mpv/audio/out/ao_wasapi.h

/*
 * This file is part of mpv.
 *
 * Original author: Jonathan Yong <10walls@gmail.com>
 *
 * mpv is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * mpv is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with mpv.  If not, see <http://www.gnu.org/licenses/>.
 */

#ifndef MP_AO_WASAPI_H_
#define MP_AO_WASAPI_H_

#include <stdbool.h>
#include <audioclient.h>
#include <audiopolicy.h>
#include <mmdeviceapi.h>
#include <avrt.h>

#include "osdep/atomics.h"

typedef struct change_notify {
    IMMNotificationClient client; /* this must be first in the structure! */
    LPWSTR monitored; /* Monitored device */
    bool is_hotplug;
    struct ao *ao;
} change_notify;

HRESULT wasapi_change_init(struct ao* ao, bool is_hotplug);
void wasapi_change_uninit(struct ao* ao);

#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)

enum wasapi_thread_state {
    WASAPI_THREAD_FEED = 0,
    WASAPI_THREAD_RESUME,
    WASAPI_THREAD_RESET,
    WASAPI_THREAD_SHUTDOWN
};

typedef struct wasapi_state {
    struct mp_log *log;
    /* Init phase */
    HRESULT init_ret;
    HANDLE hInitDone;
    int share_mode;

    /* volume control */
    DWORD vol_hw_support;
    float audio_volume;
    float previous_volume;
    float initial_volume;

    /* WASAPI handles, owned by audio thread */
    IMMDevice *pDevice;
    IAudioClient *pAudioClient;
    IAudioRenderClient *pRenderClient;
    ISimpleAudioVolume *pAudioVolume;
    IAudioEndpointVolume *pEndpointVolume;
    IAudioSessionControl *pSessionControl;
    IMMDeviceEnumerator *pEnumerator;

    /* thread handles */
    HANDLE hAudioThread; /* the thread itself */
    HANDLE hWake; /* thread wakeup event */
    atomic_int thread_state; /* enum wasapi_thread_state */

    /* for setting the audio thread priority */
    HANDLE hTask; /* AV thread */
    DWORD taskIndex; /* AV task ID */

    /* WASAPI proxy handles, for Single-Threaded Apartment communication.
       One is needed for each audio thread object that's accessed from the main thread. */
    ISimpleAudioVolume *pAudioVolumeProxy;
    IAudioEndpointVolume *pEndpointVolumeProxy;
    IAudioSessionControl *pSessionControlProxy;

    /* Streams used to marshal the proxy objects. The thread owning the actual objects
       needs to marshal proxy objects into these streams, and the thread that wants the
       proxies unmarshals them from here. */
    IStream *sAudioVolume;
    IStream *sEndpointVolume;
    IStream *sSessionControl;

    /* WASAPI internal clock information, for estimating delay */
    IAudioClock *pAudioClock;
    UINT64 clock_frequency; /* scale for the "samples" returned by the clock */
    atomic_ullong sample_count; /* the amount of samples per channel written to a GetBuffer buffer */
    LARGE_INTEGER qpc_frequency; /* frequency of windows' high resolution timer */

    /* ao options */
    int opt_exclusive;
    int opt_list;
    char *opt_device;

    /* format info */
    WAVEFORMATEXTENSIBLE format;
    size_t buffer_block_size; /* Size of each block in bytes */
    UINT32 bufferFrameCount; /* wasapi buffer block size, number of frames, frame size at format.nBlockAlign */

    /* Don't use these functions directly in case
       they are unimplemented for some reason.
       (XP shouldn't be an issue since it doesn't support wasapi, maybe wine?)
       Blob is owned by the main thread */
    struct {
        HMODULE hAvrt;
        HANDLE (WINAPI *pAvSetMmThreadCharacteristicsW)(LPCWSTR, LPDWORD);
        WINBOOL (WINAPI *pAvRevertMmThreadCharacteristics)(HANDLE);
    } VistaBlob;

    change_notify change;
} wasapi_state;

#endif