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Audio looping back on Transmit (It’s not a bug)

I’ve had a few reports of this now. Symptoms are that you hear your transmission (with radio effects, if enabled) shortly after you transmit. This is not a bug.

Transmissions only block the transmitting radio – this is actually how real aircraft radios work – you’re hearing yourself on the other radio.

To “fix” it, turn off the second radio via the audio panel, or tune it to a different frequency.

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XSB 2.0 beta 4 – Incompatible with macOS 10.11 and earlier

One of the libraries used in the new voice support uses the posix monotonic time functions which are not available in macOS prior to 10.12.

Given that the macOS upgrades are free, macOS 10.12 supports systems up to 10 years old, and it represents an unreasonable support burden to fix this issue, I will be discontinuing support for macOS 10.11 and earlier, and the documentation will be updated in the next release to reflect this change.

Please do not report any issues related to macOS versions prior to 10.12

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XSB 2.0 beta 4 – Known Issue: Crash on some macOS systems due to AVX optimisations

Update: The hotfix is now available for download.

I’ve just tracked down the cause for a crash on some macOS systems which is related to the opus audio codec.

This bug affects all macOS systems that use CPUs that do not support AVX. AVX was introduced in 2011, so all mac systems from before 2011 will not currently work because of this issue. Mac systems from after 2011 that use an older CPU (such as the 2012 MacPro hex-core) also will not work.

The crash will be characterised by X-Plane crashing when a connection is made, or the audio setup dialogue being displayed. The macOS crashlog will indicate “Exception Type:        EXC_BAD_INSTRUCTION (SIGILL)” with the crashed thread crashing in mac.xpl at silk_VAD_Init + 4

Unfortunately, the opus team accidentally force-enabled AVX optimisations in their build tooling for opus, and so if the library is built on any AVX-capable mac, the result uses AVX, irrespective as to any options we set to inhibit that support.

I’ve patched the XSquawkBox libopus to disable this and as long as this doesn’t break the Linux build (the same options get used there), this update will be published as hotfix 2.

If you are using an old Mac – please hold off further bug reports until beta 4 hotfix 2 is published.