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.. _pythonreference:
Python Reference
================
VapourSynth is separated into a core library and a Python module. This section
explains how the core library is exposed through Python and some of the
special things unique to Python scripting, such as slicing and output.
.. note::
Any script executed through the vsscript api (that means vspipe, avfs, vsvfw or
other API users) will have __name__ set to "__vapoursynth__" unlike normal Python
scripts where it usually is "__main__".
VapourSynth Structure
#####################
Most operations in the VapourSynth library are performed through the singleton
core object. This core may load plugins, which all end up in their own unit,
or namespace, so to say, to avoid naming conflicts in the contained functions.
For this reason you call a plugin function with *core.unit.Function()*.
All arguments to functions have names that are lowercase and all function names
are CamelCase. Unit names are also lowercase and usually short. This is good to
remember as a general rule.
Grammar
#######
Slicing and Other Syntactic Sugar
*********************************
The VideoNode and AudioNode class (always called "clip" in practice) supports the full
range of indexing and slicing operations in Python. If you do perform a slicing
operation on a clip, you will get a new clip back with the desired frames.
Here are a few examples.
+---------------------------------+---------------------------------------------------------------+--------------------------------------------------------+
| Operation | Description | Equivalent |
+=================================+===============================================================+========================================================+
| clip = clip[5] | Make a single frame clip containing frame number 5 | |
+---------------------------------+---------------------------------------------------------------+--------------------------------------------------------+
| clip = clip[5:11] | Make a clip containing frames 5 to 10 [#f1]_ | clip = core.std.Trim(clip, first=5, last=10) |
| | | |
| | | clip = core.std.AudioTrim(clip, first=5, last=10) |
+---------------------------------+---------------------------------------------------------------+--------------------------------------------------------+
| clip = clip[::2] | Select even numbered frames | clip = core.std.SelectEvery(clip, cycle=2, offsets=0) |
+---------------------------------+---------------------------------------------------------------+--------------------------------------------------------+
| clip = clip[1::2] | Select odd numbered frames | clip = core.std.SelectEvery(clip, cycle=2, offsets=1) |
+---------------------------------+---------------------------------------------------------------+--------------------------------------------------------+
| clip = clip[::-1] | Reverses a clip | clip = core.std.Reverse(clip) |
| | | |
| | | clip = core.std.AudioReverse(clip) |
+---------------------------------+---------------------------------------------------------------+--------------------------------------------------------+
| clip = clip1 + clip2 | The addition operator can be used to splice clips together | clip = core.std.Splice([clip1, clip2], mismatch=False) |
| | | |
| | | clip = core.std.AudioSplice([clip1, clip2]) |
+---------------------------------+---------------------------------------------------------------+--------------------------------------------------------+
| clip = clip * 10 | The multiplication operator can be used to loop a clip [#f2]_ | clip = core.std.Loop(clip, times=10) |
| | | |
| | | clip = core.std.AudioLoop(clip, times=10) |
+---------------------------------+---------------------------------------------------------------+--------------------------------------------------------+
.. [#f1] Note that frame numbers, like python arrays, start counting at 0 and the end value of slicing is not inclusive
.. [#f2] Note that multiplication by 0 is a special case that will repeat the clip up to the maximum frame count
Filters can be chained with a dot::
clip = clip.std.Trim(first=100, last=2000).std.FlipVertical()
Which is quivalent to::
clip = core.std.FlipVertical(core.std.Trim(clip, first=100, last=2000))
Python Keywords as Filter Arguments
***********************************
If a filter's argument happens to be a Python keyword, you may append
an underscore to the argument's name when invoking the filter. The Python
module will strip one trailing underscore (if present) from all filter arguments before
passing them to the filters.
::
clip = core.plugin.Filter(clip, lambda_=1)
Another way to deal with such arguments is to place them in a dictionary::
kwargs = { "lambda": 1 }
clip = core.plugin.Filter(clip, **kwargs)
VapourSynth will also support the PEP8 convention of using a single trailing
underscore to prevent collisions with python keywords.
Windows File Paths
******************
If you have a string containing backslashes, you must either prefix the
string with "r", or duplicate every single backslash. The reason is
that the backslash is an escape character in Python.
Use `os.path.normcase(path) <https://docs.python.org/3/library/os.path.html#os.path.normcase>`_
to fix Incorrect path string.
Correct example::
"B:/VapourSynth/VapourSynth.dll"
"B:\\VapourSynth\\VapourSynth.dll"
r"B:\VapourSynth\VapourSynth.dll"
Output
******
The normal way of specifying the clip(s) to output is to call
*clip.set_output()*. All standard VapourSynth components only use output
index 0, except for vspipe where it's configurable but defaults to 0.
There are also other variables that can be set to control how a format is
output. For example, setting *alt_output=1* changes the packing of the
YUV422P10 format to one that is common in professional software (like Adobe
products). Note that currently *alt_output* modes only has an effect with
YUV420P8 (I420, IYUV), YUV422P8 (YUY2, UYVY) and YUV422P10 (v210).
An example on how to get v210 output::
some_clip = core.resize.Bicubic(clip, format=vs.YUV422P10)
some_clip.set_output(alt_output=1)
An example on how to get UYVY output::
some_clip = core.resize.Bicubic(clip, format=vs.YUV422P8)
some_clip.set_output(alt_output=2)
Raw Access to Frame Data
************************
The VideoFrame and AudioFrame classes contains one picture/audio chunk and all the metadata
associated with it. It is possible to access the raw data using either
*get_read_ptr(plane)* or *get_write_ptr(plane)* and *get_stride(plane)* with ctypes.
A more Python friendly wrapping is also available where each plane/channel can be accessed
as a Python array using *frame[plane/channel]*.
To get a frame simply call *get_frame(n)* on a clip. Should you desire to get
all frames in a clip, use this code::
for frame in clip.frames():
# Do stuff with your frame
pass
Classes and Functions
#####################
.. py:attribute:: core
Gets the singleton Core object. If it is the first time the function is called,
the Core will be instantiated with the default options. This is the preferred
way to reference the core.
.. py:function:: get_outputs()
Return a read-only mapping of all outputs registered on the current node.
The mapping will automatically update when a new output is registered.
.. py:function:: get_output([index = 0])
Get a previously set output node. Throws an error if the index hasn't been
set. Will return a VideoOutputTuple containing *alpha* and the *alt_output* setting for video output and an AudioNode for audio.
.. py:function:: clear_output([index = 0])
Clears a clip previously set for output.
.. py:function:: clear_outputs()
Clears all clips set for output in the current environment.
.. py:function:: construct_signature(signature[, injected=None])
Creates a *inspect.Signature* object for the given registration signature.
If *injected* is not None, the default of the first argument of the signature will be replaced with the value supplied with injected.
.. py:function:: register_on_destroy(callback)
Registers a callback that is called when the script is being finalized.
This allows you to release resources at the end of a script.
A callback must be registered with every script that is run,
even if the code is being reused in multiple script runs.
No new callbacks can be registered when the script is already being finalized.
.. py:function:: unregister_on_destroy(callback)
Unregisters a previously added callback.
.. py:class:: Core
The *Core* class uses a singleton pattern. Use the *core* attribute to obtain an
instance. All loaded plugins are exposed as attributes of the core object.
These attributes in turn hold the functions contained in the plugin.
Use *plugins()* to obtain a full list of all currently loaded plugins
you may call this way.
.. py:attribute:: num_threads
The number of concurrent threads used by the core. Can be set to change the number. Setting to a value less than one makes it default to the number of hardware threads.
.. py:attribute:: max_cache_size
Set the upper framebuffer cache size after which memory is aggressively
freed. The value is in megabytes.
.. py:method:: plugins()
Containing all loaded plugins.
.. py:method:: get_video_format(id)
Retrieve a Format object corresponding to the specified id. Returns None if the *id* is invalid.
.. py:method:: query_video_format(color_family, sample_type, bits_per_sample, subsampling_w, subsampling_h)
Retrieve a Format object corresponding to the format information, Invalid formats throw an exception.
.. py:method:: create_video_frame(format, width, height)
Creates a new frame with uninitialized planes with the given dimensions and format.
This function is safe to call within a frame callback.
.. py:method:: add_log_handler(handler_func)
Installs a custom handler for the various error messages VapourSynth emits.
The message handler is currently global, i.e. per process, not per VSCore instance.
Returns a LogHandle object.
*handler_func* is a callback function of the form *func(MessageType, message)*.
.. py:method:: remove_log_handler(handle)
Removes a custom handler.
.. py:method:: log_message(message_type, message)
Send a message through VapourSynths logging framework.
.. py:method:: version()
Returns version information as a string.
.. py:method:: version_number()
Returns the core version as a number.
.. note::
If you are writing a library, you should use *vapoursynth.__version__* or *vapoursynth.__api_version__* instead.
.. py:method:: rule6()
Illegal behavior detection.
.. py:class:: Local
Internally, there can be more than one core. This is usually the case in previewer-applications.
Use this class to store variables that depend on the currently active core.
.. code::
l = Local()
l.test = 1
.. py:class:: VideoNode
Represents a video clip. The class itself supports indexing and slicing to
perform trim, reverse and selectevery operations. Several operators are also
defined for the VideoNode class: addition appends clips and multiplication
repeats them. Note that slicing and indexing always return a new VideoNode
object and not a VideoFrame.
.. py:attribute:: format
A Format object describing the frame data. If the format can change
between frames, this value is None.
.. py:attribute:: width
The width of the video. This value will be 0 if the width and height can
change between frames.
.. py:attribute:: height
The height of the video. This value will be 0 if the width and height can
change between frames.
.. py:attribute:: num_frames
The number of frames in the clip.
.. py:attribute:: fps
The framerate represented as a *Fraction*. It is 0/1 when the clip has a variable
framerate.
.. py:attribute:: numerator
The numerator of the framerate. If the clip has variable framerate, the value will be 0.
.. py:attribute:: denominator
The denominator of the framerate. If the clip has variable framerate, the value will be 0.
.. py:attribute:: fps_num
Deprecated, use *fps.numerator* instead
.. py:attribute:: fps_den
Deprecated, use *fps.denominator* instead
.. py:attribute:: flags
Special flags set for this clip. This attribute should normally be
ignored.
.. py:method:: get_frame(n)
Returns a VideoFrame from position *n*.
.. py:method:: get_frame_async(n)
Returns a concurrent.futures.Future-object which result will be a VideoFrame instance or sets the
exception thrown when rendering the frame.
*The future will always be in the running or completed state*
.. py:method:: get_frame_async(n, cb: callable)
:noindex:
Renders a frame in another thread. When the frame is rendered, it will either call `cb(Frame, None)` on success
or `cb(None, Exception)` if something fails.
Added: R58
.. py:method:: set_output(index = 0, alpha = None, alt_output = 0)
Set the clip to be accessible for output. This is the standard way to
specify which clip(s) to output. All VapourSynth tools (vsvfw, vsfs,
vspipe) use the clip in *index* 0. It's possible to specify an additional
containing the *alpha* to output at the same time. Currently only vspipe
takes *alpha* into consideration when outputting.
The *alt_output* argument is for optional alternate output modes. Currently
it controls the FOURCCs used for VFW-style output with certain formats.
.. py:method:: output(fileobj[, y4m = False, prefetch = 0, progress_update = None, backlog=-1])
Write the whole clip to the specified file handle. It is possible to pipe to stdout by specifying *sys.stdout* as the file.
YUV4MPEG2 headers will be added when *y4m* is true.
The current progress can be reported by passing a callback function of the form *func(current_frame, total_frames)* to *progress_update*.
The *prefetch* argument is only for debugging purposes and should never need to be changed.
The *backlog* argument is only for debugging purposes and should never need to be changed.
.. py:method:: frames([prefetch=None, backlog=None, close=False])
Returns a generator iterator of all VideoFrames in the clip. It will render multiple frames concurrently.
The *prefetch* argument defines how many frames are rendered concurrently. Is only there for debugging purposes and should never need to be changed.
The *backlog* argument defines how many unconsumed frames (including those that did not finish rendering yet) vapoursynth buffers at most before it stops rendering additional frames. This argument is there to limit the memory this function uses storing frames.
The *close* argument determines if the frame should be closed after each iteration step. It defaults to false to remain backward compatible.
.. py:method:: is_inspectable(version=None)
Returns a truthy value if you can use the node inspection API with a given version.
The python inspection-api is versioned, as the underlying API is unstable at the time of writing.
The version number will be incremented every time the python API changes.
There will be no attempt to maintain backwards compatibility as long as the API is marked as unstable.
This method may never return a truthy value.
This is the only stable function in the current inspection api-implementation.
.. note::
Be aware that introspection features must be enabled manually by the backing environment. Standalone Python-Scripts,
not running inside vspipe or other editors, have introspection enabled automatically.
.. warning::
The graph-inspection-api is unstable. Omitting the version-argument will therefore always return
None.
The current version of the unstable python graph-inspection API is 0.
Added: R58
:param version: If None, it will use the version number of the last stable API.
.. py:class:: VideoOutputTuple
This class is returned by get_output if the output is video.
.. py:attribute:: clip
A VideoNode-instance containing the color planes.
.. py:attribute:: alpha
A VideoNode-instance containing the alpha planes.
.. py:attribute:: alt_output
An integer with the alternate output mode to be used. May be ignored if no meaningful mapping exists.
.. py:class:: VideoFrame
This class represents a video frame and all metadata attached to it.
.. py:attribute:: format
A Format object describing the frame data.
.. py:attribute:: width
The width of the frame.
.. py:attribute:: height
The height of the frame.
.. py:attribute:: readonly
If *readonly* is True, the frame data and properties cannot be modified.
.. py:attribute:: props
This attribute holds all the frame's properties as a dict. They are also mapped as sub-attributes for
compatibility with older scripts. For more information, see:
`API Reference <apireference.html#reserved-frame-properties>`_
Note: This includes the data for matrix, transfer and primaries. (_Matrix,
_Transfer, _Primaries) See `Resize <functions/resize.html>`_ for more information.
.. py:method:: copy()
Returns a writable copy of the frame.
.. py:method:: close()
Forcefully releases the frame. Once freed, the you cannot call any function on the frame, nor use the associated
FrameProps.
To make sure you don't forget to close the frame, the frame is now a context-manager that automatically calls
this method for you:
.. code::
with core.std.BlankClip().get_frame(0) as f:
print(f.props)
.. py:attribute:: closed
Tells you if the frame has been closed. It will be False if the close()-method has not been called yet.
.. py:method:: get_read_ptr(plane)
Returns a pointer to the raw frame data. The data may not be modified.
Note that this is a thin wrapper for the underlying
C-api and as such calls to *get_write_ptr*, including the ones made internally by other functions in the Python bindings,
may invalidate any pointers previously gotten to the frame with
*get_read_ptr* when called.
.. py:method:: get_write_ptr(plane)
Returns a pointer to the raw frame data. It may be modified using ctypes
or some other similar python package. Note that this is a thin wrapper for the underlying
C-api and as such calls to *get_write_ptr*, including the ones made internally by other functions in the Python bindings,
may invalidate any pointers previously gotten to the frame with
*get_read_ptr* when called.
.. py:method:: get_stride(plane)
Returns the stride between lines in a *plane*.
.. py:method:: readchunks()
This method is usually used to dump the contents of a VideoFrame to disk.
The returned generator yields contiguous chunks of the VideoFrame memory.
.. code::
with open('output.raw', 'wb') as file:
with vs.core.std.BlankClip(color=[25, 50, 60]).get_frame(0) as f:
for chunk in f.readchunks():
file.write(chunk)
.. note::
Usually, the frame contents will be held in a contiguous array,
and this method will yield *n_planes* of data chunks each holding the entire plane.
Don't, however, take this for granted, as it can't be the case,
and you will iterate over lines of plane data instead, which are assured to be contiguous.
If you want to safely read the whole plane, use frame[plane_idx] to get the plane memoryview.
.. py:class:: VideoFormat
This class represents all information needed to describe a frame format. It
holds the general color type, subsampling, number of planes and so on.
The names map directly to the C API so consult it for more detailed
information.
.. py:attribute:: id
A unique *id* identifying the format.
.. py:attribute:: name
A human readable name of the format.
.. py:attribute:: color_family
Which group of colorspaces the format describes.
.. py:attribute:: sample_type
If the format is integer or floating point based.
.. py:attribute:: bits_per_sample
How many bits are used to store one sample in one plane.
.. py:attribute:: bytes_per_sample
The actual storage is padded up to 2^n bytes for efficiency.
.. py:attribute:: subsampling_w
The subsampling for the second and third plane in the horizontal
direction.
.. py:attribute:: subsampling_h
The subsampling for the second and third plane in the vertical direction.
.. py:attribute:: num_planes
The number of planes the format has.
.. py:method:: replace(core=None, **kwargs)
Returns a new format with the given modifications.
The only supported attributes that can be replaced are `color_family`,
`sample_type`, `bits_per_sample`, `subsampling_w`, `subsampling_h`.
The optional `core`-parameter defines on which core the new format
should be registered. This is usually not needed and defaults
to the core of the current environment.
.. py:class:: AudioNode
Represents an audio clip. The class itself supports indexing and slicing to
perform trim, reverse and selectevery operations. Several operators are also
defined for the AudioNode class: addition appends clips and multiplication
repeats them. Note that slicing and indexing always return a new AudioNode
object and not a AudioFrame.
.. py:attribute:: sample_type
If the format is integer or floating point based.
.. py:attribute:: bits_per_sample
How many bits are used to store one sample in one plane.
.. py:attribute:: bytes_per_sample
The actual storage is padded up to 2^n bytes for efficiency.
.. py:attribute:: channel_layout
A mask of used channels.
.. py:attribute:: num_channels
The number of channels the format has.
.. py:attribute:: sample_rate
Playback sample rate.
.. py:method:: get_frame(n)
Returns an AudioFrame from position *n*.
.. py:method:: get_frame_async(n)
Returns a concurrent.futures.Future-object which result will be an AudioFrame instance or sets the
exception thrown when rendering the frame.
*The future will always be in the running or completed state*
.. py:method:: set_output(index = 0)
Set the clip to be accessible for output.
.. py:method:: frames([prefetch=None, backlog=None])
Returns a generator iterator of all AudioFrames in the clip. It will render multiple frames concurrently.
The *prefetch* argument defines how many frames are rendered concurrently. Is only there for debugging purposes and should never need to be changed.
The *backlog* argument defines how many unconsumed frames (including those that did not finish rendering yet) vapoursynth buffers at most before it stops rendering additional frames. This argument is there to limit the memory this function uses storing frames.
.. py:method:: is_inspectable(version=None)
Returns a truthy value if you can use the node inspection API with a given version.
The python inspection-api is versioned, as the underlying API is unstable at the time of writing.
The version number will be incremented every time the python API changes.
There will be no attempt to maintain backwards compatibility as long as the API is marked as unstable.
This method may never return a truthy value.
This is the only stable function in the current inspection api-implementation.
.. note::
Be aware that introspection features must be enabled manually by the backing environment. Standalone Python-Scripts,
not running inside vspipe or other editors, have introspection enabled automatically.
.. warning::
The graph-inspection-api is unstable. Omitting the version-argument will therefore always return
None.
The current version of the unstable python graph-inspection API is 0.
Added: R58
:param version: If None, it will use the version number of the last stable API.
.. py:class:: AudioFrame
This class represents an audio frame and all metadata attached to it.
.. py:attribute:: sample_type
If the format is integer or floating point based.
.. py:attribute:: bits_per_sample
How many bits are used to store one sample in one plane.
.. py:attribute:: bytes_per_sample
The actual storage is padded up to 2^n bytes for efficiency.
.. py:attribute:: channel_layout
A mask of used channels.
.. py:attribute:: num_channels
The number of channels the format has.
.. py:attribute:: readonly
If *readonly* is True, the frame data and properties cannot be modified.
.. py:attribute:: props
This attribute holds all the frame's properties as a dict. Note that audio frame properties are fairly
non-sensical as a concept for audio due to an arbitrary number of samples being lumped together and rarely used.
.. py:method:: copy()
Returns a writable copy of the frame.
.. py:method:: get_read_ptr(plane)
Returns a pointer to the raw frame data. The data may not be modified.
.. py:method:: get_write_ptr(plane)
Returns a pointer to the raw frame data. It may be modified using ctypes
or some other similar python package.
.. py:method:: get_stride(plane)
Returns the stride between lines in a *plane*.
.. py:class:: Plugin
Plugin is a class that represents a loaded plugin and its namespace.
.. py:attribute:: namespace
The namespace of the plugin.
.. py:attribute:: name
The name string of the plugin.
.. py:attribute:: identifier
.. py:method:: functions()
Containing all the functions in the plugin, You can access it by calling *core.<namespace>.functions()*.
.. py:class:: Function
Function is a simple wrapper class for a function provided by a VapourSynth plugin.
Its main purpose is to be called and nothing else.
.. py:attribute:: name
The function name. Identical to the string used to register the function.
.. py:attribute:: plugin
The *Plugin* object the function belongs to.
.. py:attribute:: signature
Raw function signature string. Identical to the string used to register the function.
.. py:attribute:: return_signature
Raw function signature string. Identical to the return type string used register the function.
.. py:class:: Environment
This class represents an environment.
Some editors allow multiple vapoursynth-scripts to run in the same process, each of them comes with a different Core-instance and
their own set of outputs. Each core-instance with their associated outputs represent their own environment.
At any given time, only one environment can be active (in the same context). This class allows introspection about
environments and allows to switch to them at will.
.. code::
env = get_current_environment()
# sometime later
with env.use():
# Do stuff inside this env.
.. py:function:: is_single()
Returns True if the script is _not_ running inside a vsscript-Environment.
If it is running inside a vsscript-Environment, it returns False.
.. py:attribute:: env_id
Return -1 if the script is not running inside a vsscript-Environment.
Otherwise, it will return the current environment-id.
.. py:attribute:: single
See is_single()
.. py:attribute:: alive
Has the environment been destroyed by the underlying application?
.. py:method:: copy()
Creates a copy of the environment-object.
Added: R51
.. py:method:: use()
Returns a context-manager that enables the given environment in the block enclosed in the with-statement and restores the environment to the one
defined before the with-block has been encountered.
.. code::
env = get_current_environment()
with env.use():
with env.use():
pass
Added: R51
.. py:function:: get_current_environment()
Returns an Environment-object representing the environment the script is currently running in. It will raise an error if we are currently not inside any
script-environment while vsscript is being used.
This function is intended for Python-based editors using vsscript.
Added: R51
.. py:class:: EnvironmentPolicy
This class is intended for subclassing by custom Script-Runners and Editors.
Normal users don't need this class. Most methods implemented here have corresponding APIs in other parts of this module.
An instance of this class controls which environment is activated in the current context.
The exact meaning of "context" is defined by the concrete EnvironmentPolicy. A environment is represented by a :class:`EnvironmentData`-object.
To use this class, first create a subclass and then use :func:`register_policy` to get VapourSynth to use your policy. This must happen before vapoursynth is first
used. VapourSynth will automatically register an internal policy if it needs one. The subclass must be weak-referenciable!
Once the method :meth:`on_policy_registered` has been called, the policy is responsible for creating and managing environments.
Special considerations have been made to ensure the functions of class cannot be abused. You cannot retrieve the current running policy yourself.
The additional API exposed by "on_policy_registered" is only valid if the policy has been registered.
Once the policy is unregistered, all calls to the additional API will fail with a RuntimeError.
Added: R51
.. py:method:: on_policy_registered(special_api)
This method is called when the policy has successfully been registered. It proivdes additional internal methods that are hidden as they are useless and or harmful
unless you implement your own policy.
:param special_api: This is a :class:`EnvironmentPolicyAPI`-object that exposes additional API
.. py:method:: on_policy_cleared()
This method is called once the python-process exits or when unregister_policy is called by the environment-policy. This allows the policy to free the resources
used by the policy.
.. py:method:: get_current_environment()
This method is called by the module to detect which environment is currently running in the current context. If None is returned, it means that no environment is currently active.
:returns: An :class:`EnvironmentData`-object representing the currently active environment in the current context.
.. py:method:: set_environment(environment)
This method is called by the module to change the currently active environment. If None is passed to this function the policy may switch to another environment of its choosing.
Note: The function is responsible to check whether or not the environment is alive. If a dead environment is passed, it should act like None has been passed instead of the dead environment but must never error.
:param environment: The :class:`EnvironmentData` to enable in the current context.
:returns: The environment that was enabled previously.
.. py:method:: is_alive(environment)
Is the current environment still active and managed by the policy.
The default implementation checks if `EnvironmentPolicyAPI.destroy_environment` has been called on the environment.
.. py:class:: EnvironmentPolicyAPI
This class is intended to be used by custom Script-Runners and Editors. An instance of this class exposes an additional API.
The methods are bound to a specific :class:`EnvironmentPolicy`-instance and will only work if the policy is currently registered.
Added: R51
.. py:method:: wrap_environment(environment)
Creates a new :class:`Environment`-object bound to the passed environment-id.
.. warning::
This function does not check if the id corresponds to a live environment as the caller is expected to know which environments are active.
.. py:method:: create_environment(flags = 0)
Returns a :class:`Environment` that is used by the wrapper for context sensitive data used by VapourSynth.
For example it holds the currently active core object as well as the currently registered outputs.
.. py:method:: set_logger(environment, callback)
This function sets the logger for the given environment.
This logger is a callback function that accepts two parameters: Level, which is an instance of vs.MessageType and a string containing the log message.
.. py:method:: destroy_environment(environment)
Marks an environment as destroyed. Older environment-policy implementations that don't use this function still work.
Either EnvironmentPolicy.is_alive must be overridden or this method be used to mark the environment as destroyed.
Added: R52
.. py:method:: unregister_policy()
Unregisters the policy it is bound to and allows another policy to be registered.
.. py:method:: get_vapoursynth_api(version)
Exposes getVapoursynthAPI to python. Returns a ctypes.c_void_p.
Access to this function is provisional and might be removed if it is abused too much.
Added: R62
.. py:method:: get_core_ptr(environment)
Returns a ctypes.c_void_p pointing to the `Core*`-object that powers the environment.
Access to this function is provisional and might be removed if it is abused too much.
Added: R62
.. py:function:: register_policy(policy)
This function is intended for use by custom Script-Runners and Editors. It installs your custom :class:`EnvironmentPolicy`. This function only works if no other policy has been
installed.
If no policy is installed, the first environment-sensitive call will automatically register an internal policy.
Added: R50
.. note::
This must be done before VapourSynth is used in any way. Here is a non-exhaustive list that automatically register a policy:
* Using "vsscript_init" in "VSScript.h"
* Using :func:`get_outputs`
* Using :func:`get_output`
* Using :func:`clear_output`
* Using :func:`clear_outputs`
* Using :func:`get_current_environment`
* Accessing any attribute of :attr:`core`
.. py:function:: _try_enable_introspection(version=None)
Tries to enable introspection. Returns true if it succeeds.
:param version: If not passed it will use the newest stable introspection-api.
Added: R58
.. py:function:: has_policy()
This function is intended for subclassing by custom Script-Runners and Editors. This function checks if a :class:`EnvironmentPolicy` has been installed.
Added: R50
.. py:class:: EnvironmentData
Internal class that stores the context sensitive data that VapourSynth needs. It is an opaque object whose attributes you cannot access directly.
A normal user has no way of getting an instance of this object. You can only encounter EnvironmentData-objects if you work with EnvironmentPolicies.
This object is weak-referenciable meaning you can get a callback if the environment-data object is actually being freed (i.e. no other object holds an instance
to the environment data.)
Added: R50
.. py:class:: Func
Func is a simple wrapper class for VapourSynth VSFunc objects.
Its main purpose is to be called and manage reference counting.
.. py:exception:: Error
The standard exception class. This exception is thrown on most errors
encountered in VapourSynth.
Constants
#########
Video
*****
Color Family
------------
The color family constants describe groups of formats and the basic way their
color information is stored. You should be familiar with all of them apart from
maybe *YCOCG* and *COMPAT*. The latter is a special junk category for non-planar
formats. These are the declared constants in the module::
UNDEFINED
RGB
YUV
GRAY
Format
------
Format constants exactly describe a format. All common and even more uncommon
formats have handy constants predefined so in practice no one should really
need to register one of their own. These values are mostly used by the resizers
to specify which format to convert to. The naming system is quite simple. First
the color family, then the subsampling (only YUV has it) and after that how many
bits per sample in one plane. The exception to this rule is RGB, which has the
bits for all 3 planes added together. The long list of values::
NONE
GRAY8
GRAY9
GRAY10
GRAY12
GRAY14
GRAY16
GRAY32
GRAYH
GRAYS
YUV420P8
YUV422P8
YUV444P8
YUV410P8
YUV411P8
YUV440P8
YUV420P9
YUV422P9
YUV444P9
YUV420P10
YUV422P10
YUV444P10
YUV420P12
YUV422P12
YUV444P12
YUV420P14
YUV422P14
YUV444P14
YUV420P16
YUV422P16
YUV444P16
YUV444PH
YUV444PS
RGB24
RGB27
RGB30
RGB36
RGB42
RGB48
RGBH
RGBS
Chroma Location
---------------
::
CHROMA_LEFT
CHROMA_CENTER
CHROMA_TOP_LEFT
CHROMA_TOP
CHROMA_BOTTOM_LEFT
CHROMA_BOTTOM
Field Based
-----------
::
FIELD_PROGRESSIVE
FIELD_TOP
FIELD_BOTTOM
Color Range
-----------
::
RANGE_FULL
RANGE_LIMITED
Matrix Coefficients
-------------------
::
MATRIX_RGB
MATRIX_BT709
MATRIX_UNSPECIFIED
MATRIX_FCC
MATRIX_BT470_BG
MATRIX_ST170_M
MATRIX_ST240_M
MATRIX_YCGCO
MATRIX_BT2020_NCL
MATRIX_BT2020_CL
MATRIX_CHROMATICITY_DERIVED_NCL
MATRIX_CHROMATICITY_DERIVED_CL
MATRIX_ICTCP
TransferCharacteristics
-----------------------
::
TRANSFER_BT709
TRANSFER_UNSPECIFIED
TRANSFER_BT470_M
TRANSFER_BT470_BG
TRANSFER_BT601
TRANSFER_ST240_M
TRANSFER_LINEAR
TRANSFER_LOG_100
TRANSFER_LOG_316
TRANSFER_IEC_61966_2_4
TRANSFER_IEC_61966_2_1
TRANSFER_BT2020_10
TRANSFER_BT2020_12
TRANSFER_ST2084
TRANSFER_ARIB_B67
Color Primaries
---------------
::
PRIMARIES_BT709
PRIMARIES_UNSPECIFIED
PRIMARIES_BT470_M
PRIMARIES_BT470_BG
PRIMARIES_ST170_M
PRIMARIES_ST240_M
PRIMARIES_FILM
PRIMARIES_BT2020
PRIMARIES_ST428
PRIMARIES_ST431_2
PRIMARIES_ST432_1
PRIMARIES_EBU3213_E
Audio
*****
Channels
--------
::
FRONT_LEFT
FRONT_RIGHT
FRONT_CENTER
LOW_FREQUENCY
BACK_LEFT
BACK_RIGHT
FRONT_LEFT_OF_CENTER
FRONT_RIGHT_OF_CENTER
BACK_CENTER
SIDE_LEFT
SIDE_RIGHT
TOP_CENTER
TOP_FRONT_LEFT
TOP_FRONT_CENTER
TOP_FRONT_RIGHT
TOP_BACK_LEFT
TOP_BACK_CENTER
TOP_BACK_RIGHT
STEREO_LEFT
STEREO_RIGHT
WIDE_LEFT
WIDE_RIGHT
SURROUND_DIRECT_LEFT
SURROUND_DIRECT_RIGHT
LOW_FREQUENCY2
Sample Type
***********
::
INTEGER
FLOAT