the public-API contract.
 
 ## [Unreleased]
 
-_Nothing yet._
+### Fixed
+
+- Positively identified Matroska H.264 coding-order timestamp ladders now keep
+  their original presentation slots but assign each slot to its parsed picture
+  order. This removes persistent judder on the affected native/hardware VOD path
+  at startup and after seeks. The IDR-bounded policy leaves healthy/unproven
+  input untouched and preserves packet payloads, audio, and the seek-index axis.
+  It is separate from the existing missing-MP4-composition-offset policy.
 
 ## [6.71.0] - 2026-09-06
 

diff --git a/Scripts/test-h264-matroska-timestamps.sh b/Scripts/test-h264-matroska-timestamps.sh
@@ -0,0 +1,10 @@
+#!/bin/bash
+set -euo pipefail
+TASK_ROOT=$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)
+TASK_TMP=$(mktemp -d "${TMPDIR:-/tmp}/aether-matroska-time.XXXXXX")
+trap 'rm -f "$TASK_TMP/check"; rmdir "$TASK_TMP"' EXIT
+# Focused Foundation CLI test, no Apple app target or package resolution.
+xcrun swiftc -swift-version 6 \
+  "$TASK_ROOT/Sources/AetherEngine/Video/H264MatroskaTimestampRepair.swift" \
+  "$TASK_ROOT/Scripts/tests/H264MatroskaTimestampStandalone.swift" -o "$TASK_TMP/check"
+"$TASK_TMP/check" "$TASK_ROOT/Scripts/tests/Data/MatroskaCodingOrderTimestamps.json" "$@"
diff --git a/Scripts/test-h264-timestamp-controls.sh b/Scripts/test-h264-timestamp-controls.sh
@@ -0,0 +1,17 @@
+#!/bin/bash
+set -euo pipefail
+TASK_ROOT=$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)
+TASK_TMP=$(mktemp -d "${TMPDIR:-/tmp}/aether-timestamp-controls.XXXXXX")
+trap 'rm -f "$TASK_TMP/healthy.mp4" "$TASK_TMP/healthy.mkv" "$TASK_TMP/missing.mp4" "$TASK_TMP/coding-order.mkv"; rmdir "$TASK_TMP"' EXIT
+# Generated solid-colour/AAC silence fixtures only; no private media is copied or committed.
+ffmpeg -v error -f lavfi -i 'color=c=blue:s=96x64:r=30000/1001' \
+  -f lavfi -i 'anullsrc=r=48000:cl=stereo' -t 8 \
+  -c:v libx264 -preset ultrafast -pix_fmt yuv420p -bf 3 -b_strategy 0 -g 60 \
+  -sc_threshold 0 -c:a aac -movflags +faststart "$TASK_TMP/healthy.mp4"
+ffmpeg -v error -i "$TASK_TMP/healthy.mp4" -c copy "$TASK_TMP/healthy.mkv"
+ffmpeg -v error -i "$TASK_TMP/healthy.mp4" -c copy -bsf:v 'setts=pts=DTS' -movflags +faststart "$TASK_TMP/missing.mp4"
+ffmpeg -v error -i "$TASK_TMP/healthy.mp4" -c copy -bsf:v 'setts=pts=DTS' "$TASK_TMP/coding-order.mkv"
+AETHER_EXPECT_TIMESTAMP_REPAIR=0 bash "$TASK_ROOT/Scripts/test-h264-timestamp-runtime.sh" "$TASK_TMP/healthy.mp4" 0 3
+AETHER_EXPECT_TIMESTAMP_REPAIR=0 bash "$TASK_ROOT/Scripts/test-h264-timestamp-runtime.sh" "$TASK_TMP/healthy.mkv" 0 3
+AETHER_EXPECT_TIMESTAMP_REPAIR=1 bash "$TASK_ROOT/Scripts/test-h264-timestamp-runtime.sh" "$TASK_TMP/missing.mp4" 0 3
+AETHER_EXPECT_TIMESTAMP_REPAIR=1 bash "$TASK_ROOT/Scripts/test-h264-timestamp-runtime.sh" "$TASK_TMP/coding-order.mkv" 0 3
diff --git a/Scripts/test-h264-timestamp-runtime.sh b/Scripts/test-h264-timestamp-runtime.sh
@@ -0,0 +1,30 @@
+#!/bin/bash
+set -euo pipefail
+TASK_ROOT=$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)
+TASK_FFMPEG_ROOT="${AETHER_FFMPEG_CHECKOUT:-$TASK_ROOT/.build/checkouts/FFmpegBuild}"
+TASK_EXPECTED_REVISION=$(/usr/bin/ruby -rjson -e \
+  'puts JSON.parse(File.read(ARGV.fetch(0))).fetch("pins").find { |p| p.fetch("identity") == "ffmpegbuild" }.fetch("state").fetch("revision")' "$TASK_ROOT/Package.resolved")
+[[ $(git -C "$TASK_FFMPEG_ROOT" rev-parse HEAD) == "$TASK_EXPECTED_REVISION" ]] \
+  || { echo 'Frozen FFmpegBuild revision mismatch' >&2; exit 2; }
+TASK_TMP=$(mktemp -d "${TMPDIR:-/tmp}/aether-timestamp-runtime.XXXXXX")
+trap 'rm -f "$TASK_TMP/check"; rmdir "$TASK_TMP"' EXIT
+TASK_FRAMEWORK_ARGS=()
+for TASK_LIBRARY in AetherLibavformat AetherLibavcodec AetherLibavutil AetherLibswresample AetherLibdav1d AetherLibzvbi; do
+  TASK_DIR="$TASK_FFMPEG_ROOT/Sources/$TASK_LIBRARY.xcframework/macos-arm64_x86_64"
+  [[ -f "$TASK_DIR/$TASK_LIBRARY.framework/$TASK_LIBRARY" ]] || exit 2
+  TASK_FRAMEWORK_ARGS+=(-F "$TASK_DIR" -Xlinker -rpath -Xlinker "$TASK_DIR")
+done
+# Compile the actual timestamp sessions and parser against the exact bundled dependency.
+# This is a focused command-line library check, never an iOS/macOS app build or SwiftPM resolve.
+xcrun swiftc -swift-version 6 \
+  "${TASK_FRAMEWORK_ARGS[@]}" -framework AetherLibavformat -framework AetherLibavcodec -framework AetherLibavutil \
+  "$TASK_ROOT/Sources/AetherEngine/Diagnostics/PacketBalanceTracker.swift" \
+  "$TASK_ROOT/Sources/AetherEngine/Diagnostics/EngineLog.swift" \
+  "$TASK_ROOT/Sources/AetherEngine/Diagnostics/LogRedaction.swift" \
+  "$TASK_ROOT/Sources/AetherEngine/Decoder/A53SEIParser.swift" \
+  "$TASK_ROOT/Sources/AetherEngine/Decoder/CCDataParser.swift" \
+  "$TASK_ROOT/Sources/AetherEngine/Video/H264CompositionOffsetRepair.swift" \
+  "$TASK_ROOT/Sources/AetherEngine/Video/H264MatroskaTimestampRepair.swift" \
+  "$TASK_ROOT/Sources/AetherEngine/Video/H264MatroskaTimestampRepairSession.swift" \
+  "$TASK_ROOT/Scripts/tests/H264TimestampRuntimeStandalone.swift" -o "$TASK_TMP/check"
+"$TASK_TMP/check" "$@"
diff --git a/Scripts/tests/Data/MatroskaCodingOrderTimestamps.json b/Scripts/tests/Data/MatroskaCodingOrderTimestamps.json
@@ -0,0 +1,249 @@
+{
+  "video_delay": 1,
+  "packets": [
+    {
+      "pts": 0,
+      "poc": 0
+    },
+    {
+      "pts": 40,
+      "poc": 8
+    },
+    {
+      "pts": 73,
+      "poc": 2
+    },
+    {
+      "pts": 107,
+      "poc": 4
+    },
+    {
+      "pts": 140,
+      "poc": 6
+    },
+    {
+      "pts": 173,
+      "poc": 14
+    },
+    {
+      "pts": 207,
+      "poc": 10
+    },
+    {
+      "pts": 240,
+      "poc": 12
+    },
+    {
+      "pts": 274,
+      "poc": 20
+    },
+    {
+      "pts": 307,
+      "poc": 16
+    },
+    {
+      "pts": 340,
+      "poc": 18
+    },
+    {
+      "pts": 374,
+      "poc": 24
+    },
+    {
+      "pts": 407,
+      "poc": 22
+    },
+    {
+      "pts": 440,
+      "poc": 30
+    },
+    {
+      "pts": 474,
+      "poc": 26
+    },
+    {
+      "pts": 507,
+      "poc": 28
+    },
+    {
+      "pts": 541,
+      "poc": 36
+    },
+    {
+      "pts": 574,
+      "poc": 32
+    },
+    {
+      "pts": 607,
+      "poc": 34
+    },
+    {
+      "pts": 641,
+      "poc": 42
+    },
+    {
+      "pts": 674,
+      "poc": 38
+    },
+    {
+      "pts": 707,
+      "poc": 40
+    },
+    {
+      "pts": 741,
+      "poc": 48
+    },
+    {
+      "pts": 774,
+      "poc": 44
+    },
+    {
+      "pts": 807,
+      "poc": 46
+    },
+    {
+      "pts": 841,
+      "poc": 56
+    },
+    {
+      "pts": 874,
+      "poc": 50
+    },
+    {
+      "pts": 908,
+      "poc": 52
+    },
+    {
+      "pts": 941,
+      "poc": 54
+    },
+    {
+      "pts": 974,
+      "poc": 60
+    },
+    {
+      "pts": 1008,
+      "poc": 58
+    },
+    {
+      "pts": 1041,
+      "poc": 66
+    },
+    {
+      "pts": 1074,
+      "poc": 62
+    },
+    {
+      "pts": 1108,
+      "poc": 64
+    },
+    {
+      "pts": 1141,
+      "poc": 72
+    },
+    {
+      "pts": 1174,
+      "poc": 68
+    },
+    {
+      "pts": 1208,
+      "poc": 70
+    },
+    {
+      "pts": 1241,
+      "poc": 78
+    },
+    {
+      "pts": 1275,
+      "poc": 74
+    },
+    {
+      "pts": 1308,
+      "poc": 76
+    },
+    {
+      "pts": 1341,
+      "poc": 84
+    },
+    {
+      "pts": 1375,
+      "poc": 80
+    },
+    {
+      "pts": 1408,
+      "poc": 82
+    },
+    {
+      "pts": 1441,
+      "poc": 90
+    },
+    {
+      "pts": 1475,
+      "poc": 86
+    },
+    {
+      "pts": 1508,
+      "poc": 88
+    },
+    {
+      "pts": 1542,
+      "poc": 96
+    },
+    {
+      "pts": 1575,
+      "poc": 92
+    },
+    {
+      "pts": 1608,
+      "poc": 94
+    },
+    {
+      "pts": 1642,
+      "poc": 102
+    },
+    {
+      "pts": 1675,
+      "poc": 98
+    },
+    {
+      "pts": 1708,
+      "poc": 100
+    },
+    {
+      "pts": 1742,
+      "poc": 108
+    },
+    {
+      "pts": 1775,
+      "poc": 104
+    },
+    {
+      "pts": 1808,
+      "poc": 106
+    },
+    {
+      "pts": 1842,
+      "poc": 114
+    },
+    {
+      "pts": 1875,
+      "poc": 110
+    },
+    {
+      "pts": 1909,
+      "poc": 112
+    },
+    {
+      "pts": 1942,
+      "poc": 118
+    },
+    {
+      "pts": 1975,
+      "poc": 116
+    },
+    {
+      "pts": 2009,
+      "poc": 0
+    }
+  ]
+}