u/nocdoo

Hello,
I am seeking technical and engineering insights regarding an unusual AVFoundation / CoreAudio behavior on an iPhone 17 during long video recording sessions.
\*\*Device & Test Details:\*\*
\*\*Session Duration:\*\* 1 hour 26 minutes continuous recording (Default Camera App).
\*\*First 58 Seconds:\*\* Video and audio recorded perfectly.
\*\*At 58-Second Mark:\*\* A sudden, loud noise (a high-pitched or buzzing sound) occurred. Immediately following this noise, the audio stream completely dropped out and remained completely silenced.
\*\*Extreme Mute Duration (1 Hour 25 Minutes):\*\* The audio stream remained completely muted for the remaining 1 hour and 25 minutes of the session without auto-recovery.
\*\*Video Status:\*\* Throughout the entire 1 hr 26 mins, the video pipeline recorded flawlessly with zero frame drops, freezes, or crashes.
\*\*Immediate Reset:\*\* Immediately after stopping the recording, a new session was started within 10 seconds, and audio worked normally again from the start.
\*\*Official Apple Diagnostics:\*\* Checked at an official Apple Service Center — hardware and system software diagnostics returned \*\*100% PASS (No defects found)\*\*.
\*\*Questions for iOS / Audio Engineers:\*\*
Is there any known bug or race condition in iOS AVFoundation or CoreAudio where the audio capture buffer freezes/drops continuously for over 85 minutes while video encoding continues normally without throwing an exception or crashing the app?
Could a temporary software glitch or noise-cancellation algorithm error lock the audio pipeline for such an extended duration without auto-recovering until the recording session is manually stopped?
From a DSP / System Architecture perspective, is this extreme duration (1hr 25m audio lockout with normal video and immediate recovery in the next session) plausible as a purely internal OS glitch, or does it point more strongly toward external physical/EMI interference overloading the mic sensor circuit?
\*Note: This post is specifically seeking technical and engineering insights regarding iOS audio pipeline mechanisms and hardware overload responses.\*
Any technical insights or code/system-level perspectives would be greatly appreciated. Thank you!

Hello,
I am seeking technical and engineering insights regarding an unusual AVFoundation / CoreAudio behavior on an iPhone 17 during long video recording sessions.
**Device & Test Details:**
**Session Duration:** 1 hour 26 minutes continuous recording (Default Camera App).
**First 58 Seconds:** Video and audio recorded perfectly.
**At 58-Second Mark:** A sudden, loud noise (a high-pitched or buzzing sound) occurred. Immediately following this noise, the audio stream completely dropped out and remained completely silenced.
**Extreme Mute Duration (1 Hour 25 Minutes):** The audio stream remained completely muted for the remaining 1 hour and 25 minutes of the session without auto-recovery.
**Video Status:** Throughout the entire 1 hr 26 mins, the video pipeline recorded flawlessly with zero frame drops, freezes, or crashes.
**Immediate Reset:** Immediately after stopping the recording, a new session was started within 10 seconds, and audio worked normally again from the start.
**Official Apple Diagnostics:** Checked at an official Apple Service Center — hardware and system software diagnostics returned **100% PASS (No defects found)**.
**Questions for iOS / Audio Engineers:**
Is there any known bug or race condition in iOS AVFoundation or CoreAudio where the audio capture buffer freezes/drops continuously for over 85 minutes while video encoding continues normally without throwing an exception or crashing the app?
Could a temporary software glitch or noise-cancellation algorithm error lock the audio pipeline for such an extended duration without auto-recovering until the recording session is manually stopped?
From a DSP / System Architecture perspective, is this extreme duration (1hr 25m audio lockout with normal video and immediate recovery in the next session) plausible as a purely internal OS glitch, or does it point more strongly toward external physical/EMI interference overloading the mic sensor circuit?
*Note: This post is specifically seeking technical and engineering insights regarding iOS audio pipeline mechanisms and hardware overload responses.*
Any technical insights or code/system-level perspectives would be greatly appreciated. Thank you!

Hello,
I am seeking technical and engineering insights regarding an unusual AVFoundation / CoreAudio behavior on an iPhone 17 during long video recording sessions.
Device & Test Details:
Session Duration: 1 hour 26 minutes continuous recording (Default Camera App).
First 58 Seconds: Video and audio recorded perfectly.
At 58-Second Mark: A sudden, loud noise (a high-pitched or buzzing sound) occurred. Immediately following this noise, the audio stream completely dropped out and remained completely silenced.
Extreme Mute Duration (1 Hour 25 Minutes): The audio stream remained completely muted for the remaining 1 hour and 25 minutes of the session without auto-recovery.
Video Status: Throughout the entire 1 hr 26 mins, the video pipeline recorded flawlessly with zero frame drops, freezes, or crashes.
Immediate Reset: Immediately after stopping the recording, a new session was started within 10 seconds, and audio worked normally again from the start.
Official Apple Diagnostics: Checked at an official Apple Service Center — hardware and system software diagnostics returned 100% PASS (No defects found).
Questions for iOS / Audio Engineers:
Is there any known bug or race condition in iOS AVFoundation or CoreAudio where the audio capture buffer freezes/drops continuously for over 85 minutes while video encoding continues normally without throwing an exception or crashing the app?
Could a temporary software glitch or noise-cancellation algorithm error lock the audio pipeline for such an extended duration without auto-recovering until the recording session is manually stopped?
From a DSP / System Architecture perspective, is this extreme duration (1hr 25m audio lockout with normal video and immediate recovery in the next session) plausible as a purely internal OS glitch, or does it point more strongly toward external physical/EMI interference overloading the mic sensor circuit?
Note: This post is specifically seeking technical and engineering insights regarding iOS audio pipeline mechanisms and hardware overload responses.
Any technical insights or code/system-level perspectives would be greatly appreciated. Thank you!

Hello,
I am seeking technical and engineering insights regarding an unusual AVFoundation / CoreAudio behavior on an iPhone 17 during long video recording sessions.
Device & Test Details:
Session Duration: 1 hour 26 minutes continuous recording (Default Camera App).
First 58 Seconds: Video and audio recorded perfectly.
At 58-Second Mark: A sudden, loud noise (a high-pitched or buzzing sound) occurred. Immediately following this noise, the audio stream completely dropped out and remained completely silenced.
Extreme Mute Duration (1 Hour 25 Minutes): The audio stream remained completely muted for the remaining 1 hour and 25 minutes of the session without auto-recovery.
Video Status: Throughout the entire 1 hr 26 mins, the video pipeline recorded flawlessly with zero frame drops, freezes, or crashes.
Immediate Reset: Immediately after stopping the recording, a new session was started within 10 seconds, and audio worked normally again from the start.
Official Apple Diagnostics: Checked at an official Apple Service Center — hardware and system software diagnostics returned 100% PASS (No defects found).
Questions for iOS / Audio Engineers:
Is there any known bug or race condition in iOS AVFoundation or CoreAudio where the audio capture buffer freezes/drops continuously for over 85 minutes while video encoding continues normally without throwing an exception or crashing the app?
Could a temporary software glitch or noise-cancellation algorithm error lock the audio pipeline for such an extended duration without auto-recovering until the recording session is manually stopped?
From a DSP / System Architecture perspective, is this extreme duration (1hr 25m audio lockout with normal video and immediate recovery in the next session) plausible as a purely internal OS glitch, or does it point more strongly toward external physical/EMI interference overloading the mic sensor circuit?
Note: This post is specifically seeking technical and engineering insights regarding iOS audio pipeline mechanisms and hardware overload responses.
Any technical insights or code/system-level perspectives would be greatly appreciated. Thank you!