/*
 * yt - A fully featured command line YouTube client
 *
 * Copyright (C) 2017 the mpv developers
 * Copyright (C) 2024 Benedikt Peetz <benedikt.peetz@b-peetz.de>
 * SPDX-License-Identifier: GPL-3.0-or-later
 *
 * This file is part of Yt.
 *
 * You should have received a copy of the License along with this program.
 * If not, see <https://www.gnu.org/licenses/gpl-3.0.txt>.
 */

/*
 * Note: the client API is licensed under ISC (see above) to enable
 * other wrappers outside of mpv. But keep in mind that the
 * mpv core is by default still GPLv2+ - unless built with
 * -Dgpl=false, which makes it LGPLv2+.
 */

#ifndef MPV_CLIENT_API_H_
#define MPV_CLIENT_API_H_

#include <stddef.h>
#include <stdint.h>

#ifdef _WIN32
#define MPV_EXPORT __declspec (dllexport)
#define MPV_SELECTANY __declspec (selectany)
#elif defined(__GNUC__) || defined(__clang__)
#define MPV_EXPORT __attribute__ ((visibility ("default")))
#define MPV_SELECTANY
#else
#define MPV_EXPORT
#define MPV_SELECTANY
#endif

#ifdef __cpp_decltype
#define MPV_DECLTYPE decltype
#else
#define MPV_DECLTYPE __typeof__
#endif

#ifdef __cplusplus
extern "C"
{
#endif

/**
 * Mechanisms provided by this API
 * -------------------------------
 *
 * This API provides general control over mpv playback. It does not give you
 * direct access to individual components of the player, only the whole thing.
 * It's somewhat equivalent to MPlayer's slave mode. You can send commands,
 * retrieve or set playback status or settings with properties, and receive
 * events.
 *
 * The API can be used in two ways:
 * 1) Internally in mpv, to provide additional features to the command line
 *    player. Lua scripting uses this. (Currently there is no plugin API to
 *    get a client API handle in external user code. It has to be a fixed
 *    part of the player at compilation time.)
 * 2) Using mpv as a library with mpv_create(). This basically allows embedding
 *    mpv in other applications.
 *
 * Documentation
 * -------------
 *
 * The libmpv C API is documented directly in this header. Note that most
 * actual interaction with this player is done through
 * options/commands/properties, which can be accessed through this API.
 * Essentially everything is done with them, including loading a file,
 * retrieving playback progress, and so on.
 *
 * These are documented elsewhere:
 *      * http://mpv.io/manual/master/#options
 *      * http://mpv.io/manual/master/#list-of-input-commands
 *      * http://mpv.io/manual/master/#properties
 *
 * You can also look at the examples here:
 *      * https://github.com/mpv-player/mpv-examples/tree/master/libmpv
 *
 * Event loop
 * ----------
 *
 * In general, the API user should run an event loop in order to receive
 * events. This event loop should call mpv_wait_event(), which will return once
 * a new mpv client API is available. It is also possible to integrate client
 * API usage in other event loops (e.g. GUI toolkits) with the
 * mpv_set_wakeup_callback() function, and then polling for events by calling
 * mpv_wait_event() with a 0 timeout.
 *
 * Note that the event loop is detached from the actual player. Not calling
 * mpv_wait_event() will not stop playback. It will eventually congest the
 * event queue of your API handle, though.
 *
 * Synchronous vs. asynchronous calls
 * ----------------------------------
 *
 * The API allows both synchronous and asynchronous calls. Synchronous calls
 * have to wait until the playback core is ready, which currently can take
 * an unbounded time (e.g. if network is slow or unresponsive). Asynchronous
 * calls just queue operations as requests, and return the result of the
 * operation as events.
 *
 * Asynchronous calls
 * ------------------
 *
 * The client API includes asynchronous functions. These allow you to send
 * requests instantly, and get replies as events at a later point. The
 * requests are made with functions carrying the _async suffix, and replies
 * are returned by mpv_wait_event() (interleaved with the normal event stream).
 *
 * A 64 bit userdata value is used to allow the user to associate requests
 * with replies. The value is passed as reply_userdata parameter to the request
 * function. The reply to the request will have the reply
 * mpv_event->reply_userdata field set to the same value as the
 * reply_userdata parameter of the corresponding request.
 *
 * This userdata value is arbitrary and is never interpreted by the API. Note
 * that the userdata value 0 is also allowed, but then the client must be
 * careful not accidentally interpret the mpv_event->reply_userdata if an
 * event is not a reply. (For non-replies, this field is set to 0.)
 *
 * Asynchronous calls may be reordered in arbitrarily with other synchronous
 * and asynchronous calls. If you want a guaranteed order, you need to wait
 * until asynchronous calls report completion before doing the next call.
 *
 * See also the section "Asynchronous command details" in the manpage.
 *
 * Multithreading
 * --------------
 *
 * The client API is generally fully thread-safe, unless otherwise noted.
 * Currently, there is no real advantage in using more than 1 thread to access
 * the client API, since everything is serialized through a single lock in the
 * playback core.
 *
 * Basic environment requirements
 * ------------------------------
 *
 * This documents basic requirements on the C environment. This is especially
 * important if mpv is used as library with mpv_create().
 *
 * - The LC_NUMERIC locale category must be set to "C". If your program calls
 *   setlocale(), be sure not to use LC_ALL, or if you do, reset LC_NUMERIC
 *   to its sane default: setlocale(LC_NUMERIC, "C").
 * - If a X11 based VO is used, mpv will set the xlib error handler. This error
 *   handler is process-wide, and there's no proper way to share it with other
 *   xlib users within the same process. This might confuse GUI toolkits.
 * - mpv uses some other libraries that are not library-safe, such as Fribidi
 *   (used through libass), ALSA, FFmpeg, and possibly more.
 * - The FPU precision must be set at least to double precision.
 * - On Windows, mpv will call timeBeginPeriod(1).
 * - On memory exhaustion, mpv will kill the process.
 * - In certain cases, mpv may start sub processes (such as with the ytdl
 *   wrapper script).
 * - Using UNIX IPC (off by default) will override the SIGPIPE signal handler,
 *   and set it to SIG_IGN. Some invocations of the "subprocess" command will
 *   also do that.
 * - mpv may start sub processes, so overriding SIGCHLD, or waiting on all PIDs
 *   (such as calling wait()) by the parent process or any other library within
 *   the process must be avoided. libmpv itself only waits for its own PIDs.
 * - If anything in the process registers signal handlers, they must set the
 *   SA_RESTART flag. Otherwise you WILL get random failures on signals.
 *
 * Encoding of filenames
 * ---------------------
 *
 * mpv uses UTF-8 everywhere.
 *
 * On some platforms (like Linux), filenames actually do not have to be UTF-8;
 * for this reason libmpv supports non-UTF-8 strings. libmpv uses what the
 * kernel uses and does not recode filenames. At least on Linux, passing a
 * string to libmpv is like passing a string to the fopen() function.
 *
 * On Windows, filenames are always UTF-8, libmpv converts between UTF-8 and
 * UTF-16 when using win32 API functions. libmpv never uses or accepts
 * filenames in the local 8 bit encoding. It does not use fopen() either;
 * it uses _wfopen().
 *
 * On macOS, filenames and other strings taken/returned by libmpv can have
 * inconsistent unicode normalization. This can sometimes lead to problems.
 * You have to hope for the best.
 *
 * Also see the remarks for MPV_FORMAT_STRING.
 *
 * Embedding the video window
 * --------------------------
 *
 * Using the render API (in render.h) is recommended. This API requires
 * you to create and maintain an OpenGL context, to which you can render
 * video using a specific API call. This API does not include keyboard or mouse
 * input directly.
 *
 * There is an older way to embed the native mpv window into your own. You have
 * to get the raw window handle, and set it as "wid" option. This works on X11,
 * win32, and macOS only. It's much easier to use than the render API, but
 * also has various problems.
 *
 * Also see client API examples and the mpv manpage. There is an extensive
 * discussion here:
 * https://github.com/mpv-player/mpv-examples/tree/master/libmpv#methods-of-embedding-the-video-window
 *
 * Compatibility
 * -------------
 *
 * mpv development doesn't stand still, and changes to mpv internals as well as
 * to its interface can cause compatibility issues to client API users.
 *
 * The API is versioned (see MPV_CLIENT_API_VERSION), and changes to it are
 * documented in DOCS/client-api-changes.rst. The C API itself will probably
 * remain compatible for a long time, but the functionality exposed by it
 * could change more rapidly. For example, it's possible that options are
 * renamed, or change the set of allowed values.
 *
 * Defensive programming should be used to potentially deal with the fact that
 * options, commands, and properties could disappear, change their value range,
 * or change the underlying datatypes. It might be a good idea to prefer
 * MPV_FORMAT_STRING over other types to decouple your code from potential
 * mpv changes.
 *
 * Also see: DOCS/compatibility.rst
 *
 * Future changes
 * --------------
 *
 * This are the planned changes that will most likely be done on the next major
 * bump of the library:
 *
 *  - remove all symbols that are marked as deprecated
 *  - reassign enum numerical values to remove gaps
 *  - disabling all events by default
 */

/**
 * The version is incremented on each API change. The 16 lower bits form the
 * minor version number, and the 16 higher bits the major version number. If
 * the API becomes incompatible to previous versions, the major version
 * number is incremented. This affects only C part, and not properties and
 * options.
 *
 * Every API bump is described in DOCS/client-api-changes.rst
 *
 * You can use MPV_MAKE_VERSION() and compare the result with integer
 * relational operators (<, >, <=, >=).
 */
#define MPV_MAKE_VERSION(major, minor) (((major) << 16) | (minor) | 0UL)
#define MPV_CLIENT_API_VERSION MPV_MAKE_VERSION (2, 3)

/**
 * The API user is allowed to "#define MPV_ENABLE_DEPRECATED 0" before
 * including any libmpv headers. Then deprecated symbols will be excluded
 * from the headers. (Of course, deprecated properties and commands and
 * other functionality will still work.)
 */
#ifndef MPV_ENABLE_DEPRECATED
#define MPV_ENABLE_DEPRECATED 1
#endif

  /**
   * Return the MPV_CLIENT_API_VERSION the mpv source has been compiled with.
   */
  MPV_EXPORT unsigned long mpv_client_api_version (void);

  /**
   * Client context used by the client API. Every client has its own private
   * handle.
   */
  typedef struct mpv_handle mpv_handle;

  /**
   * List of error codes than can be returned by API functions. 0 and positive
   * return values always mean success, negative values are always errors.
   */
  typedef enum mpv_error
  {
    /**
     * No error happened (used to signal successful operation).
     * Keep in mind that many API functions returning error codes can also
     * return positive values, which also indicate success. API users can
     * hardcode the fact that ">= 0" means success.
     */
    MPV_ERROR_SUCCESS = 0,
    /**
     * The event ringbuffer is full. This means the client is choked, and can't
     * receive any events. This can happen when too many asynchronous requests
     * have been made, but not answered. Probably never happens in practice,
     * unless the mpv core is frozen for some reason, and the client keeps
     * making asynchronous requests. (Bugs in the client API implementation
     * could also trigger this, e.g. if events become "lost".)
     */
    MPV_ERROR_EVENT_QUEUE_FULL = -1,
    /**
     * Memory allocation failed.
     */
    MPV_ERROR_NOMEM = -2,
    /**
     * The mpv core wasn't configured and initialized yet. See the notes in
     * mpv_create().
     */
    MPV_ERROR_UNINITIALIZED = -3,
    /**
     * Generic catch-all error if a parameter is set to an invalid or
     * unsupported value. This is used if there is no better error code.
     */
    MPV_ERROR_INVALID_PARAMETER = -4,
    /**
     * Trying to set an option that doesn't exist.
     */
    MPV_ERROR_OPTION_NOT_FOUND = -5,
    /**
     * Trying to set an option using an unsupported MPV_FORMAT.
     */
    MPV_ERROR_OPTION_FORMAT = -6,
    /**
     * Setting the option failed. Typically this happens if the provided option
     * value could not be parsed.
     */
    MPV_ERROR_OPTION_ERROR = -7,
    /**
     * The accessed property doesn't exist.
     */
    MPV_ERROR_PROPERTY_NOT_FOUND = -8,
    /**
     * Trying to set or get a property using an unsupported MPV_FORMAT.
     */
    MPV_ERROR_PROPERTY_FORMAT = -9,
    /**
     * The property exists, but is not available. This usually happens when the
     * associated subsystem is not active, e.g. querying audio parameters while
     * audio is disabled.
     */
    MPV_ERROR_PROPERTY_UNAVAILABLE = -10,
    /**
     * Error setting or getting a property.
     */
    MPV_ERROR_PROPERTY_ERROR = -11,
    /**
     * General error when running a command with mpv_command and similar.
     */
    MPV_ERROR_COMMAND = -12,
    /**
     * Generic error on loading (usually used with mpv_event_end_file.error).
     */
    MPV_ERROR_LOADING_FAILED = -13,
    /**
     * Initializing the audio output failed.
     */
    MPV_ERROR_AO_INIT_FAILED = -14,
    /**
     * Initializing the video output failed.
     */
    MPV_ERROR_VO_INIT_FAILED = -15,
    /**
     * There was no audio or video data to play. This also happens if the
     * file was recognized, but did not contain any audio or video streams,
     * or no streams were selected.
     */
    MPV_ERROR_NOTHING_TO_PLAY = -16,
    /**
     * When trying to load the file, the file format could not be determined,
     * or the file was too broken to open it.
     */
    MPV_ERROR_UNKNOWN_FORMAT = -17,
    /**
     * Generic error for signaling that certain system requirements are not
     * fulfilled.
     */
    MPV_ERROR_UNSUPPORTED = -18,
    /**
     * The API function which was called is a stub only.
     */
    MPV_ERROR_NOT_IMPLEMENTED = -19,
    /**
     * Unspecified error.
     */
    MPV_ERROR_GENERIC = -20
  } mpv_error;

  /**
   * Return a string describing the error. For unknown errors, the string
   * "unknown error" is returned.
   *
   * @param error error number, see enum mpv_error
   * @return A static string describing the error. The string is completely
   *         static, i.e. doesn't need to be deallocated, and is valid forever.
   */
  MPV_EXPORT const char *mpv_error_string (int error);

  /**
   * General function to deallocate memory returned by some of the API
   * functions. Call this only if it's explicitly documented as allowed.
   * Calling this on mpv memory not owned by the caller will lead to undefined
   * behavior.
   *
   * @param data A valid pointer returned by the API, or NULL.
   */
  MPV_EXPORT void mpv_free (void *data);

  /**
   * Return the name of this client handle. Every client has its own unique
   * name, which is mostly used for user interface purposes.
   *
   * @return The client name. The string is read-only and is valid until the
   *         mpv_handle is destroyed.
   */
  MPV_EXPORT const char *mpv_client_name (mpv_handle *ctx);

  /**
   * Return the ID of this client handle. Every client has its own unique ID.
   * This ID is never reused by the core, even if the mpv_handle at hand gets
   * destroyed and new handles get allocated.
   *
   * IDs are never 0 or negative.
   *
   * Some mpv APIs (not necessarily all) accept a name in the form "@<id>" in
   * addition of the proper mpv_client_name(), where "<id>" is the ID in
   * decimal form (e.g. "@123"). For example, the "script-message-to" command
   * takes the client name as first argument, but also accepts the client ID
   * formatted in this manner.
   *
   * @return The client ID.
   */
  MPV_EXPORT int64_t mpv_client_id (mpv_handle *ctx);

  /**
   * Create a new mpv instance and an associated client API handle to control
   * the mpv instance. This instance is in a pre-initialized state,
   * and needs to be initialized to be actually used with most other API
   * functions.
   *
   * Some API functions will return MPV_ERROR_UNINITIALIZED in the
   * uninitialized state. You can call mpv_set_property() (or
   * mpv_set_property_string() and other variants, and before mpv 0.21.0
   * mpv_set_option() etc.) to set initial options. After this, call
   * mpv_initialize() to start the player, and then use e.g. mpv_command() to
   * start playback of a file.
   *
   * The point of separating handle creation and actual initialization is that
   * you can configure things which can't be changed during runtime.
   *
   * Unlike the command line player, this will have initial settings suitable
   * for embedding in applications. The following settings are different:
   * - stdin/stdout/stderr and the terminal will never be accessed. This is
   *   equivalent to setting the --no-terminal option.
   *   (Technically, this also suppresses C signal handling.)
   * - No config files will be loaded. This is roughly equivalent to using
   *   --config=no. Since libmpv 1.15, you can actually re-enable this option,
   *   which will make libmpv load config files during mpv_initialize(). If you
   *   do this, you are strongly encouraged to set the "config-dir" option too.
   *   (Otherwise it will load the mpv command line player's config.)
   *   For example:
   *      mpv_set_option_string(mpv, "config-dir", "/my/path"); // set config
   * root mpv_set_option_string(mpv, "config", "yes"); // enable config loading
   *      (call mpv_initialize() _after_ this)
   * - Idle mode is enabled, which means the playback core will enter idle mode
   *   if there are no more files to play on the internal playlist, instead of
   *   exiting. This is equivalent to the --idle option.
   * - Disable parts of input handling.
   * - Most of the different settings can be viewed with the command line
   * player by running "mpv --show-profile=libmpv".
   *
   * All this assumes that API users want a mpv instance that is strictly
   * isolated from the command line player's configuration, user settings, and
   * so on. You can re-enable disabled features by setting the appropriate
   * options.
   *
   * The mpv command line parser is not available through this API, but you can
   * set individual options with mpv_set_property(). Files for playback must be
   * loaded with mpv_command() or others.
   *
   * Note that you should avoid doing concurrent accesses on the uninitialized
   * client handle. (Whether concurrent access is definitely allowed or not has
   * yet to be decided.)
   *
   * @return a new mpv client API handle. Returns NULL on error. Currently,
   * this can happen in the following situations:
   *         - out of memory
   *         - LC_NUMERIC is not set to "C" (see general remarks)
   */
  MPV_EXPORT mpv_handle *mpv_create (void);

  /**
   * Initialize an uninitialized mpv instance. If the mpv instance is already
   * running, an error is returned.
   *
   * This function needs to be called to make full use of the client API if the
   * client API handle was created with mpv_create().
   *
   * Only the following options are required to be set _before_
   * mpv_initialize():
   *      - options which are only read at initialization time:
   *        - config
   *        - config-dir
   *        - input-conf
   *        - load-scripts
   *        - script
   *        - player-operation-mode
   *        - input-app-events (macOS)
   *      - all encoding mode options
   *
   * @return error code
   */
  MPV_EXPORT int mpv_initialize (mpv_handle *ctx);

  /**
   * Disconnect and destroy the mpv_handle. ctx will be deallocated with this
   * API call.
   *
   * If the last mpv_handle is detached, the core player is destroyed. In
   * addition, if there are only weak mpv_handles (such as created by
   * mpv_create_weak_client() or internal scripts), these mpv_handles will
   * be sent MPV_EVENT_SHUTDOWN. This function may block until these clients
   * have responded to the shutdown event, and the core is finally destroyed.
   */
  MPV_EXPORT void mpv_destroy (mpv_handle *ctx);

  /**
   * Similar to mpv_destroy(), but brings the player and all clients down
   * as well, and waits until all of them are destroyed. This function blocks.
   * The advantage over mpv_destroy() is that while mpv_destroy() merely
   * detaches the client handle from the player, this function quits the
   * player, waits until all other clients are destroyed (i.e. all mpv_handles
   * are detached), and also waits for the final termination of the player.
   *
   * Since mpv_destroy() is called somewhere on the way, it's not safe to
   * call other functions concurrently on the same context.
   *
   * Since mpv client API version 1.29:
   *  The first call on any mpv_handle will block until the core is destroyed.
   *  This means it will wait until other mpv_handle have been destroyed. If
   * you want asynchronous destruction, just run the "quit" command, and then
   * react to the MPV_EVENT_SHUTDOWN event. If another mpv_handle already
   * called mpv_terminate_destroy(), this call will not actually block. It will
   * destroy the mpv_handle, and exit immediately, while other mpv_handles
   * might still be uninitializing.
   *
   * Before mpv client API version 1.29:
   *  If this is called on a mpv_handle that was not created with mpv_create(),
   *  this function will merely send a quit command and then call
   *  mpv_destroy(), without waiting for the actual shutdown.
   */
  MPV_EXPORT void mpv_terminate_destroy (mpv_handle *ctx);

  /**
   * Create a new client handle connected to the same player core as ctx. This
   * context has its own event queue, its own mpv_request_event() state, its
   * own mpv_request_log_messages() state, its own set of observed properties,
   * and its own state for asynchronous operations. Otherwise, everything is
   * shared.
   *
   * This handle should be destroyed with mpv_destroy() if no longer
   * needed. The core will live as long as there is at least 1 handle
   * referencing it. Any handle can make the core quit, which will result in
   * every handle receiving MPV_EVENT_SHUTDOWN.
   *
   * This function can not be called before the main handle was initialized
   * with mpv_initialize(). The new handle is always initialized, unless
   * ctx=NULL was passed.
   *
   * @param ctx Used to get the reference to the mpv core; handle-specific
   *            settings and parameters are not used.
   *            If NULL, this function behaves like mpv_create() (ignores
   * name).
   * @param name The client name. This will be returned by mpv_client_name().
   * If the name is already in use, or contains non-alphanumeric characters
   * (other than '_'), the name is modified to fit. If NULL, an arbitrary name
   * is automatically chosen.
   * @return a new handle, or NULL on error
   */
  MPV_EXPORT mpv_handle *mpv_create_client (mpv_handle *ctx, const char *name);

  /**
   * This is the same as mpv_create_client(), but the created mpv_handle is
   * treated as a weak reference. If all mpv_handles referencing a core are
   * weak references, the core is automatically destroyed. (This still goes
   * through normal uninit of course. Effectively, if the last non-weak
   * mpv_handle is destroyed, then the weak mpv_handles receive
   * MPV_EVENT_SHUTDOWN and are asked to terminate as well.)
   *
   * Note if you want to use this like refcounting: you have to be aware that
   * mpv_terminate_destroy() _and_ mpv_destroy() for the last non-weak
   * mpv_handle will block until all weak mpv_handles are destroyed.
   */
  MPV_EXPORT mpv_handle *mpv_create_weak_client (mpv_handle *ctx,
                                                 const char *name);

  /**
   * Load a config file. This loads and parses the file, and sets every entry
   * in the config file's default section as if mpv_set_option_string() is
   * called.
   *
   * The filename should be an absolute path. If it isn't, the actual path used
   * is unspecified. (Note: an absolute path starts with '/' on UNIX.) If the
   * file wasn't found, MPV_ERROR_INVALID_PARAMETER is returned.
   *
   * If a fatal error happens when parsing a config file,
   * MPV_ERROR_OPTION_ERROR is returned. Errors when setting options as well as
   * other types or errors are ignored (even if options do not exist). You can
   * still try to capture the resulting error messages with
   * mpv_request_log_messages(). Note that it's possible that some options were
   * successfully set even if any of these errors happen.
   *
   * @param filename absolute path to the config file on the local filesystem
   * @return error code
   */
  MPV_EXPORT int mpv_load_config_file (mpv_handle *ctx, const char *filename);

  /**
   * Return the internal time in nanoseconds. This has an arbitrary start
   * offset, but will never wrap or go backwards.
   *
   * Note that this is always the real time, and doesn't necessarily have to do
   * with playback time. For example, playback could go faster or slower due to
   * playback speed, or due to playback being paused. Use the "time-pos"
   * property instead to get the playback status.
   *
   * Unlike other libmpv APIs, this can be called at absolutely any time (even
   * within wakeup callbacks), as long as the context is valid.
   *
   * Safe to be called from mpv render API threads.
   */
  MPV_EXPORT int64_t mpv_get_time_ns (mpv_handle *ctx);

  /**
   * Same as mpv_get_time_ns but in microseconds.
   */
  MPV_EXPORT int64_t mpv_get_time_us (mpv_handle *ctx);

  /**
   * Data format for options and properties. The API functions to get/set
   * properties and options support multiple formats, and this enum describes
   * them.
   */
  typedef enum mpv_format
  {
    /**
     * Invalid. Sometimes used for empty values. This is always defined to 0,
     * so a normal 0-init of mpv_format (or e.g. mpv_node) is guaranteed to set
     * this it to MPV_FORMAT_NONE (which makes some things saner as
     * consequence).
     */
    MPV_FORMAT_NONE = 0,
    /**
     * The basic type is char*. It returns the raw property string, like
     * using ${=property} in input.conf (see input.rst).
     *
     * NULL isn't an allowed value.
     *
     * Warning: although the encoding is usually UTF-8, this is not always the
     *          case. File tags often store strings in some legacy codepage,
     *          and even filenames don't necessarily have to be in UTF-8 (at
     *          least on Linux). If you pass the strings to code that requires
     *          valid UTF-8, you have to sanitize it in some way.
     *          On Windows, filenames are always UTF-8, and libmpv converts
     *          between UTF-8 and UTF-16 when using win32 API functions. See
     *          the "Encoding of filenames" section for details.
     *
     * Example for reading:
     *
     *     char *result = NULL;
     *     if (mpv_get_property(ctx, "property", MPV_FORMAT_STRING, &result) <
     * 0) goto error; printf("%s\n", result); mpv_free(result);
     *
     * Or just use mpv_get_property_string().
     *
     * Example for writing:
     *
     *     char *value = "the new value";
     *     // yep, you pass the address to the variable
     *     // (needed for symmetry with other types and mpv_get_property)
     *     mpv_set_property(ctx, "property", MPV_FORMAT_STRING, &value);
     *
     * Or just use mpv_set_property_string().
     *
     */
    MPV_FORMAT_STRING = 1,
    /**
     * The basic type is char*. It returns the OSD property string, like
     * using ${property} in input.conf (see input.rst). In many cases, this
     * is the same as the raw string, but in other cases it's formatted for
     * display on OSD. It's intended to be human readable. Do not attempt to
     * parse these strings.
     *
     * Only valid when doing read access. The rest works like
     * MPV_FORMAT_STRING.
     */
    MPV_FORMAT_OSD_STRING = 2,
    /**
     * The basic type is int. The only allowed values are 0 ("no")
     * and 1 ("yes").
     *
     * Example for reading:
     *
     *     int result;
     *     if (mpv_get_property(ctx, "property", MPV_FORMAT_FLAG, &result) < 0)
     *         goto error;
     *     printf("%s\n", result ? "true" : "false");
     *
     * Example for writing:
     *
     *     int flag = 1;
     *     mpv_set_property(ctx, "property", MPV_FORMAT_FLAG, &flag);
     */
    MPV_FORMAT_FLAG = 3,
    /**
     * The basic type is int64_t.
     */
    MPV_FORMAT_INT64 = 4,
    /**
     * The basic type is double.
     */
    MPV_FORMAT_DOUBLE = 5,
    /**
     * The type is mpv_node.
     *
     * For reading, you usually would pass a pointer to a stack-allocated
     * mpv_node value to mpv, and when you're done you call
     * mpv_free_node_contents(&node).
     * You're expected not to write to the data - if you have to, copy it
     * first (which you have to do manually).
     *
     * For writing, you construct your own mpv_node, and pass a pointer to the
     * API. The API will never write to your data (and copy it if needed), so
     * you're free to use any form of allocation or memory management you like.
     *
     * Warning: when reading, always check the mpv_node.format member. For
     *          example, properties might change their type in future versions
     *          of mpv, or sometimes even during runtime.
     *
     * Example for reading:
     *
     *     mpv_node result;
     *     if (mpv_get_property(ctx, "property", MPV_FORMAT_NODE, &result) < 0)
     *         goto error;
     *     printf("format=%d\n", (int)result.format);
     *     mpv_free_node_contents(&result).
     *
     * Example for writing:
     *
     *     mpv_node value;
     *     value.format = MPV_FORMAT_STRING;
     *     value.u.string = "hello";
     *     mpv_set_property(ctx, "property", MPV_FORMAT_NODE, &value);
     */
    MPV_FORMAT_NODE = 6,
    /**
     * Used with mpv_node only. Can usually not be used directly.
     */
    MPV_FORMAT_NODE_ARRAY = 7,
    /**
     * See MPV_FORMAT_NODE_ARRAY.
     */
    MPV_FORMAT_NODE_MAP = 8,
    /**
     * A raw, untyped byte array. Only used only with mpv_node, and only in
     * some very specific situations. (Some commands use it.)
     */
    MPV_FORMAT_BYTE_ARRAY = 9
  } mpv_format;

  /**
   * Generic data storage.
   *
   * If mpv writes this struct (e.g. via mpv_get_property()), you must not
   * change the data. In some cases (mpv_get_property()), you have to free it
   * with mpv_free_node_contents(). If you fill this struct yourself, you're
   * also responsible for freeing it, and you must not call
   * mpv_free_node_contents().
   */
  typedef struct mpv_node
  {
    union
    {
      char *string;   /** valid if format==MPV_FORMAT_STRING */
      int flag;       /** valid if format==MPV_FORMAT_FLAG   */
      int64_t int64;  /** valid if format==MPV_FORMAT_INT64  */
      double double_; /** valid if format==MPV_FORMAT_DOUBLE */
      /**
       * valid if format==MPV_FORMAT_NODE_ARRAY
       *    or if format==MPV_FORMAT_NODE_MAP
       */
      struct mpv_node_list *list;
      /**
       * valid if format==MPV_FORMAT_BYTE_ARRAY
       */
      struct mpv_byte_array *ba;
    } u;
    /**
     * Type of the data stored in this struct. This value rules what members in
     * the given union can be accessed. The following formats are currently
     * defined to be allowed in mpv_node:
     *
     *  MPV_FORMAT_STRING       (u.string)
     *  MPV_FORMAT_FLAG         (u.flag)
     *  MPV_FORMAT_INT64        (u.int64)
     *  MPV_FORMAT_DOUBLE       (u.double_)
     *  MPV_FORMAT_NODE_ARRAY   (u.list)
     *  MPV_FORMAT_NODE_MAP     (u.list)
     *  MPV_FORMAT_BYTE_ARRAY   (u.ba)
     *  MPV_FORMAT_NONE         (no member)
     *
     * If you encounter a value you don't know, you must not make any
     * assumptions about the contents of union u.
     */
    mpv_format format;
  } mpv_node;

  /**
   * (see mpv_node)
   */
  typedef struct mpv_node_list
  {
    /**
     * Number of entries. Negative values are not allowed.
     */
    int num;
    /**
     * MPV_FORMAT_NODE_ARRAY:
     *  values[N] refers to value of the Nth item
     *
     * MPV_FORMAT_NODE_MAP:
     *  values[N] refers to value of the Nth key/value pair
     *
     * If num > 0, values[0] to values[num-1] (inclusive) are valid.
     * Otherwise, this can be NULL.
     */
    mpv_node *values;
    /**
     * MPV_FORMAT_NODE_ARRAY:
     *  unused (typically NULL), access is not allowed
     *
     * MPV_FORMAT_NODE_MAP:
     *  keys[N] refers to key of the Nth key/value pair. If num > 0, keys[0] to
     *  keys[num-1] (inclusive) are valid. Otherwise, this can be NULL.
     *  The keys are in random order. The only guarantee is that keys[N]
     * belongs to the value values[N]. NULL keys are not allowed.
     */
    char **keys;
  } mpv_node_list;

  /**
   * (see mpv_node)
   */
  typedef struct mpv_byte_array
  {
    /**
     * Pointer to the data. In what format the data is stored is up to whatever
     * uses MPV_FORMAT_BYTE_ARRAY.
     */
    void *data;
    /**
     * Size of the data pointed to by ptr.
     */
    size_t size;
  } mpv_byte_array;

  /**
   * Frees any data referenced by the node. It doesn't free the node itself.
   * Call this only if the mpv client API set the node. If you constructed the
   * node yourself (manually), you have to free it yourself.
   *
   * If node->format is MPV_FORMAT_NONE, this call does nothing. Likewise, if
   * the client API sets a node with this format, this function doesn't need to
   * be called. (This is just a clarification that there's no danger of
   * anything strange happening in these cases.)
   */
  MPV_EXPORT void mpv_free_node_contents (mpv_node *node);

  /**
   * Set an option. Note that you can't normally set options during runtime. It
   * works in uninitialized state (see mpv_create()), and in some cases in at
   * runtime.
   *
   * Using a format other than MPV_FORMAT_NODE is equivalent to constructing a
   * mpv_node with the given format and data, and passing the mpv_node to this
   * function.
   *
   * Note: this is semi-deprecated. For most purposes, this is not needed
   * anymore. Starting with mpv version 0.21.0 (version 1.23) most options can
   * be set with mpv_set_property() (and related functions), and even before
   *       mpv_initialize(). In some obscure corner cases, using this function
   *       to set options might still be required (see
   *       "Inconsistencies between options and properties" in the manpage).
   * Once these are resolved, the option setting functions might be fully
   *       deprecated.
   *
   * @param name Option name. This is the same as on the mpv command line, but
   *             without the leading "--".
   * @param format see enum mpv_format.
   * @param[in] data Option value (according to the format).
   * @return error code
   */
  MPV_EXPORT int mpv_set_option (mpv_handle *ctx, const char *name,
                                 mpv_format format, void *data);

  /**
   * Convenience function to set an option to a string value. This is like
   * calling mpv_set_option() with MPV_FORMAT_STRING.
   *
   * @return error code
   */
  MPV_EXPORT int mpv_set_option_string (mpv_handle *ctx, const char *name,
                                        const char *data);

  /**
   * Send a command to the player. Commands are the same as those used in
   * input.conf, except that this function takes parameters in a pre-split
   * form.
   *
   * The commands and their parameters are documented in input.rst.
   *
   * Does not use OSD and string expansion by default (unlike
   * mpv_command_string() and input.conf).
   *
   * @param[in] args NULL-terminated list of strings. Usually, the first item
   *                 is the command, and the following items are arguments.
   * @return error code
   */
  MPV_EXPORT int mpv_command (mpv_handle *ctx, const char **args);

  /**
   * Same as mpv_command(), but allows passing structured data in any format.
   * In particular, calling mpv_command() is exactly like calling
   * mpv_command_node() with the format set to MPV_FORMAT_NODE_ARRAY, and
   * every arg passed in order as MPV_FORMAT_STRING.
   *
   * Does not use OSD and string expansion by default.
   *
   * The args argument can have one of the following formats:
   *
   * MPV_FORMAT_NODE_ARRAY:
   *      Positional arguments. Each entry is an argument using an arbitrary
   *      format (the format must be compatible to the used command). Usually,
   *      the first item is the command name (as MPV_FORMAT_STRING). The order
   *      of arguments is as documented in each command description.
   *
   * MPV_FORMAT_NODE_MAP:
   *      Named arguments. This requires at least an entry with the key "name"
   *      to be present, which must be a string, and contains the command name.
   *      The special entry "_flags" is optional, and if present, must be an
   *      array of strings, each being a command prefix to apply. All other
   *      entries are interpreted as arguments. They must use the argument
   * names as documented in each command description. Some commands do not
   *      support named arguments at all, and must use MPV_FORMAT_NODE_ARRAY.
   *
   * @param[in] args mpv_node with format set to one of the values documented
   *                 above (see there for details)
   * @param[out] result Optional, pass NULL if unused. If not NULL, and if the
   *                    function succeeds, this is set to command-specific
   * return data. You must call mpv_free_node_contents() to free it (again,
   * only if the command actually succeeds). Not many commands actually use
   * this at all.
   * @return error code (the result parameter is not set on error)
   */
  MPV_EXPORT int mpv_command_node (mpv_handle *ctx, mpv_node *args,
                                   mpv_node *result);

  /**
   * This is essentially identical to mpv_command() but it also returns a
   * result.
   *
   * Does not use OSD and string expansion by default.
   *
   * @param[in] args NULL-terminated list of strings. Usually, the first item
   *                 is the command, and the following items are arguments.
   * @param[out] result Optional, pass NULL if unused. If not NULL, and if the
   *                    function succeeds, this is set to command-specific
   * return data. You must call mpv_free_node_contents() to free it (again,
   * only if the command actually succeeds). Not many commands actually use
   * this at all.
   * @return error code (the result parameter is not set on error)
   */
  MPV_EXPORT int mpv_command_ret (mpv_handle *ctx, const char **args,
                                  mpv_node *result);

  /**
   * Same as mpv_command, but use input.conf parsing for splitting arguments.
   * This is slightly simpler, but also more error prone, since arguments may
   * need quoting/escaping.
   *
   * This also has OSD and string expansion enabled by default.
   */
  MPV_EXPORT int mpv_command_string (mpv_handle *ctx, const char *args);

  /**
   * Same as mpv_command, but run the command asynchronously.
   *
   * Commands are executed asynchronously. You will receive a
   * MPV_EVENT_COMMAND_REPLY event. This event will also have an
   * error code set if running the command failed. For commands that
   * return data, the data is put into mpv_event_command.result.
   *
   * The only case when you do not receive an event is when the function call
   * itself fails. This happens only if parsing the command itself (or
   * otherwise validating it) fails, i.e. the return code of the API call is
   * not 0 or positive.
   *
   * Safe to be called from mpv render API threads.
   *
   * @param reply_userdata the value mpv_event.reply_userdata of the reply will
   *                       be set to (see section about asynchronous calls)
   * @param args NULL-terminated list of strings (see mpv_command())
   * @return error code (if parsing or queuing the command fails)
   */
  MPV_EXPORT int mpv_command_async (mpv_handle *ctx, uint64_t reply_userdata,
                                    const char **args);

  /**
   * Same as mpv_command_node(), but run it asynchronously. Basically, this
   * function is to mpv_command_node() what mpv_command_async() is to
   * mpv_command().
   *
   * See mpv_command_async() for details.
   *
   * Safe to be called from mpv render API threads.
   *
   * @param reply_userdata the value mpv_event.reply_userdata of the reply will
   *                       be set to (see section about asynchronous calls)
   * @param args as in mpv_command_node()
   * @return error code (if parsing or queuing the command fails)
   */
  MPV_EXPORT int mpv_command_node_async (mpv_handle *ctx,
                                         uint64_t reply_userdata,
                                         mpv_node *args);

  /**
   * Signal to all async requests with the matching ID to abort. This affects
   * the following API calls:
   *
   *      mpv_command_async
   *      mpv_command_node_async
   *
   * All of these functions take a reply_userdata parameter. This API function
   * tells all requests with the matching reply_userdata value to try to return
   * as soon as possible. If there are multiple requests with matching ID, it
   * aborts all of them.
   *
   * This API function is mostly asynchronous itself. It will not wait until
   * the command is aborted. Instead, the command will terminate as usual, but
   * with some work not done. How this is signaled depends on the specific
   * command (for example, the "subprocess" command will indicate it by
   * "killed_by_us" set to true in the result). How long it takes also depends
   * on the situation. The aborting process is completely asynchronous.
   *
   * Not all commands may support this functionality. In this case, this
   * function will have no effect. The same is true if the request using the
   * passed reply_userdata has already terminated, has not been started yet, or
   * was never in use at all.
   *
   * You have to be careful of race conditions: the time during which the abort
   * request will be effective is _after_ e.g. mpv_command_async() has
   * returned, and before the command has signaled completion with
   * MPV_EVENT_COMMAND_REPLY.
   *
   * @param reply_userdata ID of the request to be aborted (see above)
   */
  MPV_EXPORT void mpv_abort_async_command (mpv_handle *ctx,
                                           uint64_t reply_userdata);

  /**
   * Set a property to a given value. Properties are essentially variables
   * which can be queried or set at runtime. For example, writing to the pause
   * property will actually pause or unpause playback.
   *
   * If the format doesn't match with the internal format of the property,
   * access usually will fail with MPV_ERROR_PROPERTY_FORMAT. In some cases,
   * the data is automatically converted and access succeeds. For example,
   * MPV_FORMAT_INT64 is always converted to MPV_FORMAT_DOUBLE, and access
   * using MPV_FORMAT_STRING usually invokes a string parser. The same happens
   * when calling this function with MPV_FORMAT_NODE: the underlying format may
   * be converted to another type if possible.
   *
   * Using a format other than MPV_FORMAT_NODE is equivalent to constructing a
   * mpv_node with the given format and data, and passing the mpv_node to this
   * function. (Before API version 1.21, this was different.)
   *
   * Note: starting with mpv 0.21.0 (client API version 1.23), this can be used
   * to set options in general. It even can be used before mpv_initialize() has
   * been called. If called before mpv_initialize(), setting properties not
   * backed by options will result in MPV_ERROR_PROPERTY_UNAVAILABLE. In some
   * cases, properties and options still conflict. In these cases,
   *       mpv_set_property() accesses the options before mpv_initialize(), and
   *       the properties after mpv_initialize(). These conflicts will be
   * removed in mpv 0.23.0. See mpv_set_option() for further remarks.
   *
   * @param name The property name. See input.rst for a list of properties.
   * @param format see enum mpv_format.
   * @param[in] data Option value.
   * @return error code
   */
  MPV_EXPORT int mpv_set_property (mpv_handle *ctx, const char *name,
                                   mpv_format format, void *data);

  /**
   * Convenience function to set a property to a string value.
   *
   * This is like calling mpv_set_property() with MPV_FORMAT_STRING.
   */
  MPV_EXPORT int mpv_set_property_string (mpv_handle *ctx, const char *name,
                                          const char *data);

  /**
   * Convenience function to delete a property.
   *
   * This is equivalent to running the command "del [name]".
   *
   * @param name The property name. See input.rst for a list of properties.
   * @return error code
   */
  MPV_EXPORT int mpv_del_property (mpv_handle *ctx, const char *name);

  /**
   * Set a property asynchronously. You will receive the result of the
   * operation as MPV_EVENT_SET_PROPERTY_REPLY event. The mpv_event.error field
   * will contain the result status of the operation. Otherwise, this function
   * is similar to mpv_set_property().
   *
   * Safe to be called from mpv render API threads.
   *
   * @param reply_userdata see section about asynchronous calls
   * @param name The property name.
   * @param format see enum mpv_format.
   * @param[in] data Option value. The value will be copied by the function. It
   *                 will never be modified by the client API.
   * @return error code if sending the request failed
   */
  MPV_EXPORT int mpv_set_property_async (mpv_handle *ctx,
                                         uint64_t reply_userdata,
                                         const char *name, mpv_format format,
                                         void *data);

  /**
   * Read the value of the given property.
   *
   * If the format doesn't match with the internal format of the property,
   * access usually will fail with MPV_ERROR_PROPERTY_FORMAT. In some cases,
   * the data is automatically converted and access succeeds. For example,
   * MPV_FORMAT_INT64 is always converted to MPV_FORMAT_DOUBLE, and access
   * using MPV_FORMAT_STRING usually invokes a string formatter.
   *
   * @param name The property name.
   * @param format see enum mpv_format.
   * @param[out] data Pointer to the variable holding the option value. On
   *                  success, the variable will be set to a copy of the option
   *                  value. For formats that require dynamic memory
   * allocation, you can free the value with mpv_free() (strings) or
   *                  mpv_free_node_contents() (MPV_FORMAT_NODE).
   * @return error code
   */
  MPV_EXPORT int mpv_get_property (mpv_handle *ctx, const char *name,
                                   mpv_format format, void *data);

  /**
   * Return the value of the property with the given name as string. This is
   * equivalent to mpv_get_property() with MPV_FORMAT_STRING.
   *
   * See MPV_FORMAT_STRING for character encoding issues.
   *
   * On error, NULL is returned. Use mpv_get_property() if you want
   * fine-grained error reporting.
   *
   * @param name The property name.
   * @return Property value, or NULL if the property can't be retrieved. Free
   *         the string with mpv_free().
   */
  MPV_EXPORT char *mpv_get_property_string (mpv_handle *ctx, const char *name);

  /**
   * Return the property as "OSD" formatted string. This is the same as
   * mpv_get_property_string, but using MPV_FORMAT_OSD_STRING.
   *
   * @return Property value, or NULL if the property can't be retrieved. Free
   *         the string with mpv_free().
   */
  MPV_EXPORT char *mpv_get_property_osd_string (mpv_handle *ctx,
                                                const char *name);

  /**
   * Get a property asynchronously. You will receive the result of the
   * operation as well as the property data with the
   * MPV_EVENT_GET_PROPERTY_REPLY event. You should check the mpv_event.error
   * field on the reply event.
   *
   * Safe to be called from mpv render API threads.
   *
   * @param reply_userdata see section about asynchronous calls
   * @param name The property name.
   * @param format see enum mpv_format.
   * @return error code if sending the request failed
   */
  MPV_EXPORT int mpv_get_property_async (mpv_handle *ctx,
                                         uint64_t reply_userdata,
                                         const char *name, mpv_format format);

  /**
   * Get a notification whenever the given property changes. You will receive
   * updates as MPV_EVENT_PROPERTY_CHANGE. Note that this is not very precise:
   * for some properties, it may not send updates even if the property changed.
   * This depends on the property, and it's a valid feature request to ask for
   * better update handling of a specific property. (For some properties, like
   * ``clock``, which shows the wall clock, this mechanism doesn't make too
   * much sense anyway.)
   *
   * Property changes are coalesced: the change events are returned only once
   * the event queue becomes empty (e.g. mpv_wait_event() would block or return
   * MPV_EVENT_NONE), and then only one event per changed property is returned.
   *
   * You always get an initial change notification. This is meant to initialize
   * the user's state to the current value of the property.
   *
   * Normally, change events are sent only if the property value changes
   * according to the requested format. mpv_event_property will contain the
   * property value as data member.
   *
   * Warning: if a property is unavailable or retrieving it caused an error,
   *          MPV_FORMAT_NONE will be set in mpv_event_property, even if the
   *          format parameter was set to a different value. In this case, the
   *          mpv_event_property.data field is invalid.
   *
   * If the property is observed with the format parameter set to
   * MPV_FORMAT_NONE, you get low-level notifications whether the property
   * _may_ have changed, and the data member in mpv_event_property will be
   * unset. With this mode, you will have to determine yourself whether the
   * property really changed. On the other hand, this mechanism can be faster
   * and uses less resources.
   *
   * Observing a property that doesn't exist is allowed. (Although it may still
   * cause some sporadic change events.)
   *
   * Keep in mind that you will get change notifications even if you change a
   * property yourself. Try to avoid endless feedback loops, which could happen
   * if you react to the change notifications triggered by your own change.
   *
   * Only the mpv_handle on which this was called will receive the property
   * change events, or can unobserve them.
   *
   * Safe to be called from mpv render API threads.
   *
   * @param reply_userdata This will be used for the mpv_event.reply_userdata
   *                       field for the received MPV_EVENT_PROPERTY_CHANGE
   *                       events. (Also see section about asynchronous calls,
   *                       although this function is somewhat different from
   *                       actual asynchronous calls.)
   *                       If you have no use for this, pass 0.
   *                       Also see mpv_unobserve_property().
   * @param name The property name.
   * @param format see enum mpv_format. Can be MPV_FORMAT_NONE to omit values
   *               from the change events.
   * @return error code (usually fails only on OOM or unsupported format)
   */
  MPV_EXPORT int mpv_observe_property (mpv_handle *mpv,
                                       uint64_t reply_userdata,
                                       const char *name, mpv_format format);

  /**
   * Undo mpv_observe_property(). This will remove all observed properties for
   * which the given number was passed as reply_userdata to
   * mpv_observe_property.
   *
   * Safe to be called from mpv render API threads.
   *
   * @param registered_reply_userdata ID that was passed to
   * mpv_observe_property
   * @return negative value is an error code, >=0 is number of removed
   * properties on success (includes the case when 0 were removed)
   */
  MPV_EXPORT int mpv_unobserve_property (mpv_handle *mpv,
                                         uint64_t registered_reply_userdata);

  typedef enum mpv_event_id
  {
    /**
     * Nothing happened. Happens on timeouts or sporadic wakeups.
     */
    MPV_EVENT_NONE = 0,
    /**
     * Happens when the player quits. The player enters a state where it tries
     * to disconnect all clients. Most requests to the player will fail, and
     * the client should react to this and quit with mpv_destroy() as soon as
     * possible.
     */
    MPV_EVENT_SHUTDOWN = 1,
    /**
     * See mpv_request_log_messages().
     */
    MPV_EVENT_LOG_MESSAGE = 2,
    /**
     * Reply to a mpv_get_property_async() request.
     * See also mpv_event and mpv_event_property.
     */
    MPV_EVENT_GET_PROPERTY_REPLY = 3,
    /**
     * Reply to a mpv_set_property_async() request.
     * (Unlike MPV_EVENT_GET_PROPERTY, mpv_event_property is not used.)
     */
    MPV_EVENT_SET_PROPERTY_REPLY = 4,
    /**
     * Reply to a mpv_command_async() or mpv_command_node_async() request.
     * See also mpv_event and mpv_event_command.
     */
    MPV_EVENT_COMMAND_REPLY = 5,
    /**
     * Notification before playback start of a file (before the file is
     * loaded). See also mpv_event and mpv_event_start_file.
     */
    MPV_EVENT_START_FILE = 6,
    /**
     * Notification after playback end (after the file was unloaded).
     * See also mpv_event and mpv_event_end_file.
     */
    MPV_EVENT_END_FILE = 7,
    /**
     * Notification when the file has been loaded (headers were read etc.), and
     * decoding starts.
     */
    MPV_EVENT_FILE_LOADED = 8,
#if MPV_ENABLE_DEPRECATED
    /**
     * Idle mode was entered. In this mode, no file is played, and the playback
     * core waits for new commands. (The command line player normally quits
     * instead of entering idle mode, unless --idle was specified. If mpv
     * was started with mpv_create(), idle mode is enabled by default.)
     *
     * @deprecated This is equivalent to using mpv_observe_property() on the
     *             "idle-active" property. The event is redundant, and might be
     *             removed in the far future. As a further warning, this event
     *             is not necessarily sent at the right point anymore (at the
     *             start of the program), while the property behaves correctly.
     */
    MPV_EVENT_IDLE = 11,
    /**
     * Sent every time after a video frame is displayed. Note that currently,
     * this will be sent in lower frequency if there is no video, or playback
     * is paused - but that will be removed in the future, and it will be
     * restricted to video frames only.
     *
     * @deprecated Use mpv_observe_property() with relevant properties instead
     *             (such as "playback-time").
     */
    MPV_EVENT_TICK = 14,
#endif
    /**
     * Triggered by the script-message input command. The command uses the
     * first argument of the command as client name (see mpv_client_name()) to
     * dispatch the message, and passes along all arguments starting from the
     * second argument as strings.
     * See also mpv_event and mpv_event_client_message.
     */
    MPV_EVENT_CLIENT_MESSAGE = 16,
    /**
     * Happens after video changed in some way. This can happen on resolution
     * changes, pixel format changes, or video filter changes. The event is
     * sent after the video filters and the VO are reconfigured. Applications
     * embedding a mpv window should listen to this event in order to resize
     * the window if needed.
     * Note that this event can happen sporadically, and you should check
     * yourself whether the video parameters really changed before doing
     * something expensive.
     */
    MPV_EVENT_VIDEO_RECONFIG = 17,
    /**
     * Similar to MPV_EVENT_VIDEO_RECONFIG. This is relatively uninteresting,
     * because there is no such thing as audio output embedding.
     */
    MPV_EVENT_AUDIO_RECONFIG = 18,
    /**
     * Happens when a seek was initiated. Playback stops. Usually it will
     * resume with MPV_EVENT_PLAYBACK_RESTART as soon as the seek is finished.
     */
    MPV_EVENT_SEEK = 20,
    /**
     * There was a discontinuity of some sort (like a seek), and playback
     * was reinitialized. Usually happens on start of playback and after
     * seeking. The main purpose is allowing the client to detect when a seek
     * request is finished.
     */
    MPV_EVENT_PLAYBACK_RESTART = 21,
    /**
     * Event sent due to mpv_observe_property().
     * See also mpv_event and mpv_event_property.
     */
    MPV_EVENT_PROPERTY_CHANGE = 22,
    /**
     * Happens if the internal per-mpv_handle ringbuffer overflows, and at
     * least 1 event had to be dropped. This can happen if the client doesn't
     * read the event queue quickly enough with mpv_wait_event(), or if the
     * client makes a very large number of asynchronous calls at once.
     *
     * Event delivery will continue normally once this event was returned
     * (this forces the client to empty the queue completely).
     */
    MPV_EVENT_QUEUE_OVERFLOW = 24,
    /**
     * Triggered if a hook handler was registered with mpv_hook_add(), and the
     * hook is invoked. If you receive this, you must handle it, and continue
     * the hook with mpv_hook_continue().
     * See also mpv_event and mpv_event_hook.
     */
    MPV_EVENT_HOOK = 25,
    // Internal note: adjust INTERNAL_EVENT_BASE when adding new events.
  } mpv_event_id;

  /**
   * Return a string describing the event. For unknown events, NULL is
   * returned.
   *
   * Note that all events actually returned by the API will also yield a
   * non-NULL string with this function.
   *
   * @param event event ID, see see enum mpv_event_id
   * @return A static string giving a short symbolic name of the event. It
   *         consists of lower-case alphanumeric characters and can include "-"
   *         characters. This string is suitable for use in e.g. scripting
   *         interfaces.
   *         The string is completely static, i.e. doesn't need to be
   * deallocated, and is valid forever.
   */
  MPV_EXPORT const char *mpv_event_name (mpv_event_id event);

  typedef struct mpv_event_property
  {
    /**
     * Name of the property.
     */
    const char *name;
    /**
     * Format of the data field in the same struct. See enum mpv_format.
     * This is always the same format as the requested format, except when
     * the property could not be retrieved (unavailable, or an error happened),
     * in which case the format is MPV_FORMAT_NONE.
     */
    mpv_format format;
    /**
     * Received property value. Depends on the format. This is like the
     * pointer argument passed to mpv_get_property().
     *
     * For example, for MPV_FORMAT_STRING you get the string with:
     *
     *    char *value = *(char **)(event_property->data);
     *
     * Note that this is set to NULL if retrieving the property failed (the
     * format will be MPV_FORMAT_NONE).
     */
    void *data;
  } mpv_event_property;

  /**
   * Numeric log levels. The lower the number, the more important the message
   * is. MPV_LOG_LEVEL_NONE is never used when receiving messages. The string
   * in the comment after the value is the name of the log level as used for
   * the mpv_request_log_messages() function. Unused numeric values are unused,
   * but reserved for future use.
   */
  typedef enum mpv_log_level
  {
    MPV_LOG_LEVEL_NONE = 0,   /// "no"    - disable absolutely all messages
    MPV_LOG_LEVEL_FATAL = 10, /// "fatal" - critical/aborting errors
    MPV_LOG_LEVEL_ERROR = 20, /// "error" - simple errors
    MPV_LOG_LEVEL_WARN = 30,  /// "warn"  - possible problems
    MPV_LOG_LEVEL_INFO = 40,  /// "info"  - informational message
    MPV_LOG_LEVEL_V = 50,     /// "v"     - noisy informational message
    MPV_LOG_LEVEL_DEBUG = 60, /// "debug" - very noisy technical information
    MPV_LOG_LEVEL_TRACE = 70, /// "trace" - extremely noisy
  } mpv_log_level;

  typedef struct mpv_event_log_message
  {
    /**
     * The module prefix, identifies the sender of the message. As a special
     * case, if the message buffer overflows, this will be set to the string
     * "overflow" (which doesn't appear as prefix otherwise), and the text
     * field will contain an informative message.
     */
    const char *prefix;
    /**
     * The log level as string. See mpv_request_log_messages() for possible
     * values. The level "no" is never used here.
     */
    const char *level;
    /**
     * The log message. It consists of 1 line of text, and is terminated with
     * a newline character. (Before API version 1.6, it could contain multiple
     * or partial lines.)
     */
    const char *text;
    /**
     * The same contents as the level field, but as a numeric ID.
     * Since API version 1.6.
     */
    mpv_log_level log_level;
  } mpv_event_log_message;

  /// Since API version 1.9.
  typedef enum mpv_end_file_reason
  {
    /**
     * The end of file was reached. Sometimes this may also happen on
     * incomplete or corrupted files, or if the network connection was
     * interrupted when playing a remote file. It also happens if the
     * playback range was restricted with --end or --frames or similar.
     */
    MPV_END_FILE_REASON_EOF = 0,
    /**
     * Playback was stopped by an external action (e.g. playlist controls).
     */
    MPV_END_FILE_REASON_STOP = 2,
    /**
     * Playback was stopped by the quit command or player shutdown.
     */
    MPV_END_FILE_REASON_QUIT = 3,
    /**
     * Some kind of error happened that lead to playback abort. Does not
     * necessarily happen on incomplete or broken files (in these cases, both
     * MPV_END_FILE_REASON_ERROR or MPV_END_FILE_REASON_EOF are possible).
     *
     * mpv_event_end_file.error will be set.
     */
    MPV_END_FILE_REASON_ERROR = 4,
    /**
     * The file was a playlist or similar. When the playlist is read, its
     * entries will be appended to the playlist after the entry of the current
     * file, the entry of the current file is removed, and a MPV_EVENT_END_FILE
     * event is sent with reason set to MPV_END_FILE_REASON_REDIRECT. Then
     * playback continues with the playlist contents.
     * Since API version 1.18.
     */
    MPV_END_FILE_REASON_REDIRECT = 5,
  } mpv_end_file_reason;

  /// Since API version 1.108.
  typedef struct mpv_event_start_file
  {
    /**
     * Playlist entry ID of the file being loaded now.
     */
    int64_t playlist_entry_id;
  } mpv_event_start_file;

  typedef struct mpv_event_end_file
  {
    /**
     * Corresponds to the values in enum mpv_end_file_reason.
     *
     * Unknown values should be treated as unknown.
     */
    mpv_end_file_reason reason;
    /**
     * If reason==MPV_END_FILE_REASON_ERROR, this contains a mpv error code
     * (one of MPV_ERROR_...) giving an approximate reason why playback
     * failed. In other cases, this field is 0 (no error).
     * Since API version 1.9.
     */
    int error;
    /**
     * Playlist entry ID of the file that was being played or attempted to be
     * played. This has the same value as the playlist_entry_id field in the
     * corresponding mpv_event_start_file event.
     * Since API version 1.108.
     */
    int64_t playlist_entry_id;
    /**
     * If loading ended, because the playlist entry to be played was for
     * example a playlist, and the current playlist entry is replaced with a
     * number of other entries. This may happen at least with
     * MPV_END_FILE_REASON_REDIRECT (other event types may use this for similar
     * but different purposes in the future). In this case, playlist_insert_id
     * will be set to the playlist entry ID of the first inserted entry, and
     * playlist_insert_num_entries to the total number of inserted playlist
     * entries. Note this in this specific case, the ID of the last inserted
     * entry is playlist_insert_id+num-1. Beware that depending on
     * circumstances, you may observe the new playlist entries before seeing
     * the event (e.g. reading the "playlist" property or getting a property
     * change notification before receiving the event). Since API
     * version 1.108.
     */
    int64_t playlist_insert_id;
    /**
     * See playlist_insert_id. Only non-0 if playlist_insert_id is valid. Never
     * negative.
     * Since API version 1.108.
     */
    int playlist_insert_num_entries;
  } mpv_event_end_file;

  typedef struct mpv_event_client_message
  {
    /**
     * Arbitrary arguments chosen by the sender of the message. If num_args >
     * 0, you can access args[0] through args[num_args - 1] (inclusive). What
     * these arguments mean is up to the sender and receiver.
     * None of the valid items are NULL.
     */
    int num_args;
    const char **args;
  } mpv_event_client_message;

  typedef struct mpv_event_hook
  {
    /**
     * The hook name as passed to mpv_hook_add().
     */
    const char *name;
    /**
     * Internal ID that must be passed to mpv_hook_continue().
     */
    uint64_t id;
  } mpv_event_hook;

  // Since API version 1.102.
  typedef struct mpv_event_command
  {
    /**
     * Result data of the command. Note that success/failure is signaled
     * separately via mpv_event.error. This field is only for result data
     * in case of success. Most commands leave it at MPV_FORMAT_NONE. Set
     * to MPV_FORMAT_NONE on failure.
     */
    mpv_node result;
  } mpv_event_command;

  typedef struct mpv_event
  {
    /**
     * One of mpv_event. Keep in mind that later ABI compatible releases might
     * add new event types. These should be ignored by the API user.
     */
    mpv_event_id event_id;
    /**
     * This is mainly used for events that are replies to (asynchronous)
     * requests. It contains a status code, which is >= 0 on success, or < 0
     * on error (a mpv_error value). Usually, this will be set if an
     * asynchronous request fails.
     * Used for:
     *  MPV_EVENT_GET_PROPERTY_REPLY
     *  MPV_EVENT_SET_PROPERTY_REPLY
     *  MPV_EVENT_COMMAND_REPLY
     */
    int error;
    /**
     * If the event is in reply to a request (made with this API and this
     * API handle), this is set to the reply_userdata parameter of the request
     * call. Otherwise, this field is 0.
     * Used for:
     *  MPV_EVENT_GET_PROPERTY_REPLY
     *  MPV_EVENT_SET_PROPERTY_REPLY
     *  MPV_EVENT_COMMAND_REPLY
     *  MPV_EVENT_PROPERTY_CHANGE
     *  MPV_EVENT_HOOK
     */
    uint64_t reply_userdata;
    /**
     * The meaning and contents of the data member depend on the event_id:
     *  MPV_EVENT_GET_PROPERTY_REPLY:     mpv_event_property*
     *  MPV_EVENT_PROPERTY_CHANGE:        mpv_event_property*
     *  MPV_EVENT_LOG_MESSAGE:            mpv_event_log_message*
     *  MPV_EVENT_CLIENT_MESSAGE:         mpv_event_client_message*
     *  MPV_EVENT_START_FILE:             mpv_event_start_file* (since v1.108)
     *  MPV_EVENT_END_FILE:               mpv_event_end_file*
     *  MPV_EVENT_HOOK:                   mpv_event_hook*
     *  MPV_EVENT_COMMAND_REPLY*          mpv_event_command*
     *  other: NULL
     *
     * Note: future enhancements might add new event structs for existing or
     * new event types.
     */
    void *data;
  } mpv_event;

  /**
   * Convert the given src event to a mpv_node, and set *dst to the result.
   * *dst is set to a MPV_FORMAT_NODE_MAP, with fields for corresponding
   * mpv_event and mpv_event.data/mpv_event_* fields.
   *
   * The exact details are not completely documented out of laziness. A start
   * is located in the "Events" section of the manpage.
   *
   * *dst may point to newly allocated memory, or pointers in mpv_event. You
   * must copy the entire mpv_node if you want to reference it after mpv_event
   * becomes invalid (such as making a new mpv_wait_event() call, or destroying
   * the mpv_handle from which it was returned). Call mpv_free_node_contents()
   * to free any memory allocations made by this API function.
   *
   * Safe to be called from mpv render API threads.
   *
   * @param dst Target. This is not read and fully overwritten. Must be
   * released with mpv_free_node_contents(). Do not write to pointers returned
   *            by it. (On error, this may be left as an empty node.)
   * @param src The source event. Not modified (it's not const due to the
   * author's prejudice of the C version of const).
   * @return error code (MPV_ERROR_NOMEM only, if at all)
   */
  MPV_EXPORT int mpv_event_to_node (mpv_node *dst, mpv_event *src);

  /**
   * Enable or disable the given event.
   *
   * Some events are enabled by default. Some events can't be disabled.
   *
   * (Informational note: currently, all events are enabled by default, except
   *  MPV_EVENT_TICK.)
   *
   * Safe to be called from mpv render API threads.
   *
   * @param event See enum mpv_event_id.
   * @param enable 1 to enable receiving this event, 0 to disable it.
   * @return error code
   */
  MPV_EXPORT int mpv_request_event (mpv_handle *ctx, mpv_event_id event,
                                    int enable);

  /**
   * Enable or disable receiving of log messages. These are the messages the
   * command line player prints to the terminal. This call sets the minimum
   * required log level for a message to be received with
   * MPV_EVENT_LOG_MESSAGE.
   *
   * @param min_level Minimal log level as string. Valid log levels:
   *                      no fatal error warn info v debug trace
   *                  The value "no" disables all messages. This is the
   * default. An exception is the value "terminal-default", which uses the log
   * level as set by the "--msg-level" option. This works even if the terminal
   * is disabled. (Since API version 1.19.) Also see mpv_log_level.
   * @return error code
   */
  MPV_EXPORT int mpv_request_log_messages (mpv_handle *ctx,
                                           const char *min_level);

  /**
   * Wait for the next event, or until the timeout expires, or if another
   * thread makes a call to mpv_wakeup(). Passing 0 as timeout will never wait,
   * and is suitable for polling.
   *
   * The internal event queue has a limited size (per client handle). If you
   * don't empty the event queue quickly enough with mpv_wait_event(), it will
   * overflow and silently discard further events. If this happens, making
   * asynchronous requests will fail as well (with MPV_ERROR_EVENT_QUEUE_FULL).
   *
   * Only one thread is allowed to call this on the same mpv_handle at a time.
   * The API won't complain if more than one thread calls this, but it will
   * cause race conditions in the client when accessing the shared mpv_event
   * struct. Note that most other API functions are not restricted by this, and
   * no API function internally calls mpv_wait_event(). Additionally,
   * concurrent calls to different mpv_handles are always safe.
   *
   * As long as the timeout is 0, this is safe to be called from mpv render API
   * threads.
   *
   * @param timeout Timeout in seconds, after which the function returns even
   * if no event was received. A MPV_EVENT_NONE is returned on timeout. A value
   * of 0 will disable waiting. Negative values will wait with an infinite
   * timeout.
   * @return A struct containing the event ID and other data. The pointer (and
   *         fields in the struct) stay valid until the next mpv_wait_event()
   *         call, or until the mpv_handle is destroyed. You must not write to
   *         the struct, and all memory referenced by it will be automatically
   *         released by the API on the next mpv_wait_event() call, or when the
   *         context is destroyed. The return value is never NULL.
   */
  MPV_EXPORT mpv_event *mpv_wait_event (mpv_handle *ctx, double timeout);

  /**
   * Interrupt the current mpv_wait_event() call. This will wake up the thread
   * currently waiting in mpv_wait_event(). If no thread is waiting, the next
   * mpv_wait_event() call will return immediately (this is to avoid lost
   * wakeups).
   *
   * mpv_wait_event() will receive a MPV_EVENT_NONE if it's woken up due to
   * this call. But note that this dummy event might be skipped if there are
   * already other events queued. All what counts is that the waiting thread
   * is woken up at all.
   *
   * Safe to be called from mpv render API threads.
   */
  MPV_EXPORT void mpv_wakeup (mpv_handle *ctx);

  /**
   * Set a custom function that should be called when there are new events. Use
   * this if blocking in mpv_wait_event() to wait for new events is not
   * feasible.
   *
   * Keep in mind that the callback will be called from foreign threads. You
   * must not make any assumptions of the environment, and you must return as
   * soon as possible (i.e. no long blocking waits). Exiting the callback
   * through any other means than a normal return is forbidden (no throwing
   * exceptions, no longjmp() calls). You must not change any local thread
   * state (such as the C floating point environment).
   *
   * You are not allowed to call any client API functions inside of the
   * callback. In particular, you should not do any processing in the callback,
   * but wake up another thread that does all the work. The callback is meant
   * strictly for notification only, and is called from arbitrary core parts of
   * the player, that make no considerations for reentrant API use or allowing
   * the callee to spend a lot of time doing other things. Keep in mind that
   * it's also possible that the callback is called from a thread while a mpv
   * API function is called (i.e. it can be reentrant).
   *
   * In general, the client API expects you to call mpv_wait_event() to receive
   * notifications, and the wakeup callback is merely a helper utility to make
   * this easier in certain situations. Note that it's possible that there's
   * only one wakeup callback invocation for multiple events. You should call
   * mpv_wait_event() with no timeout until MPV_EVENT_NONE is reached, at which
   * point the event queue is empty.
   *
   * If you actually want to do processing in a callback, spawn a thread that
   * does nothing but call mpv_wait_event() in a loop and dispatches the result
   * to a callback.
   *
   * Only one wakeup callback can be set.
   *
   * @param cb function that should be called if a wakeup is required
   * @param d arbitrary userdata passed to cb
   */
  MPV_EXPORT void mpv_set_wakeup_callback (mpv_handle *ctx,
                                           void (*cb) (void *d), void *d);

  /**
   * Block until all asynchronous requests are done. This affects functions
   * like mpv_command_async(), which return immediately and return their result
   * as events.
   *
   * This is a helper, and somewhat equivalent to calling mpv_wait_event() in a
   * loop until all known asynchronous requests have sent their reply as event,
   * except that the event queue is not emptied.
   *
   * In case you called mpv_suspend() before, this will also forcibly reset the
   * suspend counter of the given handle.
   */
  MPV_EXPORT void mpv_wait_async_requests (mpv_handle *ctx);

  /**
   * A hook is like a synchronous event that blocks the player. You register
   * a hook handler with this function. You will get an event, which you need
   * to handle, and once things are ready, you can let the player continue with
   * mpv_hook_continue().
   *
   * Currently, hooks can't be removed explicitly. But they will be implicitly
   * removed if the mpv_handle it was registered with is destroyed. This also
   * continues the hook if it was being handled by the destroyed mpv_handle
   * (but this should be avoided, as it might mess up order of hook execution).
   *
   * Hook handlers are ordered globally by priority and order of registration.
   * Handlers for the same hook with same priority are invoked in order of
   * registration (the handler registered first is run first). Handlers with
   * lower priority are run first (which seems backward).
   *
   * See the "Hooks" section in the manpage to see which hooks are currently
   * defined.
   *
   * Some hooks might be reentrant (so you get multiple MPV_EVENT_HOOK for the
   * same hook). If this can happen for a specific hook type, it will be
   * explicitly documented in the manpage.
   *
   * Only the mpv_handle on which this was called will receive the hook events,
   * or can "continue" them.
   *
   * @param reply_userdata This will be used for the mpv_event.reply_userdata
   *                       field for the received MPV_EVENT_HOOK events.
   *                       If you have no use for this, pass 0.
   * @param name The hook name. This should be one of the documented names. But
   *             if the name is unknown, the hook event will simply be never
   *             raised.
   * @param priority See remarks above. Use 0 as a neutral default.
   * @return error code (usually fails only on OOM)
   */
  MPV_EXPORT int mpv_hook_add (mpv_handle *ctx, uint64_t reply_userdata,
                               const char *name, int priority);

  /**
   * Respond to a MPV_EVENT_HOOK event. You must call this after you have
   * handled the event. There is no way to "cancel" or "stop" the hook.
   *
   * Calling this will will typically unblock the player for whatever the hook
   * is responsible for (e.g. for the "on_load" hook it lets it continue
   * playback).
   *
   * It is explicitly undefined behavior to call this more than once for each
   * MPV_EVENT_HOOK, to pass an incorrect ID, or to call this on a mpv_handle
   * different from the one that registered the handler and received the event.
   *
   * @param id This must be the value of the mpv_event_hook.id field for the
   *           corresponding MPV_EVENT_HOOK.
   * @return error code
   */
  MPV_EXPORT int mpv_hook_continue (mpv_handle *ctx, uint64_t id);

#if MPV_ENABLE_DEPRECATED

  /**
   * Return a UNIX file descriptor referring to the read end of a pipe. This
   * pipe can be used to wake up a poll() based processing loop. The purpose of
   * this function is very similar to mpv_set_wakeup_callback(), and provides
   * a primitive mechanism to handle coordinating a foreign event loop and the
   * libmpv event loop. The pipe is non-blocking. It's closed when the
   * mpv_handle is destroyed. This function always returns the same value (on
   * success).
   *
   * This is in fact implemented using the same underlying code as for
   * mpv_set_wakeup_callback() (though they don't conflict), and it is as if
   * each callback invocation writes a single 0 byte to the pipe. When the pipe
   * becomes readable, the code calling poll() (or select()) on the pipe should
   * read all contents of the pipe and then call mpv_wait_event(c, 0) until
   * no new events are returned. The pipe contents do not matter and can just
   * be discarded. There is not necessarily one byte per readable event in the
   * pipe. For example, the pipes are non-blocking, and mpv won't block if the
   * pipe is full. Pipes are normally limited to 4096 bytes, so if there are
   * more than 4096 events, the number of readable bytes can not equal the
   * number of events queued. Also, it's possible that mpv does not write to
   * the pipe once it's guaranteed that the client was already signaled. See
   * the example below how to do it correctly.
   *
   * Example:
   *
   *  int pipefd = mpv_get_wakeup_pipe(mpv);
   *  if (pipefd < 0)
   *      error();
   *  while (1) {
   *      struct pollfd pfds[1] = {
   *          { .fd = pipefd, .events = POLLIN },
   *      };
   *      // Wait until there are possibly new mpv events.
   *      poll(pfds, 1, -1);
   *      if (pfds[0].revents & POLLIN) {
   *          // Empty the pipe. Doing this before calling mpv_wait_event()
   *          // ensures that no wakeups are missed. It's not so important to
   *          // make sure the pipe is really empty (it will just cause some
   *          // additional wakeups in unlikely corner cases).
   *          char unused[256];
   *          read(pipefd, unused, sizeof(unused));
   *          while (1) {
   *              mpv_event *ev = mpv_wait_event(mpv, 0);
   *              // If MPV_EVENT_NONE is received, the event queue is empty.
   *              if (ev->event_id == MPV_EVENT_NONE)
   *                  break;
   *              // Process the event.
   *              ...
   *          }
   *      }
   *  }
   *
   * @deprecated this function will be removed in the future. If you need this
   *             functionality, use mpv_set_wakeup_callback(), create a pipe
   *             manually, and call write() on your pipe in the callback.
   *
   * @return A UNIX FD of the read end of the wakeup pipe, or -1 on error.
   *         On MS Windows/MinGW, this will always return -1.
   */
  MPV_EXPORT int mpv_get_wakeup_pipe (mpv_handle *ctx);

#endif

/**
 * Defining MPV_CPLUGIN_DYNAMIC_SYM during plugin compilation will replace
 * mpv_* functions with function pointers. Those pointer will be initialized
 * when loading the plugin.
 *
 * It is recommended to use this symbol table when targeting Windows. The
 * loader does not have notion of global symbols. Loading cplugin into mpv
 * process will not allow this plugin to call any of the symbols that may be
 * available in other modules. Instead cplugin has to link explicitly to
 * specific PE binary, libmpv-2.dll/mpv.exe or any other binary that may have
 * linked mpv statically. This limits portability of cplugin as it would need
 * to be compiled separately for each of target PE binary that includes mpv's
 * symbols. Which in practice is unrealistic, as we want one cplugin to be
 * loaded without those restrictions.
 *
 * Instead of linking to any PE binary, we create function pointers for all
 * mpv's exported symbols. For convenience names of entrypoints are redefined
 * to those pointer, so no changes are required in cplugin source code, except
 * of defining MPV_CPLUGIN_DYNAMIC_SYM. Those function pointer are exported to
 * make them available for mpv to init with correct values during runtime,
 * before calling `mpv_open_cplugin`.
 *
 * Note that those pointers are decorated with `selectany` attribute, so no
 * need to worry about multiple definitions, linker will keep only single
 * instance.
 */
#ifdef MPV_CPLUGIN_DYNAMIC_SYM

#define MPV_DEFINE_SYM_PTR(name)                                              \
  MPV_SELECTANY MPV_EXPORT MPV_DECLTYPE (name) * pfn_##name;

  MPV_DEFINE_SYM_PTR (mpv_client_api_version)
#define mpv_client_api_version pfn_mpv_client_api_version
  MPV_DEFINE_SYM_PTR (mpv_error_string)
#define mpv_error_string pfn_mpv_error_string
  MPV_DEFINE_SYM_PTR (mpv_free)
#define mpv_free pfn_mpv_free
  MPV_DEFINE_SYM_PTR (mpv_client_name)
#define mpv_client_name pfn_mpv_client_name
  MPV_DEFINE_SYM_PTR (mpv_client_id)
#define mpv_client_id pfn_mpv_client_id
  MPV_DEFINE_SYM_PTR (mpv_create)
#define mpv_create pfn_mpv_create
  MPV_DEFINE_SYM_PTR (mpv_initialize)
#define mpv_initialize pfn_mpv_initialize
  MPV_DEFINE_SYM_PTR (mpv_destroy)
#define mpv_destroy pfn_mpv_destroy
  MPV_DEFINE_SYM_PTR (mpv_terminate_destroy)
#define mpv_terminate_destroy pfn_mpv_terminate_destroy
  MPV_DEFINE_SYM_PTR (mpv_create_client)
#define mpv_create_client pfn_mpv_create_client
  MPV_DEFINE_SYM_PTR (mpv_create_weak_client)
#define mpv_create_weak_client pfn_mpv_create_weak_client
  MPV_DEFINE_SYM_PTR (mpv_load_config_file)
#define mpv_load_config_file pfn_mpv_load_config_file
  MPV_DEFINE_SYM_PTR (mpv_get_time_ns)
#define mpv_get_time_ns pfn_mpv_get_time_ns
  MPV_DEFINE_SYM_PTR (mpv_get_time_us)
#define mpv_get_time_us pfn_mpv_get_time_us
  MPV_DEFINE_SYM_PTR (mpv_free_node_contents)
#define mpv_free_node_contents pfn_mpv_free_node_contents
  MPV_DEFINE_SYM_PTR (mpv_set_option)
#define mpv_set_option pfn_mpv_set_option
  MPV_DEFINE_SYM_PTR (mpv_set_option_string)
#define mpv_set_option_string pfn_mpv_set_option_string
  MPV_DEFINE_SYM_PTR (mpv_command)
#define mpv_command pfn_mpv_command
  MPV_DEFINE_SYM_PTR (mpv_command_node)
#define mpv_command_node pfn_mpv_command_node
  MPV_DEFINE_SYM_PTR (mpv_command_ret)
#define mpv_command_ret pfn_mpv_command_ret
  MPV_DEFINE_SYM_PTR (mpv_command_string)
#define mpv_command_string pfn_mpv_command_string
  MPV_DEFINE_SYM_PTR (mpv_command_async)
#define mpv_command_async pfn_mpv_command_async
  MPV_DEFINE_SYM_PTR (mpv_command_node_async)
#define mpv_command_node_async pfn_mpv_command_node_async
  MPV_DEFINE_SYM_PTR (mpv_abort_async_command)
#define mpv_abort_async_command pfn_mpv_abort_async_command
  MPV_DEFINE_SYM_PTR (mpv_set_property)
#define mpv_set_property pfn_mpv_set_property
  MPV_DEFINE_SYM_PTR (mpv_set_property_string)
#define mpv_set_property_string pfn_mpv_set_property_string
  MPV_DEFINE_SYM_PTR (mpv_del_property)
#define mpv_del_property pfn_mpv_del_property
  MPV_DEFINE_SYM_PTR (mpv_set_property_async)
#define mpv_set_property_async pfn_mpv_set_property_async
  MPV_DEFINE_SYM_PTR (mpv_get_property)
#define mpv_get_property pfn_mpv_get_property
  MPV_DEFINE_SYM_PTR (mpv_get_property_string)
#define mpv_get_property_string pfn_mpv_get_property_string
  MPV_DEFINE_SYM_PTR (mpv_get_property_osd_string)
#define mpv_get_property_osd_string pfn_mpv_get_property_osd_string
  MPV_DEFINE_SYM_PTR (mpv_get_property_async)
#define mpv_get_property_async pfn_mpv_get_property_async
  MPV_DEFINE_SYM_PTR (mpv_observe_property)
#define mpv_observe_property pfn_mpv_observe_property
  MPV_DEFINE_SYM_PTR (mpv_unobserve_property)
#define mpv_unobserve_property pfn_mpv_unobserve_property
  MPV_DEFINE_SYM_PTR (mpv_event_name)
#define mpv_event_name pfn_mpv_event_name
  MPV_DEFINE_SYM_PTR (mpv_event_to_node)
#define mpv_event_to_node pfn_mpv_event_to_node
  MPV_DEFINE_SYM_PTR (mpv_request_event)
#define mpv_request_event pfn_mpv_request_event
  MPV_DEFINE_SYM_PTR (mpv_request_log_messages)
#define mpv_request_log_messages pfn_mpv_request_log_messages
  MPV_DEFINE_SYM_PTR (mpv_wait_event)
#define mpv_wait_event pfn_mpv_wait_event
  MPV_DEFINE_SYM_PTR (mpv_wakeup)
#define mpv_wakeup pfn_mpv_wakeup
  MPV_DEFINE_SYM_PTR (mpv_set_wakeup_callback)
#define mpv_set_wakeup_callback pfn_mpv_set_wakeup_callback
  MPV_DEFINE_SYM_PTR (mpv_wait_async_requests)
#define mpv_wait_async_requests pfn_mpv_wait_async_requests
  MPV_DEFINE_SYM_PTR (mpv_hook_add)
#define mpv_hook_add pfn_mpv_hook_add
  MPV_DEFINE_SYM_PTR (mpv_hook_continue)
#define mpv_hook_continue pfn_mpv_hook_continue
  MPV_DEFINE_SYM_PTR (mpv_get_wakeup_pipe)
#define mpv_get_wakeup_pipe pfn_mpv_get_wakeup_pipe

#endif

#ifdef __cplusplus
}
#endif

#endif