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Merged
WyattBlue merged 1 commit into from
Jan 22, 2026
Merged

Make filter/graph pure #2114

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120 changes: 75 additions & 45 deletions av/filter/graph.pyx → av/filter/graph.py
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Original file line number Diff line number Diff line change
@@ -1,22 +1,23 @@
import warnings
from fractions import Fraction

from av.audio.format cimport AudioFormat
from av.audio.frame cimport AudioFrame
from av.audio.layout cimport AudioLayout
from av.error cimport err_check
from av.filter.context cimport FilterContext, wrap_filter_context
from av.filter.filter cimport Filter, wrap_filter
from av.video.format cimport VideoFormat
from av.video.frame cimport VideoFrame


cdef class Graph:
import cython
from cython.cimports.av.audio.format import AudioFormat
from cython.cimports.av.audio.frame import AudioFrame
from cython.cimports.av.audio.layout import AudioLayout
from cython.cimports.av.error import err_check
from cython.cimports.av.filter.context import FilterContext, wrap_filter_context
from cython.cimports.av.filter.filter import Filter, wrap_filter
from cython.cimports.av.video.format import VideoFormat
from cython.cimports.av.video.frame import VideoFrame


@cython.cclass
class Graph:
def __cinit__(self):
self.ptr = lib.avfilter_graph_alloc()
self.configured = False
self._name_counts = {}

self._nb_filters_seen = 0
self._context_by_ptr = {}
self._context_by_name = {}
Expand All @@ -25,21 +26,23 @@ def __cinit__(self):
def __dealloc__(self):
if self.ptr:
# This frees the graph, filter contexts, links, etc..
lib.avfilter_graph_free(&self.ptr)
lib.avfilter_graph_free(cython.address(self.ptr))

cdef str _get_unique_name(self, str name):
@cython.cfunc
def _get_unique_name(self, name: str) -> str:
count = self._name_counts.get(name, 0)
self._name_counts[name] = count + 1
if count:
return "%s_%s" % (name, count)
else:
return name

cpdef configure(self, bint auto_buffer=True, bint force=False):
@cython.ccall
def configure(self, auto_buffer: cython.bint = True, force: cython.bint = False):
if self.configured and not force:
return

err_check(lib.avfilter_graph_config(self.ptr, NULL))
err_check(lib.avfilter_graph_config(self.ptr, cython.NULL))
self.configured = True

# We get auto-inserted stuff here.
Expand All @@ -54,22 +57,23 @@ def link_nodes(self, *nodes):
return self

def add(self, filter, args=None, **kwargs):
cdef Filter cy_filter
cy_filter: Filter
if isinstance(filter, str):
cy_filter = Filter(filter)
elif isinstance(filter, Filter):
cy_filter = filter
else:
raise TypeError("filter must be a string or Filter")

cdef str name = self._get_unique_name(kwargs.pop("name", None) or cy_filter.name)

cdef lib.AVFilterContext *ptr = lib.avfilter_graph_alloc_filter(self.ptr, cy_filter.ptr, name)
name: str = self._get_unique_name(kwargs.pop("name", None) or cy_filter.name)
ptr: cython.pointer[lib.AVFilterContext] = lib.avfilter_graph_alloc_filter(
self.ptr, cy_filter.ptr, name
)
if not ptr:
raise RuntimeError("Could not allocate AVFilterContext")

# Manually construct this context (so we can return it).
cdef FilterContext ctx = wrap_filter_context(self, cy_filter, ptr)
ctx: FilterContext = wrap_filter_context(self, cy_filter, ptr)
ctx.init(args, **kwargs)
self._register_context(ctx)

Expand All @@ -80,28 +84,38 @@ def add(self, filter, args=None, **kwargs):

return ctx

cdef _register_context(self, FilterContext ctx):
self._context_by_ptr[<long>ctx.ptr] = ctx
@cython.cfunc
def _register_context(self, ctx: FilterContext):
self._context_by_ptr[cython.cast(cython.long, ctx.ptr)] = ctx
self._context_by_name[ctx.ptr.name] = ctx
self._context_by_type.setdefault(ctx.filter.ptr.name, []).append(ctx)

cdef _auto_register(self):
cdef int i
cdef lib.AVFilterContext *c_ctx
cdef Filter filter_
cdef FilterContext py_ctx
@cython.cfunc
def _auto_register(self):
i: cython.int
c_ctx: cython.pointer[lib.AVFilterContext]
filter_: Filter
py_ctx: FilterContext
# We assume that filters are never removed from the graph. At this
# point we don't expose that in the API, so we should be okay...
for i in range(self._nb_filters_seen, self.ptr.nb_filters):
c_ctx = self.ptr.filters[i]
if <long>c_ctx in self._context_by_ptr:
if cython.cast(cython.long, c_ctx) in self._context_by_ptr:
continue
filter_ = wrap_filter(c_ctx.filter)
py_ctx = wrap_filter_context(self, filter_, c_ctx)
self._register_context(py_ctx)
self._nb_filters_seen = self.ptr.nb_filters

def add_buffer(self, template=None, width=None, height=None, format=None, name=None, time_base=None):
def add_buffer(
self,
template=None,
width=None,
height=None,
format=None,
name=None,
time_base=None,
):
if template is not None:
if width is None:
width = template.width
Expand All @@ -119,9 +133,11 @@ def add_buffer(self, template=None, width=None, height=None, format=None, name=N
if format is None:
raise ValueError("missing format")
if time_base is None:
warnings.warn("missing time_base. Guessing 1/1000 time base. "
"This is deprecated and may be removed in future releases.",
DeprecationWarning)
warnings.warn(
"missing time_base. Guessing 1/1000 time base. "
"This is deprecated and may be removed in future releases.",
DeprecationWarning,
)
time_base = Fraction(1, 1000)

return self.add(
Expand All @@ -133,7 +149,16 @@ def add_buffer(self, template=None, width=None, height=None, format=None, name=N
pixel_aspect="1/1",
)

def add_abuffer(self, template=None, sample_rate=None, format=None, layout=None, channels=None, name=None, time_base=None):
def add_abuffer(
self,
template=None,
sample_rate=None,
format=None,
layout=None,
channels=None,
name=None,
time_base=None,
):
"""
Convenience method for adding `abuffer <https://ffmpeg.org/ffmpeg-filters.html#abuffer>`_.
"""
Expand All @@ -159,15 +184,15 @@ def add_abuffer(self, template=None, sample_rate=None, format=None, layout=None,
if time_base is None:
time_base = Fraction(1, sample_rate)

kwargs = dict(
sample_rate=str(sample_rate),
sample_fmt=AudioFormat(format).name,
time_base=str(time_base),
)
kwargs = {
"sample_rate": f"{sample_rate}",
"sample_fmt": AudioFormat(format).name,
"time_base": f"{time_base}",
}
if layout:
kwargs["channel_layout"] = AudioLayout(layout).name
if channels:
kwargs["channels"] = str(channels)
kwargs["channels"] = f"{channels}"

return self.add("abuffer", name=name, **kwargs)

Expand All @@ -182,27 +207,32 @@ def set_audio_frame_size(self, frame_size):
if not sinks:
raise ValueError("missing abuffersink filter")
for sink in sinks:
lib.av_buffersink_set_frame_size((<FilterContext>sink).ptr, frame_size)
lib.av_buffersink_set_frame_size(
cython.cast(FilterContext, sink).ptr, frame_size
)

def push(self, frame):
if frame is None:
contexts = self._context_by_type.get("buffer", []) + self._context_by_type.get("abuffer", [])
contexts = self._context_by_type.get(
"buffer", []
) + self._context_by_type.get("abuffer", [])
elif isinstance(frame, VideoFrame):
contexts = self._context_by_type.get("buffer", [])
elif isinstance(frame, AudioFrame):
contexts = self._context_by_type.get("abuffer", [])
else:
raise ValueError(f"can only AudioFrame, VideoFrame or None; got {type(frame)}")
raise ValueError(
f"can only AudioFrame, VideoFrame or None; got {type(frame)}"
)

for ctx in contexts:
ctx.push(frame)

def vpush(self, VideoFrame frame):
def vpush(self, frame: VideoFrame | None):
"""Like `push`, but only for VideoFrames."""
for ctx in self._context_by_type.get("buffer", []):
ctx.push(frame)


# TODO: Test complex filter graphs, add `at: int = 0` arg to pull() and vpull().
def pull(self):
vsinks = self._context_by_type.get("buffersink", [])
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