From 7f05ad42539af6ef900d429efda4e45e19e5bb93 Mon Sep 17 00:00:00 2001
From: WyattBlue <wyattblue@auto-editor.com>
Date: Thu, 22 Jan 2026 23:34:07 -0500
Subject: [PATCH] Make av/format pure

---
 av/{format.pyx => format.py} | 76 ++++++++++++++++++++----------------
 1 file changed, 43 insertions(+), 33 deletions(-)
 rename av/{format.pyx => format.py} (74%)

diff --git a/av/format.pyx b/av/format.py
similarity index 74%
rename from av/format.pyx
rename to av/format.py
index 2eb386649..a0bf0bd90 100644
--- a/av/format.pyx
+++ b/av/format.py
@@ -1,22 +1,28 @@
-cimport libav as lib
-
-from av.descriptor cimport wrap_avclass
-
 from enum import Flag
 
+import cython
+import cython.cimports.libav as lib
+from cython.cimports.av.descriptor import wrap_avclass
 
-cdef object _cinit_bypass_sentinel = object()
+_cinit_bypass_sentinel = cython.declare(object, object())
 
-cdef ContainerFormat build_container_format(lib.AVInputFormat* iptr, lib.AVOutputFormat* optr):
+
+@cython.cfunc
+def build_container_format(
+    iptr: cython.pointer[lib.AVInputFormat], optr: cython.pointer[lib.AVOutputFormat]
+) -> ContainerFormat:
     if not iptr and not optr:
         raise ValueError("needs input format or output format")
-    cdef ContainerFormat format = ContainerFormat.__new__(ContainerFormat, _cinit_bypass_sentinel)
+    format: ContainerFormat = ContainerFormat.__new__(
+        ContainerFormat, _cinit_bypass_sentinel
+    )
     format.iptr = iptr
     format.optr = optr
     format.name = optr.name if optr else iptr.name
     return format
 
 
+# fmt: off
 class Flags(Flag):
     no_file = lib.AVFMT_NOFILE
     need_number: "Needs '%d' in filename." = lib.AVFMT_NEEDNUMBER
@@ -36,8 +42,11 @@ class Flags(Flag):
     # If not set the timestamp will be shifted in `av_write_frame()` and `av_interleaved_write_frame()`
     # so they start from 0. The user or muxer can override this through AVFormatContext.avoid_negative_ts
     seek_to_pts: "Seeking is based on PTS" = lib.AVFMT_SEEK_TO_PTS
+# fmt: on
+
 
-cdef class ContainerFormat:
+@cython.cclass
+class ContainerFormat:
     """Descriptor of a container format.
 
     :param str name: The name of the format.
@@ -59,7 +68,7 @@ def __cinit__(self, name, mode=None):
             self.iptr = lib.av_find_input_format(name)
 
         if mode is None or mode == "w":
-            self.optr = lib.av_guess_format(name, NULL, NULL)
+            self.optr = lib.av_guess_format(name, cython.NULL, cython.NULL)
 
         if not self.iptr and not self.optr:
             raise ValueError(f"no container format {name!r}")
@@ -81,30 +90,30 @@ def options(self):
     @property
     def input(self):
         """An input-only view of this format."""
-        if self.iptr == NULL:
+        if self.iptr == cython.NULL:
             return None
-        elif self.optr == NULL:
+        elif self.optr == cython.NULL:
             return self
         else:
-            return build_container_format(self.iptr, NULL)
+            return build_container_format(self.iptr, cython.NULL)
 
     @property
     def output(self):
         """An output-only view of this format."""
-        if self.optr == NULL:
+        if self.optr == cython.NULL:
             return None
-        elif self.iptr == NULL:
+        elif self.iptr == cython.NULL:
             return self
         else:
-            return build_container_format(NULL, self.optr)
+            return build_container_format(cython.NULL, self.optr)
 
     @property
     def is_input(self):
-        return self.iptr != NULL
+        return self.iptr != cython.NULL
 
     @property
     def is_output(self):
-        return self.optr != NULL
+        return self.optr != cython.NULL
 
     @property
     def long_name(self):
@@ -114,7 +123,7 @@ def long_name(self):
 
     @property
     def extensions(self):
-        cdef set exts = set()
+        exts: set = set()
         if self.iptr and self.iptr.extensions:
             exts.update(self.iptr.extensions.split(","))
         if self.optr and self.optr.extensions:
@@ -128,9 +137,8 @@ def flags(self):
 
         :rtype: int
         """
-        return (
-            (self.iptr.flags if self.iptr else 0) |
-            (self.optr.flags if self.optr else 0)
+        return (self.iptr.flags if self.iptr else 0) | (
+            self.optr.flags if self.optr else 0
         )
 
     @property
@@ -138,32 +146,34 @@ def no_file(self):
         return bool(self.flags & lib.AVFMT_NOFILE)
 
 
-cdef get_output_format_names():
-    names = set()
-    cdef const lib.AVOutputFormat *ptr
-    cdef void *opaque = NULL
+@cython.cfunc
+def get_output_format_names() -> set:
+    names: set = set()
+    ptr: cython.pointer[cython.const[lib.AVOutputFormat]]
+    opaque: cython.p_void = cython.NULL
     while True:
-        ptr = lib.av_muxer_iterate(&opaque)
+        ptr = lib.av_muxer_iterate(cython.address(opaque))
         if ptr:
             names.add(ptr.name)
         else:
             break
     return names
 
-cdef get_input_format_names():
-    names = set()
-    cdef const lib.AVInputFormat *ptr
-    cdef void *opaque = NULL
+
+@cython.cfunc
+def get_input_format_names() -> set:
+    names: set = set()
+    ptr: cython.pointer[cython.const[lib.AVInputFormat]]
+    opaque: cython.p_void = cython.NULL
     while True:
-        ptr = lib.av_demuxer_iterate(&opaque)
+        ptr = lib.av_demuxer_iterate(cython.address(opaque))
         if ptr:
             names.add(ptr.name)
         else:
             break
     return names
 
+
 formats_available = get_output_format_names()
 formats_available.update(get_input_format_names())
-
-
 format_descriptor = wrap_avclass(lib.avformat_get_class())