Allow for some error in volume testing.

BUG=616
TESTED=voe_auto_test:VolumeTest.* now passes on a MacBook

Review URL: https://webrtc-codereview.appspot.com/1028005

git-svn-id: http://webrtc.googlecode.com/svn/trunk/webrtc@3348 4adac7df-926f-26a2-2b94-8c16560cd09d

1 files changed, 20 insertions, 6 deletions

diff --git a/voice_engine/test/auto_test/standard/volume_test.cc b/voice_engine/test/auto_test/standard/volume_test.cc
index 9328ad3a..d7b192fc 100644
--- a/voice_engine/test/auto_test/standard/volume_test.cc
+++ b/voice_engine/test/auto_test/standard/volume_test.cc
@@ -10,6 +10,20 @@
 
 #include "after_streaming_fixture.h"
 
+namespace {
+
+void ExpectVolumeNear(int expected, int actual) {
+  // The hardware volume may be more coarsely quantized than [0, 255], so
+  // it is not always reasonable to expect to get exactly what we set. This
+  // allows for some error.
+  const int kMaxVolumeError = 10;
+  EXPECT_NEAR(expected, actual, kMaxVolumeError);
+  EXPECT_GE(actual, 0);
+  EXPECT_LE(actual, 255);
+}
+
+}  // namespace
+
 class VolumeTest : public AfterStreamingFixture {
 };
 
@@ -33,20 +47,20 @@ TEST_F(VolumeTest, SetVolumeBeforePlayoutWorks) {
   EXPECT_EQ(0, voe_volume_control_->SetSpeakerVolume(200));
   unsigned int volume;
   EXPECT_EQ(0, voe_volume_control_->GetSpeakerVolume(volume));
-  EXPECT_EQ(200u, volume);
+  ExpectVolumeNear(200u, volume);
 
   PausePlaying();
   ResumePlaying();
   EXPECT_EQ(0, voe_volume_control_->GetSpeakerVolume(volume));
   // Ensure the volume has not changed after resuming playout.
-  EXPECT_EQ(200u, volume);
+  ExpectVolumeNear(200u, volume);
 
   PausePlaying();
   EXPECT_EQ(0, voe_volume_control_->SetSpeakerVolume(100));
   ResumePlaying();
   // Ensure the volume set while paused is retained.
   EXPECT_EQ(0, voe_volume_control_->GetSpeakerVolume(volume));
-  EXPECT_EQ(100u, volume);
+  ExpectVolumeNear(100u, volume);
 
   EXPECT_EQ(0, voe_volume_control_->SetSpeakerVolume(original_volume));
 }
@@ -60,20 +74,20 @@ TEST_F(VolumeTest, ManualSetVolumeWorks) {
   EXPECT_EQ(0, voe_volume_control_->SetSpeakerVolume(0));
   unsigned int volume;
   EXPECT_EQ(0, voe_volume_control_->GetSpeakerVolume(volume));
-  EXPECT_EQ(0u, volume);
+  ExpectVolumeNear(0u, volume);
   Sleep(1000);
 
   TEST_LOG("Setting speaker volume to 100 out of 255.\n");
   EXPECT_EQ(0, voe_volume_control_->SetSpeakerVolume(100));
   EXPECT_EQ(0, voe_volume_control_->GetSpeakerVolume(volume));
-  EXPECT_EQ(100u, volume);
+  ExpectVolumeNear(100u, volume);
   Sleep(1000);
 
   // Set the volume to 255 very briefly so we don't blast the poor user
   // listening to this. This is just to test the call succeeds.
   EXPECT_EQ(0, voe_volume_control_->SetSpeakerVolume(255));
   EXPECT_EQ(0, voe_volume_control_->GetSpeakerVolume(volume));
-  EXPECT_EQ(255u, volume);
+  ExpectVolumeNear(255u, volume);
 
   TEST_LOG("Setting speaker volume to the original %d out of 255.\n",
       original_volume);