mpv/libmpv/client.h

813 lines
31 KiB
C

/* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
/*
* Note: the client API is licensed under ISC (see above) to ease
* interoperability with other licenses. But keep in mind that the
* mpv core is still mostly GPLv2+. It's up to lawyers to decide
* whether applications using this API are affected by the GPL.
* One argument against this is that proprietary applications
* using mplayer in slave mode is apparently tolerated, and this
* API is basically equivalent to slave mode.
*/
#ifndef MPV_CLIENT_API_H_
#define MPV_CLIENT_API_H_
#include <stdint.h>
#ifdef __cplusplus
extern "C" {
#endif
/**
* Warning: this API is still work in progress. This notice will be removed
* once the API is considered reasonably stable.
*/
/**
* 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.
*
* Event loop
* ----------
*
* In general, the API user should run an event loop (with mpv_wait_event())
* in order to receive events, although it also should be 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.)
*
* Currently, asynchronous calls are always strictly ordered (even with
* synchronous calls) for each client, although that may change in the future.
*
* 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.
* - The FPU precision must be set at least to double precision.
* - On Windows, mpv will call timeBeginPeriod(1).
*
* Embedding the video window
* --------------------------
*
* Currently you have to get the raw window handle, and set it as "wid" option.
* This works on X11 and win32 only. In addition, it works with a few VOs only,
* and VOs which do not support this will just create a freestanding window.
*
* Both on X11 and win32, the player will fill the window referenced by the
* "wid" option fully and letterbox the video (i.e. add black bars if the
* aspect ratio of the window and the video mismatch).
*/
/**
* The version is incremented on each change. The 16 lower bits are incremented
* if something in mpv is changed that might affect the client API, but doesn't
* change C API itself (like the removal of an option or a property). The higher
* 16 bits are incremented if the C API itself changes.
*/
#define MPV_CLIENT_API_VERSION 0x00000000UL
/**
* Return the MPV_CLIENT_API_VERSION the mpv source has been compiled with.
*/
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,
} 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.
*/
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.
*/
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
* mpv_destroy() is called.
*/
const char *mpv_client_name(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.
*
* Most API functions will return MPV_ERROR_UNINITIALIZED in the uninitialized
* state. You can call mpv_set_option() (or mpv_set_option_string() and other
* variants) 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
* --no-config (but actually the code path for loading config files is
* disabled).
* - 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.
*
* 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_option(). 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
*/
mpv_handle *mpv_create(void);
/**
* Initialize an uninitialized mpv instance. If the mpv instance is already
* running, an error is retuned.
*
* This function needs to be called to make full use of the client API if the
* client API handle was created with mpv_create().
*
* @return error code
*/
int mpv_initialize(mpv_handle *ctx);
/**
* Disconnect and destroy the client context. ctx will be deallocated with this
* API call. This leaves the player running. If you want to be sure that the
* player is terminated, send a "quit" command, and wait until the
* MPV_EVENT_SHUTDOWN event is received.
*/
void mpv_destroy(mpv_handle *ctx);
/**
* Stop the playback thread. Normally, the client API stops the playback thread
* automatically in order to process requests. However, the playback thread is
* restarted again after the request was processed. Then the playback thread
* will continue to display the next video frame, during which it will not
* reply to any requests. (This takes up to 50ms.)
*
* (Internally, it first renders the video and other things, and then blocks
* until it can be displayed - and it won't react to anything else in that
* time. The main reason for that is that the VO is in a "in between" state,
* in which it can't process normal requests - for example, OSD redrawing or
* screenshots would be broken.)
*
* This is usually a problem: only 1 request per video frame will be executed,
* which will make the client API to appear extremely slow.
*
* Suspending the playback thread allows you to prevent the playback thread from
* running, so that you can make multiple accesses without being blocked.
*
* Suspension is reentrant and recursive for convenience. Any thread can call
* the suspend function multiple times, and the playback thread will remain
* suspended until the last thread resumes it. Note that during suspension,
* clients still have concurrent access to the core, which is serialized through
* a single mutex.
*
* Call mpv_resume() to resume the playback thread. You must call mpv_resume()
* for each mpv_suspend() call. Calling mpv_resume() more often than
* mpv_suspend() is not allowed.
*
* Calling this on an uninitialized player (see mpv_create()) will deadlock.
*
* Note: the need for this call might go away at some point.
*/
void mpv_suspend(mpv_handle *ctx);
/**
* See mpv_suspend().
*/
void mpv_resume(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.
*/
MPV_FORMAT_NONE = 0,
/**
* The basic type is char*. It returns the raw property string, like
* using ${=property} in input.conf (see input.rst).
*
* 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);
*
* Example for writing:
*
* char *value = "the new value";
* mpv_set_property(ctx, "property", MPV_FORMAT_STRING, (void *)value);
*
*/
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,
} mpv_format;
/**
* 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 idle
* mode.
*
* You can use mpv_set_property() to change options during playback, but this
* does not work with all options.
*
* @param name Option name. This is the same as on the mpv command line, but
* without the leading "--".
* @param format see enum mpv_format. Currently, only MPV_FORMAT_STRING is valid.
* @param[in] data Option value (according to the format).
* @return error code
*/
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
*/
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.
*
* Caveat: currently, commands do not report whether they run successfully. If
* the command exists and its arguments are not broken, always success
* will be returned.
*
* @param[in] args NULL-terminated list of strings. Usually, the first item
* is the command, and the following items are arguments.
* @return error code
*/
int mpv_command(mpv_handle *ctx, const char **args);
/**
* 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.
*/
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.)
*
* @param reply_userdata see section about asynchronous calls
* @param args NULL-terminated list of strings (see mpv_command())
* @return error code
*/
int mpv_command_async(mpv_handle *ctx, uint64_t reply_userdata,
const char **args);
/**
* 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.
*
* @param name The property name. See input.rst for a list of properties.
* @param format see enum mpv_format. Currently, only MPV_FORMAT_STRING is valid.
* @param[in] data Option value.
* @return error code
*/
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.
*/
int mpv_set_property_string(mpv_handle *ctx, const char *name, const char *data);
/**
* Set a property asynchronously. You will receive the result of the operation
* as MPV_EVENT_PROPERTY_SET_REPLY event. The mpv_event.error field will contain
* the result status of the operation. Otherwise, this function is similar to
* mpv_set_property().
*
* @param reply_userdata see section about asynchronous calls
* @param name The property name.
* @param format see enum mpv_format. Currently, only MPV_FORMAT_STRING is valid.
* @param[in] data Option value. The value will be copied by the function.
* @return error code if sending the request failed
*/
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.
*
* @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. You can free the value with mpv_free().
* @return error code
*/
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.
*
* 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().
*/
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().
*/
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.
*
* @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
*/
int mpv_get_property_async(mpv_handle *ctx, uint64_t reply_userdata,
const char *name, mpv_format format);
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
* mpv_wait_event() will always return instantly (returning new shutdown
* events if no other events are queued). 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() request.
*/
MPV_EVENT_COMMAND_REPLY = 5,
/**
* Notification before playback start of a file.
*/
MPV_EVENT_START_FILE = 6,
/**
* Notification after playback end (after the file was unloaded).
*/
MPV_EVENT_END_FILE = 7,
/**
* Notification when the file has been loaded (headers were read etc.), and
* decoding starts.
*/
MPV_EVENT_PLAYBACK_START = 8,
/**
* The list of video/audio/subtitle tracks was changed.
*/
MPV_EVENT_TRACKS_CHANGED = 9,
/**
* A video/audio/subtitle track was switched on or off.
*/
MPV_EVENT_TRACK_SWITCHED = 10,
/**
* 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.)
*/
MPV_EVENT_IDLE = 11,
/**
* Playback was paused.
*/
MPV_EVENT_PAUSE = 12,
/**
* Playback was unpaused.
*/
MPV_EVENT_UNPAUSE = 13,
/**
* Sent every time after a video frame is displayed (or in lower frequency
* if there is no video, or playback is paused).
*/
MPV_EVENT_TICK = 14,
/**
* Triggered by the script_dispatch input command. The command uses the
* client name (see mpv_client_name()) to dispatch keyboard or mouse input
* to a client.
*/
MPV_EVENT_SCRIPT_INPUT_DISPATCH = 15,
} 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.
*/
const char *mpv_event_name(mpv_event_id event);
typedef struct mpv_event_property {
/**
* Name of the property.
*/
const char *name;
/**
* Format of the given data. See enum mpv_format.
* This is always the same format as the requested format.
*/
mpv_format format;
/**
* Received property value. Depends on the format.
* Note that this is set to NULL if retrieving the property failed.
* See mpv_event.error for the status.
*/
void *data;
} mpv_event_property;
typedef struct mpv_event_log_message {
/**
* The module prefix, identifies the sender of the message.
*/
const char *prefix;
/**
* The log level as string. See mpv_request_log_messages() for possible
* values.
*/
const char *level;
/**
* The log message. Note that this is the direct output of a printf()
* style output API. The text will contain embedded newlines, and it's
* possible that a single message contains multiple lines, or that a
* message contains a partial line.
*
* It's safe to display messages only if they end with a newline character,
* and to buffer them otherwise.
*/
const char *text;
} mpv_event_log_message;
typedef struct mpv_event_script_input_dispatch {
/**
* Arbitrary integer value that was provided as argument to the
* script_dispatch input command.
*/
int arg0;
/**
* Type of the input. Currently either "keyup_follows" (basically a key
* down event), or "press" (either a single key event, or a key up event
* following a "keyup_follows" event).
*/
const char *type;
} mpv_event_script_input_dispatch;
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.
*/
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.
*/
uint64_t reply_userdata;
/**
* The meaning and contents of data member depend on the event_id:
* MPV_EVENT_GET_PROPERTY_REPLY: mpv_event_property*
* MPV_EVENT_LOG_MESSAGE: mpv_event_log_message*
* MPV_EVENT_SCRIPT_INPUT_DISPATCH: mpv_event_script_input_dispatch*
* other: NULL
*
* Note: future enhancements might add new event struct for existing or new
* event types.
*/
void *data;
} mpv_event;
/**
* 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.)
*
* @param event See enum mpv_event_id.
* @param enable 1 to enable receiving this event, 0 to disable it.
* @return error code
*/
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 status v debug trace
* The value "no" disables all messages. This is the default.
*/
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 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().
*
* @param timeout Timeout in seconds, after which the function returns even if
* no event was received. A MPV_EVENT_NONE is returned on
* timeout. Values <= 0 will disable waiting.
* @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 mpv_destroy() is called. You must not write to
* the struct, and all memory referenced by it will be automatically
* released by the API. The return value is never NULL.
*/
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 another events queued. All what counts is that the waiting thread
* is woken up.
*/
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. 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.
*
* 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.
*
* 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.
*/
void mpv_set_wakeup_callback(mpv_handle *ctx, void (*cb)(void *d), void *d);
#ifdef __cplusplus
}
#endif
#endif