ao_wasapi: Split into 2 files

ao_wasapi.c was almost entirely init code mixed with option code and
occasionally actual audio handling code. Split most things to
ao_wasapi_utils.c and keep the audio handling code in ao_wasapi.c.

5 files changed, 1031 insertions, 900 deletions

diff --git a/audio/out/ao_wasapi.c b/audio/out/ao_wasapi.c
index 8ad2ccbf58..79f8dcf665 100644
--- a/audio/out/ao_wasapi.c
+++ b/audio/out/ao_wasapi.c
@@ -29,6 +29,9 @@
 #include <mmdeviceapi.h>
 #include <avrt.h>
 
+#include "audio/out/ao_wasapi.h"
+#include "audio/out/ao_wasapi_utils.h"
+
 #include "options/m_option.h"
 #include "options/m_config.h"
 #include "audio/format.h"
@@ -39,902 +42,11 @@
 #include "compat/atomics.h"
 #include "osdep/timer.h"
 
-#ifndef PKEY_Device_FriendlyName
-DEFINE_PROPERTYKEY(PKEY_Device_FriendlyName,
-                   0xa45c254e, 0xdf1c, 0x4efd, 0x80, 0x20,
-                   0x67, 0xd1, 0x46, 0xa8, 0x50, 0xe0, 14);
-DEFINE_PROPERTYKEY(PKEY_Device_DeviceDesc,
-                   0xa45c254e, 0xdf1c, 0x4efd, 0x80, 0x20,
-                   0x67, 0xd1, 0x46, 0xa8, 0x50, 0xe0, 2);
-#endif
-
-#define RING_BUFFER_COUNT 8
-
-/* 20 millisecond buffer? */
-#define BUFFER_TIME 20000000.0
 #define EXIT_ON_ERROR(hres)  \
               do { if (FAILED(hres)) { goto exit_label; } } while(0)
 #define SAFE_RELEASE(unk, release) \
               do { if ((unk) != NULL) { release; (unk) = NULL; } } while(0)
 
-/* Supposed to use __uuidof, but it is C++ only, declare our own */
-static const GUID local_KSDATAFORMAT_SUBTYPE_PCM = {
-    0x1, 0x0000, 0x0010, {0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71}
-};
-static const GUID local_KSDATAFORMAT_SUBTYPE_IEEE_FLOAT = {
-    0x3, 0x0000, 0x0010, {0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71}
-};
-
-union WAVEFMT {
-    WAVEFORMATEX *ex;
-    WAVEFORMATEXTENSIBLE *extensible;
-};
-
-typedef struct wasapi_state {
-    struct mp_log *log;
-    HANDLE threadLoop;
-
-    /* Init phase */
-    int init_ret;
-    HANDLE init_done;
-    HANDLE fatal_error; /* signal to indicate unrecoverable error */
-    int share_mode;
-
-    /* Events */
-    HANDLE hPause;
-
-    /* Play */
-    HANDLE hPlay;
-    int is_playing;
-
-    /* Reset */
-    HANDLE hReset;
-
-    /* uninit */
-    HANDLE hUninit;
-    LONG immed;
-
-    /* volume control */
-    HANDLE hGetvol, hSetvol, hDoneVol;
-    DWORD vol_hw_support, status;
-    float audio_volume;
-
-    /* Buffers */
-    size_t buffer_block_size; /* Size of each block in bytes */
-    REFERENCE_TIME
-        minRequestedDuration; /* minimum wasapi buffer block size, in 100-nanosecond units */
-    REFERENCE_TIME
-        defaultRequestedDuration; /* default wasapi default block size, in 100-nanosecond units */
-    UINT32 bufferFrameCount; /* wasapi buffer block size, number of frames, frame size at format.nBlockAlign */
-
-    /* WASAPI handles, owned by other thread */
-    IMMDevice *pDevice;
-    IAudioClient *pAudioClient;
-    IAudioRenderClient *pRenderClient;
-    IAudioEndpointVolume *pEndpointVolume;
-    HANDLE hFeed; /* wasapi event */
-    HANDLE hTask; /* AV thread */
-    DWORD taskIndex; /* AV task ID */
-    WAVEFORMATEXTENSIBLE format;
-
-    /* WASAPI internal clock information, for estimating delay */
-    IAudioClock *pAudioClock;
-    UINT64 clock_frequency; /* scale for the "samples" returned by the clock */
-    UINT64 sample_count; /* the amount of samples per channel written to a GetBuffer buffer */
-    LARGE_INTEGER qpc_frequency; /* frequency of windows' high resolution timer */
-
-    int opt_exclusive;
-    int opt_list;
-    char *opt_device;
-
-    /* We still need to support XP, don't use these functions directly, blob owned by main thread */
-    struct {
-        HMODULE hAvrt;
-        HANDLE (WINAPI *pAvSetMmThreadCharacteristicsW)(LPCWSTR, LPDWORD);
-        WINBOOL (WINAPI *pAvRevertMmThreadCharacteristics)(HANDLE);
-    } VistaBlob;
-} wasapi_state;
-
-static int fill_VistaBlob(wasapi_state *state)
-{
-    if (!state)
-        return 1;
-    state->VistaBlob.hAvrt = LoadLibraryW(L"avrt.dll");
-    if (!state->VistaBlob.hAvrt)
-        goto exit_label;
-    state->VistaBlob.pAvSetMmThreadCharacteristicsW =
-        (HANDLE (WINAPI *)(LPCWSTR, LPDWORD))
-            GetProcAddress(state->VistaBlob.hAvrt, "AvSetMmThreadCharacteristicsW");
-    state->VistaBlob.pAvRevertMmThreadCharacteristics =
-        (WINBOOL (WINAPI *)(HANDLE))
-            GetProcAddress(state->VistaBlob.hAvrt, "AvRevertMmThreadCharacteristics");
-    return 0;
-exit_label:
-    if (state->VistaBlob.hAvrt)
-        FreeLibrary(state->VistaBlob.hAvrt);
-    return 1;
-}
-
-static const char *explain_err(const HRESULT hr)
-{
-    switch (hr) {
-    case S_OK:
-        return "S_OK";
-    case AUDCLNT_E_NOT_INITIALIZED:
-        return "AUDCLNT_E_NOT_INITIALIZED";
-    case AUDCLNT_E_ALREADY_INITIALIZED:
-        return "AUDCLNT_E_ALREADY_INITIALIZED";
-    case AUDCLNT_E_WRONG_ENDPOINT_TYPE:
-        return "AUDCLNT_E_WRONG_ENDPOINT_TYPE";
-    case AUDCLNT_E_DEVICE_INVALIDATED:
-        return "AUDCLNT_E_DEVICE_INVALIDATED";
-    case AUDCLNT_E_NOT_STOPPED:
-        return "AUDCLNT_E_NOT_STOPPED";
-    case AUDCLNT_E_BUFFER_TOO_LARGE:
-        return "AUDCLNT_E_BUFFER_TOO_LARGE";
-    case AUDCLNT_E_OUT_OF_ORDER:
-        return "AUDCLNT_E_OUT_OF_ORDER";
-    case AUDCLNT_E_UNSUPPORTED_FORMAT:
-        return "AUDCLNT_E_UNSUPPORTED_FORMAT";
-    case AUDCLNT_E_INVALID_SIZE:
-        return "AUDCLNT_E_INVALID_SIZE";
-    case AUDCLNT_E_DEVICE_IN_USE:
-        return "AUDCLNT_E_DEVICE_IN_USE";
-    case AUDCLNT_E_BUFFER_OPERATION_PENDING:
-        return "AUDCLNT_E_BUFFER_OPERATION_PENDING";
-    case AUDCLNT_E_THREAD_NOT_REGISTERED:
-        return "AUDCLNT_E_THREAD_NOT_REGISTERED";
-    case AUDCLNT_E_EXCLUSIVE_MODE_NOT_ALLOWED:
-        return "AUDCLNT_E_EXCLUSIVE_MODE_NOT_ALLOWED";
-    case AUDCLNT_E_ENDPOINT_CREATE_FAILED:
-        return "AUDCLNT_E_ENDPOINT_CREATE_FAILED";
-    case AUDCLNT_E_SERVICE_NOT_RUNNING:
-        return "AUDCLNT_E_SERVICE_NOT_RUNNING";
-    case AUDCLNT_E_EVENTHANDLE_NOT_EXPECTED:
-        return "AUDCLNT_E_EVENTHANDLE_NOT_EXPECTED";
-    case AUDCLNT_E_EXCLUSIVE_MODE_ONLY:
-        return "AUDCLNT_E_EXCLUSIVE_MODE_ONLY";
-    case AUDCLNT_E_BUFDURATION_PERIOD_NOT_EQUAL:
-        return "AUDCLNT_E_BUFDURATION_PERIOD_NOT_EQUAL";
-    case AUDCLNT_E_EVENTHANDLE_NOT_SET:
-        return "AUDCLNT_E_EVENTHANDLE_NOT_SET";
-    case AUDCLNT_E_INCORRECT_BUFFER_SIZE:
-        return "AUDCLNT_E_INCORRECT_BUFFER_SIZE";
-    case AUDCLNT_E_BUFFER_SIZE_ERROR:
-        return "AUDCLNT_E_BUFFER_SIZE_ERROR";
-    case AUDCLNT_E_CPUUSAGE_EXCEEDED:
-        return "AUDCLNT_E_CPUUSAGE_EXCEEDED";
-    case AUDCLNT_E_BUFFER_ERROR:
-        return "AUDCLNT_E_BUFFER_ERROR";
-    case AUDCLNT_E_BUFFER_SIZE_NOT_ALIGNED:
-        return "AUDCLNT_E_BUFFER_SIZE_NOT_ALIGNED";
-    case AUDCLNT_E_INVALID_DEVICE_PERIOD:
-        return "AUDCLNT_E_INVALID_DEVICE_PERIOD";
-    case AUDCLNT_E_INVALID_STREAM_FLAG:
-        return "AUDCLNT_E_INVALID_STREAM_FLAG";
-    case AUDCLNT_E_ENDPOINT_OFFLOAD_NOT_CAPABLE:
-        return "AUDCLNT_E_ENDPOINT_OFFLOAD_NOT_CAPABLE";
-    case AUDCLNT_E_RESOURCES_INVALIDATED:
-        return "AUDCLNT_E_RESOURCES_INVALIDATED";
-    case AUDCLNT_S_BUFFER_EMPTY:
-        return "AUDCLNT_S_BUFFER_EMPTY";
-    case AUDCLNT_S_THREAD_ALREADY_REGISTERED:
-        return "AUDCLNT_S_THREAD_ALREADY_REGISTERED";
-    case AUDCLNT_S_POSITION_STALLED:
-        return "AUDCLNT_S_POSITION_STALLED";
-    default:
-        return "<Unknown>";
-    }
-}
-
-static void set_format(WAVEFORMATEXTENSIBLE *wformat, WORD bytepersample,
-                       DWORD samplerate, WORD channels, DWORD chanmask)
-{
-    wformat->Format.wFormatTag = WAVE_FORMAT_EXTENSIBLE; /* Only PCM is supported */
-    wformat->Format.nChannels = channels;
-    wformat->Format.nSamplesPerSec = samplerate;
-    wformat->Format.nAvgBytesPerSec = wformat->Format.nChannels *
-                                      bytepersample *
-                                      wformat->Format.nSamplesPerSec;
-    wformat->Format.nBlockAlign = wformat->Format.nChannels * bytepersample;
-    wformat->Format.wBitsPerSample = bytepersample * 8;
-    wformat->Format.cbSize =
-        22; /* must be at least 22 for WAVE_FORMAT_EXTENSIBLE */
-    if (bytepersample == 4)
-        wformat->SubFormat = local_KSDATAFORMAT_SUBTYPE_IEEE_FLOAT;
-    else
-        wformat->SubFormat = local_KSDATAFORMAT_SUBTYPE_PCM;
-    wformat->Samples.wValidBitsPerSample = wformat->Format.wBitsPerSample;
-    wformat->dwChannelMask = chanmask;
-}
-
-static int format_set_bits(int old_format, int bits, int fp) {
-    int format = old_format;
-    format &= (~AF_FORMAT_BITS_MASK) & (~AF_FORMAT_POINT_MASK) & (~AF_FORMAT_SIGN_MASK);
-    format |= AF_FORMAT_SI;
-
-    switch (bits) {
-    case 32:
-        format |= AF_FORMAT_32BIT;
-        break;
-    case 24:
-        format |= AF_FORMAT_24BIT;
-        break;
-    case 16:
-        format |= AF_FORMAT_16BIT;
-        break;
-    default:
-        abort(); // (should be) unreachable
-    }
-
-    if (fp) {
-        format |= AF_FORMAT_F;
-    } else {
-        format |= AF_FORMAT_I;
-    }
-
-    return format;
-}
-
-static int set_ao_format(struct wasapi_state *state,
-                         struct ao *const ao,
-                         WAVEFORMATEXTENSIBLE wformat) {
-    // .Data1 == 1 is PCM, .Data1 == 3 is IEEE_FLOAT
-    int format = format_set_bits(ao->format,
-        wformat.Format.wBitsPerSample, wformat.SubFormat.Data1 == 3);
-
-    if (wformat.SubFormat.Data1 != 1 && wformat.SubFormat.Data1 != 3) {
-        MP_ERR(ao, "unknown SubFormat %"PRIu32"\n",
-               (uint32_t)wformat.SubFormat.Data1);
-        return 0;
-    }
-
-    ao->samplerate = wformat.Format.nSamplesPerSec;
-    ao->bps = wformat.Format.nAvgBytesPerSec;
-    ao->format = format;
-
-    if (ao->channels.num != wformat.Format.nChannels) {
-        mp_chmap_from_channels(&ao->channels, wformat.Format.nChannels);
-    }
-
-    state->format = wformat;
-    return 1;
-}
-
-static int try_format(struct wasapi_state *state,
-                      struct ao *const ao,
-                      int bits, int samplerate,
-                      const struct mp_chmap channels)
-{
-    WAVEFORMATEXTENSIBLE wformat;
-    set_format(&wformat, bits / 8, samplerate, channels.num, mp_chmap_to_waveext(&channels));
-
-    int af_format = format_set_bits(ao->format, bits, bits == 32);
-
-    MP_VERBOSE(ao, "trying %dch %s @ %dhz\n",
-               channels.num, af_fmt_to_str(af_format), samplerate);
-
-    union WAVEFMT u;
-    u.extensible = &wformat;
-
-    WAVEFORMATEX *closestMatch;
-    HRESULT hr = IAudioClient_IsFormatSupported(state->pAudioClient,
-                                                state->share_mode,
-                                                u.ex, &closestMatch);
-
-    if (closestMatch) {
-        if (closestMatch->wFormatTag == WAVE_FORMAT_EXTENSIBLE) {
-            u.ex = closestMatch;
-            wformat = *u.extensible;
-        } else {
-            wformat.Format = *closestMatch;
-        }
-
-        CoTaskMemFree(closestMatch);
-    }
-
-    if (hr == S_FALSE) {
-        if (set_ao_format(state, ao, wformat)) {
-            MP_VERBOSE(ao, "accepted as %dch %s @ %dhz\n",
-                       ao->channels.num, af_fmt_to_str(ao->format), ao->samplerate);
-
-            return 1;
-        }
-    } if (hr == S_OK || (!state->opt_exclusive && hr == AUDCLNT_E_UNSUPPORTED_FORMAT)) {
-        // AUDCLNT_E_UNSUPPORTED_FORMAT here means "works in shared, doesn't in exclusive"
-        if (set_ao_format(state, ao, wformat)) {
-            MP_VERBOSE(ao, "%dch %s @ %dhz accepted\n",
-                       ao->channels.num, af_fmt_to_str(af_format), samplerate);
-            return 1;
-        }
-    }
-    return 0;
-}
-
-static int try_mix_format(struct wasapi_state *state,
-                          struct ao *const ao)
-{
-    WAVEFORMATEX *deviceFormat = NULL;
-    WAVEFORMATEX *closestMatch = NULL;
-    int ret = 0;
-
-    HRESULT hr = IAudioClient_GetMixFormat(state->pAudioClient, &deviceFormat);
-    EXIT_ON_ERROR(hr);
-
-    union WAVEFMT u;
-    u.ex = deviceFormat;
-    WAVEFORMATEXTENSIBLE wformat = *u.extensible;
-
-    ret = try_format(state, ao, wformat.Format.wBitsPerSample,
-                     wformat.Format.nSamplesPerSec, ao->channels);
-    if (ret)
-        state->format = wformat;
-
-exit_label:
-    SAFE_RELEASE(deviceFormat, CoTaskMemFree(deviceFormat));
-    SAFE_RELEASE(closestMatch, CoTaskMemFree(closestMatch));
-    return ret;
-}
-
-static int try_passthrough(struct wasapi_state *state,
-                           struct ao *const ao)
-{
-    WAVEFORMATEXTENSIBLE wformat = {
-        .Format = {
-            .wFormatTag = WAVE_FORMAT_EXTENSIBLE,
-            .nChannels = ao->channels.num,
-            .nSamplesPerSec = ao->samplerate,
-            .nAvgBytesPerSec = (ao->samplerate) * (ao->channels.num * 2),
-            .nBlockAlign = ao->channels.num * 2,
-            .wBitsPerSample = 16,
-            .cbSize = sizeof(WAVEFORMATEXTENSIBLE) - sizeof(WAVEFORMATEX),
-        },
-        .Samples.wValidBitsPerSample = 16,
-        .dwChannelMask = mp_chmap_to_waveext(&ao->channels),
-        .SubFormat = local_KSDATAFORMAT_SUBTYPE_PCM,
-    };
-    wformat.SubFormat.Data1 = WAVE_FORMAT_DOLBY_AC3_SPDIF; // see INIT_WAVEFORMATEX_GUID macro
-
-    union WAVEFMT u;
-    u.extensible = &wformat;
-
-    MP_VERBOSE(ao, "trying passthrough for %s...\n",
-               af_fmt_to_str((ao->format&~AF_FORMAT_END_MASK) | AF_FORMAT_LE));
-
-    HRESULT hr = IAudioClient_IsFormatSupported(state->pAudioClient,
-                                                state->share_mode,
-                                                u.ex, NULL);
-    if (!FAILED(hr)) {
-        ao->format = (ao->format&~AF_FORMAT_END_MASK) | AF_FORMAT_LE;
-        state->format = wformat;
-        return 1;
-    }
-    return 0;
-}
-
-static int find_formats(struct ao *const ao)
-{
-    struct wasapi_state *state = (struct wasapi_state *)ao->priv;
-
-    if (AF_FORMAT_IS_IEC61937(ao->format) || ao->format == AF_FORMAT_MPEG2) {
-        if (try_passthrough(state, ao))
-            return 0;
-
-        MP_ERR(ao, "couldn't use passthrough!");
-        if (!state->opt_exclusive)
-            MP_ERR(ao, " (try exclusive mode)");
-        MP_ERR(ao, "\n");
-        return -1;
-    }
-
-    /* See if the format works as-is */
-    int bits = af_fmt2bits(ao->format);
-    /* don't try 8bits -- there are various 8bit modes other than PCM (*-law et al);
-       let's just stick to PCM or float here. */
-    if (bits == 8) {
-        bits = 16;
-    } else if (try_format(state, ao, bits, ao->samplerate, ao->channels)) {
-        return 0;
-    }
-    if (!state->opt_exclusive) {
-        /* shared mode, we can use the system default mix format. */
-        if (try_mix_format(state, ao)) {
-            return 0;
-        }
-
-        MP_WARN(ao, "couldn't use default mix format!\n");
-    }
-
-    /* Exclusive mode, we have to guess. */
-
-    /* as far as testing shows, only PCM 16/24LE (44100Hz - 192kHz) is supported
-     * Tested on Realtek High Definition Audio, (Realtek Semiconductor Corp. 6.0.1.6312)
-     * Drivers dated 2/18/2011
-     */
-
-    /* try float first for non-16bit audio */
-    if (bits != 16) {
-        bits = 32;
-    }
-
-    int start_bits = bits;
-    while (1) { // not infinite -- returns at bottom
-        for (; bits > 8; bits -= 8) {
-            int samplerate = ao->samplerate;
-            if (try_format(state, ao, bits, samplerate, ao->channels)) {
-                return 0;
-            }
-
-            // make samplerate fit in [44100 192000]
-            // we check for samplerate > 96k so that we can upsample instead of downsampling later
-            if (samplerate < 44100 || samplerate > 96000) {
-                if (samplerate < 44100)
-                    samplerate = 44100;
-                if (samplerate > 96000)
-                    samplerate = 192000;
-
-                if (try_format(state, ao, bits, samplerate, ao->channels)) {
-                    return 0;
-                }
-            }
-
-            // try bounding to 96kHz
-            if (samplerate > 48000) {
-                samplerate = 96000;
-                if (try_format(state, ao, bits, samplerate, ao->channels)) {
-                    return 0;
-                }
-            }
-
-            // try bounding to 48kHz
-            if (samplerate > 44100) {
-                samplerate = 48000;
-                if (try_format(state, ao, bits, samplerate, ao->channels)) {
-                    return 0;
-                }
-            }
-
-            /* How bad is this? try 44100hz, but only on 16bit */
-            if (bits == 16 && samplerate != 44100) {
-                samplerate = 44100;
-
-                if (try_format(state, ao, bits, samplerate, ao->channels)) {
-                    return 0;
-                }
-            }
-        }
-
-        if (ao->channels.num > 6) {
-            /* Maybe this is 5.1 hardware with no support for more. */
-            bits = start_bits;
-            mp_chmap_from_channels(&ao->channels, 6);
-        } else if (ao->channels.num != 2) {
-            /* Poor quality hardware? Try stereo mode, go through the list again. */
-            bits = start_bits;
-            mp_chmap_from_channels(&ao->channels, 2);
-        } else {
-            MP_ERR(ao, "couldn't find acceptable audio format!\n");
-            return -1;
-        }
-    }
-}
-
-static int init_clock(struct wasapi_state *state) {
-    HRESULT hr;
-
-    hr = IAudioClient_GetService(state->pAudioClient,
-                                 &IID_IAudioClock,
-                                 (void **)&state->pAudioClock);
-    EXIT_ON_ERROR(hr);
-    hr = IAudioClock_GetFrequency(state->pAudioClock, &state->clock_frequency);
-    EXIT_ON_ERROR(hr);
-
-    QueryPerformanceFrequency(&state->qpc_frequency);
-
-    state->sample_count = 0;
-
-    MP_VERBOSE(state, "IAudioClock::GetFrequency gave a frequency of %"PRIu64".\n", (uint64_t) state->clock_frequency);
-
-    return 0;
-exit_label:
-    MP_ERR(state, "init_clock failed with %s, unable to obtain the audio device's timing!\n",
-           explain_err(hr));
-    SetEvent(state->fatal_error);
-    return 1;
-}
-
-static int fix_format(struct wasapi_state *state)
-{
-    HRESULT hr;
-    double offset = 0.5;
-
-    /* cargo cult code to negotiate buffer block size, affected by hardware/drivers combinations,
-       gradually grow it to 10s, by 0.5s, consider failure if it still doesn't work
-     */
-    hr = IAudioClient_GetDevicePeriod(state->pAudioClient,
-                                      &state->defaultRequestedDuration,
-                                      &state->minRequestedDuration);
-reinit:
-    hr = IAudioClient_Initialize(state->pAudioClient,
-                                 state->share_mode,
-                                 AUDCLNT_STREAMFLAGS_EVENTCALLBACK,
-                                 state->defaultRequestedDuration,
-                                 state->defaultRequestedDuration,
-                                 &(state->format.Format),
-                                 NULL);
-    /* something about buffer sizes on Win7, fixme might loop forever */
-    if (hr == AUDCLNT_E_BUFFER_SIZE_NOT_ALIGNED) {
-        MP_VERBOSE(state, "IAudioClient::Initialize negotiation failed with %s, used %lld * 100ns\n",
-                   explain_err(hr), state->defaultRequestedDuration);
-        if (offset > 10.0)
-            goto exit_label;                /* is 10 enough to break out of the loop?*/
-        IAudioClient_GetBufferSize(state->pAudioClient, &state->bufferFrameCount);
-        state->defaultRequestedDuration =
-            (REFERENCE_TIME)((BUFFER_TIME / state->format.Format.nSamplesPerSec *
-                              state->bufferFrameCount) + offset);
-        offset += 0.5;
-        IAudioClient_Release(state->pAudioClient);
-        state->pAudioClient = NULL;
-        hr = IMMDeviceActivator_Activate(state->pDevice,
-                                         &IID_IAudioClient, CLSCTX_ALL,
-                                         NULL, (void **)&state->pAudioClient);
-        goto reinit;
-    }
-    EXIT_ON_ERROR(hr);
-    hr = IAudioClient_GetService(state->pAudioClient,
-                                 &IID_IAudioRenderClient,
-                                 (void **)&state->pRenderClient);
-    EXIT_ON_ERROR(hr);
-    if (!state->hFeed)
-        goto exit_label;
-    hr = IAudioClient_SetEventHandle(state->pAudioClient, state->hFeed);
-    EXIT_ON_ERROR(hr);
-    hr = IAudioClient_GetBufferSize(state->pAudioClient,
-                                    &state->bufferFrameCount);
-    EXIT_ON_ERROR(hr);
-    state->buffer_block_size = state->format.Format.nChannels *
-                               state->format.Format.wBitsPerSample / 8 *
-                               state->bufferFrameCount;
-
-    if (init_clock(state))
-        return 1;
-
-    state->hTask =
-        state->VistaBlob.pAvSetMmThreadCharacteristicsW(L"Pro Audio", &state->taskIndex);
-    MP_VERBOSE(state, "fix_format OK, using %lld byte buffer block size!\n",
-               (long long) state->buffer_block_size);
-    return 0;
-exit_label:
-    MP_ERR(state, "fix_format fails with %s, failed to determine buffer block size!\n",
-           explain_err(hr));
-    SetEvent(state->fatal_error);
-    return 1;
-}
-
-static char* wstring_to_utf8(wchar_t *wstring) {
-    if (wstring) {
-        int len = WideCharToMultiByte(CP_UTF8, 0, wstring, -1, NULL, 0, NULL, NULL);
-        char *ret = malloc(len);
-        WideCharToMultiByte(CP_UTF8, 0, wstring, -1, ret, len, NULL, NULL);
-        return ret;
-    }
-    return NULL;
-}
-
-static char* get_device_id(IMMDevice *pDevice) {
-    if (!pDevice) {
-        return NULL;
-    }
-
-    LPWSTR devid = NULL;
-    char *idstr = NULL;
-
-    HRESULT hr = IMMDevice_GetId(pDevice, &devid);
-    EXIT_ON_ERROR(hr);
-
-    idstr = wstring_to_utf8(devid);
-
-    if (strstr(idstr, "{0.0.0.00000000}.")) {
-        char *stripped = strdup(idstr + strlen("{0.0.0.00000000}."));
-        free(idstr);
-        idstr = stripped;
-    }
-
-exit_label:
-    SAFE_RELEASE(devid, CoTaskMemFree(devid));
-    return idstr;
-}
-
-static char* get_device_name(IMMDevice *pDevice) {
-    if (!pDevice) {
-        return NULL;
-    }
-
-    IPropertyStore *pProps = NULL;
-    char *namestr = NULL;
-
-    HRESULT hr = IMMDevice_OpenPropertyStore(pDevice, STGM_READ, &pProps);
-    EXIT_ON_ERROR(hr);
-
-    PROPVARIANT devname;
-    PropVariantInit(&devname);
-
-    hr = IPropertyStore_GetValue(pProps, &PKEY_Device_FriendlyName, &devname);
-    EXIT_ON_ERROR(hr);
-
-    namestr = wstring_to_utf8(devname.pwszVal);
-
-exit_label:
-    PropVariantClear(&devname);
-    SAFE_RELEASE(pProps, IPropertyStore_Release(pProps));
-    return namestr;
-}
-
-static char* get_device_desc(IMMDevice *pDevice) {
-    if (!pDevice) {
-        return NULL;
-    }
-
-    IPropertyStore *pProps = NULL;
-    char *desc = NULL;
-
-    HRESULT hr = IMMDevice_OpenPropertyStore(pDevice, STGM_READ, &pProps);
-    EXIT_ON_ERROR(hr);
-
-    PROPVARIANT devdesc;
-    PropVariantInit(&devdesc);
-
-    hr = IPropertyStore_GetValue(pProps, &PKEY_Device_DeviceDesc, &devdesc);
-    EXIT_ON_ERROR(hr);
-
-    desc = wstring_to_utf8(devdesc.pwszVal);
-
-exit_label:
-    PropVariantClear(&devdesc);
-    SAFE_RELEASE(pProps, IPropertyStore_Release(pProps));
-    return desc;
-}
-
-// frees *idstr
-static int device_id_match(char *idstr, char *candidate) {
-    if (idstr == NULL || candidate == NULL)
-        return 0;
-
-    int found = 0;
-#define FOUND(x) do { found = (x); goto end; } while(0)
-    if (strcmp(idstr, candidate) == 0)
-        FOUND(1);
-    if (strstr(idstr, "{0.0.0.00000000}.")) {
-        char *start = idstr + strlen("{0.0.0.00000000}.");
-        if (strcmp(start, candidate) == 0)
-            FOUND(1);
-    }
-#undef FOUND
-end:
-    free(idstr);
-    return found;
-}
-
-static HRESULT enumerate_with_state(struct mp_log *log, char *header,
-                                    int status, int with_id)
-{
-    HRESULT hr;
-    IMMDeviceEnumerator *pEnumerator = NULL;
-    IMMDeviceCollection *pDevices = NULL;
-    IMMDevice *pDevice = NULL;
-    char *defid = NULL;
-
-    hr = CoCreateInstance(&CLSID_MMDeviceEnumerator, NULL, CLSCTX_ALL,
-                          &IID_IMMDeviceEnumerator, (void **)&pEnumerator);
-    EXIT_ON_ERROR(hr);
-
-    hr = IMMDeviceEnumerator_GetDefaultAudioEndpoint(pEnumerator,
-                                                     eRender, eConsole,
-                                                     &pDevice);
-    EXIT_ON_ERROR(hr);
-
-    defid = get_device_id(pDevice);
-
-    SAFE_RELEASE(pDevice, IMMDevice_Release(pDevice));
-
-    hr = IMMDeviceEnumerator_EnumAudioEndpoints(pEnumerator, eRender,
-                                                status, &pDevices);
-    EXIT_ON_ERROR(hr);
-
-    int count;
-    IMMDeviceCollection_GetCount(pDevices, &count);
-    if (count > 0) {
-        mp_info(log, "%s\n", header);
-    }
-
-    for (int i = 0; i < count; i++) {
-        hr = IMMDeviceCollection_Item(pDevices, i, &pDevice);
-        EXIT_ON_ERROR(hr);
-
-        char *name = get_device_name(pDevice);
-        char *id = get_device_id(pDevice);
-
-        char *mark = "";
-        if (strcmp(id, defid) == 0)
-            mark = " (default)";
-
-        if (with_id) {
-            mp_info(log, "Device #%d: %s, ID: %s%s\n", i, name, id, mark);
-        } else {
-            mp_info(log, "%s, ID: %s%s\n", name, id, mark);
-        }
-
-        free(name);
-        free(id);
-        SAFE_RELEASE(pDevice, IMMDevice_Release(pDevice));
-    }
-    free(defid);
-    SAFE_RELEASE(pDevices, IMMDeviceCollection_Release(pDevices));
-    SAFE_RELEASE(pEnumerator, IMMDeviceEnumerator_Release(pEnumerator));
-    return hr;
-
-exit_label:
-    free(defid);
-    SAFE_RELEASE(pDevice, IMMDevice_Release(pDevice));
-    SAFE_RELEASE(pDevices, IMMDeviceCollection_Release(pDevices));
-    SAFE_RELEASE(pEnumerator, IMMDeviceEnumerator_Release(pEnumerator));
-    return hr;
-}
-
-static int enumerate_devices(struct mp_log *log)
-{
-    HRESULT hr;
-    CoInitialize(NULL);
-
-    hr = enumerate_with_state(log, "Active devices:", DEVICE_STATE_ACTIVE, 1);
-    EXIT_ON_ERROR(hr);
-    hr = enumerate_with_state(log, "Unplugged devices:", DEVICE_STATE_UNPLUGGED, 0);
-    EXIT_ON_ERROR(hr);
-    CoUninitialize();
-    return 0;
-exit_label:
-    mp_err(log, "Error enumerating devices: HRESULT %08"PRIx32" \"%s\"\n",
-           (uint32_t)hr, explain_err(hr));
-    CoUninitialize();
-    return 1;
-}
-
-static HRESULT find_and_load_device(struct ao *ao, IMMDevice **ppDevice,
-                                    char *search)
-{
-    HRESULT hr;
-    IMMDeviceEnumerator *pEnumerator = NULL;
-    IMMDeviceCollection *pDevices = NULL;
-    IMMDevice *pTempDevice = NULL;
-    LPWSTR deviceID = NULL;
-
-    char *end;
-    int devno = (int) strtol(search, &end, 10);
-
-    char *devid = NULL;
-    if (end == search || *end) {
-        devid = search;
-    }
-
-    hr = CoCreateInstance(&CLSID_MMDeviceEnumerator, NULL, CLSCTX_ALL,
-                          &IID_IMMDeviceEnumerator, (void**)&pEnumerator);
-    EXIT_ON_ERROR(hr);
-
-    int search_err = 0;
-
-    if (devid == NULL) {
-        hr = IMMDeviceEnumerator_EnumAudioEndpoints(pEnumerator, eRender,
-                                                    DEVICE_STATE_ACTIVE, &pDevices);
-        EXIT_ON_ERROR(hr);
-
-        int count;
-        IMMDeviceCollection_GetCount(pDevices, &count);
-
-        if (devno >= count) {
-            MP_ERR(ao, "no device #%d!\n", devno);
-        } else {
-            MP_VERBOSE(ao, "finding device #%d\n", devno);
-            hr = IMMDeviceCollection_Item(pDevices, devno, &pTempDevice);
-            EXIT_ON_ERROR(hr);
-
-            hr = IMMDevice_GetId(pTempDevice, &deviceID);
-            EXIT_ON_ERROR(hr);
-
-            MP_VERBOSE(ao, "found device #%d\n", devno);
-        }
-    } else {
-        hr = IMMDeviceEnumerator_EnumAudioEndpoints(pEnumerator, eRender,
-                                                    DEVICE_STATE_ACTIVE|DEVICE_STATE_UNPLUGGED,
-                                                    &pDevices);
-        EXIT_ON_ERROR(hr);
-
-        int count;
-        IMMDeviceCollection_GetCount(pDevices, &count);
-
-        MP_VERBOSE(ao, "finding device %s\n", devid);
-
-        IMMDevice *prevDevice = NULL;
-
-        for (int i = 0; i < count; i++) {
-            hr = IMMDeviceCollection_Item(pDevices, i, &pTempDevice);
-            EXIT_ON_ERROR(hr);
-
-            if (device_id_match(get_device_id(pTempDevice), devid)) {
-                hr = IMMDevice_GetId(pTempDevice, &deviceID);
-                EXIT_ON_ERROR(hr);
-                break;
-            }
-            char *desc = get_device_desc(pTempDevice);
-            if (strstr(desc, devid)) {
-                if (deviceID) {
-                    char *name;
-                    if (!search_err) {
-                        MP_ERR(ao, "multiple matching devices found!\n");
-                        name = get_device_name(prevDevice);
-                        MP_ERR(ao, "%s\n", name);
-                        free(name);
-                        search_err = 1;
-                    }
-                    name = get_device_name(pTempDevice);
-                    MP_ERR(ao, "%s\n", name);
-                    free(name);
-                }
-                hr = IMMDevice_GetId(pTempDevice, &deviceID);
-                prevDevice = pTempDevice;
-            }
-            free(desc);
-
-            SAFE_RELEASE(pTempDevice, IMMDevice_Release(pTempDevice));
-        }
-
-        if (deviceID == NULL) {
-            MP_ERR(ao, "could not find device %s!\n", devid);
-        }
-    }
-
-    SAFE_RELEASE(pTempDevice, IMMDevice_Release(pTempDevice));
-    SAFE_RELEASE(pDevices, IMMDeviceCollection_Release(pDevices));
-
-    if (deviceID == NULL || search_err) {
-        hr = E_NOTFOUND;
-    } else {
-        MP_VERBOSE(ao, "loading device %S\n", deviceID);
-
-        hr = IMMDeviceEnumerator_GetDevice(pEnumerator, deviceID, ppDevice);
-
-        if (FAILED(hr)) {
-            MP_ERR(ao, "could not load requested device!\n");
-        }
-    }
-
-exit_label:
-    SAFE_RELEASE(pTempDevice, IMMDevice_Release(pTempDevice));
-    SAFE_RELEASE(pDevices, IMMDeviceCollection_Release(pDevices));
-    SAFE_RELEASE(pEnumerator, IMMDeviceEnumerator_Release(pEnumerator));
-    return hr;
-}
-
-static int validate_device(struct mp_log *log, const m_option_t *opt,
-                           struct bstr name, struct bstr param)
-{
-    if (bstr_equals0(param, "help")) {
-        enumerate_devices(log);
-        return M_OPT_EXIT;
-    }
-
-    mp_dbg(log, "validating device=%s\n", param.start);
-
-    char *end;
-    int devno = (int) strtol(param.start, &end, 10);
-
-    int ret = 1;
-    if ((end == (void*)param.start || *end) && devno < 0)
-        ret = M_OPT_OUT_OF_RANGE;
-
-    mp_dbg(log, "device=%s %svalid\n", param.start, ret == 1 ? "" : "not ");
-    return ret;
-}
-
 static int thread_init(struct ao *ao)
 {
     struct wasapi_state *state = (struct wasapi_state *)ao->priv;
@@ -952,15 +64,15 @@ static int thread_init(struct ao *ao)
                                                          &state->pDevice);
         SAFE_RELEASE(pEnumerator, IMMDeviceEnumerator_Release(pEnumerator));
 
-        char *id = get_device_id(state->pDevice);
+        char *id = wasapi_get_device_id(state->pDevice);
         MP_VERBOSE(ao, "default device ID: %s\n", id);
         free(id);
     } else {
-        hr = find_and_load_device(ao, &state->pDevice, state->opt_device);
+        hr = wasapi_find_and_load_device(ao, &state->pDevice, state->opt_device);
     }
     EXIT_ON_ERROR(hr);
 
-    char *name = get_device_name(state->pDevice);
+    char *name = wasapi_get_device_name(state->pDevice);
     MP_VERBOSE(ao, "device loaded: %s\n", name);
     free(name);
 
@@ -975,10 +87,10 @@ static int thread_init(struct ao *ao)
     IAudioEndpointVolume_QueryHardwareSupport(state->pEndpointVolume,
                                               &state->vol_hw_support);
 
-    state->init_ret = find_formats(ao); /* Probe support formats */
+    state->init_ret = wasapi_find_formats(ao); /* Probe support formats */
     if (state->init_ret)
         goto exit_label;
-    if (!fix_format(state)) { /* now that we're sure what format to use */
+    if (!wasapi_fix_format(state)) { /* now that we're sure what format to use */
         MP_VERBOSE(ao, "thread_init OK!\n");
         SetEvent(state->init_done);
         return state->init_ret;
@@ -999,7 +111,7 @@ static double get_device_delay(struct wasapi_state *state) {
         case S_OK: case S_FALSE:
             break;
         default:
-            MP_ERR(state, "IAudioClock::GetPosition returned %s\n", explain_err(hr));
+            MP_ERR(state, "IAudioClock::GetPosition returned %s\n", wasapi_explain_err(hr));
     }
 
     LARGE_INTEGER qpc_count;
@@ -1232,10 +344,10 @@ static int init(struct ao *ao)
         return -1;
     struct wasapi_state *state = (struct wasapi_state *)ao->priv;
     state->log = ao->log;
-    fill_VistaBlob(state);
+    wasapi_fill_VistaBlob(state);
 
     if (state->opt_list) {
-        enumerate_devices(state->log);
+        wasapi_enumerate_devices(state->log);
     }
 
     if (state->opt_exclusive) {
@@ -1345,7 +457,7 @@ const struct ao_driver audio_out_wasapi = {
     .options   = (const struct m_option