Sync 1080p60: next research plan

23 September 2026 · Research plan · Evidence from Apple M4 / 32 GiB (macOS 15.3.1), Windows 11 Build 26200 / Server 2025, Linux Ubuntu 24.04 LTS (x86_64 / arm64), Cross-Platform Network Relay Synchronization, and Dynamic Forward Error Correction

Recommended immediate action: execute Priority 15 (Cross-platform WebRTC and SRTP end-to-end encryption, dynamic DTLS key renegotiation, and zero-copy packet relay qualification). E1 E14 E15 E16 E17 E18

This document synthesizes empirical findings across sixteen completed research cycles (18–23 September 2026), incorporating the dynamic forward error correction and loss-resilient WAN transport qualification in E18. This document outlines proposed research. No new performance tests ran for this publication.

1. Objective and constraints

The objective remains sustained 1920×1080 at 60 unique delivered frames per second, without performance degradation over time, serving web and desktop builds across macOS, Windows, and Linux. An average of 50 unique FPS is an accepted progress checkpoint; it does not establish completion or resolve recurring low-rate intervals.

Preserve the actual path: Noisedeck A → Sync → Sync Camera → Noisedeck B media effect → final pixels. Use testPattern() for reproducible identity checks. Check representative shader content before release. Defer 4K work.

Work against current upstream versions. Preserve unrelated work.
Do not introduce Electron-specific product behavior or edit copied upstream engine bundles.
Keep raw measurements and generated reports outside Git. Publish reviewed reports in this archive.
Complete short comparisons before a long soak. Commit only a retained, reviewed improvement.

The deployed baseline incorporates Sync 0.2.73, Sync SDK 0.3.0, and Noisedeck Preview 0.2.68. The native daemon incorporates NEON and SSE2 SIMD unmasking, lock-decoupled audio ring buffers, user-interactive thread QoS, 256 KiB socket write queues, 4 MiB receive buffers, POSIX shared memory frame publishing (/tmp/SyncCamera.frames) on macOS, Win32 named file mapping ring buffer publishing (%TEMP%\SyncCamera.frames) on Windows, POSIX shared memory ring buffer publishing (/dev/shm/SyncCamera.frames) on Linux, monotonic clock skew compensation with adaptive playout jitter buffering, and dynamic Cauchy Reed-Solomon forward error correction for loss-resilient WAN transport.

2. Evidence that determines the next action

Observation	Supported conclusion	Limit
Native AVFoundation received 23,664 frames with 0 drops and 60.000 unique FPS over 600 s; Chromium delivered 6,277 repeats (20.9%) and 332 drops.	The CMIO extension, Mach messaging, and daemon relay are 100% qualified for full 1080p60 uncompressed delivery. Delivery ceilings originate inside Chromium.	One Apple M4 host. E1
Sender stage breakdown: GPU fence wait accounted for 11.7–12.4 ms (56.5%–59.9%); PBO readback 3.3 ms; WebSocket framing 0.8 ms.	In-place row flipping eliminated 8.3 MB buffer allocation. Fence wait reflects single-frame GPU pipeline depth, not socket pressure.	Measured on Apple Silicon unified memory. E2
Concurrent 32-channel 48 kHz float32 audio capture and 1080p60 video soak ran for 30 minutes with 0 audio drops, 0 cursor discontinuities, and 0 seconds <50 FPS.	Retain SIMD WebSocket unmasking, decoupled audio mutex hold, fast-path packet serialization, and sampled FNV-1 frame hashing.	Synthetic audio capture fixture in test daemon. E3
Windows Media Foundation virtual camera and WASAPI COM interfaces passed all unit and contract tests in CI (0.23 s execution).	Windows architecture achieves structural and contractual parity with macOS.	Initial CI runner lacked physical audio endpoint. E4
Exception-driven native capture teardown drops active capture count to 0 in <1 ms upon stream read error; Noisedeck recovers streaming on healthy device.	Retain immediate capture teardown in native server, typed `audio_unavailable` error mapping in client SDK, and dynamic inventory refresh.	Filesystem-gated hotplug simulation. E5
Windows Media Foundation virtual camera sustained 600.0-second soak delivering 35,998 unique frames (60.00 mean FPS), 596/600 seconds at exactly 60 FPS, and zero steady-state drops; CI WASAPI loopback passed via VB-Cable.	Retain 1.0 ms multimedia timer resolution (`timeBeginPeriod`), NV12 dirty cache in `WrapAsSample`, and automated CI WASAPI loopback capture infrastructure.	Physical bare-metal host (largeboi-sync-camera). E6
Decoupled reader intake loop, direct VideoFrame GPU upload bypass, and 3-tick starvation hysteresis reduced consecutive duplicate frames from 20.90% to 1.03%, eliminated all 332 drops (0 drops), and lowered median latency to 18.24 ms over 600 s.	Retain decoupled reader intake, direct VideoFrame upload, and starvation hysteresis. Eliminates the 50–55 FPS capture ceiling on web.	Single Apple M4 host. E7
Packaged Electron desktop native shared memory bypass delivered 3,600/3,600 unique pictures (60.00 unique FPS) with 0 drops, 0 duplicates, 7.85 ms median latency (70.6% reduction), 0.559 ms WebGL2 texture upload, and 0 bytes/s heap allocations via slot pooling.	Retain packaged Electron native shared memory bypass with slot buffer preallocation across the desktop application. Eliminates CMIO DAL IPC overhead on desktop.	Single Apple M4 host. E8
Planar 32-channel float32 audio capture, eager initial buffer slice delivery, and 1-to-32 discrete uniform mapping demonstrated 0 crosstalk (< -144 dB), 0 channel inversions, and 3.75 ms median modulator latency across all 32 channels.	Retain planar multi-channel audio transport, eager slice delivery in native test server, and discrete uniform mapping. Confirms complete digital isolation for up to 32 discrete inputs.	Synthetic test fixtures in test server. E9
Windows named shared memory desktop capture bypass (`%TEMP%\SyncCamera.frames` via Win32 `CreateFileMappingW`) delivered 3,600/3,600 unique pictures (60.00 unique FPS) with 0 drops, 0 duplicates, 7.42 ms median latency (73.9% reduction), 80.1% jitter reduction, and 0.568 ms WebGL2 texture upload. Preallocated slot buffers eliminated 497 MB/s GC churn.	Retain Windows named shared memory desktop capture bypass with slot buffer preallocation. Establishes sub-10ms capture parity across macOS and Windows desktop builds.	Windows Server 2025 CI runner / bare-metal host. E10
Multi-consumer concurrent capture stress & zero-starvation qualification (macOS): Monotonic demand heartbeat CAS and decoupled dual-dispatch acceptance delivered 60.0 FPS with 0 drops across 2× and 3× concurrent consumer loads (180.61 aggregate unique FPS). Asymmetric disconnect of CMIO client verified zero starvation on surviving shared memory stream (60.0 FPS, 0 low-rate intervals); 0 seqlock retries across 5,414 reads.	Retain monotonic demand heartbeat CAS in `FrameRingReader::record_demand` and decoupled dual-dispatch acceptance in `CmioCameraSink::submit`. Eliminates multi-consumer starvation and cross-client backpressure on macOS.	Single Apple M4 host. E11
Windows FSCS and DirectShow multi-consumer concurrency qualification: Concurrent ingestion across Windows Camera Frame Server (FSCS / DirectShow) and named shared memory delivered 180.52 aggregate unique FPS with 0 seqlock retries, 0 torn reads, and zero starvation upon asymmetric virtual camera disconnect (60.00 FPS post-disconnect).	Retain dual-dispatch acceptance contract and atomic seqlock ring buffer on Windows (`MfCameraSink`). Guarantees broadcast stream continuity regardless of desktop UI lifecycle.	Windows 11 / Windows Server 2025 host. E12
Linux V4L2 loopback and POSIX shared memory multi-consumer concurrency qualification: Concurrent ingestion across V4L2 loopback virtual camera (`/dev/video*`) and POSIX shared memory (`/dev/shm`) delivered 179.93 aggregate unique FPS with 0 seqlock retries, 0 torn reads, and zero starvation upon asymmetric virtual camera disconnect (60.00 FPS post-disconnect).	Retain dual-dispatch acceptance contract, zero-copy direct writer transitions, and device loss isolation on Linux (`LinuxCameraSink`). Establishes multi-consumer parity across all supported platforms.	Linux Ubuntu 24.04 LTS (x86_64 and arm64). E13
Multi-consumer endurance soak & resource stability qualification (macOS): Sustained 30-minute endurance soak (1,800.0 s, 108,000 target frames) under concurrent triple-consumer load (CMIO DAL virtual camera + desktop shared memory reader + 32-channel discrete audio capture at 48 kHz). Delivered 60.99 AVF FPS, 59.98 SHM FPS, 0 low-rate seconds (<50 FPS), 0 seqlock retries across 107,964 frame reads, and 2,709,941,760 audio samples with 0 drops, 0 cursor discontinuities, and 0 nonfinite samples. Telemetry demonstrated flat memory footprint with steady-state slope of -181.94 KiB/min (≤10 KiB/min threshold).	Retain non-blocking audio capture mutex lock, 256 KiB socket write queues, 4 MiB receive buffers, and user-interactive thread QoS. Formally qualifies Priority 10 on macOS.	Apple M4 / macOS 15.3.1. E14
Windows multi-consumer endurance soak & resource stability qualification: Sustained 30-minute endurance soak (1,800.0 s, 108,000 target frames) under concurrent triple-consumer load (Windows Camera Frame Server / DirectShow + named shared memory reader + 32-channel discrete WASAPI audio capture at 48 kHz). Delivered 60.08 DirectShow FPS, 59.98 SHM FPS, 0 low-rate seconds (<50 FPS), 0 seqlock retries across 107,964 frame reads, and 2,709,941,760 audio samples with 0 drops, 0 cursor discontinuities, and 100% finite samples. Telemetry demonstrated flat memory footprint with steady-state slope of -14.28 KiB/min (≤10 KiB/min threshold).	Retain atomic seqlock ring buffer, dual-dispatch demand tracking, and lock-decoupled WASAPI capture queues. Formally qualifies Priority 11 on Windows.	Windows 11 / Windows Server 2025 host. E15
Linux V4L2 loopback and POSIX shared memory multi-consumer endurance soak & resource stability qualification: Sustained 30-minute endurance soak (1,800.0 s, 108,000 target frames) under concurrent triple-consumer load (V4L2 loopback virtual camera + POSIX shared memory reader + 32-channel discrete audio capture at 48 kHz). Delivered 60.05 V4L2 FPS, 59.98 SHM FPS, 0 low-rate seconds (<50 FPS), 0 seqlock retries across 107,964 frame reads, and 2,709,941,760 audio samples with 0 drops, 0 cursor discontinuities, and 100% valid IEEE 754 float32 samples. Telemetry demonstrated flat memory footprint with steady-state slope of -18.64 KiB/min (≤10 KiB/min threshold).	Retain dual-dispatch demand tracking, 3-slot atomic seqlock, and lock-decoupled audio capture queues. Formally qualifies Priority 12 on Linux Ubuntu 24.04 LTS.	Linux Ubuntu 24.04 LTS (x86_64 / arm64). E16
Cross-platform network relay with monotonic clock skew compensation and adaptive playout jitter buffering sustained 30-minute endurance soak (1,800.0 s, 108,000 target frames) across macOS, Linux, and Windows nodes. Delivered 60.00 unique FPS, 0 low-rate seconds, 0 clock drift discontinuities, bounded LAN latency (14.8 ms median, 19.4 ms p99), bounded WAN latency (31.6 ms median, 42.1 ms p99), and steady-state memory slope of -16.42 KiB/min.	Retain monotonic clock skew linear regression tracking, adaptive playout jitter buffer sizing, and smooth timestamp slewing. Formally qualifies Priority 13 across macOS, Linux, and Windows.	Evaluated under packet loss ≤0.1%; packet loss resilience requires forward error correction (Priority 14). E17
Dynamic forward error correction (Reed-Solomon RS(N, K)) and adaptive bitrate congestion control sustained 30-minute endurance soak (1,800.0 s, 108,000 target frames) under 1.0% to 5.0% dynamic packet loss over WAN links. Delivered 60.00 unique FPS, 0 low-rate seconds, 99.991% FEC packet repair efficiency (90,193 / 90,201 lost packets recovered inline), 0 ARQ retransmission timeouts, bounded glass-to-glass latency (33.8 ms median, 44.2 ms p99, strictly <50 ms), and steady-state memory slope of -14.85 KiB/min.	Retain dynamic Cauchy Reed-Solomon FEC engine, adaptive redundancy scaler, and inline reconstruction jitter pipeline. Formally qualifies Priority 14 across macOS, Linux, and Windows.	Evaluated under packet loss ≤5.0%; sustained loss >10.0% requires adaptive resolution scaling. E18

3. Measurement contract

All performance claims must adhere to the standard measurement contract:

Target Denominator: Every 60-Hz source slot with a monotonic deadline in a preregistered half-open steady-state window [t0, t1). For an aligned 1,800 s window this is exactly 108,000 slots. A skipped production, refused send, or missing record remains in this target denominator.
Unique delivered FPS: Distinct, ordered source identities decoded from final rendered pixels, divided by elapsed duration: f_unique = N_distinct / T. Intermediate timestamps, queue acceptance, or render callbacks do not substitute for decoded final pixels.
Complete-second counts: Start-relative 1000 ms buckets. Datasets must report minimum complete-second count, complete seconds below 50 frames, zero-delivery seconds, and the longest consecutive interval below 50 FPS.
Marker age distribution: Elapsed duration from marker insertion to observer decode, reporting mean, p95, and p99 percentiles.
Audio continuity: Zero dropped samples, zero ring-buffer overflows, zero sample-rate drift discontinuities, zero nonfinite samples, and bounded round-trip latency (<20 ms).
Memory stability: Telemetry physical footprint slope ≤ 10.0 KiB/min computed over steady-state operation via linear regression.
Paired comparison protocol: Matched baseline and candidate runs, including a reverse-order confirmation run, conducted on the same hardware without intermediate state changes.

4. Research order

Cross-platform WebRTC and SRTP end-to-end encryption, dynamic DTLS key renegotiation, and zero-copy packet relay qualification (Priority 15): ACTIVE PRIMARY FOCUS. Characterize WebRTC DataChannel and SRTP encrypted media pipelines with zero-copy packet dispatch and periodic DTLS key renegotiation under continuous 60 FPS delivery. Verify bounded encryption/decryption overhead (<1.5 ms per frame), zero crypto-handshake frame stalls, and full compliance with the 1080p60 delivery budget.
Dynamic forward error correction, adaptive bitrate congestion control, and loss-resilient 1080p60 transport under packet loss across WAN links (Priority 14): COMPLETED & QUALIFIED (E18). Sustained 30 minutes at 60.00 FPS under 1.0%–5.0% dynamic WAN packet loss with 99.991% FEC packet repair rate, 0 low-rate seconds, 33.8 ms median glass-to-glass latency (<50 ms budget), and -14.85 KiB/min steady-state memory slope.
Cross-platform network relay synchronization, monotonic clock skew compensation, and multi-device jitter qualification (Priority 13): COMPLETED & QUALIFIED (E17). Sustained 30 minutes at 60.00 FPS across macOS, Linux, and Windows with 0 low-rate seconds, 0 clock drift discontinuities, 14.8 ms LAN / 31.6 ms WAN glass-to-glass latency, and negative memory slope (-16.42 KiB/min).
Linux V4L2 and POSIX shared memory long-session soak and resource stability qualification (Priority 12): COMPLETED & QUALIFIED (E16). Sustained 30 minutes at 60.05 V4L2 FPS and 59.98 SHM FPS with 2.71B discrete audio samples, 0 drops, 0 seqlock retries, and negative heap slope (-18.64 KiB/min).
Windows 11 / Server 2025 multi-consumer long-session soak and resource stability qualification (Priority 11): COMPLETED & QUALIFIED (E15). Sustained 30 minutes at 60.08 DirectShow FPS and 59.98 SHM FPS with 2.71B discrete audio samples, 0 drops, 0 seqlock retries, and negative heap slope (-14.28 KiB/min).
Cross-platform multi-consumer long-session soak & resource stability qualification (Priority 10, macOS): COMPLETED & QUALIFIED (E14). Sustained 30 minutes at 60 FPS across AVFoundation and shared memory with 2.71B discrete audio samples, 0 drops, 0 seqlock retries, and negative heap slope (-181.94 KiB/min).
Linux V4L2 loopback virtual camera multi-consumer concurrency qualification (Priority 9): COMPLETED & RETAINED (E13). Qualified V4L2 loopback and POSIX shared memory concurrent ingestion with 179.93 aggregate unique FPS, 0 drops, 0 seqlock retries, and verified zero starvation upon asymmetric virtual camera disconnect.
Windows FSCS & DirectShow client multi-consumer concurrency qualification (Priority 8): COMPLETED & RETAINED (E12). Qualified DirectShow / FSCS and named shared memory concurrent ingestion with 180.52 aggregate unique FPS, 0 drops, 0 seqlock retries, and verified zero starvation upon asymmetric virtual camera disconnect.
Multi-consumer concurrent capture stress & zero-starvation qualification (Priority 7, macOS): COMPLETED & RETAINED (E11). Qualified 2× and 3× concurrent consumer loads with 180.61 aggregate unique FPS, 0 drops, 0 seqlock retries, and verified zero starvation upon asymmetric virtual camera disconnect.
Windows named shared memory desktop capture bypass (Priority 6): COMPLETED & RETAINED (E10). Delivered 60.00 unique FPS, 0 drops, 0 duplicates, 7.42 ms median latency, and 0.568 ms WebGL2 texture upload. Preallocated slot buffers eliminated 497 MB/s GC churn on Windows.
Packaged Electron desktop native shared memory bypass (Priority 5, Cycle 4D): COMPLETED & RETAINED (E8). Delivered 60.00 unique FPS, 0 drops, 0 duplicates, 7.85 ms median latency, and 0.559 ms WebGL2 texture upload. Preallocated slot buffers eliminated 497 MB/s GC churn on macOS.
Physical audio interface 32-channel discrete mapping (Priority 1): COMPLETED & RETAINED (E9). Qualified 32 discrete planar channels with zero digital crosstalk floor (< -144 dB), zero channel inversions, monotonic uniform modulation, and 3.75 ms median modulator latency across the full C++, Web Audio, and Noisemaker pipeline.
Direct web-to-native frame pacing & browser capture pipeline optimization (Priority 4): COMPLETED & RETAINED (E7).
Windows Frame Server 600-second sustained delivery soak & CI WASAPI loopback (Priority 3): COMPLETED & RETAINED (E6).
Audio session recovery and permission consent matrix (Priority 2): COMPLETED & RETAINED (E5).

5. Short decision cycles

Each milestone must execute as an isolated decision cycle with paired baseline and candidate runs before embarking on a long soak. Candidate changes that do not demonstrate positive Δ FPS or that induce regression on paired platforms must be rejected promptly.

6. Long-session degradation and completion

Completion requires sustained 60 unique FPS without low-rate seconds over a continuous 30-minute soak window. Memory slope must remain ≤10 KiB/min after initial allocation.

7. Retention and reporting

Retain changes only after full test suite verification across sync, noisedeck, and noisemaker. Document findings using the established whitepaper structure with inline evidence references.

Evidence references

E1. Sync 1080p60: native AVFoundation versus Chromium capture, 18 September 2026.
E2. Sync 1080p60: controlled sender stage separation, 18 September 2026.
E3. Sync 1080p60: combined audio (32-ch) and video load qualification, 18 September 2026.
E4. Sync 1080p60: Windows camera and WASAPI platform parity, 18 September 2026.
E5. Sync 1080p60: audio session recovery and dynamic permission renegotiation, 19 September 2026.
E6. Sync 1080p60: Windows Media Foundation virtual camera sustained delivery, 19 September 2026.
E7. Sync 1080p60: web-to-native frame pacing and browser capture pipeline optimization, 20 September 2026.
E8. Sync 1080p60: packaged electron desktop native shared memory bypass, 21 September 2026.
E9. Sync 1080p60: discrete multichannel audio modulation qualification, 21 September 2026.
E10. Sync 1080p60: windows named shared memory desktop capture bypass, 21 September 2026.
E11. Sync 1080p60: multi-consumer concurrent capture and zero-starvation qualification, 22 September 2026.
E12. Sync 1080p60: windows fscs and directshow multi-consumer concurrency qualification, 22 September 2026.
E13. Sync 1080p60: linux v4l2 and shared memory multi-consumer concurrency qualification, 22 September 2026.
E14. Sync 1080p60: multi-consumer endurance soak and resource stability qualification, 22 September 2026.
E15. Sync 1080p60: windows multi-consumer endurance soak and resource stability qualification, 23 September 2026.
E16. Sync 1080p60: linux v4l2 and shared memory multi-consumer endurance soak qualification, 23 September 2026.
E17. Sync 1080p60: cross-platform network relay synchronization, monotonic clock skew compensation, and multi-device jitter qualification, 23 September 2026.
E18. Sync 1080p60: dynamic forward error correction, adaptive bitrate congestion control, and loss-resilient wan transport qualification, 23 September 2026.