path: root/mpv.py

# -*- coding: utf-8 -*-
# vim: ts=4 sw=4 et
#
# Python MPV library module
# Copyright (C) 2017-2022 Sebastian Götte <code@jaseg.net>
#
# This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public
# License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later
# version.
#
# This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License along with this program; if not, write to the Free
# Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
#

from ctypes import *
import ctypes.util
import threading
import os
import sys
from warnings import warn
from functools import partial, wraps
from contextlib import contextmanager
from concurrent.futures import Future, InvalidStateError
import collections
import re
import traceback

if os.name == 'nt':
    # Note: mpv-2.dll with API version 2 corresponds to mpv v0.35.0. Most things should work with the fallback, too.
    dll = ctypes.util.find_library('mpv-2.dll') or ctypes.util.find_library('mpv-1.dll')
    if dll is None:
        raise OSError('Cannot find mpv-1.dll or mpv-2.dll in your system %PATH%. One way to deal with this is to ship '
                      'the dll with your script and put the directory your script is in into %PATH% before '
                      '"import mpv": os.environ["PATH"] = os.path.dirname(__file__) + os.pathsep + os.environ["PATH"] '
                      'If mpv-1.dll is located elsewhere, you can add that path to os.environ["PATH"].')
    backend = CDLL(dll)
    fs_enc = 'utf-8'
else:
    import locale
    lc, enc = locale.getlocale(locale.LC_NUMERIC)
    # libmpv requires LC_NUMERIC to be set to "C". Since messing with global variables everyone else relies upon is
    # still better than segfaulting, we are setting LC_NUMERIC to "C".
    locale.setlocale(locale.LC_NUMERIC, 'C')

    sofile = ctypes.util.find_library('mpv')
    if sofile is None:
        raise OSError("Cannot find libmpv in the usual places. Depending on your distro, you may try installing an "
                "mpv-devel or mpv-libs package. If you have libmpv around but this script can't find it, consult "
                "the documentation for ctypes.util.find_library which this script uses to look up the library "
                "filename.")
    backend = CDLL(sofile)
    fs_enc = sys.getfilesystemencoding()


class ShutdownError(SystemError):
    pass

class EventOverflowError(SystemError):
    pass

class MpvHandle(c_void_p):
    pass

class MpvRenderCtxHandle(c_void_p):
    pass

class PropertyUnavailableError(AttributeError):
    pass

class ErrorCode(object):
    """For documentation on these, see mpv's libmpv/client.h."""
    SUCCESS                 = 0
    EVENT_QUEUE_FULL        = -1
    NOMEM                   = -2
    UNINITIALIZED           = -3
    INVALID_PARAMETER       = -4
    OPTION_NOT_FOUND        = -5
    OPTION_FORMAT           = -6
    OPTION_ERROR            = -7
    PROPERTY_NOT_FOUND      = -8
    PROPERTY_FORMAT         = -9
    PROPERTY_UNAVAILABLE    = -10
    PROPERTY_ERROR          = -11
    COMMAND                 = -12
    LOADING_FAILED          = -13
    AO_INIT_FAILED          = -14
    VO_INIT_FAILED          = -15
    NOTHING_TO_PLAY         = -16
    UNKNOWN_FORMAT          = -17
    UNSUPPORTED             = -18
    NOT_IMPLEMENTED         = -19
    GENERIC                 = -20

    EXCEPTION_DICT = {
             0:     None,
            -1:     lambda *a: MemoryError('mpv event queue full', *a),
            -2:     lambda *a: MemoryError('mpv cannot allocate memory', *a),
            -3:     lambda *a: ValueError('Uninitialized mpv handle used', *a),
            -4:     lambda *a: ValueError('Invalid value for mpv parameter', *a),
            -5:     lambda *a: AttributeError('mpv option does not exist', *a),
            -6:     lambda *a: TypeError('Tried to set mpv option using wrong format', *a),
            -7:     lambda *a: ValueError('Invalid value for mpv option', *a),
            -8:     lambda *a: AttributeError('mpv property does not exist', *a),
            # Currently (mpv 0.18.1) there is a bug causing a PROPERTY_FORMAT error to be returned instead of
            # INVALID_PARAMETER when setting a property-mapped option to an invalid value.
            -9:     lambda *a: TypeError('Tried to get/set mpv property using wrong format, or passed invalid value', *a),
            -10:    lambda *a: PropertyUnavailableError('mpv property is not available', *a),
            -11:    lambda *a: RuntimeError('Generic error getting or setting mpv property', *a),
            -12:    lambda *a: SystemError('Error running mpv command', *a),
            -14:    lambda *a: RuntimeError('Initializing the audio output failed', *a),
            -15:    lambda *a: RuntimeError('Initializing the video output failed'),
            -16:    lambda *a: RuntimeError('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.'),
            -17:    lambda *a: RuntimeError('When trying to load the file, the file format could not be determined, '
                                            'or the file was too broken to open it'),
            -18:    lambda *a: ValueError('Generic error for signaling that certain system requirements are not fulfilled'),
            -19:    lambda *a: NotImplementedError('The API function which was called is a stub only'),
            -20:    lambda *a: RuntimeError('Unspecified error') }

    @staticmethod
    def human_readable(ec):
        return _mpv_error_string(ec).decode('utf-8')

    @staticmethod
    def default_error_handler(ec, *args):
        return ValueError(ErrorCode.human_readable(ec), ec, *args)

    @classmethod
    def exception_for_ec(kls, ec, *args):
        ec = 0 if ec > 0 else ec
        ex = kls.EXCEPTION_DICT.get(ec, kls.default_error_handler)
        if ex:
            return ex(ec, *args)

    @classmethod
    def raise_for_ec(kls, ec, func, *args):
        ex = kls.exception_for_ec(ec, *args)
        if ex:
            raise ex

MpvGlGetProcAddressFn = CFUNCTYPE(c_void_p, c_void_p, c_char_p)
class MpvOpenGLInitParams(Structure):
    _fields_ = [('get_proc_address', MpvGlGetProcAddressFn),
            ('get_proc_address_ctx', c_void_p),
            ('extra_exts', c_void_p)]

    def __init__(self, get_proc_address):
        self.get_proc_address = get_proc_address
        self.get_proc_address_ctx = None
        self.extra_exts = None

class MpvOpenGLFBO(Structure):
    _fields_ = [('fbo', c_int),
            ('w', c_int),
            ('h', c_int),
            ('internal_format', c_int)]

    def __init__(self, w, h, fbo=0, internal_format=0):
        self.w, self.h = w, h
        self.fbo = fbo
        self.internal_format = internal_format

class MpvRenderFrameInfo(Structure):
    _fields_ = [('flags', c_int64),
            ('target_time', c_int64)]

    def as_dict(self):
        return {'flags': self.flags,
                'target_time': self.target_time}

class MpvOpenGLDRMParams(Structure):
    _fields_ = [('fd', c_int),
        ('crtc_id', c_int),
        ('connector_id', c_int),
        ('atomic_request_ptr', c_void_p),
        ('render_fd', c_int)]

class MpvOpenGLDRMDrawSurfaceSize(Structure):
    _fields_ = [('width', c_int), ('height', c_int)]

class MpvOpenGLDRMParamsV2(Structure):
    _fields_ = [('fd', c_int),
        ('crtc_id', c_int),
        ('connector_id', c_int),
        ('atomic_request_ptr', c_void_p),
        ('render_fd', c_int)]

    def __init__(self, crtc_id, connector_id, atomic_request_ptr, fd=-1, render_fd=-1):
        self.crtc_id, self.connector_id = crtc_id, connector_id
        self.atomic_request_ptr = atomic_request_ptr
        self.fd, self.render_fd = fd, render_fd


class MpvRenderParam(Structure):
    _fields_ = [('type_id', c_int),
                ('data', c_void_p)]

    # maps human-readable type name to (type_id, argtype) tuple.
    # The type IDs come from libmpv/render.h
    TYPES = {"invalid"                 :(0, None),
            "api_type"                 :(1, str),
            "opengl_init_params"       :(2, MpvOpenGLInitParams),
            "opengl_fbo"               :(3, MpvOpenGLFBO),
            "flip_y"                   :(4, bool),
            "depth"                    :(5, int),
            "icc_profile"              :(6, bytes),
            "ambient_light"            :(7, int),
            "x11_display"              :(8, c_void_p),
            "wl_display"               :(9, c_void_p),
            "advanced_control"         :(10, bool),
            "next_frame_info"          :(11, MpvRenderFrameInfo),
            "block_for_target_time"    :(12, bool),
            "skip_rendering"           :(13, bool),
            "drm_display"              :(14, MpvOpenGLDRMParams),
            "drm_draw_surface_size"    :(15, MpvOpenGLDRMDrawSurfaceSize),
            "drm_display_v2"           :(16, MpvOpenGLDRMParamsV2)}

    def __init__(self, name, value=None):
        if name not in self.TYPES:
            raise ValueError('unknown render param type "{}"'.format(name))
        self.type_id, cons = self.TYPES[name]
        if cons is None:
            self.value = None
            self.data = c_void_p()
        elif cons is str:
            self.value = value
            self.data = cast(c_char_p(value.encode('utf-8')), c_void_p)
        elif cons is bytes:
            self.value = MpvByteArray(value)
            self.data = cast(pointer(self.value), c_void_p)
        elif cons is bool:
            self.value = c_int(int(bool(value)))
            self.data = cast(pointer(self.value), c_void_p)
        elif cons is c_void_p:
            self.value = value
            self.data = cast(self.value, c_void_p)
        else:
            self.value = cons(**value)
            self.data = cast(pointer(self.value), c_void_p)

def kwargs_to_render_param_array(kwargs):
    t = MpvRenderParam * (len(kwargs)+1)
    return t(*kwargs.items(), ('invalid', None))

class MpvFormat(c_int):
    NONE        = 0
    STRING      = 1
    OSD_STRING  = 2
    FLAG        = 3
    INT64       = 4
    DOUBLE      = 5
    NODE        = 6
    NODE_ARRAY  = 7
    NODE_MAP    = 8
    BYTE_ARRAY  = 9

    def __eq__(self, other):
        return self is other or self.value == other or self.value == int(other)

    def __repr__(self):
        return ['NONE', 'STRING', 'OSD_STRING', 'FLAG', 'INT64', 'DOUBLE', 'NODE', 'NODE_ARRAY', 'NODE_MAP',
                'BYTE_ARRAY'][self.value]

    def __hash__(self):
        return self.value


class MpvEventID(c_int):
    NONE                    = 0
    SHUTDOWN                = 1
    LOG_MESSAGE             = 2
    GET_PROPERTY_REPLY      = 3
    SET_PROPERTY_REPLY      = 4
    COMMAND_REPLY           = 5
    START_FILE              = 6
    END_FILE                = 7
    FILE_LOADED             = 8
    CLIENT_MESSAGE          = 16
    VIDEO_RECONFIG          = 17
    AUDIO_RECONFIG          = 18
    SEEK                    = 20
    PLAYBACK_RESTART        = 21
    PROPERTY_CHANGE         = 22
    QUEUE_OVERFLOW          = 24
    HOOK                    = 25

    ANY = ( SHUTDOWN, LOG_MESSAGE, GET_PROPERTY_REPLY, SET_PROPERTY_REPLY, COMMAND_REPLY, START_FILE, END_FILE,
            FILE_LOADED, CLIENT_MESSAGE, VIDEO_RECONFIG, AUDIO_RECONFIG, SEEK, PLAYBACK_RESTART, PROPERTY_CHANGE)

    def __repr__(self):
        return f'<MpvEventID {self.value} (_mpv_event_name(self.value).decode("utf-8"))>'

    @classmethod
    def from_str(kls, s):
        return getattr(kls, s.upper().replace('-', '_'))


identity_decoder = lambda b: b
strict_decoder = lambda b: b.decode('utf-8')
def lazy_decoder(b):
    try:
        return b.decode('utf-8')
    except UnicodeDecodeError:
        return b

class MpvNodeList(Structure):
    def array_value(self, decoder=identity_decoder):
        return [ self.values[i].node_value(decoder) for i in range(self.num) ]

    def dict_value(self, decoder=identity_decoder):
        return { self.keys[i].decode('utf-8'):
                self.values[i].node_value(decoder) for i in range(self.num) }

class MpvByteArray(Structure):
    _fields_ = [('data', c_void_p),
                ('size', c_size_t)]

    def __init__(self, value):
        self._value = value
        self.data = cast(c_char_p(value), c_void_p)
        self.size = len(value)

    def bytes_value(self):
        return cast(self.data, POINTER(c_char))[:self.size]

class MpvNode(Structure):
    def node_value(self, decoder=identity_decoder):
        return MpvNode.node_cast_value(self.val, self.format.value, decoder)

    @staticmethod
    def node_cast_value(v, fmt=MpvFormat.NODE, decoder=identity_decoder):
        if fmt == MpvFormat.NONE:
            return None
        elif fmt == MpvFormat.STRING:
            return decoder(v.string)
        elif fmt == MpvFormat.OSD_STRING:
            return v.string.decode('utf-8')
        elif fmt == MpvFormat.FLAG:
            return bool(v.flag)
        elif fmt == MpvFormat.INT64:
            return v.int64
        elif fmt == MpvFormat.DOUBLE:
            return v.double
        else:
            if not v.node: # Check for null pointer
                return None
            if fmt == MpvFormat.NODE:
                return v.node.contents.node_value(decoder)
            elif fmt == MpvFormat.NODE_ARRAY:
                return v.list.contents.array_value(decoder)
            elif fmt == MpvFormat.NODE_MAP:
                return v.map.contents.dict_value(decoder)
            elif fmt == MpvFormat.BYTE_ARRAY:
                return v.byte_array.contents.bytes_value()
            else:
                raise TypeError('Unknown MPV node format {}. Please submit a bug report.'.format(fmt))

class MpvNodeUnion(Union):
    _fields_ = [('string', c_char_p),
                ('flag', c_int),
                ('int64', c_int64),
                ('double', c_double),
                ('node', POINTER(MpvNode)),
                ('list', POINTER(MpvNodeList)),
                ('map', POINTER(MpvNodeList)),
                ('byte_array', POINTER(MpvByteArray))]

MpvNode._fields_ = [('val', MpvNodeUnion),
                    ('format', MpvFormat)]

MpvNodeList._fields_ = [('num', c_int),
                        ('values', POINTER(MpvNode)),
                        ('keys', POINTER(c_char_p))]

class MpvEvent(Structure):
    _fields_ = [('event_id', MpvEventID),
                ('error', c_int),
                ('reply_userdata', c_ulonglong),
                ('_data', c_void_p)]

    @property
    def data(self):
        dtype = {
            MpvEventID.GET_PROPERTY_REPLY:     MpvEventProperty,
            MpvEventID.PROPERTY_CHANGE:        MpvEventProperty,
            MpvEventID.LOG_MESSAGE:            MpvEventLogMessage,
            MpvEventID.CLIENT_MESSAGE:         MpvEventClientMessage,
            MpvEventID.START_FILE:             MpvEventStartFile,
            MpvEventID.END_FILE:               MpvEventEndFile,
            MpvEventID.HOOK:                   MpvEventHook,
            MpvEventID.COMMAND_REPLY:          MpvEventCommand,
            }.get(self.event_id.value)
        return cast(self._data, POINTER(dtype)).contents if dtype else None

    def as_dict(self, decoder=identity_decoder):
        out = cast(create_string_buffer(sizeof(MpvNode)), POINTER(MpvNode))
        _mpv_event_to_node(out, pointer(self))
        rv = out.contents.node_value(decoder=decoder)
        _mpv_free_node_contents(out)
        return rv

    def __str__(self):
        d = self.data
        return f'<{type(d).__name__} ({self.event_id.value}) err={self.error} p={self.reply_userdata:016x} d={self.as_dict()}>'

class MpvEventProperty(Structure):
    _fields_ = [('_name', c_char_p),
                ('format', MpvFormat),
                ('data', MpvNodeUnion)]

    @property
    def name(self):
        return self._name.decode("utf-8")

    @property
    def value(self):
        return MpvNode.node_cast_value(self.data, self.format.value, decoder=lazy_decoder)

class MpvEventLogMessage(Structure):
    _fields_ = [('_prefix', c_char_p),
                ('_level', c_char_p),
                ('_text', c_char_p)]

    @property
    def prefix(self):
        return self._prefix.decode("utf-8")

    @property
    def level(self):
        return self._level.decode("utf-8")

    @property
    def text(self):
        return lazy_decoder(self._text)

class MpvEventEndFile(Structure):
    _fields_ = [('reason', c_int),
                ('error', c_int)]

    EOF                 = 0
    RESTARTED           = 1
    ABORTED             = 2
    QUIT                = 3
    ERROR               = 4
    REDIRECT            = 5

class MpvEventStartFile(Structure):
    _fields_ = [('playlist_entry_id', c_ulonglong),]

class MpvEventClientMessage(Structure):
    _fields_ = [('_num_args', c_int),
                ('_args', POINTER(c_char_p))]

    @property
    def args(self):
        return [ self._args[i] for i in range(self._num_args) ]

class MpvEventCommand(Structure):
    _fields_ = [('_result', MpvNode)]

    def unpack(self, decoder=identity_decoder):
        return self._result.node_value(decoder=decoder)

    @property
    def result(self):
        return self.unpack()

class MpvEventHook(Structure):
    _fields_ = [('_name', c_char_p),
                ('id', c_ulonglong),]

    
    @property
    def name(self):
        return self._name.decode("utf-8")

StreamReadFn = CFUNCTYPE(c_int64, c_void_p, POINTER(c_char), c_uint64)
StreamSeekFn = CFUNCTYPE(c_int64, c_void_p, c_int64)
StreamSizeFn = CFUNCTYPE(c_int64, c_void_p)
StreamCloseFn = CFUNCTYPE(None, c_void_p)
StreamCancelFn = CFUNCTYPE(None, c_void_p)

class StreamCallbackInfo(Structure):
    _fields_ = [('cookie', c_void_p),
                ('read', StreamReadFn),
                ('seek', StreamSeekFn),
                ('size', StreamSizeFn),
                ('close', StreamCloseFn),
                ('cancel', StreamCancelFn)]

StreamOpenFn = CFUNCTYPE(c_int, c_void_p, c_char_p, POINTER(StreamCallbackInfo))

WakeupCallback = CFUNCTYPE(None, c_void_p)

RenderUpdateFn = CFUNCTYPE(None, c_void_p)

def _handle_func(name, args, restype, errcheck, ctx=MpvHandle, deprecated=False):
    func = getattr(backend, name)
    func.argtypes = [ctx] + args if ctx else args
    if restype is not None:
        func.restype = restype
    if errcheck is not None:
        func.errcheck = errcheck
    if deprecated:
        @wraps(func)
        def wrapper(*args, **kwargs):
            if not wrapper.warned: # Only warn on first invocation to prevent spamming
                warn("Backend C api has been deprecated: " + name, DeprecationWarning, stacklevel=2)
                wrapper.warned = True
            return func(*args, **kwargs)
        wrapper.warned = False

        globals()['_'+name] = wrapper
    else:
        globals()['_'+name] = func

def bytes_free_errcheck(res, func, *args):
    notnull_errcheck(res, func, *args)
    rv = cast(res, c_void_p).value
    _mpv_free(res)
    return rv

def notnull_errcheck(res, func, *args):
    if res is None:
        raise RuntimeError('Underspecified error in MPV when calling {} with args {!r}: NULL pointer returned.'\
                'Please consult your local debugger.'.format(func.__name__, args))
    return res

ec_errcheck = ErrorCode.raise_for_ec

backend.mpv_client_api_version.restype = c_ulong
def _mpv_client_api_version():
    ver = backend.mpv_client_api_version()
    return ver>>16, ver&0xFFFF

MPV_VERSION = _mpv_client_api_version()
if MPV_VERSION < (1, 108):
    ver = '.'.join(str(num) for num in MPV_VERSION)
    raise RuntimeError(f"python-mpv requires libmpv with an API version of 1.108 or higher (libmpv >= 0.33), but you have an older version ({ver}).")

backend.mpv_free.argtypes = [c_void_p]
_mpv_free = backend.mpv_free

backend.mpv_free_node_contents.argtypes = [c_void_p]
_mpv_free_node_contents = backend.mpv_free_node_contents

backend.mpv_create.restype = MpvHandle
_mpv_create = backend.mpv_create

_handle_func('mpv_create_client',           [c_char_p],                                 MpvHandle, notnull_errcheck)
_handle_func('mpv_create_weak_client',      [c_char_p],                                 MpvHandle, notnull_errcheck)
_handle_func('mpv_client_name',             [],                                         c_char_p, errcheck=None)
_handle_func('mpv_initialize',              [],                                         c_int, ec_errcheck)
_handle_func('mpv_destroy',                 [],                                         None, errcheck=None)
_handle_func('mpv_terminate_destroy',       [],                                         None, errcheck=None)
_handle_func('mpv_load_config_file',        [c_char_p],                                 c_int, ec_errcheck)
_handle_func('mpv_get_time_us',             [],                                         c_ulonglong, errcheck=None)

_handle_func('mpv_set_option',              [c_char_p, MpvFormat, c_void_p],            c_int, ec_errcheck)
_handle_func('mpv_set_option_string',       [c_char_p, c_char_p],                       c_int, ec_errcheck)

_handle_func('mpv_command',                 [POINTER(c_char_p)],                        c_int, ec_errcheck)
_handle_func('mpv_command_string',          [c_char_p, c_char_p],                       c_int, ec_errcheck)
_handle_func('mpv_command_async',           [c_ulonglong, POINTER(c_char_p)],           c_int, ec_errcheck)
_handle_func('mpv_command_node',            [POINTER(MpvNode), POINTER(MpvNode)],       c_int, ec_errcheck)
_handle_func('mpv_command_node_async',      [c_ulonglong, POINTER(MpvNode)],            c_int, ec_errcheck)
_handle_func('mpv_abort_async_command',     [c_ulonglong],                              None, errcheck=None)

_handle_func('mpv_set_property',            [c_char_p, MpvFormat, c_void_p],            c_int, ec_errcheck)
_handle_func('mpv_set_property_string',     [c_char_p, c_char_p],                       c_int, ec_errcheck)
_handle_func('mpv_set_property_async',      [c_ulonglong, c_char_p, MpvFormat,c_void_p],c_int, ec_errcheck)
_handle_func('mpv_get_property',            [c_char_p, MpvFormat, c_void_p],            c_int, ec_errcheck)
_handle_func('mpv_get_property_string',     [c_char_p],                                 c_void_p, bytes_free_errcheck)
_handle_func('mpv_get_property_osd_string', [c_char_p],                                 c_void_p, bytes_free_errcheck)
_handle_func('mpv_get_property_async',      [c_ulonglong, c_char_p, MpvFormat],         c_int, ec_errcheck)
_handle_func('mpv_observe_property',        [c_ulonglong, c_char_p, MpvFormat],         c_int, ec_errcheck)
_handle_func('mpv_unobserve_property',      [c_ulonglong],                              c_int, ec_errcheck)

_handle_func('mpv_event_name',              [c_int],                                    c_char_p, errcheck=None, ctx=None)
_handle_func('mpv_event_to_node',           [POINTER(MpvNode), POINTER(MpvEvent)],      c_int, ec_errcheck, ctx=None)
_handle_func('mpv_error_string',            [c_int],                                    c_char_p, errcheck=None, ctx=None)

_handle_func('mpv_request_event',           [MpvEventID, c_int],                        c_int, ec_errcheck)
_handle_func('mpv_request_log_messages',    [c_char_p],                                 c_int, ec_errcheck)
_handle_func('mpv_wait_event',              [c_double],                                 POINTER(MpvEvent), errcheck=None)
_handle_func('mpv_wakeup',                  [],                                         None, errcheck=None)
_handle_func('mpv_set_wakeup_callback',     [WakeupCallback, c_void_p],                 None, errcheck=None)

_handle_func('mpv_stream_cb_add_ro',        [c_char_p, c_void_p, StreamOpenFn],         c_int, ec_errcheck)

_handle_func('mpv_render_context_create',               [MpvRenderCtxHandle, MpvHandle, POINTER(MpvRenderParam)],   c_int, ec_errcheck,     ctx=None)
_handle_func('mpv_render_context_set_parameter',        [MpvRenderParam],                                           c_int, ec_errcheck,     ctx=MpvRenderCtxHandle)
_handle_func('mpv_render_context_get_info',             [MpvRenderParam],                                           c_int, ec_errcheck,     ctx=MpvRenderCtxHandle)
_handle_func('mpv_render_context_set_update_callback',  [RenderUpdateFn, c_void_p],                                 None, errcheck=None,    ctx=MpvRenderCtxHandle)
_handle_func('mpv_render_context_update',               [],                                                         c_int64, errcheck=None, ctx=MpvRenderCtxHandle)
_handle_func('mpv_render_context_render',               [POINTER(MpvRenderParam)],                                  c_int, ec_errcheck,     ctx=MpvRenderCtxHandle)
_handle_func('mpv_render_context_report_swap',          [],                                                         None, errcheck=None,    ctx=MpvRenderCtxHandle)
_handle_func('mpv_render_context_free',                 [],                                                         None, errcheck=None,    ctx=MpvRenderCtxHandle)


def _mpv_coax_proptype(value, proptype=str):
    """Intelligently coax the given python value into something that can be understood as a proptype property."""
    if type(value) is bytes:
        return value;
    elif type(value) is bool:
        return b'yes' if value else b'no'
    elif proptype in (str, int, float):
        return str(proptype(value)).encode('utf-8')
    else:
        raise TypeError('Cannot coax value of type {} into property type {}'.format(type(value), proptype))

def _make_node_str_list(l):
    """Take a list of python objects and make a MPV string node array from it.

    As an example, the python list ``l = [ "foo", 23, false ]`` will result in the following MPV node object::

        struct mpv_node {
            .format = MPV_NODE_ARRAY,
            .u.list = *(struct mpv_node_array){
                .num = len(l),
                .keys = NULL,
                .values = struct mpv_node[len(l)] {
                    { .format = MPV_NODE_STRING, .u.string = l[0] },
                    { .format = MPV_NODE_STRING, .u.string = l[1] },
                    ...
                }
            }
        }
    """
    char_ps = [ c_char_p(_mpv_coax_proptype(e, str)) for e in l ]
    node_list = MpvNodeList(
        num=len(l),
        keys=None,
        values=( MpvNode * len(l))( *[ MpvNode(
                format=MpvFormat.STRING,
                val=MpvNodeUnion(string=p))
            for p in char_ps ]))
    node = MpvNode(
        format=MpvFormat.NODE_ARRAY,
        val=MpvNodeUnion(list=pointer(node_list)))
    return char_ps, node_list, node, cast(pointer(node), c_void_p)

def _make_node_str_map(d):
    """Take a dict of python objects and make a MPV string node map from it. """
    char_ps = [ (c_char_p(k.encode('utf-8')), c_char_p(_mpv_coax_proptype(v, str))) for k, v in d.items() ]
    node_list = MpvNodeList(
        num=len(d),
        keys=( c_char_p * len(d))( *[k for k, v in char_ps] ),
        values=( MpvNode * len(d))( *[ MpvNode(
                format=MpvFormat.STRING,
                val=MpvNodeUnion(string=v))
            for k, v in char_ps ]))
    node = MpvNode(
        format=MpvFormat.NODE_MAP,
        val=MpvNodeUnion(map=pointer(node_list)))
    return char_ps, node_list, node, cast(pointer(node), c_void_p)


def _event_generator(handle):
    while True:
        event = _mpv_wait_event(handle, -1).contents
        if event.event_id.value == MpvEventID.NONE:
            raise StopIteration()
        yield event


def _create_null_term_cmd_arg_array(name, args):
    args = [name.encode('utf-8')] + [(arg if type(arg) is bytes else str(arg).encode('utf-8'))
                                     for arg in args if arg is not None] + [None]
    return (c_char_p * len(args))(*args)


_py_to_mpv = lambda name: name.replace('_', '-')
_mpv_to_py = lambda name: name.replace('-', '_')

_drop_nones = lambda *args: [ arg for arg in args if arg is not None ]

class _Proxy:
    def __init__(self, mpv):
        super().__setattr__('mpv', mpv)

class _PropertyProxy(_Proxy):
    def __dir__(self):
        return super().__dir__() + [ name.replace('-', '_') for name in self.mpv.property_list ]

class _FileLocalProxy(_Proxy):
    def __getitem__(self, name):
        return self.mpv.__getitem__(name, file_local=True)

    def __setitem__(self, name, value):
        return self.mpv.__setitem__(name, value, file_local=True)

    def __iter__(self):
        return iter(self.mpv)

class _OSDPropertyProxy(_PropertyProxy):
    def __getattr__(self, name):
        return self.mpv._get_property(_py_to_mpv(name), fmt=MpvFormat.OSD_STRING)

    def __setattr__(self, _name, _value):
        raise AttributeError('OSD properties are read-only. Please use the regular property API for writing.')

class _DecoderPropertyProxy(_PropertyProxy):
    def __init__(self, mpv, decoder):
        super().__init__(mpv)
        super().__setattr__('_decoder', decoder)

    def __getattr__(self, name):
        return self.mpv._get_property(_py_to_mpv(name), decoder=self._decoder)

    def __setattr__(self, name, value):
        setattr(self.mpv, _py_to_mpv(name), value)

class GeneratorStream:
    """Transform a python generator into an mpv-compatible stream object. The total size of the file can be indicated to
    mpv using the size argument to __init__. Seeking is not supported.
    """

    def __init__(self, generator_fun, size=None):
        self._generator_fun = generator_fun
        self.size = size

    def seek(self, offset):
        self._read_iter = iter(self._generator_fun())
        self._read_chunk = b''
        return 0 # We only support seeking to the first byte atm
        # implementation in case seeking to arbitrary offsets would be necessary
        # while offset > 0:
        #     offset -= len(self.read(offset))
        # return offset

    def read(self, size):
        if not self._read_chunk:
            try:
                self._read_chunk += next(self._read_iter)
            except StopIteration:
                return b''
        rv, self._read_chunk = self._read_chunk[:size], self._read_chunk[size:]
        return rv

    def close(self):
        self._read_iter = iter([]) # make next read() call return EOF

    def cancel(self):
        self._read_iter = iter([]) # make next read() call return EOF


class ImageOverlay:
    def __init__(self, m, overlay_id, img=None, pos=(0, 0)):
        self.m = m
        self.overlay_id = overlay_id
        self.pos = pos
        self._size = None
        if img is not None:
            self.update(img)

    def update(self, img=None, pos=None):
        from PIL import Image
        if img is not None:
            self.img = img
        img = self.img

        w, h = img.size
        stride = w*4

        if pos is not None:
            self.pos = pos
        x, y = self.pos

        # Pre-multiply alpha channel
        bg = Image.new('RGBA', (w, h),  (0, 0, 0, 0))
        out = Image.alpha_composite(bg, img)

        # Copy image to ctypes buffer
        if img.size != self._size:
            self._buf = create_string_buffer(w*h*4)
            self._size = img.size

        ctypes.memmove(self._buf, out.tobytes('raw', 'BGRA'), w*h*4)
        source = '&' + str(addressof(self._buf))

        self.m.overlay_add(self.overlay_id, x, y, source, 0, 'bgra', w, h, stride)

    def remove(self):
        self.m.remove_overlay(self.overlay_id)


class FileOverlay:
    def __init__(self, m, overlay_id, filename=None, size=None, stride=None, pos=(0,0)):
        self.m = m
        self.overlay_id = overlay_id
        self.pos = pos
        self.size = size
        self.stride = stride
        if filename is not None:
            self.update(filename)

    def update(self, filename=None, size=None, stride=None, pos=None):
        if filename is not None:
            self.filename = filename

        if pos is not None:
            self.pos = pos

        if size is not None:
            self.size = size

        if stride is not None:
            self.stride = stride

        x, y = self.pos
        w, h = self.size
        stride = self.stride or 4*w

        self.m.overlay_add(self, self.overlay_id, x, y, self.filename, 0, 'bgra', w, h, stride)

    def remove(self):
        self.m.remove_overlay(self.overlay_id)


class MPV(object):
    """See man mpv(1) for the details of the implemented commands. All mpv properties can be accessed as
    ``my_mpv.some_property`` and all mpv options can be accessed as ``my_mpv['some-option']``.

    By default, properties are returned as decoded ``str`` and an error is thrown if the value does not contain valid
    utf-8. To get a decoded ``str`` if possibly but ``bytes`` instead of an error if not, use
    ``my_mpv.lazy.some_property``. To always get raw ``bytes``, use ``my_mpv.raw.some_property``.  To access a
    property's decoded OSD value, use ``my_mpv.osd.some_property``.

    To get API information on an option, use ``my_mpv.option_info('option-name')``. To get API information on a
    property, use ``my_mpv.properties['property-name']``. Take care to use mpv's dashed-names instead of the
    underscore_names exposed on the python object.

    To make your program not barf hard the first time its used on a weird file system **always** access properties
    containing file names or file tags through ``MPV.raw``.  """

    def __init__(self, *extra_mpv_flags, log_handler=None, start_event_thread=True, loglevel=None, **extra_mpv_opts):
        """Create an MPV instance.

        Extra arguments and extra keyword arguments will be passed to mpv as options.
        """

        self.handle = _mpv_create()
        self._event_thread = None
        self._core_shutdown = False

        _mpv_set_option_string(self.handle, b'audio-display', b'no')
        istr = lambda o: ('yes' if o else 'no') if type(o) is bool else str(o)
        try:
            for flag in extra_mpv_flags:
                _mpv_set_option_string(self.handle, flag.encode('utf-8'), b'')
            for k,v in extra_mpv_opts.items():
                _mpv_set_option_string(self.handle, k.replace('_', '-').encode('utf-8'), istr(v).encode('utf-8'))
        finally:
            _mpv_initialize(self.handle)

        self.osd = _OSDPropertyProxy(self)
        self.file_local = _FileLocalProxy(self)
        self.raw    = _DecoderPropertyProxy(self, identity_decoder)
        self.strict = _DecoderPropertyProxy(self, strict_decoder)
        self.lazy   = _DecoderPropertyProxy(self, lazy_decoder)

        self._event_callbacks = []
        self._command_reply_callbacks = {}
        self._event_handler_lock = threading.Lock()
        self._property_handlers = collections.defaultdict(lambda: [])
        self._quit_handlers = set()
        self._message_handlers = {}
        self._key_binding_handlers = {}
        self._event_handle = _mpv_create_client(self.handle, b'py_event_handler')
        self._log_handler = log_handler
        self._stream_protocol_cbs = {}
        self._stream_protocol_frontends = collections.defaultdict(lambda: {})
        self.register_stream_protocol('python', self._python_stream_open)
        self._python_streams = {}
        self._python_stream_catchall = None
        self.overlay_ids = set()
        self.overlays = {}
        if loglevel is not None or log_handler is not None:
            self.set_loglevel(loglevel or 'terminal-default')
        if start_event_thread:
            self._event_thread = threading.Thread(target=self._loop, name='MPVEventHandlerThread')
            self._event_thread.daemon = True
            self._event_thread.start()
        else:
            self._event_thread = None

    def _loop(self):
        for event in _event_generator(self._event_handle):
            try:
                eid = event.event_id.value

                with self._event_handler_lock:
                    if eid == MpvEventID.SHUTDOWN:
                        self._core_shutdown = True

                for callback in self._event_callbacks:
                    callback(event)

                if eid == MpvEventID.PROPERTY_CHANGE:
                    pc = event.data
                    name, value, _fmt = pc.name, pc.value, pc.format
                    for handler in self._property_handlers[name]:
                        handler(name, value)

                if eid == MpvEventID.LOG_MESSAGE and self._log_handler is not None:
                    ev = event.data
                    self._log_handler(ev.level, ev.prefix, ev.text)

                if eid == MpvEventID.CLIENT_MESSAGE:
                    # {'event': {'args': ['key-binding', 'foo', 'u-', 'g']}, 'reply_userdata': 0, 'error': 0, 'event_id': 16}
                    target, *args = event.data.args
                    target = target.decode("utf-8")
                    if target in self._message_handlers:
                        self._message_handlers[target](*args)

                if eid == MpvEventID.COMMAND_REPLY:
                    key = event.reply_userdata
                    callback = self._command_reply_callbacks.pop(key, None)
                    if callback:
                        callback(ErrorCode.exception_for_ec(event.error), event.data)

                if eid == MpvEventID.QUEUE_OVERFLOW:
                    # cache list, since error handlers will unregister themselves
                    for cb in list(self._command_reply_callbacks.values()):
                        cb(EventOverflowError('libmpv event queue has flown over because events have not been processed fast enough'), None)

                if eid == MpvEventID.SHUTDOWN:
                    _mpv_destroy(self._event_handle)
                    for cb in list(self._command_reply_callbacks.values()):
                        cb(ShutdownError('libmpv core has been shutdown'), None)
                    return

            except Exception as e:
                print('Exception inside python-mpv event loop:', file=sys.stderr)
                traceback.print_exc()

    @property
    def core_shutdown(self):
        """Property indicating whether the core has been shut down. Possible causes for this are e.g. the `quit` command
        or a user closing the mpv window."""
        return self._core_shutdown

    def check_core_alive(self):
        """ This method can be used as a sanity check to tests whether the core is still alive at the time it is
        called."""
        if self._core_shutdown:
            raise ShutdownError('libmpv core has been shutdown')

    def wait_until_paused(self, timeout=None):
        """Waits until playback of the current title is paused or done. Raises a ShutdownError if the core is shutdown while
        waiting."""
        self.wait_for_property('core-idle', timeout=timeout)

    def wait_for_playback(self, timeout=None):
        """Waits until playback of the current title is finished. Raises a ShutdownError if the core is shutdown while
        waiting.
        """
        self.wait_for_event('end_file', timeout=timeout)

    def wait_until_playing(self, timeout=None):
        """Waits until playback of the current title has started. Raises a ShutdownError if the core is shutdown while
        waiting."""
        self.wait_for_property('core-idle', lambda idle: not idle, timeout=timeout)

    def wait_for_property(self, name, cond=lambda val: val, level_sensitive=True, timeout=None):
        """Waits until ``cond`` evaluates to a truthy value on the named property. This can be used to wait for
        properties such as ``idle_active`` indicating the player is done with regular playback and just idling around.
        Raises a ShutdownError when the core is shutdown while waiting.
        """
        with self.prepare_and_wait_for_property(name, cond, level_sensitive, timeout=timeout) as result:
            pass
        return result.result()

    def wait_for_shutdown(self, timeout=None):
        '''Wait for core to shutdown (e.g. through quit() or terminate()).'''
        try:
            self.wait_for_event(None, timeout=timeout)
        except ShutdownError:
            return

    def _set_error_handler(self, future):
        @self.event_callback('shutdown', 'queue-overflow')
        def shutdown_handler(event):
            nonlocal future
            try:
                if event.event_id.value == MpvEventID.SHUTDOWN:
                    future.set_exception(ShutdownError('libmpv core has been shutdown'))
                else:
                    future.set_exception(EventOverflowError('libmpv event queue has flown over because events have not been processed fast enough'))
            except InvalidStateError:
                pass
        return shutdown_handler.unregister_mpv_events

    @contextmanager
    def prepare_and_wait_for_property(self, name, cond=lambda val: val, level_sensitive=True, timeout=None):
        """Context manager that waits until ``cond`` evaluates to a truthy value on the named property. See
        prepare_and_wait_for_event for usage.
        Raises a ShutdownError when the core is shutdown while waiting. Re-raises any errors inside ``cond``.
        """
        result = Future()

        def observer(name, val):
            try:
                rv = cond(val)
                if rv:
                    result.set_result(rv)
            except Exception as e:
                try:
                    result.set_exception(e)
                except InvalidStateError:
                    pass
            except InvalidStateError:
                pass
        self.observe_property(name, observer)
        err_unregister = self._set_error_handler(result)

        try:
            result.set_running_or_notify_cancel()
            yield result

            rv = cond(getattr(self, name.replace('-', '_')))
            if level_sensitive and rv:
                result.set_result(rv)

            else:
                self.check_core_alive()
                result.result(timeout)
        finally:
            err_unregister()
            self.unobserve_property(name, observer)

    def wait_for_event(self, *event_types, cond=lambda evt: True, timeout=None):
        """Waits for the indicated event(s). If cond is given, waits until cond(event) is true. Raises a ShutdownError
        if the core is shutdown while waiting. This also happens when 'shutdown' is in event_types. Re-raises any error
        inside ``cond``.
        """
        with self.prepare_and_wait_for_event(*event_types, cond=cond, timeout=timeout) as result:
            pass
        return result.result()

    @contextmanager
    def prepare_and_wait_for_event(self, *event_types, cond=lambda evt: True, timeout=None):
        """Context manager that waits for the indicated event(s) like wait_for_event after running. If cond is given,
        waits until cond(event) is true. Raises a ShutdownError if the core is shutdown while waiting. This also happens
        when 'shutdown' is in event_types. Re-raises any error inside ``cond``.

        Compared to wait_for_event this handles the case where a thread waits for an event it itself causes in a
        thread-safe way. An example from the testsuite is:

        with self.m.prepare_and_wait_for_event('client_message'):
            self.m.keypress(key)

        Using just wait_for_event it would be impossible to ensure the event is caught since it may already have been
        handled in the interval between keypress(...) running and a subsequent wait_for_event(...) call.
        """
        result = Future()

        @self.event_callback(*event_types)
        def target_handler(evt):

            try:
                rv = cond(evt)
                if rv:
                    result.set_result(rv)
            except Exception as e:
                try:
                    result.set_exception(e)
                except InvalidStateError:
                    pass
            except InvalidStateError:
                pass

        err_unregister = self._set_error_handler(result)

        try:
            result.set_running_or_notify_cancel()
            yield result
            self.check_core_alive()
            result.result(timeout)

        finally:
            err_unregister()
            target_handler.unregister_mpv_events()

    def __del__(self):
        if self.handle:
            self.terminate()

    def terminate(self):
        """Properly terminates this player instance. Preferably use this instead of relying on python's garbage
        collector to cause this to be called from the object's destructor.

        This method will detach the main libmpv handle and wait for mpv to shut down and the event thread to finish.
        """
        self.handle, handle = None, self.handle
        if threading.current_thread() is self._event_thread:
            raise UserWarning('terminate() should not be called from event thread (e.g. from a callback function). If '
                    'you want to terminate mpv from here, please call quit() instead, then sync the main thread '
                    'against the event thread using e.g. wait_for_shutdown(), then terminate() from the main thread. '
                    'This call has been transformed into a call to quit().')
            self.quit()
        else:
            _mpv_terminate_destroy(handle)
            if self._event_thread:
                self._event_thread.join()

    def set_loglevel(self, level):
        """Set MPV's log level. This adjusts which output will be sent to this object's log handlers. If you just want
        mpv's regular terminal output, you don't need to adjust this but just need to pass a log handler to the MPV
        constructur such as ``MPV(log_handler=print)``.

        Valid log levels are "no", "fatal", "error", "warn", "info", "v" "debug" and "trace". For details see your mpv's
        client.h header file.
        """
        _mpv_request_log_messages(self._event_handle, level.encode('utf-8'))

    def string_command(self, name, *args):
        """Execute a raw command."""
        args = _create_null_term_cmd_arg_array(name, args)
        _mpv_command(self.handle, args)

    def command_async(self, name, *args, callback=None, decoder=lazy_decoder, **kwargs):
        """Same as mpv_command, but run the command asynchronously. If you provide a callback, that callback will be
        called after completion or on error. This method returns a future that evaluates to the result of the callback
        (if given), and the result of the libmpv call otherwise.

        Usage example:

            future = player.command_async(...)
            try:
                print('The result was', future.result())
            except Exception as e:
                print('mpv returned an error:', e)
        """

        future = Future()
        future.set_running_or_notify_cancel()

        if callback is None:
            def callback(error, result):
                if error:
                    raise error
                return result

        def wrapper(error, result):
            try:
                result = result.unpack(decoder)
                future.set_result(callback(error, result))
            except Exception as e:
                try:
                    future.set_exception(e)
                except InvalidStateError:
                    pass

        def abort():
            _mpv_abort_async_command(self._event_handle, id(future))
            del self._command_reply_callbacks[id(future)]
        future.cancel = abort

        self._command_reply_callbacks[id(future)] = wrapper

        if kwargs:
            if args:
                raise ValueError('Can only call mpv commands either using positional or using named arguments, not a mix of both.')
            kwargs['name'] = name
            _1, _2, _3, pointer = _make_node_str_map(kwargs)
        else:
            _1, _2, _3, pointer = _make_node_str_list([name, *args])

        ppointer = cast(pointer, POINTER(MpvNode))
        _mpv_command_node_async(self._event_handle, id(future), ppointer)
        return future


    def node_command(self, name, *args, decoder=strict_decoder):
        self.command(name, *args, decoder=decoder)

    def command(self, name, *args, decoder=strict_decoder, **kwargs):
        if kwargs:
            if args:
                raise ValueError('Can only call mpv commands either using positional or using named arguments, not a mix of both.')
            kwargs['name'] = name
            _1, _2, _3, pointer = _make_node_str_map(kwargs)
        else:
            _1, _2, _3, pointer = _make_node_str_list([name, *args])

        out = cast(create_string_buffer(sizeof(MpvNode)), POINTER(MpvNode))
        ppointer = cast(pointer, POINTER(MpvNode))
        _mpv_command_node(self.handle, ppointer, out)
        rv = out.contents.node_value(decoder=decoder)
        _mpv_free_node_contents(out)
        return rv

    def seek(self, amount, reference="relative", precision="keyframes"):
        """Mapped mpv seek command, see man mpv(1)."""
        self.command('seek', amount, reference, precision)

    def revert_seek(self):
        """Mapped mpv revert_seek command, see man mpv(1)."""
        self.command('revert_seek');

    def frame_step(self):
        """Mapped mpv frame-step command, see man mpv(1)."""
        self.command('frame-step')

    def frame_back_step(self):
        """Mapped mpv frame_back_step command, see man mpv(1)."""
        self.command('frame_back_step')

    def property_add(self, name, value=1):
        """Add the given value to the property's value. On overflow or underflow, clamp the property to the maximum. If
        ``value`` is omitted, assume ``1``.
        """
        self.command('add', name, value)

    def property_multiply(self, name, factor):
        """Multiply the value of a property with a numeric factor."""
        self.command('multiply', name, factor)

    def cycle(self, name, direction='up'):
        """Cycle the given property. ``up`` and ``down`` set the cycle direction. On overflow, set the property back to
        the minimum, on underflow set it to the maximum. If ``up`` or ``down`` is omitted, assume ``up``.
        """
        self.command('cycle', name, direction)

    def screenshot(self, includes='subtitles', mode='single'):
        """Mapped mpv screenshot command, see man mpv(1)."""
        self.command('screenshot', includes, mode)

    def screenshot_to_file(self, filename, includes='subtitles'):
        """Mapped mpv screenshot_to_file command, see man mpv(1)."""
        self.command('screenshot_to_file', filename.encode(fs_enc), includes)

    def screenshot_raw(self, includes='subtitles'):
        """Mapped mpv screenshot_raw command, see man mpv(1). Returns a pillow Image object."""
        from PIL import Image
        res = self.command('screenshot-raw', includes)
        if res['format'] != 'bgr0':
            raise ValueError('Screenshot in unknown format "{}". Currently, only bgr0 is supported.'
                    .format(res['format']))
        img = Image.frombytes('RGBA', (res['stride']//4, res['h']), res['data'])
        b,g,r,a = img.split()
        return Image.merge('RGB', (r,g,b))

    def allocate_overlay_id(self):
        free_ids = set(range(64)) - self.overlay_ids
        if not free_ids:
            raise IndexError('All overlay IDs are in use')
        next_id, *_ = sorted(free_ids)
        self.overlay_ids.add(next_id)
        return next_id

    def free_overlay_id(self, overlay_id):
        self.overlay_ids.remove(overlay_id)

    def create_file_overlay(self, filename=None, size=None, stride=None, pos=(0,0)):
        overlay_id = self.allocate_overlay_id()
        overlay = FileOverlay(self, overlay_id, filename, size, stride, pos)
        self.overlays[overlay_id] = overlay
        return overlay

    def create_image_overlay(self, img=None, pos=(0,0)):
        overlay_id = self.allocate_overlay_id()
        overlay = ImageOverlay(self, overlay_id, img, pos)
        self.overlays[overlay_id] = overlay
        return overlay

    def remove_overlay(self, overlay_id):
        self.overlay_remove(overlay_id)
        self.free_overlay_id(overlay_id)
        del self.overlays[overlay_id]

    def playlist_next(self, mode='weak'):
        """Mapped mpv playlist_next command, see man mpv(1)."""
        self.command('playlist_next', mode)

    def playlist_prev(self, mode='weak'):
        """Mapped mpv playlist_prev command, see man mpv(1)."""
        self.command('playlist_prev', mode)

    def playlist_play_index(self, idx):
        """Mapped mpv playlist-play-index command, see man mpv(1)."""
        self.command('playlist-play-index', idx)

    @staticmethod
    def _encode_options(options):
        return ','.join('{}={}'.format(_py_to_mpv(str(key)), str(val)) for key, val in options.items())

    def loadfile(self, filename, mode='replace', **options):
        """Mapped mpv loadfile command, see man mpv(1)."""
        self.command('loadfile', filename.encode(fs_enc), mode, MPV._encode_options(options))

    def loadlist(self, playlist, mode='replace'):
        """Mapped mpv loadlist command, see man mpv(1)."""
        self.command('loadlist', playlist.encode(fs_enc), mode)

    def playlist_clear(self):
        """Mapped mpv playlist_clear command, see man mpv(1)."""
        self.command('playlist_clear')

    def playlist_remove(self, index='current'):
        """Mapped mpv playlist_remove command, see man mpv(1)."""
        self.command('playlist_remove', index)

    def playlist_move(self, index1, index2):
        """Mapped mpv playlist_move command, see man mpv(1)."""
        self.command('playlist_move', index1, index2)

    def playlist_shuffle(self):
        """Mapped mpv playlist-shuffle command, see man mpv(1)."""
        self.command('playlist-shuffle')

    def playlist_unshuffle(self):
        """Mapped mpv playlist-unshuffle command, see man mpv(1)."""
        self.command('playlist-unshuffle')

    def run(self, command, *args):
        """Mapped mpv run command, see man mpv(1)."""
        self.command('run', command, *args)

    def quit(self, code=None):
        """Mapped mpv quit command, see man mpv(1)."""
        self.command('quit', code)

    def quit_watch_later(self, code=None):
        """Mapped mpv quit_watch_later command, see man mpv(1)."""
        self.command('quit_watch_later', code)

    def stop(self, keep_playlist=False):
        """Mapped mpv stop command, see man mpv(1)."""
        if keep_playlist:
            self.command('stop', 'keep-playlist')
        else:
            self.command('stop')

    def audio_add(self, url, flags='select', title=None, lang=None):
        """Mapped mpv audio_add command, see man mpv(1)."""
        self.command('audio_add', url.encode(fs_enc), *_drop_nones(flags, title, lang))

    def audio_remove(self, audio_id=None):
        """Mapped mpv audio_remove command, see man mpv(1)."""
        self.command('audio_remove', audio_id)

    def audio_reload(self, audio_id=None):
        """Mapped mpv audio_reload command, see man mpv(1)."""
        self.command('audio_reload', audio_id)

    def video_add(self, url, flags='select', title=None, lang=None, albumart=None):
        """Mapped mpv video_add command, see man mpv(1)."""
        self.command('video_add', url.encode(fs_enc), *_drop_nones(flags, title, lang, albumart))

    def video_remove(self, video_id=None):
        """Mapped mpv video_remove command, see man mpv(1)."""
        self.command('video_remove', video_id)

    def video_reload(self, video_id=None):
        """Mapped mpv video_reload command, see man mpv(1)."""
        self.command('video_reload', video_id)

    def sub_add(self, url, flags='select', title=None, lang=None):
        """Mapped mpv sub_add command, see man mpv(1)."""
        self.command('sub_add', url.encode(fs_enc), *_drop_nones(flags, title, lang))

    def sub_remove(self, sub_id=None):
        """Mapped mpv sub_remove command, see man mpv(1)."""
        self.command('sub_remove', sub_id)

    def sub_reload(self, sub_id=None):
        """Mapped mpv sub_reload command, see man mpv(1)."""
        self.command('sub_reload', sub_id)

    def sub_step(self, skip):
        """Mapped mpv sub_step command, see man mpv(1)."""
        self.command('sub_step', skip)

    def sub_seek(self, skip):
        """Mapped mpv sub_seek command, see man mpv(1)."""
        self.command('sub_seek', skip)

    def toggle_osd(self):
        """Mapped mpv osd command, see man mpv(1)."""
        self.command('osd')

    def print_text(self, text):
        """Mapped mpv print-text command, see man mpv(1)."""
        self.command('print-text', text)

    def show_text(self, string, duration='-1', level=None):
        """Mapped mpv show_text command, see man mpv(1)."""
        self.command('show_text', string, duration, level)

    def expand_text(self, text):
        """Mapped mpv expand-text command, see man mpv(1)."""
        return self.command('expand-text', text)

    def expand_path(self, path):
        """Mapped mpv expand-path command, see man mpv(1)."""
        return self.command('expand-path', path)

    def show_progress(self):
        """Mapped mpv show_progress command, see man mpv(1)."""
        self.command('show_progress')

    def rescan_external_files(self, mode='reselect'):
        """Mapped mpv rescan-external-files command, see man mpv(1)."""
        self.command('rescan-external-files', mode)

    def discnav(self, command):
        """Mapped mpv discnav command, see man mpv(1)."""
        self.command('discnav', command)

    def mouse(x, y, button=None, mode='single'):
        """Mapped mpv mouse command, see man mpv(1)."""
        if button is None:
            self.command('mouse', x, y, mode)
        else:
            self.command('mouse', x, y, button, mode)

    def keypress(self, name):
        """Mapped mpv keypress command, see man mpv(1)."""
        self.command('keypress', name)

    def keydown(self, name):
        """Mapped mpv keydown command, see man mpv(1)."""
        self.command('keydown', name)

    def keyup(self, name=None):
        """Mapped mpv keyup command, see man mpv(1)."""
        if name is None:
            self.command('keyup')
        else:
            self.command('keyup', name)

    def keybind(self, name, command):
        """Mapped mpv keybind command, see man mpv(1)."""
        self.command('keybind', name, command)

    def write_watch_later_config(self):
        """Mapped mpv write_watch_later_config command, see man mpv(1)."""
        self.command('write_watch_later_config')

    def overlay_add(self, overlay_id, x, y, file_or_fd, offset, fmt, w, h, stride):
        """Mapped mpv overlay_add command, see man mpv(1)."""
        self.command('overlay_add', overlay_id, x, y, file_or_fd, offset, fmt, w, h, stride)

    def overlay_remove(self, overlay_id):
        """Mapped mpv overlay_remove command, see man mpv(1)."""
        self.command('overlay_remove', overlay_id)

    def osd_overlay(self, overlay_id, data, res_x=0, res_y=720, z=0, hidden=False):
        self.command('osd_overlay', id=overlay_id, data=data, res_x=res_x, res_y=res_Y, z=z, hidden=hidden,
        format='ass-events')

    def osd_overlay_remove(self, overlay_id):
        self.command('osd_overlay', id=overlay_id, format='none')

    def script_message(self, *args):
        """Mapped mpv script_message command, see man mpv(1)."""
        self.command('script_message', *args)

    def script_message_to(self, target, *args):
        """Mapped mpv script_message_to command, see man mpv(1)."""
        self.command('script_message_to', target, *args)

    def drop_buffers(self):
        self.command('drop_buffers')

    def vf_command(self, label, command, argument):
        self.command('vf_command', label, command, argument)

    def af_command(self, label, command, argument):
        self.command('af_command', label, command, argument)

    def observe_property(self, name, handler):
        """Register an observer on the named property. An observer is a function that is called with the new property
        value every time the property's value is changed. The basic function signature is ``fun(property_name,
        new_value)`` with new_value being the decoded property value as a python object. This function can be used as a
        function decorator if no handler is given.

        To unregister the observer, call either of ``mpv.unobserve_property(name, handler)``,
        ``mpv.unobserve_all_properties(handler)`` or the handler's ``unregister_mpv_properties`` attribute::

            @player.observe_property('volume')
            def my_handler(new_volume, *):
                print("It's loud!", volume)

            my_handler.unregister_mpv_properties()

        exit_handler is a function taking no arguments that is called when the underlying mpv handle is terminated (e.g.
        from calling MPV.terminate() or issuing a "quit" input command).
        """
        self._property_handlers[name].append(handler)
        _mpv_observe_property(self._event_handle, hash(name)&0xffffffffffffffff, name.encode('utf-8'), MpvFormat.NODE)

    def property_observer(self, name):
        """Function decorator to register a property observer. See ``MPV.observe_property`` for details."""
        def wrapper(fun):
            self.observe_property(name, fun)
            fun.unobserve_mpv_properties = lambda: self.unobserve_property(name, fun)
            return fun
        return wrapper

    def unobserve_property(self, name, handler):
        """Unregister a property observer. This requires both the observed property's name and the handler function that
        was originally registered as one handler could be registered for several properties. To unregister a handler
        from *all* observed properties see ``unobserve_all_properties``.
        """
        self._property_handlers[name].remove(handler)
        if not self._property_handlers[name]:
            _mpv_unobserve_property(self._event_handle, hash(name)&0xffffffffffffffff)

    def unobserve_all_properties(self, handler):
        """Unregister a property observer from *all* observed properties."""
        for name in self._property_handlers:
            self.unobserve_property(name, handler)

    def register_message_handler(self, target, handler=None):
        """Register a mpv script message handler. This can be used to communicate with embedded lua scripts. Pass the
        script message target name this handler should be listening to and the handler function.

        WARNING: Only one handler can be registered at a time for any given target.

        To unregister the message handler, call its ``unregister_mpv_messages`` function::

            player = mpv.MPV()
            @player.message_handler('foo')
            def my_handler(some, args):
                print(args)

            my_handler.unregister_mpv_messages()
        """
        self._register_message_handler_internal(target, handler)

    def _register_message_handler_internal(self, target, handler):
        self._message_handlers[target] = handler

    def unregister_message_handler(self, target_or_handler):
        """Unregister a mpv script message handler for the given script message target name.

        You can also call the ``unregister_mpv_messages`` function attribute set on the handler function when it is
        registered.
        """
        if isinstance(target_or_handler, str):
            del self._message_handlers[target_or_handler]
        else:
            for key, val in self._message_handlers.items():
                if val == target_or_handler:
                    del self._message_handlers[key]

    def message_handler(self, target):
        """Decorator to register a mpv script message handler.

        WARNING: Only one handler can be registered at a time for any given target.

        To unregister the message handler, call its ``unregister_mpv_messages`` function::

            player = mpv.MPV()
            @player.message_handler('foo')
            def my_handler(some, args):
                print(args)

            my_handler.unregister_mpv_messages()
        """
        def register(handler):
            self._register_message_handler_internal(target, handler)
            handler.unregister_mpv_messages = lambda: self.unregister_message_handler(handler)
            return handler
        return register

    def register_event_callback(self, callback):
        """Register a blanket event callback receiving all event types.

        To unregister the event callback, call its ``unregister_mpv_events`` function::

            player = mpv.MPV()
            @player.event_callback('shutdown')
            def my_handler(event):
                print('It ded.')

            my_handler.unregister_mpv_events()
        """
        self._event_callbacks.append(callback)

    def unregister_event_callback(self, callback):
        """Unregiser an event callback."""
        self._event_callbacks.remove(callback)

    def event_callback(self, *event_types):
        """Function decorator to register a blanket event callback for the given event types. Event types can be given
        as str (e.g.  'start-file'), integer or MpvEventID object.

        WARNING: Due to the way this is filtering events, this decorator cannot be chained with itself.

        To unregister the event callback, call its ``unregister_mpv_events`` function::

            player = mpv.MPV()
            @player.event_callback('shutdown')
            def my_handler(event):
                print('It ded.')

            my_handler.unregister_mpv_events()
        """
        def register(callback):
            with self._event_handler_lock:
                self.check_core_alive()
                types = [MpvEventID.from_str(t) if isinstance(t, str) else t for t in event_types] or MpvEventID.ANY
                @wraps(callback)
                def wrapper(event, *args, **kwargs):
                    if event.event_id.value in types:
                        callback(event, *args, **kwargs)
                self._event_callbacks.append(wrapper)
                wrapper.unregister_mpv_events = partial(self.unregister_event_callback, wrapper)
                return wrapper
        return register

    @staticmethod
    def _binding_name(callback_or_cmd):
        return 'py_kb_{:016x}'.format(hash(callback_or_cmd)&0xffffffffffffffff)

    def on_key_press(self, keydef, mode='force'):
        """Function decorator to register a simplified key binding. The callback is called whenever the key given is
        *pressed*.

        To unregister the callback function, you can call its ``unregister_mpv_key_bindings`` attribute::

            player = mpv.MPV()
            @player.on_key_press('Q')
            def binding():
                print('blep')

            binding.unregister_mpv_key_bindings()

        WARNING: For a single keydef only a single callback/command can be registered at the same time. If you register
        a binding multiple times older bindings will be overwritten and there is a possibility of references leaking. So
        don't do that.

        The BIG FAT WARNING regarding untrusted keydefs from the key_binding method applies here as well.
        """
        def register(fun):
            @self.key_binding(keydef, mode)
            @wraps(fun)
            def wrapper(state='p-', name=None, char=None):
                if state[0] in ('d', 'p'):
                    fun()
            return wrapper
        return register

    def key_binding(self, keydef, mode='force'):
        """Function decorator to register a low-level key binding.

        The callback function signature is ``fun(key_state, key_name)`` where ``key_state`` is either ``'U'`` for "key
        up" or ``'D'`` for "key down".

        The keydef format is: ``[Shift+][Ctrl+][Alt+][Meta+]<key>`` where ``<key>`` is either the literal character the
        key produces (ASCII or Unicode character), or a symbolic name (as printed by ``mpv --input-keylist``).

        To unregister the callback function, you can call its ``unregister_mpv_key_bindings`` attribute::

            player = mpv.MPV()
            @player.key_binding('Q')
            def binding(state, name, char):
                print('blep')

            binding.unregister_mpv_key_bindings()

        WARNING: For a single keydef only a single callback/command can be registered at the same time. If you register
        a binding multiple times older bindings will be overwritten and there is a possibility of references leaking. So
        don't do that.

        BIG FAT WARNING: mpv's key binding mechanism is pretty powerful.  This means, you essentially get arbitrary code
        exectution through key bindings. This interface makes some limited effort to sanitize the keydef given in the
        first parameter, but YOU SHOULD NOT RELY ON THIS IN FOR SECURITY. If your input comes from config files, this is
        completely fine--but, if you are about to pass untrusted input into this parameter, better double-check whether
        this is secure in your case.
        """
        def register(fun):
            fun.mpv_key_bindings = getattr(fun, 'mpv_key_bindings', []) + [keydef]
            def unregister_all():
                for keydef in fun.mpv_key_bindings:
                    self.unregister_key_binding(keydef)
            fun.unregister_mpv_key_bindings = unregister_all

            self.register_key_binding(keydef, fun, mode)
            return fun
        return register

    def register_key_binding(self, keydef, callback_or_cmd, mode='force'):
        """Register a key binding. This takes an mpv keydef and either a string containing a mpv command or a python
        callback function.  See ``MPV.key_binding`` for details.
        """
        if not re.match(r'(Shift+)?(Ctrl+)?(Alt+)?(Meta+)?(.|\w+)', keydef):
            raise ValueError('Invalid keydef. Expected format: [Shift+][Ctrl+][Alt+][Meta+]<key>\n'
                    '<key> is either the literal character the key produces (ASCII or Unicode character), or a '
                    'symbolic name (as printed by --input-keylist')
        binding_name = MPV._binding_name(keydef)
        if callable(callback_or_cmd):
            self._key_binding_handlers[binding_name] = callback_or_cmd
            self.register_message_handler('key-binding', self._handle_key_binding_message)
            self.command('define-section',
                    binding_name, '{} script-binding py_event_handler/{}'.format(keydef, binding_name), mode)
        elif isinstance(callback_or_cmd, str):
            self.command('define-section', binding_name, '{} {}'.format(keydef, callback_or_cmd), mode)
        else:
            raise TypeError('register_key_binding expects either an str with an mpv command or a python callable.')
        self.command('enable-section', binding_name, 'allow-hide-cursor+allow-vo-dragging')

    def _handle_key_binding_message(self, binding_name, key_state, key_name=None, key_char=None):
        binding_name = binding_name.decode('utf-8')
        key_state = key_state.decode('utf-8')
        key_name = key_name.decode('utf-8') if key_name is not None else None
        key_char = key_char.decode('utf-8') if key_char is not None else None
        self._key_binding_handlers[binding_name](key_state, key_name, key_char)

    def unregister_key_binding(self, keydef):
        """Unregister a key binding by keydef."""
        binding_name = MPV._binding_name(keydef)
        self.command('disable-section', binding_name)
        self.command('define-section', binding_name, '')
        if binding_name in self._key_binding_handlers:
            del self._key_binding_handlers[binding_name]
            if not self._key_binding_handlers:
                self.unregister_message_handler('key-binding')

    def register_stream_protocol(self, proto, open_fn=None):
        """ Register a custom stream protocol as documented in libmpv/stream_cb.h:
            https://github.com/mpv-player/mpv/blob/master/libmpv/stream_cb.h

            proto is the protocol scheme, e.g. "foo" for "foo://" urls.

            This function can either be used with two parameters or it can be used as a decorator on the target
            function.

            open_fn is a function taking an URI string and returning an mpv stream object.
            open_fn may raise a ValueError to signal libmpv the URI could not be opened.

            The mpv stream protocol is as follows:
            class Stream:
                @property
                def size(self):
                    return None # unknown size
                    return size # int with size in bytes

                def read(self, size):
                    ...
                    return read # non-empty bytes object with input
                    return b'' # empty byte object signals permanent EOF

                def seek(self, pos): # optional
                    return new_offset # integer with new byte offset. The new offset may be before the requested offset
                    in case an exact seek is inconvenient.

                def close(self): # optional
                    ...

                def cancel(self): # optional
                    Abort a running read() or seek() operation
                    ...

        """

        def decorator(open_fn):
            @StreamOpenFn
            def open_backend(_userdata, uri, cb_info):
                try:
                    frontend = open_fn(uri.decode('utf-8'))
                except ValueError:
                    return ErrorCode.LOADING_FAILED

                def read_backend(_userdata, buf, bufsize):
                    data = frontend.read(bufsize)
                    for i in range(len(data)):
                        buf[i] = data[i]
                    return len(data)

                cb_info.contents.cookie = None
                read = cb_info.contents.read = StreamReadFn(read_backend)
                close = cb_info.contents.close = StreamCloseFn(lambda _userdata: frontend.close())

                seek, size, cancel = None, None, None
                if hasattr(frontend, 'seek'):
                    seek = cb_info.contents.seek = StreamSeekFn(lambda _userdata, offx: frontend.seek(offx))
                if hasattr(frontend, 'size') and frontend.size is not None:
                    size = cb_info.contents.size = StreamSizeFn(lambda _userdata: frontend.size)
                if hasattr(frontend, 'cancel'):
                    cancel = cb_info.contents.cancel = StreamCancelFn(lambda _userdata: frontend.cancel())

                # keep frontend and callbacks in memory forever (TODO)
                frontend._registered_callbacks = [read, close, seek, size, cancel]
                self._stream_protocol_frontends[proto][uri] = frontend
                return 0

            if proto in self._stream_protocol_cbs:
                raise KeyError('Stream protocol already registered')
            self._stream_protocol_cbs[proto] = [open_backend]
            _mpv_stream_cb_add_ro(self.handle, proto.encode('utf-8'), c_void_p(), open_backend)

            return open_fn

        if open_fn is not None:
            decorator(open_fn)
        return decorator

    # Convenience functions
    def play(self, filename):
        """Play a path or URL (requires ``ytdl`` option to be set)."""
        self.loadfile(filename)

    @property
    def playlist_filenames(self):
        """Return all playlist item file names/URLs as a list of strs."""
        return [element['filename'] for element in self.playlist]

    def playlist_append(self, filename, **options):
        """Append a path or URL to the playlist. This does not start playing the file automatically. To do that, use
        ``MPV.loadfile(filename, 'append-play')``."""
        self.loadfile(filename, 'append', **options)

    # "Python stream" logic. This is some porcelain for directly playing data from python generators.

    def _python_stream_open(self, uri):
        """Internal handler for python:// protocol streams registered through @python_stream(...) and
        @python_stream_catchall
        """
        name, = re.fullmatch('python://(.*)', uri).groups()

        if name in self._python_streams:
            generator_fun, size = self._python_streams[name]
        else:
            if self._python_stream_catchall is not None:
                generator_fun, size = self._python_stream_catchall(name)
            else:
                raise ValueError('Python stream name not found and no catch-all defined')

        return GeneratorStream(generator_fun, size)

    def python_stream(self, name=None, size=None):
        """Register a generator for the python stream with the given name.

        name is the name, i.e. the part after the "python://" in the URI, that this generator is registered as.
        size is the total number of bytes in the stream (if known).

        Any given name can only be registered once. The catch-all can also only be registered once. To unregister a
        stream, call the .unregister function set on the callback.

        The generator signals EOF by returning, manually raising StopIteration or by yielding b'', an empty bytes
        object.

        The generator may be called multiple times if libmpv seeks or loops.

        See also: @mpv.python_stream_catchall

        @mpv.python_stream('foobar')
        def reader():
            for chunk in chunks:
                yield chunk
        mpv.play('python://foobar')
        mpv.wait_for_playback()
        reader.unregister()
        """
        def register(cb):
            if name in self._python_streams:
                raise KeyError('Python stream name "{}" is already registered'.format(name))
            self._python_streams[name] = (cb, size)
            def unregister():
                if name not in self._python_streams or\
                        self._python_streams[name][0] is not cb: # This is just a basic sanity check
                    raise RuntimeError('Python stream has already been unregistered')
                del self._python_streams[name]
            cb.unregister = unregister
            return cb
        return register

    def python_stream_catchall(self, cb):
        """ Register a catch-all python stream to be called when no name matches can be found. Use this decorator on a
        function that takes a name argument and returns a (generator, size) tuple (with size being None if unknown).

        An invalid URI can be signalled to libmpv by raising a ValueError inside the callback.

        See also: @mpv.python_stream(name, size)

        @mpv.python_stream_catchall
        def catchall(name):
            if not name.startswith('foo'):
                raise ValueError('Unknown Name')

            def foo_reader():
                with open(name, 'rb') as f:
                    while True:
                        chunk = f.read(1024)
                        if not chunk:
                            break
                        yield chunk
            return foo_reader, None
        mpv.play('python://foo23')
        mpv.wait_for_playback()
        catchall.unregister()
        """
        if self._python_stream_catchall is not None:
            raise KeyError('A catch-all python stream is already registered')

        self._python_stream_catchall = cb
        def unregister():
            if self._python_stream_catchall is not cb:
                    raise RuntimeError('This catch-all python stream has already been unregistered')
            self._python_stream_catchall = None
        cb.unregister = unregister
        return cb

    # Property accessors
    def _get_property(self, name, decoder=strict_decoder, fmt=MpvFormat.NODE):
        self.check_core_alive()
        out = create_string_buffer(sizeof(MpvNode))
        try:
            cval = _mpv_get_property(self.handle, name.encode('utf-8'), fmt, out)

            if fmt is MpvFormat.OSD_STRING:
                return cast(out, POINTER(c_char_p)).contents.value.decode('utf-8')
            elif fmt is MpvFormat.NODE:
                rv = cast(out, POINTER(MpvNode)).contents.node_value(decoder=decoder)
                _mpv_free_node_contents(out)
                return rv
            else:
                raise TypeError('_get_property only supports NODE and OSD_STRING formats.')
        except PropertyUnavailableError as ex:
            return None

    def _set_property(self, name, value):
        self.check_core_alive()
        ename = name.encode('utf-8')
        if isinstance(value, (list, set, dict)):
            _1, _2, _3, pointer = _make_node_str_list(value)
            _mpv_set_property(self.handle, ename, MpvFormat.NODE, pointer)
        else:
            _mpv_set_property_string(self.handle, ename, _mpv_coax_proptype(value))

    def __getattr__(self, name):
        return self._get_property(_py_to_mpv(name), lazy_decoder)

    def __setattr__(self, name, value):
            try:
                if name != 'handle' and not name.startswith('_'):
                    self._set_property(_py_to_mpv(name), value)
                else:
                    super().__setattr__(name, value)
            except AttributeError:
                super().__setattr__(name, value)

    def __dir__(self):
        return super().__dir__() + [ name.replace('-', '_') for name in self.property_list ]

    @property
    def properties(self):
        return { name: self.option_info(name) for name in self.property_list }

    # Dict-like option access
    def __getitem__(self, name, file_local=False):
        """Get an option value."""
        prefix = 'file-local-options/' if file_local else 'options/'
        return self._get_property(prefix+name, lazy_decoder)

    def __setitem__(self, name, value, file_local=False):
        """Set an option value."""
        prefix = 'file-local-options/' if file_local else 'options/'
        return self._set_property(prefix+name, value)

    def __iter__(self):
        """Iterate over all option names."""
        return iter(self.options)

    def option_info(self, name):
        """Get information on the given option."""
        try:
            return self._get_property('option-info/'+name)
        except AttributeError:
            return None


class MpvRenderContext:
    def __init__(self, mpv, api_type, **kwargs):
        self._mpv = mpv
        kwargs['api_type'] = api_type

        buf = cast(create_string_buffer(sizeof(MpvRenderCtxHandle)), POINTER(MpvRenderCtxHandle))
        _mpv_render_context_create(buf, mpv.handle, kwargs_to_render_param_array(kwargs))
        self._handle = buf.contents

    def free(self):
        _mpv_render_context_free(self._handle)

    def __setattr__(self, name, value):
        if name.startswith('_'):
            super().__setattr__(name, value)

        elif name == 'update_cb':
            func = value if value else (lambda: None)
            self._update_cb = value
            self._update_fn_wrapper = RenderUpdateFn(lambda _userdata: func())
            _mpv_render_context_set_update_callback(self._handle, self._update_fn_wrapper, None)

        else:
            param = MpvRenderParam(name, value)
            _mpv_render_context_set_parameter(self._handle, param)

    def __getattr__(self, name):
        if name == 'update_cb':
            return self._update_cb

        elif name == 'handle':
            return self._handle

        param = MpvRenderParam(name)
        data_type = type(param.data.contents)
        buf = cast(create_string_buffer(sizeof(data_type)), POINTER(data_type))
        param.data = buf
        _mpv_render_context_get_info(self._handle, param)
        return buf.contents.as_dict()

    def update(self):
        """ Calls mpv_render_context_update and returns the MPV_RENDER_UPDATE_FRAME flag (see render.h) """
        return bool(_mpv_render_context_update(self._handle) & 1)

    def render(self, **kwargs):
        _mpv_render_context_render(self._handle, kwargs_to_render_param_array(kwargs))

    def report_swap(self):
        _mpv_render_context_report_swap(self._handle)