[Problem]: pop noise in begin 10s when use old iOS device which upgrade to iPadOS 26.2

[andygaof]

What happened?

I have a gen 5 iPad mini, when it use older iPadOS, after connect to shairport-sync 5.0 AirPlay 2, It work fine, the DAC shows the rate is 44.1. I upgrade to iPados 26.2 two days ago. When play some songs like RENAISSANCE, Shani Diluka version of Apple Music. I always has random pop noise in first 10 seconds. This not happens in 4.3.3 version AirPlay 1. Change ALSA settings of 5.0 can not fix.

log.txt

Relevant log output

The log.txt has startup information and part of playback information

System Information.

AllWinner T113-S4(256MB) SOC, Gustartd R30 DAC

Configuration Information.

shairport-sync --displayConfig
         0.009040833 "shairport.c:2129" >> Display Config Start.
         0.027015875 "shairport.c:2129" 
         0.000738834 "shairport.c:2129" From "uname -a":
         0.000089291 "shairport.c:2129"  Linux R30 5.4.61-rt37 #1 SMP PREEMPT Wed Oct 16 11:30:48 CST 2024 armv7l GNU/Linux
         0.085648500 "shairport.c:2129" 
         0.000117875 "shairport.c:2129" From /etc/os-release:
         0.000753125 "shairport.c:2129"  Arch Linux ARM
         0.046817459 "shairport.c:2129" 
         0.000150500 "shairport.c:2129" From /sys/firmware/devicetree/base/model:
         0.000883208 "shairport.c:2129"  sun8iw20
         0.001665083 "shairport.c:2129" 
         0.000122292 "shairport.c:2129" Shairport Sync Version String:
         0.000600500 "shairport.c:2129"  4.3.3-OpenSSL-Avahi-dns_sd-ALSA-jack-pa-stdout-pipe-soxr-metadata-mqtt-sysconfdir:/etc
         0.000823833 "shairport.c:2129" 
         0.000858959 "shairport.c:2129" Command Line:
         0.000580666 "shairport.c:2129"  shairport-sync --displayConfig
         0.001492334 "shairport.c:2129" 
         0.000129291 "shairport.c:2129" Configuration File:
         0.000066917 "shairport.c:2129"  /etc/shairport-sync.conf
         0.000058000 "shairport.c:2129" 
         0.000598833 "shairport.c:2129" Configuration File Settings:
         0.000123709 "shairport.c:2129"  general : 
         0.000073708 "shairport.c:2129"  {
         0.000060000 "shairport.c:2129"    airplay_2 = "no";
         0.000058042 "shairport.c:2129"  };
         0.000056166 "shairport.c:2129"  alsa : 
         0.000057167 "shairport.c:2129"  {
         0.000054833 "shairport.c:2129"    output_device = "hw:0";
         0.000055417 "shairport.c:2129"    output_rate = 48000;
         0.000056667 "shairport.c:2129"    output_format = "S32_LE";
         0.000057000 "shairport.c:2129"    output_channels = 2;
         0.000061416 "shairport.c:2129"    disable_synchronization = "yes";
         0.000060417 "shairport.c:2129"    period_size = 400;
         0.000056458 "shairport.c:2129"    buffer_size = 8192;
         0.000055542 "shairport.c:2129"    use_mmap_if_available = "yes";
         0.000055875 "shairport.c:2129"    use_hardware_mute_if_available = "no";
         0.000056000 "shairport.c:2129"    maximum_stall_time = 1;
         0.000059167 "shairport.c:2129"    use_precision_timing = "no";
         0.000055083 "shairport.c:2129"  };
         0.000055250 "shairport.c:2129"  pipewire : 
         0.000053833 "shairport.c:2129"  {
         0.000053375 "shairport.c:2129"  };
         0.000055084 "shairport.c:2129"  pulseaudio : 
         0.000055458 "shairport.c:2129"  {
         0.000053625 "shairport.c:2129"  };
         0.000052375 "shairport.c:2129"  stdout : 
         0.000055083 "shairport.c:2129"  {
         0.000304834 "shairport.c:2129"  };
         0.000167291 "shairport.c:2129"  ao : 
         0.000138834 "shairport.c:2129"  {
         0.000142541 "shairport.c:2129"  };
         0.000306792 "shairport.c:2129"  metadata : 
         0.000153125 "shairport.c:2129"  {
         0.000133917 "shairport.c:2129"    enabled = "no";
         0.000138041 "shairport.c:2129"  };
         0.000131792 "shairport.c:2129"  diagnostics : 
         0.000131958 "shairport.c:2129"  {
         0.000132750 "shairport.c:2129"    disable_resend_requests = "no";
         0.000133750 "shairport.c:2129"    log_output_to = "stdout";
         0.000132459 "shairport.c:2129"    log_verbosity = 3;
         0.000317583 "shairport.c:2129"  };
         0.000175125 "shairport.c:2129" 
         0.000148000 "shairport.c:2129" >> Display Config End.
         0.000137833 "shairport.c:2131" >> Goodbye!
         0.000151292 "shairport.c:1588" exit function called...
         0.000275208 "shairport.c:1598" Stopping the activity monitor.
         0.000168459 "shairport.c:1600" Stopping the activity monitor done.
         0.000142291 "shairport.c:1603" Stopping DACP Monitor
         0.000156209 "shairport.c:1605" Stopping DACP Monitor Done
         0.000143708 "shairport.c:1634" Stopping metadata hub
         0.000140625 "shairport.c:1636" Stopping metadata done
         0.000145625 "shairport.c:1640" Stopping metadata
         0.000310083 "shairport.c:1642" Stopping metadata done
         0.000193959 "mdns.c:137" Can't stop a DACP monitor -- no mdns_dacp_monitor_stop registered.
         0.000157791 "shairport.c:1725" normal exit

PulseAudio or PipeWire installed?

• Check if your system uses a Sound Server.

How did you install Shairport Sync?

Built from source

Check previous issues

• Confirm

[mikebrady]

Thanks for the post. A quick question: you say the DAC is running at 44100, but do you mean 48000?

[mikebrady]

Another question, please. Is your Apple Music quality set to Lossless or High Resolution Lossless? If so, does the problem recur if you turn off Lossless and purge the Apple Music local storage?

[andygaof]

Thanks for the post. A quick question: you say the DAC is running at 44100, but do you mean 48000?

I mean when iPad with older iPadOS, the DAC shows the rate is 44100. After upgrade to iPadOS 26.2 the DAC shows the rate is 48000. But even I set rate to 44100 when iPad running on iPadOS 26.2, the pop noise still there.

[andygaof]

Another question, please. Is your Apple Music quality set to Lossless or High Resolution Lossless? If so, does the problem recur if you turn off Lossless and purge the Apple Music local storage?

If set quality to AAC, the pop noise is there, after set to ALAC(24/48), seems the pop noise disappeared.

[mikebrady]

Thanks. I've been trying this track, and haven't been able to get the popping noise, I'm afraid.

Let me suggest you temporarily remove or comment out as many of the settings in the config file as possible. You could leave the alsa output_device and remove or comment out all the rest, to see what happens.

One setting that you could turn on, however, is to enable the gathering of statistics, and maybe you could post some of them here.

FYI "airplay_2" is not a recognised setting and is ignored.

As a matter of interest, what is the output device?