Don't reinit encoder when rotation changes.

webrtc/modules/video_coding/codecs/vp9/test/vp9_impl_unittest.cc

 /*
  *  Copyright (c) 2017 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 32 matching lines @@
   encoded_frame._frameType = kVideoFrameKey;
   EXPECT_EQ(WEBRTC_VIDEO_CODEC_OK,
             decoder_->Decode(encoded_frame, false, nullptr));
   std::unique_ptr<VideoFrame> decoded_frame;
   rtc::Optional<uint8_t> decoded_qp;
   ASSERT_TRUE(WaitForDecodedFrame(&decoded_frame, &decoded_qp));
   ASSERT_TRUE(decoded_frame);
   EXPECT_GT(I420PSNR(input_frame_.get(), decoded_frame.get()), 36);
 }
 
+// We only test the encoder here, since the decoded frame rotation is set based
+// on the CVO RTP header extension in VCMDecodedFrameCallback::Decoded.
+// TODO(brandtr): Consider passing through the rotation flag through the decoder
+// in the same way as done in the encoder.
+TEST_F(TestVp9Impl, EncodedRotationEqualsInputRotation) {
+  input_frame_->set_rotation(kVideoRotation_0);
+  EXPECT_EQ(WEBRTC_VIDEO_CODEC_OK,
+            encoder_->Encode(*input_frame_, nullptr, nullptr));
+  EncodedImage encoded_frame;
+  ASSERT_TRUE(WaitForEncodedFrame(&encoded_frame));
+  EXPECT_EQ(kVideoRotation_0, encoded_frame.rotation_);
+
+  input_frame_->set_rotation(kVideoRotation_90);
+  EXPECT_EQ(WEBRTC_VIDEO_CODEC_OK,
+            encoder_->Encode(*input_frame_, nullptr, nullptr));
+  ASSERT_TRUE(WaitForEncodedFrame(&encoded_frame));
+  EXPECT_EQ(kVideoRotation_90, encoded_frame.rotation_);
+}
+
 TEST_F(TestVp9Impl, DecodedQpEqualsEncodedQp) {
   EXPECT_EQ(WEBRTC_VIDEO_CODEC_OK,
             encoder_->Encode(*input_frame_, nullptr, nullptr));
   EncodedImage encoded_frame;
   ASSERT_TRUE(WaitForEncodedFrame(&encoded_frame));
   // First frame should be a key frame.
   encoded_frame._frameType = kVideoFrameKey;
   EXPECT_EQ(WEBRTC_VIDEO_CODEC_OK,
             decoder_->Decode(encoded_frame, false, nullptr));
   std::unique_ptr<VideoFrame> decoded_frame;
   rtc::Optional<uint8_t> decoded_qp;
   ASSERT_TRUE(WaitForDecodedFrame(&decoded_frame, &decoded_qp));
   ASSERT_TRUE(decoded_frame);
   ASSERT_TRUE(decoded_qp);
   EXPECT_EQ(encoded_frame.qp_, *decoded_qp);
 }
 
 }  // namespace webrtc