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mpv/libmpv/client.h

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/* 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
/**
* 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 in order to receive events.
* This even loop should call mpv_wait_event(), which will return once a new
* mpv client API is available. It should also 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.
* - 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.
*
* 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).
*
* On OSX, embedding is not yet possible, because Cocoa makes this non-trivial.
*
* 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.
*/
/**
* 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(1, 10)
/**
* 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,
/**
* General error when running a command with mpv_command and similar.
*/
MPV_ERROR_COMMAND = -12,
/**
* Generic error on loading (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
} 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 the
* mpv_handle is destroyed.
*/
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 mpv_handle. 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, or use mpv_terminate_destroy().
*/
void mpv_detach_destroy(mpv_handle *ctx);
/**
* Similar to mpv_detach_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_detach_destroy() is that while mpv_detach_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_detach_destroy() is called somewhere on the way, it's not safe to
* call other functions concurrently on the same context.
*
* 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_detach_destroy(), without waiting for the actual shutdown.
*/
void mpv_terminate_destroy(mpv_handle *ctx);
/**
* 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.
*
* The same restrictions as with mpv_set_option() apply: some options can't
* be set outside of idle or uninitialized state, and many options don't
* take effect immediately.
*
* @param filename absolute path to the config file on the local filesystem
* @return error code
*/
int mpv_load_config_file(mpv_handle *ctx, const char *filename);
/**
* Stop the playback thread. This means the core will stop doing anything, and
* only run and answer to client API requests. This is sometimes useful; for
* example, no new frame will be queued to the video output, so doing requests
* which have to wait on the video output can run instantly.
*
* 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, all
* 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.
*/
void mpv_suspend(mpv_handle *ctx);
/**
* See mpv_suspend().
*/
void mpv_resume(mpv_handle *ctx);
/**
* Return the internal time in microseconds. 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.
*/
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.
*/
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.
*
* 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_STRING, &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
} 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;
} 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_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;
/**
* 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.)
*/
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.
*
* Changing options at runtime does not always work. For some options, attempts
* to change them simply fails. Many other options may require reloading the
* file for changes to take effect. In general, you should prefer calling
* mpv_set_property() to change settings during playback, because the property
* mechanism guarantees that changes take effect immediately.
*
* @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
*/
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.
*
* @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 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.
*
* @param[in] args mpv_node with format set to MPV_FORMAT_NODE_ARRAY; 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).
* @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).
* Currently, no command uses this, but that can change in
* the future.
* @return error code (the result parameter is not set on error)
*/
int mpv_command_node(mpv_handle *ctx, mpv_node *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.
*/
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 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)
*/
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. Retrieving the result is not
* supported yet.
*
* @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)
*/
int mpv_command_node_async(mpv_handle *ctx, uint64_t reply_userdata,
mpv_node *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.
*
* 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.
*
* @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
*/
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_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().
*
* @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
*/
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
*/
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().
*/
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);
/**
* 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.
*
* 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 changd. 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.
*
* @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)
*/
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.
*
* @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)
*/
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
* 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_detach_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 (before the file is loaded).
*/
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,
/**
* The list of video/audio/subtitle tracks was changed. (E.g. a new track
* was found. This doesn't necessarily indicate a track switch; for this,
* MPV_EVENT_TRACK_SWITCHED is used.)
*
* @deprecated This is equivalent to using mpv_observe_property() on the
* "track-list" property. The event is redundant, and might
* be removed in the far future.
*/
MPV_EVENT_TRACKS_CHANGED = 9,
/**
* A video/audio/subtitle track was switched on or off.
*
* @deprecated This is equivalent to using mpv_observe_property() on the
* "vid", "aid", and "sid" properties. The event is redundant,
* and might be removed in the far future.
*/
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. This indicates the user pause state.
*
* The user pause state is the state the user requested (changed with the
* "pause" property). There is an internal pause state too, which is entered
* if e.g. the network is too slow (the "core-idle" property generally
* indicates whether the core is playing or waiting).
*
* This event is sent whenever any pause states change, not only the user
* state. You might get multiple events in a row while these states change
* independently. But the event ID sent always indicates the user pause
* state.
*
* If you don't want to deal with this, use mpv_observe_property() on the
* "pause" property and ignore MPV_EVENT_PAUSE/UNPAUSE. Likewise, the
* "core-idle" property tells you whether video is actually playing or not.
*
* @deprecated The event is redundant with mpv_observe_property() as
* mentioned above, and might be removed in the far future.
*/
MPV_EVENT_PAUSE = 12,
/**
* Playback was unpaused. See MPV_EVENT_PAUSE for not so obvious details.
*
* @deprecated The event is redundant with mpv_observe_property() as
* explained in the MPV_EVENT_PAUSE comments, and might be
* removed in the far future.
*/
MPV_EVENT_UNPAUSE = 13,
/**
* 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.
*/
MPV_EVENT_TICK = 14,
/**
* @deprecated This was used internally with the internal "script_dispatch"
* command to dispatch keyboard and mouse input for the OSC.
* It was never useful in general and has been completely
* replaced with "script_binding".
* This event never happens anymore, and is included in this
* header only for compatibility.
*/
MPV_EVENT_SCRIPT_INPUT_DISPATCH = 15,
/**
* 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 metadata (like file tags) is possibly updated. (It's left
* unspecified whether this happens on file start or only when it changes
* within a file.)
*
* @deprecated This is equivalent to using mpv_observe_property() on the
* "metadata" property. The event is redundant, and might
* be removed in the far future.
*/
MPV_EVENT_METADATA_UPDATE = 19,
/**
* 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 after seeking, or ordered chapter
* segment switches. 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 when the current chapter changes.
*
* @deprecated This is equivalent to using mpv_observe_property() on the
* "chapter" property. The event is redundant, and might
* be removed in the far future.
*/
MPV_EVENT_CHAPTER_CHANGE = 23
// 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.
*/
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).
* See mpv_event.error for the status.
*/
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,
} mpv_end_file_reason;
typedef struct mpv_event_end_file {
/**
* Corresponds to the values in enum mpv_end_file_reason (the "int" type
* will be replaced with mpv_end_file_reason on the next ABI bump).
*
* Unknown values should be treated as unknown.
*/
int 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;
} mpv_event_end_file;
/** @deprecated see MPV_EVENT_SCRIPT_INPUT_DISPATCH for remarks
*/
typedef struct mpv_event_script_input_dispatch {
int arg0;
const char *type;
} mpv_event_script_input_dispatch;
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 {
/**
* 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
*/
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_END_FILE: mpv_event_end_file*
* other: NULL
*
* Note: future enhancements might add new event structs 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.
* Also see mpv_log_level.
*/
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(). This does not apply to concurrent
* calls of this function on different mpv_handles: these are always safe.
*
* @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. 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 other events queued. All what counts is that the waiting thread
* is woken up at all.
*/
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. 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
*/
void mpv_set_wakeup_callback(mpv_handle *ctx, void (*cb)(void *d), void *d);
/**
* 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.
* ...
* }
* }
* }
*
* @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.
*/
int mpv_get_wakeup_pipe(mpv_handle *ctx);
#ifdef __cplusplus
}
#endif
#endif
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