Drop support for deprecated h264_omx

The `h264_omx` codec was used to support hardware accelerated encoding
on Raspberry Pi, but it hasn't been shipped with Raspbian for several
releases.

Author: jlaine

src/aiortc/codecs/h264.py

@@ -122,7 +122,7 @@ def decode(self, encoded_frame: JitterFrame) -> List[Frame]:
 
 def create_encoder_context(
     codec_name: str, width: int, height: int, bitrate: int
-) -> Tuple[VideoCodecContext, bool]:
+) -> VideoCodecContext:
     codec = cast(VideoCodecContext, av.CodecContext.create(codec_name, "w"))
     codec.width = width
     codec.height = height
@@ -133,18 +133,17 @@ def create_encoder_context(
     codec.options = {
         "profile": "baseline",
         "level": "31",
-        "tune": "zerolatency",  # does nothing using h264_omx
+        "tune": "zerolatency",
     }
     codec.open()
-    return codec, codec_name == "h264_omx"
+    return codec
 
 
 class H264Encoder(Encoder):
     def __init__(self) -> None:
         self.buffer_data = b""
         self.buffer_pts: Optional[int] = None
         self.codec: Optional[VideoCodecContext] = None
-        self.codec_buffering = False
         self.__target_bitrate = DEFAULT_BITRATE
 
     @staticmethod
@@ -286,32 +285,16 @@ def _encode_frame(
             frame.pict_type = av.video.frame.PictureType.NONE
 
         if self.codec is None:
-            try:
-                self.codec, self.codec_buffering = create_encoder_context(
-                    "h264_omx", frame.width, frame.height, bitrate=self.target_bitrate
-                )
-            except Exception:
-                self.codec, self.codec_buffering = create_encoder_context(
-                    "libx264",
-                    frame.width,
-                    frame.height,
-                    bitrate=self.target_bitrate,
-                )
+            self.codec = create_encoder_context(
+                "libx264",
+                frame.width,
+                frame.height,
+                bitrate=self.target_bitrate,
+            )
 
         data_to_send = b""
         for package in self.codec.encode(frame):
-            package_bytes = bytes(package)
-            if self.codec_buffering:
-                # delay sending to ensure we accumulate all packages
-                # for a given PTS
-                if package.pts == self.buffer_pts:
-                    self.buffer_data += package_bytes
-                else:
-                    data_to_send += self.buffer_data
-                    self.buffer_data = package_bytes
-                    self.buffer_pts = package.pts
-            else:
-                data_to_send += package_bytes
+            data_to_send += bytes(package)
 
         if data_to_send:
             yield from self._split_bitstream(data_to_send)

tests/test_h264.py

@@ -3,7 +3,7 @@
 from contextlib import redirect_stderr
 from unittest import TestCase
 
-from aiortc.codecs import get_decoder, get_encoder, h264
+from aiortc.codecs import get_decoder, get_encoder
 from aiortc.codecs.h264 import H264Decoder, H264Encoder, H264PayloadDescriptor
 from aiortc.jitterbuffer import JitterFrame
 from aiortc.rtcrtpparameters import RTCRtpCodecParameters
@@ -147,28 +147,6 @@ def test_encoder_pack(self):
         self.assertEqual(payloads, [b"\x00"])
         self.assertEqual(timestamp, 90)
 
-    def test_encoder_buffering(self):
-        create_encoder_context = h264.create_encoder_context
-
-        def mock_create_encoder_context(*args, **kwargs):
-            codec, _ = create_encoder_context(*args, **kwargs)
-            return FragmentedCodecContext(codec), True
-
-        h264.create_encoder_context = mock_create_encoder_context
-        try:
-            encoder = get_encoder(H264_CODEC)
-            self.assertIsInstance(encoder, H264Encoder)
-
-            frame = self.create_video_frame(width=640, height=480, pts=0)
-            packages, timestamp = encoder.encode(frame)
-            self.assertEqual(len(packages), 0)
-
-            frame = self.create_video_frame(width=640, height=480, pts=3000)
-            packages, timestamp = encoder.encode(frame)
-            self.assertGreaterEqual(len(packages), 1)
-        finally:
-            h264.create_encoder_context = create_encoder_context
-
     def test_encoder_target_bitrate(self):
         encoder = get_encoder(H264_CODEC)
         self.assertIsInstance(encoder, H264Encoder)