Reduce the runtime of some ACM tests in modules_tests

webrtc/modules/audio_coding/test/TestRedFec.cc

 /*
  *  Copyright (c) 2012 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 435 matching lines @@
                                      samplingFreqHz, 1), -1);
   EXPECT_GT(myACM->RegisterSendCodec(myCodecParam), -1);
 
   // Initialization was successful.
   return 0;
 }
 
 void TestRedFec::Run() {
   AudioFrame audioFrame;
   int32_t outFreqHzB = _outFileB.SamplingFrequency();
+  // Set test length to 500 ms (50 blocks of 10 ms each).
+  _inFileA.SetNum10MsBlocksToRead(50);
+  // Fast-forward 1 second (100 blocks) since the file starts with silence.
+  _inFileA.FastForward(100);
 
   while (!_inFileA.EndOfFile()) {
     EXPECT_GT(_inFileA.Read10MsData(audioFrame), 0);
     EXPECT_GE(_acmA->Add10MsData(audioFrame), 0);
     EXPECT_EQ(0, _acmB->PlayoutData10Ms(outFreqHzB, &audioFrame));
     _outFileB.Write10MsData(audioFrame.data_, audioFrame.samples_per_channel_);
   }
   _inFileA.Rewind();
 }
 
 void TestRedFec::OpenOutFile(int16_t test_number) {
   std::string file_name;
   std::stringstream file_stream;
   file_stream << webrtc::test::OutputPath();
   file_stream << "TestRedFec_outFile_";
   file_stream << test_number << ".pcm";
   file_name = file_stream.str();
   _outFileB.Open(file_name, 16000, "wb");
 }
 
 }  // namespace webrtc