Expose global_quality in CodecContext

Author: WyattBlue

CHANGELOG.rst

@@ -28,6 +28,9 @@ We are operating with `semantic versioning <https://semver.org>`_.
 v17.0.2 (next)
 --------------
 
+Features:
+- Expose ``AVCodecContext.global_quality`` by :gh-user:`WyattBlue` in (:pr:`2246`).
+
 Fixes:
 
 

av/codec/context.py

@@ -590,6 +590,23 @@ def codec_tag(self, value):
         else:
             raise ValueError("Codec tag should be a 4 character string.")
 
+    @property
+    @cython.cdivision(True)
+    def global_quality(self):
+        """Global quality for codecs which cannot change it per frame.
+
+        Stored internally in lambda units; this property converts to/from
+        QP units using ``FF_QP2LAMBDA``.
+
+        Wraps :ffmpeg:`AVCodecContext.global_quality`.
+
+        """
+        return self.ptr.global_quality // lib.FF_QP2LAMBDA
+
+    @global_quality.setter
+    def global_quality(self, value: cython.int):
+        self.ptr.global_quality = value * lib.FF_QP2LAMBDA
+
     @property
     def bit_rate(self):
         return self.ptr.bit_rate if self.ptr.bit_rate > 0 else None

av/codec/context.pyi

@@ -62,6 +62,7 @@ class CodecContext:
     extradata: bytes | None
     time_base: Fraction
     codec_tag: str
+    global_quality: int
     bit_rate: int | None
     bit_rate_tolerance: int
     thread_count: int

include/avutil.pxd

@@ -18,6 +18,8 @@ cdef extern from "libavutil/avutil.h" nogil:
     cdef char* avutil_configuration()
     cdef char* avutil_license()
 
+    int FF_QP2LAMBDA
+
     cdef enum AVPictureType:
         AV_PICTURE_TYPE_NONE
         AV_PICTURE_TYPE_I

tests/test_codec_context.py

@@ -68,6 +68,11 @@ def iter_raw_frames(
 
 
 class TestCodecContext(TestCase):
+    def test_global_quality(self):
+        ctx = Codec("mpeg4", "w").create()
+        ctx.global_quality = 5
+        assert ctx.global_quality == 5
+
     def test_skip_frame_default(self):
         ctx = Codec("png", "w").create()
         assert ctx.skip_frame == "DEFAULT"