I see that the CMakeLists.txt file for libsoundio has two separate options for building dynamic vs. static libraries.

I take it this was inspired by Libtool, which in its usual way of working compiles both static and shared libraries in one pass.

However, in CMake, it is conventional to build either one or the other, controlled by the special variable BUILD_SHARED_LIBS. I've put together a patch that simplifies the listfile accordingly.

(I don't currently have a proper setup to prepare a Git pull request, and I see that GitHub still doesn't allow issue attachments, so I've uploaded my patch here.)

The immediate issue that spurred this was breakage when I disabled the dynamic lib and attempted to build the examples. The examples are hard-coded to use the shared form of the library. It would be possible to code the listfile so the examples/tests link with one or the other as appropriate, but because this approach is foreign to CMake anyway, I believe reducing the complexity is preferable.

Oh, and as an extra, I added a bit to set CMAKE_INSTALL_RPATH. This allows the executables linked to a shared libsoundio to work in the install tree (without needing to set LD_LIBRARY_PATH) as well as the build tree.

I built libsoundio on a Macbook Pro (OS X 10.9.5). The output of sio_list_devices is

$ ./sio_list_devices
--------Input Devices--------

Built-in Microphone (default)
  id: AppleHDAEngineInput:1B,0,1,0:1
  channel layouts:
    Stereo
  current layout: Stereo
  sample rates:
    44100 - 44100
  current sample rate: 44100
  formats: float 32-bit LE
  min software latency: 0.00031746 sec
  max software latency: 0.20897959 sec
  current software latency: 0.01160998 sec


--------Output Devices--------

Built-in Output (default)
  id: AppleHDAEngineOutput:1B,0,1,1:0
  channel layouts:
    Stereo
  current layout: Stereo
  sample rates:
    44100 - 44100
    48000 - 48000
    88200 - 88200
    96000 - 96000
  current sample rate: 44100
  formats: float 32-bit LE
  min software latency: 0.00031746 sec
  max software latency: 0.41795918 sec
  current software latency: 0.01160998 sec


2 devices found

When I run sio_sine, the program runs, but there is no sound generated. Here's the output shown when I try the various keyboard commands:

$ ./sio_sine 
Backend: CoreAudio
Output device: Built-in Output
'p\n' - pause
'u\n' - unpause
'c\n' - clear buffer
'q\n' - quit
p
pausing result: (no error)
u
unpausing result: (no error)
c
clear buffer result: incompatible backend
q

I assume I have to configure something, but I don't know what it is.

I've started this via: https://github.com/andrewrk/libsoundio/compare/master...tresf:master

cd libsoundio
mkdir build out; cd build
export MINGW_ARCH=32 # defaults to 64
cmake .. -DCMAKE_TOOLCHAIN_FILE=../cmake/MingwToolchain.cmake \
-DCMAKE_INSTALL_PREFIX=../out
make install

I'm not a C/C++ programmer, so I'm having difficulties with the compilation issues. I'm sure these are all very basic. Help appreciated...

Scanning dependencies of target libsoundio_shared
[  3%] Building C object CMakeFiles/libsoundio_shared.dir/src/soundio.c.obj
[  6%] Building C object CMakeFiles/libsoundio_shared.dir/src/util.c.obj
[  9%] Building C object CMakeFiles/libsoundio_shared.dir/src/os.c.obj
[ 12%] Building C object CMakeFiles/libsoundio_shared.dir/src/dummy.c.obj
[ 15%] Building C object CMakeFiles/libsoundio_shared.dir/src/channel_layout.c.obj
[ 18%] Building C object CMakeFiles/libsoundio_shared.dir/src/ring_buffer.c.obj
Linking C shared library libsoundio.dll
CMakeFiles/libsoundio_shared.dir/objects.a(soundio.c.obj):soundio.c:(.data+0x14): undefined reference to `soundio_wasapi_init'
collect2: error: ld returned 1 exit status
make[2]: *** [libsoundio.dll] Error 1
make[1]: *** [CMakeFiles/libsoundio_shared.dir/all] Error 2
make: *** [all] Error 2

In the interests of greater compatibility, accommodation of long upgrade cycles, and wider adoption of libsoundio in general, I would like the library to be compatible with a C99 build environment.

This means addressing src/atomics.h.

I reviewed issue #48, and I believe the proposal there was not the right approach. It brought in a whole implementation of stdatomic.h adapted from FreeBSD, and not only would have imposed a new maintenance burden on libsoundio, it required either Clang, GCC 4.7+, or some non-standard compiler builtins. And at any rate, it was overkill for what was needed: a C99-friendly implementation of the SOUNDIO_ATOMIC_* macros, no more and no less.

Here I submit a patch with a first-draft cut of these macros built on POSIX-thread mutexes. This kinda-sorta works on Linux as-is, but there are three issues I'd like to address that will require changes elsewhere:

1. This should use SoundIoOsMutex instead of pthread_mutex_t, so that it can work outside of POSIX. But that brings us to...

2. These atomic types need initialization. Straight pthread_mutex_t allows static initialization, and at least on Linux, PTHREAD_MUTEX_INITIALIZER is all zeroes, so starting with zeroed-out memory is enough. But that's not always going to be the case, and of course a SoundIoOsMutex needs to come from soundio_os_mutex_create().

   The initialization, and destruction, can be wrapped up in new macros consistent with the existing ones. Something like

      SOUNDIO_ATOMIC_INIT(rb->write_offset, 0);
      /* ... */
      SOUNDIO_ATOMIC_DESTROY(rb->write_offset);
   

3. This implementation makes use of GCC-specific statement expressions, as well as typeof(). I found this to be a necessary evil to reproduce the type-agnostic nature of the macros (i.e. the same macro works with a long, int, bool or flag).

   I'd like to suggest redrawing these macros to include the type (so e.g. SOUNDIO_ATOMIC_LOAD() becomes SOUNDIO_ATOMIC_INT_LOAD(), SOUNDIO_ATOMIC_BOOL_LOAD() and so on). This would allow implementing the macros using [static inline] functions, with which compiler compatibility will no longer be an issue.

   (A possible alternative approach is to do an OO-in-C thing, placing function pointers with appropriate argument/return types inside the atomic-type structs, and then the macros expand to a call to the appropriate function pointer. That should allow the macros to remain type-agnostic. But I'd prefer the simpler approach enabled by going with type-specific macros.)

In addition to all that, I put in some better feature-test logic, since this kind of thing really needs it. (The C++ case would need an external check for the <atomic> header, so it is left commented out for now.) Better to give a clear #error instead of a confusing syntax error.

A.K.A. make libsoundio work on all major OSes (does the CoreAudio backend work on iOS?) A.K.A. better than SDL A.K.A. 500 lines and some hard work gets you surprisingly far A.K.A. The Cubs are still going to win the World Series, I just know it

Couple points:

• Android has a special audio state it calls the "fast track," which skips software mixing and ties to reduce latency as much as possible. The keys to this are matching the device's natural sample rate and buffer size.

  Unfortunately, there's no officially supported way to get this information outside of a JVM running inside an Android Activity. There are varying degrees of hacks around this, but they could be disappeared anytime or, worse, crash the entire process (ex. calling JNI_GetCreatedJavaVMs on Android without a pre-existing JVM raises an assertion error, so you can't easily opportunistically attach to a JVM. Even if you did get around it, there's still no officially supported way to get an Activity handle from the global context.)

  In an ideal world, the backend would default to the fastest sample rate and a proper multiple of buffer size. Failing that, sample rate can be set manually and buffer size can be requested proportional to latency and sample rate.

• I only implemented support for output devices. If that's a deal-breaker, I can go read-up on how input devices work on Android. They have some quirks that make them different from output devices and might possibly need JVM access (with the problems inherent in that, as described above).

• This backend does not support calling soundio_outstream_begin_write/soundio_outstream_end_write multiple times in a single write callback. This part of the libsoundio API has always seemed weird to me, and it doesn't map well onto OpenSL ES. If you do call the functions more than once, you'll get an error because the backend buffers are full.

• No underflow callbacks. I couldn't figure this one out. There's an interface called SLPrefetchStatusItf that looks like it could be handy here, but in local testing it only raised events when a write callback was not in the process of being called, which made it pretty much useless (since by the time the callback ends, the underflow state has been "fixed"). It also seems to randomly cause assertion errors when used with Android's buffer queue implementation, and nobody on the Internet knows why.

  I thought about implementing an additional thread to intercept write callbacks from OpenSL ES, but then you'd lose out on the special thread priority that audio callbacks get and it complicates the code.

• Requires API level 21 / Android 5.0 Lollipop or greater. The main feature this brings is floating-point support. The rest of the codebase doesn't work with API levels lower than that anyways.

• Android doesn't have a /tmp folder, but it does follow the POSIX convention of pointing the TMPDIR environment variable to an appropriate location. I just added this location to os.c for the sake of simplicity, though ideally it would read the right environment variables.

• Testing this out is a little hairy depending on your system, but something like this plopped in at the top of CMakeLists.txt (before project(...)) did the trick for me:

set(BUILD_DYNAMIC_LIBS OFF CACHE BOOL "" FORCE) set(CMAKE_SYSROOT /usr/local/Cellar/android-ndk/r13/platforms/android-24/arch-arm) set(CMAKE_C_COMPILER /usr/local/Cellar/android-ndk/r13/toolchains/arm-linux-androideabi-4.9/prebuilt/darwin-x86_64/bin/arm-linux-androideabi-gcc) set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fPIC") set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -pie")

   Follow that up with a

   ```bash
adb push sio_sine /data/local/tmp && adb shell /data/local/tmp/sio_sine

and you'll hear the sweet dulcet tones of a sine wave coming from your device's speakers.

• Overall, the libsoundio API was a pleasure to work with! It's verbose in many places, but I never ran into any problems mapping OpenSL ES onto the abstraction model or figuring out where things belonged.

• I took a look at the v2 branch, I think the only change that affect this is the int to enum SoundIoError change in function prototypes.

EDIT: Added support for input devices.

• Supposedly, not all devices support all sample rates. However, on my LG G4 all sample rates seem to be supported. I'm not sure what will happen if you try to open a device with an unsupported sample rate. Anecdotal evidence on the internet says sometimes it immediately fails and sometimes it just returns corrupted audio.

• Is it useful to know if a device is currently unavailable due to permissions problems? I'm leaning towards yes, though it's not straightforward to figure out from the backend. On my device, the error code for lacking permissions was SL_RESULT_CONTENT_UNSUPPORTED, but according to the spec it should probably be SL_RESULT_PERMISSION_DENIED.

• Android lets you make requests for different recording profiles: GENERIC, CAMCORDER, VOICE_COMMUNICATION, and VOICE_RECOGNITION. The camcorder request could be exposed as a separate device (and probably should, though it's not guaranteed to actually be different), but what about the VOICE_* options? They might be too high-level for this project, and more appropriate for an effects layer.

• Recording floating-point data is supported starting in API level 23 / Android 6.0 Marshmallow. I put a check into the backend init function to try opening a device in that format, which seems to work (tested on an emulator running API level 21).

• Recording is much more difficult to test, because command-line processes don't have permissions to access input devices. To try this out I ended up creating a NativeActivity with copy-pasted code from sio_record. This worked on my real device, but not on the emulator because I couldn't figure out where I had permission to write files. Should there be a small sample app for testing (probably similar to sio_microphone), or is that too complicated?

If libsoundio is to become a widely used library, it would be great if symbol versioning was provided. Symbol versioning is a more fine grained version of allowing multiple (ABI-incompatible) libraries to coexist in the same system.

Under the current scheme, you have libsoundio.so.1. If an ABI-breaking change needed to be made, then libsoundio.so.2 would be able to exist side by side with libsoundio.so.1. However, there is still potential for trouble:

1. App foo is compiled against version 2.
2. foo loads a plugin bar, which is linked to version 1.
3. Errors occur as the linker somehow determines it needs to use only one version of the library for any given symbol that exists in both libraries, but it can only choose one.

Using a version script tags each function with a trailing string (arbitrary). If a version 2 is released that changes that string, then the runtime linker can use that trailing string to disambiguate between the versions, and so both libraries can coexist in the same process. The version can be inspected via objdump -T $library. You can check eg libpulse has all functions tagged with PULSE_0

Symbol versioning can also be used to avoid bumping the version even while making ABI-breaking changes. This is a more advanced usage that is overkill in many cases, but is eg used by glibc (check out objdump -T /lib/x86_64-linux-gnu/libc.so.6|grep strtod on a debian system).

The basic usage is fairly simple. All that is needed is that a list of all the exported symbols be listed in a file that then is passed to the linker via the -Wl,--version-script=$file flag:

LIBSOUNDIO_1 {
global:
    soundio_backend_count;
    soundio_backend_name;
    soundio_best_matching_channel_layout;
    soundio_channel_layout_builtin_count;
    soundio_channel_layout_detect_builtin;
    soundio_channel_layout_equal;
    soundio_channel_layout_find_channel;
    soundio_channel_layout_get_builtin;
    soundio_channel_layout_get_default;
    soundio_connect;
    soundio_connect_backend;
    soundio_create;
    soundio_default_input_device_index;
    soundio_default_output_device_index;
    soundio_destroy;
    soundio_device_equal;
    soundio_device_nearest_sample_rate;
    soundio_device_ref;
    soundio_device_sort_channel_layouts;
    soundio_device_supports_format;
    soundio_device_supports_layout;
    soundio_device_supports_sample_rate;
    soundio_device_unref;
    soundio_disconnect;
    soundio_flush_events;
    soundio_force_device_scan;
    soundio_format_string;
    soundio_get_backend;
    soundio_get_bytes_per_sample;
    soundio_get_channel_name;
    soundio_get_input_device;
    soundio_get_output_device;
    soundio_have_backend;
    soundio_input_device_count;
    soundio_instream_begin_read;
    soundio_instream_create;
    soundio_instream_destroy;
    soundio_instream_end_read;
    soundio_instream_get_latency;
    soundio_instream_open;
    soundio_instream_pause;
    soundio_instream_start;
    soundio_output_device_count;
    soundio_outstream_begin_write;
    soundio_outstream_clear_buffer;
    soundio_outstream_create;
    soundio_outstream_destroy;
    soundio_outstream_end_write;
    soundio_outstream_get_latency;
    soundio_outstream_open;
    soundio_outstream_pause;
    soundio_outstream_start;
    soundio_parse_channel_id;
    soundio_ring_buffer_advance_read_ptr;
    soundio_ring_buffer_advance_write_ptr;
    soundio_ring_buffer_capacity;
    soundio_ring_buffer_clear;
    soundio_ring_buffer_create;
    soundio_ring_buffer_destroy;
    soundio_ring_buffer_fill_count;
    soundio_ring_buffer_free_count;
    soundio_ring_buffer_read_ptr;
    soundio_ring_buffer_write_ptr;
    soundio_sort_channel_layouts;
    soundio_strerror;
    soundio_wait_events;
    soundio_wakeup;
local: *;
};

Then, if a change is made that requires bumping SONAME, all you need to do is change the version script to LIBSOUNDIO_2.

More information in the ld manual

Hi,

Older ALSA (Ubuntu 10) does not have support for channel mapping. Could we have an #ifdef for that? A runtime check would be even better if at all possible.

Thanks.

it seems always return a error here:

(System is MacOS, Mac OS X 10.12.5)

coreaudio.c

// Possible errors:
//  * SoundIoErrorNoMem
//  * SoundIoErrorEncodingString
static int from_cf_string(CFStringRef string_ref, char **out_str, int *out_str_len) {
    assert(string_ref);
    CFIndex length = CFStringGetLength(string_ref);
    CFIndex max_size = CFStringGetMaximumSizeForEncoding(length, kCFStringEncodingUTF8);
    char *buf = ALLOCATE_NONZERO(char, max_size);
    if (!buf)
        return SoundIoErrorNoMem;
//    comment it then the demo of list devices works well other wise always return SoundIoErrorEncodingString error
//    if (!CFStringGetCString(string_ref, buf, max_size, kCFStringEncodingUTF8)) {
//        free(buf);
//        return SoundIoErrorEncodingString;
//    }
 
    *out_str = buf; 
    *out_str_len = strlen(buf);
    return 0;
}

libsoundio-older-gcc.patch.txt

This patch against the Git v2 branch contains the following:

• New implementation of SOUNDIO_ATOMIC_* based on GCC's __sync_*() builtins
• Better feature-macro test logic in atomics.h to select the appropriate implementation of SOUNDIO_ATOMIC_*
• CMake logic to determine support for -std=c11, as well as some warning flags that older GCC versions don't know about

This is not really an issue, but as there is no mention of it in the docs ...

When building against the three available linux backends (alsa, pulseaudio and jack), the binaries have de facto a dependency to these libraries.

I'm about to try to build them statically to avoid package dependencies and/or different builds for every linux distribution flavor. But would you recommend it ?

I could also try to dlopen those, which would have the benefit of using the packaged version, but at the risk of a mismatch of ABIs.

Also, what are you planning to do for your other project Genesis ?

Here, I will describe a build problem that happens when I try to compile libsoundio under a debian stable environment.

= Background

Here's my system: memlab$ uname -a Linux memlab 3.16.0-4-amd64 #1 SMP Debian 3.16.7-ckt20-1+deb8u3 (2016-01-17) x86_64 GNU/Linux memlab$ apt-cache show clang | grep Version Version: 1:3.5-25 memlab$

I downloaded libsoundio-1.1.0.tar.gz and unpacked it.

= Cmake steps

$ cd libsoundio-1.1.0; mkdir build; cd build; cmake .. -- The C compiler identification is Clang 3.5.0 -- Check for working C compiler: /usr/bin/cc -- Check for working C compiler: /usr/bin/cc -- works -- Detecting C compiler ABI info -- Detecting C compiler ABI info - done Configuring libsoundio version 1.1.0 -- Looking for include file pthread.h -- Looking for include file pthread.h - found -- Looking for pthread_create -- Looking for pthread_create - not found -- Looking for pthread_create in pthreads -- Looking for pthread_create in pthreads - not found -- Looking for pthread_create in pthread -- Looking for pthread_create in pthread - found -- Found Threads: TRUE
-- Found JACK: /usr/lib/x86_64-linux-gnu/libjack.so
-- Found PULSEAUDIO: /usr/lib/x86_64-linux-gnu/libpulse.so
-- Found ALSA: /usr/lib/x86_64-linux-gnu/libasound.so (found version "1.0.28") -- Could NOT find COREAUDIO (missing: COREAUDIO_LIBRARY COREAUDIO_INCLUDE_DIR) -- Could NOT find WASAPI (missing: WASAPI_INCLUDE_DIR)

Installation Summary

• Install Directory : /usr/local
• Build Type : Debug
• Build static libs : ON
• Build examples : ON
• Build tests : ON

System Dependencies

• threads : OK
• JACK (optional) : OK
• PulseAudio (optional) : OK
• ALSA (optional) : OK
• CoreAudio (optional) : not found
• WASAPI (optional) : not found

-- Configuring done -- Generating done -- Build files have been written to: /home/cturner/saga/20160304.memlab.cturner.ad.libsoundio/000.poc/libsoundio-1.1.0/build $

= Make

memlab$ make Scanning dependencies of target libsoundio_shared [ 2%] Building C object CMakeFiles/libsoundio_shared.dir/src/soundio.c.o /home/cturner/saga/20160304.memlab.cturner.ad.libsoundio/000.poc/libsoundio-1.1.0/src/soundio.c:180:47: error: illegal initializer type 'atomic_flag' (aka '_Atomic(struct (anonymous struct at /usr/bin/../lib/gcc/x86_64-linux-gnu/4.9/include/stdatomic.h:232:17))') static struct SoundIoAtomicFlag rtprio_seen = SOUNDIO_ATOMIC_FLAG_INIT; ^ /home/cturner/saga/20160304.memlab.cturner.ad.libsoundio/000.poc/libsoundio-1.1.0/src/atomics.h:68:35: note: expanded from macro 'SOUNDIO_ATOMIC_FLAG_INIT'

define SOUNDIO_ATOMIC_FLAG_INIT {ATOMIC_FLAG_INIT}

                              ^

/usr/bin/../lib/gcc/x86_64-linux-gnu/4.9/include/stdatomic.h:241:26: note: expanded from macro 'ATOMIC_FLAG_INIT'

define ATOMIC_FLAG_INIT { 0 }

                            ^

1 error generated. CMakeFiles/libsoundio_shared.dir/build.make:54: recipe for target 'CMakeFiles/libsoundio_shared.dir/src/soundio.c.o' failed make[2]: *** [CMakeFiles/libsoundio_shared.dir/src/soundio.c.o] Error 1 CMakeFiles/Makefile2:192: recipe for target 'CMakeFiles/libsoundio_shared.dir/all' failed make[1]: *** [CMakeFiles/libsoundio_shared.dir/all] Error 2 Makefile:117: recipe for target 'all' failed make: *** [all] Error 2 memlab$

= Notes

I'd be happy to be a part of the solution for this, but I'm not particularly skilled with compiler tool-chains and would benefit from guidance.

Shortly after building this, I also tried to build zig language. Zig failed because debian stable is running an older version of LLVM than is required by zig.

This makes me think - an approach to fixing this might be for me to create a compiler toolchain in isolation. For example, a barebones linux under qemu, and then install tools from source towards being able to build this. I could put some towards this, but - again - would appreciate guidance on what to focus on.

As mentioned in #256, builds on macOS 12 are failing due to the usage of deprecated kAudioObjectPropertyElementMaster (now kAudioObjectPropertyElementMain).

The issue was addressed in #259 which was unfortunately backwards incompatible with previous macOS versions. I've included a backwards compatible fix here.

NOTE_TRIGGER is available only on 10.6+, and 10.5.x and early versions of 10.6 does not have it yet. Use EV_TRIGGER when available, but no NOTE_TRIGGER. Fix is borrowed from Apple libdispatch.

Basic implementation of Sdk.zig.

Can build static and dynamic libraries.

• [x] Linux (tested with pulse, alsa)
• [ ] Windows (fails to cross-compile link ole32)
• [ ] macOs (don't have a test device)

libsoundio is available as a port in vcpkg, a C++ library manager that simplifies installation for libsoundio and other project dependencies. Documenting the install process here will help users get started by providing a single set of commands to build libsoundio, ready to be included in their projects.

We also test whether our library ports build in various configurations (dynamic, static) on various platforms (OSX, Linux, Windows: x86, x64) to keep a wide coverage for users.

I'm a maintainer for vcpkg, and here is what the port script looks like. We try to keep the library maintained as close as possible to the original library. :)

This is up to date arch linux with mingw-w64-binutils 2.38-3, mingw-w64-cmake 1-39, mingw-w64-configure 0.1.1-1,1mingw-w64-crt 10.0.0-1, mingw-w64-environment 1-4, mingw-w64-gcc 12.1.0-1, mingw-w64-headers 10.0.0-1

2.0.0 and b810bf2e9c4afc822c4843322cd08f7b36668109 compile without issues. Current 8ab36069123a8b38e247ace55f8a6b3e6ee14f5f fails due to error: redefinition of ‘IID_IMMDeviceEnumerator’ and others which could be fixed by defining __IMMDeviceEnumerator_INTERFACE_DEFINED__, __ISimpleAudioVolume_INTERFACE_DEFINED__, __MMDeviceAPILib_LIBRARY_DEFINED__ etc:

$ x86_64-w64-mingw32-cmake -D BUILD_TESTS=OFF -D BUILD_STATIC_LIBS=ON -D ENABLE_JACK=OFF .. && make
CMake Deprecation Warning at CMakeLists.txt:1 (cmake_minimum_required):
  Compatibility with CMake < 2.8.12 will be removed from a future version of
  CMake.

  Update the VERSION argument <min> value or use a ...<max> suffix to tell
  CMake that the project does not need compatibility with older versions.


-- The C compiler identification is GNU 12.1.0
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working C compiler: /usr/bin/x86_64-w64-mingw32-gcc - skipped
-- Detecting C compile features
-- Detecting C compile features - done
Configuring libsoundio version 2.0.0
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD - Success
-- Found Threads: TRUE
CMake Warning (dev) at /usr/share/cmake/Modules/FindPackageHandleStandardArgs.cmake:438 (message):
  The package name passed to `find_package_handle_standard_args` (PULSEAUDIO)
  does not match the name of the calling package (PulseAudio).  This can lead
  to problems in calling code that expects `find_package` result variables
  (e.g., `_FOUND`) to follow a certain pattern.
Call Stack (most recent call first):
  cmake/FindPulseAudio.cmake:14 (find_package_handle_standard_args)
  CMakeLists.txt:65 (find_package)
This warning is for project developers.  Use -Wno-dev to suppress it.

-- Could NOT find PULSEAUDIO (missing: PULSEAUDIO_LIBRARY PULSEAUDIO_INCLUDE_DIR)
-- Could NOT find ALSA (missing: ALSA_LIBRARY ALSA_INCLUDE_DIR)
CMake Warning (dev) at /usr/share/cmake/Modules/FindPackageHandleStandardArgs.cmake:438 (message):
  The package name passed to `find_package_handle_standard_args` (COREAUDIO)
  does not match the name of the calling package (CoreAudio).  This can lead
  to problems in calling code that expects `find_package` result variables
  (e.g., `_FOUND`) to follow a certain pattern.
Call Stack (most recent call first):
  cmake/FindCoreAudio.cmake:14 (find_package_handle_standard_args)
  CMakeLists.txt:99 (find_package)
This warning is for project developers.  Use -Wno-dev to suppress it.

-- Could NOT find COREAUDIO (missing: COREAUDIO_LIBRARY COREAUDIO_INCLUDE_DIR)
-- Looking for audioclient.h
-- Looking for audioclient.h - found
-- Found WASAPI: 1

Installation Summary
--------------------
* Install Directory            : /usr/x86_64-w64-mingw32
* Build Type                   : Debug
* Build static libs            : ON
* Build examples               : ON
* Build tests                  : OFF

System Dependencies
-------------------
* threads                      : OK
* JACK       (optional)        : disabled
* PulseAudio (optional)        : not found
* ALSA       (optional)        : not found
* CoreAudio  (optional)        : not found
* WASAPI     (optional)        : OK

-- Configuring done
-- Generating done
CMake Warning:
  Manually-specified variables were not used by the project:

    CMAKE_CXX_IMPLICIT_INCLUDE_DIRECTORIES


-- Build files have been written to: /tmp/lsio0/libsoundio/build
[  4%] Building C object CMakeFiles/libsoundio_shared.dir/src/soundio.c.obj
[  8%] Building C object CMakeFiles/libsoundio_shared.dir/src/util.c.obj
[ 12%] Building C object CMakeFiles/libsoundio_shared.dir/src/os.c.obj
[ 16%] Building C object CMakeFiles/libsoundio_shared.dir/src/dummy.c.obj
[ 20%] Building C object CMakeFiles/libsoundio_shared.dir/src/channel_layout.c.obj
[ 25%] Building C object CMakeFiles/libsoundio_shared.dir/src/ring_buffer.c.obj
[ 29%] Building C object CMakeFiles/libsoundio_shared.dir/src/wasapi.c.obj
/tmp/lsio0/libsoundio/src/wasapi.c:34:20: error: redefinition of ‘CLSID_MMDeviceEnumerator’
   34 | static const CLSID CLSID_MMDeviceEnumerator = {
      |                    ^~~~~~~~~~~~~~~~~~~~~~~~
In file included from /usr/x86_64-w64-mingw32/include/combaseapi.h:156,
                 from /usr/x86_64-w64-mingw32/include/objbase.h:14,
                 from /usr/x86_64-w64-mingw32/include/ole2.h:17,
                 from /usr/x86_64-w64-mingw32/include/audioclient.h:13,
                 from /tmp/lsio0/libsoundio/src/wasapi.c:17:
/usr/x86_64-w64-mingw32/include/mmdeviceapi.h:965:1: note: previous definition of ‘CLSID_MMDeviceEnumerator’ with type ‘GUID’
  965 | DEFINE_GUID(CLSID_MMDeviceEnumerator, 0xbcde0395, 0xe52f, 0x467c, 0x8e,0x3d, 0xc4,0x57,0x92,0x91,0x69,0x2e);
      | ^~~~~~~~~~~
/tmp/lsio0/libsoundio/src/wasapi.c:37:20: error: redefinition of ‘IID_IMMDeviceEnumerator’
   37 | static const IID   IID_IMMDeviceEnumerator   = {
      |                    ^~~~~~~~~~~~~~~~~~~~~~~
/usr/x86_64-w64-mingw32/include/mmdeviceapi.h:582:1: note: previous definition of ‘IID_IMMDeviceEnumerator’ with type ‘GUID’
  582 | DEFINE_GUID(IID_IMMDeviceEnumerator, 0xa95664d2, 0x9614, 0x4f35, 0xa7,0x46, 0xde,0x8d,0xb6,0x36,0x17,0xe6);
      | ^~~~~~~~~~~
/tmp/lsio0/libsoundio/src/wasapi.c:41:20: error: redefinition of ‘IID_IMMNotificationClient’
   41 | static const IID   IID_IMMNotificationClient = {
      |                    ^~~~~~~~~~~~~~~~~~~~~~~~~
/usr/x86_64-w64-mingw32/include/mmdeviceapi.h:168:1: note: previous definition of ‘IID_IMMNotificationClient’ with type ‘GUID’
  168 | DEFINE_GUID(IID_IMMNotificationClient, 0x7991eec9, 0x7e89, 0x4d85, 0x83,0x90, 0x6c,0x70,0x3c,0xec,0x60,0xc0);
      | ^~~~~~~~~~~
/tmp/lsio0/libsoundio/src/wasapi.c:45:20: error: redefinition of ‘IID_IAudioClient’
   45 | static const IID   IID_IAudioClient = {
      |                    ^~~~~~~~~~~~~~~~
/usr/x86_64-w64-mingw32/include/audioclient.h:201:1: note: previous definition of ‘IID_IAudioClient’ with type ‘GUID’
  201 | DEFINE_GUID(IID_IAudioClient, 0x1cb9ad4c, 0xdbfa, 0x4c32, 0xb1,0x78, 0xc2,0xf5,0x68,0xa7,0x03,0xb2);
      | ^~~~~~~~~~~
/tmp/lsio0/libsoundio/src/wasapi.c:49:20: error: redefinition of ‘IID_IAudioRenderClient’
   49 | static const IID   IID_IAudioRenderClient    = {
      |                    ^~~~~~~~~~~~~~~~~~~~~~
/usr/x86_64-w64-mingw32/include/audioclient.h:879:1: note: previous definition of ‘IID_IAudioRenderClient’ with type ‘GUID’
  879 | DEFINE_GUID(IID_IAudioRenderClient, 0xf294acfc, 0x3146, 0x4483, 0xa7,0xbf, 0xad,0xdc,0xa7,0xc2,0x60,0xe2);
      | ^~~~~~~~~~~
/tmp/lsio0/libsoundio/src/wasapi.c:53:20: error: redefinition of ‘IID_IAudioSessionControl’
   53 | static const IID   IID_IAudioSessionControl  = {
      |                    ^~~~~~~~~~~~~~~~~~~~~~~~
/usr/x86_64-w64-mingw32/include/audiopolicy.h:276:1: note: previous definition of ‘IID_IAudioSessionControl’ with type ‘GUID’
  276 | DEFINE_GUID(IID_IAudioSessionControl, 0xf4b1a599, 0x7266, 0x4319, 0xa8,0xca, 0xe7,0x0a,0xcb,0x11,0xe8,0xcd);
      | ^~~~~~~~~~~
/tmp/lsio0/libsoundio/src/wasapi.c:57:20: error: redefinition of ‘IID_IAudioSessionEvents’
   57 | static const IID   IID_IAudioSessionEvents   = {
      |                    ^~~~~~~~~~~~~~~~~~~~~~~
/usr/x86_64-w64-mingw32/include/audiopolicy.h:116:1: note: previous definition of ‘IID_IAudioSessionEvents’ with type ‘GUID’
  116 | DEFINE_GUID(IID_IAudioSessionEvents, 0x24918acc, 0x64b3, 0x37c1, 0x8c,0xa9, 0x74,0xa6,0x6e,0x99,0x57,0xa8);
      | ^~~~~~~~~~~
/tmp/lsio0/libsoundio/src/wasapi.c:61:18: error: redefinition of ‘IID_IMMEndpoint’
   61 | static const IID IID_IMMEndpoint = {
      |                  ^~~~~~~~~~~~~~~
/usr/x86_64-w64-mingw32/include/mmdeviceapi.h:505:1: note: previous definition of ‘IID_IMMEndpoint’ with type ‘GUID’
  505 | DEFINE_GUID(IID_IMMEndpoint, 0x1be09788, 0x6894, 0x4089, 0x85,0x86, 0x9a,0x2a,0x6c,0x26,0x5a,0xc5);
      | ^~~~~~~~~~~
/tmp/lsio0/libsoundio/src/wasapi.c:65:18: error: redefinition of ‘IID_IAudioClockAdjustment’
   65 | static const IID IID_IAudioClockAdjustment = {
      |                  ^~~~~~~~~~~~~~~~~~~~~~~~~
/usr/x86_64-w64-mingw32/include/audioclient.h:1266:1: note: previous definition of ‘IID_IAudioClockAdjustment’ with type ‘GUID’
 1266 | DEFINE_GUID(IID_IAudioClockAdjustment, 0xf6e4c0a0, 0x46d9, 0x4fb8, 0xbe,0x21, 0x57,0xa3,0xef,0x2b,0x62,0x6c);
      | ^~~~~~~~~~~
/tmp/lsio0/libsoundio/src/wasapi.c:69:18: error: redefinition of ‘IID_IAudioCaptureClient’
   69 | static const IID IID_IAudioCaptureClient = {
      |                  ^~~~~~~~~~~~~~~~~~~~~~~
/usr/x86_64-w64-mingw32/include/audioclient.h:972:1: note: previous definition of ‘IID_IAudioCaptureClient’ with type ‘GUID’
  972 | DEFINE_GUID(IID_IAudioCaptureClient, 0xc8adbd64, 0xe71e, 0x48a0, 0xa4,0xde, 0x18,0x5c,0x39,0x5c,0xd3,0x17);
      | ^~~~~~~~~~~
/tmp/lsio0/libsoundio/src/wasapi.c:73:18: error: redefinition of ‘IID_ISimpleAudioVolume’
   73 | static const IID IID_ISimpleAudioVolume = {
      |                  ^~~~~~~~~~~~~~~~~~~~~~
/usr/x86_64-w64-mingw32/include/audioclient.h:1346:1: note: previous definition of ‘IID_ISimpleAudioVolume’ with type ‘GUID’
 1346 | DEFINE_GUID(IID_ISimpleAudioVolume, 0x87ce5498, 0x68d6, 0x44e5, 0x92,0x15, 0x6d,0xa4,0x7e,0xf8,0x83,0xd8);
      | ^~~~~~~~~~~
/tmp/lsio0/libsoundio/src/wasapi.c: In function ‘deinit_refresh_devices’:
/tmp/lsio0/libsoundio/src/wasapi.c:489:5: error: this ‘if’ clause does not guard... [-Werror=misleading-indentation]
  489 |     if (rd->mm_device)
      |     ^~
/tmp/lsio0/libsoundio/src/wasapi.c:491:9: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the ‘if’
  491 |         if (rd->default_render_device)
      |         ^~
/tmp/lsio0/libsoundio/src/wasapi.c: At top level:
/tmp/lsio0/libsoundio/src/wasapi.c:65:18: error: ‘IID_IAudioClockAdjustment’ defined but not used [-Werror=unused-const-variable=]
   65 | static const IID IID_IAudioClockAdjustment = {
      |                  ^~~~~~~~~~~~~~~~~~~~~~~~~
/tmp/lsio0/libsoundio/src/wasapi.c:57:20: error: ‘IID_IAudioSessionEvents’ defined but not used [-Werror=unused-const-variable=]
   57 | static const IID   IID_IAudioSessionEvents   = {
      |                    ^~~~~~~~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors
make[2]: *** [CMakeFiles/libsoundio_shared.dir/build.make:167: CMakeFiles/libsoundio_shared.dir/src/wasapi.c.obj] Error 1
make[1]: *** [CMakeFiles/Makefile2:94: CMakeFiles/libsoundio_shared.dir/all] Error 2
make: *** [Makefile:136: all] Error 2

a46b0f21c397cd095319f8c9feccf0f1e50e31ba fails due to -Werror=misleading-indentation which should be fixed by indenting properly in src/wasapi.c:

</details>

If a layout is not in builtin_channel_layouts, the corresponding char* SoundIoDevice::name will be NULL which should either be documented here: https://github.com/andrewrk/libsoundio/blob/8ab36069123a8b38e247ace55f8a6b3e6ee14f5f/soundio/soundio.h#L307 or changed to a generic name like "unknown layout" here: https://github.com/andrewrk/libsoundio/blob/8ab36069123a8b38e247ace55f8a6b3e6ee14f5f/src/channel_layout.c#L435