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V4.1.1 Telemetry & Stability

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@dfeen87 dfeen87 released this 27 Oct 11:55
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v4.1.1
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Learn about vigilant mode.

ISLA v4.1.1 — LIVE Efficiency, Telemetry & Interface Stability

Let the Music Flow. With Greater Clarity.

ISLA v4.1.1 is a focused engineering patch that builds on the Audio Control Center and playback improvements introduced in v4.1.0.

This update improves the lifecycle of LIVE Remastered processing, expands real-time diagnostic visibility, refines the operator interface, and strengthens regression testing.

Release Transparency: ISLA v4.1.1 improves processing efficiency and diagnostic observability. However, intermittent LIVE audio interruptions remain under investigation, particularly with native macOS audio capture and certain physical playback-device configurations. The changes in this patch should not be interpreted as a verified solution to all audio interruptions. Remastered processing remains experimental, and automated testing does not guarantee uninterrupted playback on every system.

What's Improved

1. More Efficient LIVE Remastered Processing

ISLA now retires the inactive Remastered processing bank after transitioning back to Production.

  • Stops unnecessary Remastered processing after its output is no longer selected.
  • Releases inactive Remastered processing history.
  • Creates fresh processing history when Remastered is selected again.
  • Preserves the existing warm-up behavior and 5-millisecond crossfade.
  • Maintains Production processing history to support clean transitions.

This optimization reduces unnecessary work when Remastered is inactive without changing the underlying musical processing algorithms.

Important: Both processing paths may still perform work while Remastered is actively selected. Further optimization will be guided by measured performance.

2. New LIVE Processing Telemetry

A dedicated LIVE Processing — Engine & Budget category has been introduced within the Audio Control Center.

Developers and operators can now inspect:

  • Requested versus worker-applied processing engine.
  • Remastered processing-bank status.
  • Nominal audio-block processing interval.
  • Last and peak worker processing times.
  • Separate Production and Remastered processing measurements.
  • Total processed blocks and Remastered blocks.
  • Processing-budget exceedances.
  • Inactive Remastered-bank retirements.

These measurements provide additional evidence for diagnosing processing behavior and investigating potential performance bottlenecks.

Worker wall-clock measurements are approximate and must not be confused with actual CPU utilization or proof of native audio-driver failure.

3. Clearer LIVE Start, Stop & Failure Indicators

The LIVE monitoring interface has received targeted usability improvements.

  • Light-green Start LIVE button when ready.
  • Darker-green indication when LIVE monitoring is confirmed active.
  • Light-red Stop LIVE button for clearer operator recognition.
  • Dedicated monitoring-state indicator.
  • More visible explanations when audio stops unexpectedly.
  • Improved vertical spacing and control accessibility.

The interface reflects authoritative application state rather than assuming that clicking a button guarantees audio playback.

Safety preservation: ISLA does not automatically restart monitoring after a fatal audio failure. The operator must address the interruption and explicitly restart the session.

4. More Precise Audio Buffer Diagnostics

LIVE diagnostics now provide additional information about application audio-buffer failures.

Previously, certain queue failures appeared under a combined overflow/contention message.

The updated diagnostics distinguish whether a failed buffer write resulted from:

  • A full application audio queue.
  • Nonblocking lock contention.

Existing buffer high-water measurements are also surfaced.

This improved observability should help identify the origin of future interruptions without altering buffer capacities or weakening the established safety shutdown mechanisms.

5. Stronger Automated Regression Testing

Additional acceptance coverage strengthens confidence in:

  • Remastered processing-bank retirement and reinitialization.
  • Engine switching at 44.1 kHz and 48 kHz.
  • Production audio equivalence following Remastered retirement.
  • Crossfade continuity and processing history.
  • Processing telemetry and workload counters.
  • LIVE input-buffer failure classification.
  • Accurate interface state indicators.
  • Existing playback and audio-control interactions.

Earlier test-harness scheduling improvements also reduce nondeterministic failures involving simulated native audio callbacks.

The associated pull-request validation completed successfully across the required macOS and Linux test environments, including the strict Linux build.

Engineering Findings & Known Limitations

Physical listening tests conducted during development identified two distinct LIVE failure scenarios.

Application-buffer interruption: One session stopped following an application input-buffer overflow/contention event without a corresponding native device-overflow report.

Native capture interruption: Another session reported repeated native input-overflow events. ISLA completed an initial recovery before stopping safely when another capture discontinuity occurred within the recovery quiet interval.

In the latter session, Production processing remained below the nominal audio-block processing budget in the recorded measurements, and Remastered processing was inactive.

These observations do not establish Remastered computational overload as the cause of those interruptions.

Traditional ALIVE file playback demonstrated successful operation independently of LIVE system-audio monitoring. The experimental ALIVE Remastered preparation limit remains 30 seconds; longer recordings continue to use standard ALIVE playback or require a shorter research excerpt.

Future investigations will prioritize native audio-device synchronization, capture-buffer behavior, callback scheduling, and longer physical-device listening sessions.

Preservation & Compatibility

This patch preserves:

  • The established Velvet, Legato, and Melt musical processing profiles.
  • Original/Bypass behavior.
  • Existing research algorithms and frozen research evidence.
  • Audio-buffer safety limits and recovery policies.
  • Manual Start/Stop control and audio-device ownership.
  • Existing ALIVE playback and Remastered admission requirements.
  • The MIT open-source licensing model.

No experimental research results are reclassified or represented as scientifically validated by this update.

Development References

ISLA continues to evolve through reproducible research, careful engineering, transparent limitations, and community participation.

Let the Music Flow. 🎹💙

ISLA — Open-Source Audio Processing & Research | MIT License

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