New interface (AudioDecoderFactory), with an implementation

webrtc/modules/audio_coding/codecs/audio_decoder_factory_unittest.cc

Index: webrtc/modules/audio_coding/codecs/audio_decoder_factory_unittest.cc
diff --git a/webrtc/modules/audio_coding/codecs/audio_decoder_factory_unittest.cc b/webrtc/modules/audio_coding/codecs/audio_decoder_factory_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..53d14b3be75da80d6a3831015bdb23b7134aa532
--- /dev/null
+++ b/webrtc/modules/audio_coding/codecs/audio_decoder_factory_unittest.cc
@@ -0,0 +1,102 @@
+/*
+ *  Copyright (c) 2016 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.
+ */
+
+#include "testing/gtest/include/gtest/gtest.h"
+#include "webrtc/modules/audio_coding/codecs/builtin_audio_decoder_factory.h"
+
+namespace webrtc {
+
+TEST(AudioDecoderFactoryTest, CreateUnknownDecoder) {
+  std::unique_ptr<AudioDecoderFactory> adf = CreateBuiltinAudioDecoderFactory();
+  ASSERT_TRUE(adf);
+  EXPECT_FALSE(adf->MakeAudioDecoder(SdpAudioFormat("rey", 8000, 1)));
+}
+
+TEST(AudioDecoderFactoryTest, CreatePcmu) {
+  std::unique_ptr<AudioDecoderFactory> adf = CreateBuiltinAudioDecoderFactory();
+  ASSERT_TRUE(adf);
+  EXPECT_FALSE(adf->MakeAudioDecoder(SdpAudioFormat("pcmu", 8000, 0)));

[the sun, 2016/04/27 20:34:14]

It would be good to have documentation along the lines of:
// pcmu supports only 8kHz clock rate, with 1 to 3 channels.

[kwiberg-webrtc, 2016/04/28 12:35:51]

Right. I'll add that.

+  EXPECT_TRUE(adf->MakeAudioDecoder(SdpAudioFormat("pcmu", 8000, 1)));
+  EXPECT_TRUE(adf->MakeAudioDecoder(SdpAudioFormat("pcmu", 8000, 2)));
+  EXPECT_TRUE(adf->MakeAudioDecoder(SdpAudioFormat("pcmu", 8000, 3)));
+  EXPECT_FALSE(adf->MakeAudioDecoder(SdpAudioFormat("pcmu", 16000, 1)));
+}
+
+TEST(AudioDecoderFactoryTest, CreatePcma) {
+  std::unique_ptr<AudioDecoderFactory> adf = CreateBuiltinAudioDecoderFactory();
+  ASSERT_TRUE(adf);
+  EXPECT_FALSE(adf->MakeAudioDecoder(SdpAudioFormat("pcma", 8000, 0)));
+  EXPECT_TRUE(adf->MakeAudioDecoder(SdpAudioFormat("pcma", 8000, 1)));
+  EXPECT_TRUE(adf->MakeAudioDecoder(SdpAudioFormat("pcma", 8000, 2)));
+  EXPECT_TRUE(adf->MakeAudioDecoder(SdpAudioFormat("pcma", 8000, 3)));
+  EXPECT_FALSE(adf->MakeAudioDecoder(SdpAudioFormat("pcma", 16000, 1)));
+}
+
+TEST(AudioDecoderFactoryTest, CreateIlbc) {
+  std::unique_ptr<AudioDecoderFactory> adf = CreateBuiltinAudioDecoderFactory();
+  ASSERT_TRUE(adf);
+  EXPECT_FALSE(adf->MakeAudioDecoder(SdpAudioFormat("ilbc", 8000, 0)));
+  EXPECT_TRUE(adf->MakeAudioDecoder(SdpAudioFormat("ilbc", 8000, 1)));
+  EXPECT_FALSE(adf->MakeAudioDecoder(SdpAudioFormat("ilbc", 8000, 2)));
+  EXPECT_FALSE(adf->MakeAudioDecoder(SdpAudioFormat("ilbc", 16000, 1)));
+}
+
+TEST(AudioDecoderFactoryTest, CreateIsac) {
+  std::unique_ptr<AudioDecoderFactory> adf = CreateBuiltinAudioDecoderFactory();
+  ASSERT_TRUE(adf);
+  EXPECT_FALSE(adf->MakeAudioDecoder(SdpAudioFormat("isac", 16000, 0)));
+  EXPECT_TRUE(adf->MakeAudioDecoder(SdpAudioFormat("isac", 16000, 1)));
+  EXPECT_FALSE(adf->MakeAudioDecoder(SdpAudioFormat("isac", 16000, 2)));
+  EXPECT_FALSE(adf->MakeAudioDecoder(SdpAudioFormat("isac", 8000, 1)));
+  EXPECT_FALSE(adf->MakeAudioDecoder(SdpAudioFormat("isac", 48000, 1)));

[the sun, 2016/04/27 20:34:14]

ch count 3?

[kwiberg-webrtc, 2016/04/28 12:35:51]

I already test that 2 doesn't work. If I'm gonna test more than one past the
working variants, I should simply test all reasonably small values and have a
predicate that says which should succeed.

+#ifdef WEBRTC_ARCH_ARM
+  EXPECT_FALSE(adf->MakeAudioDecoder(SdpAudioFormat("isac", 32000, 1)));
+#else
+  EXPECT_TRUE(adf->MakeAudioDecoder(SdpAudioFormat("isac", 32000, 1)));
+#endif
+}
+
+TEST(AudioDecoderFactoryTest, CreateL16) {
+  std::unique_ptr<AudioDecoderFactory> adf = CreateBuiltinAudioDecoderFactory();
+  ASSERT_TRUE(adf);
+  const int clockrates[] = {8000, 16000, 32000, 48000};
+  for (int clockrate : clockrates) {
+    EXPECT_FALSE(adf->MakeAudioDecoder(SdpAudioFormat("l16", clockrate, 0)));
+    for (int channels = 1; channels < 10; ++channels) {

[the sun, 2016/04/27 20:34:14]

Do we really need to test all channel counts? Can we just test 1, 2 and "many"?

[kwiberg-webrtc, 2016/04/28 12:35:51]

Sure, that's probably fine. Will do.

+      EXPECT_TRUE(
+          adf->MakeAudioDecoder(SdpAudioFormat("l16", clockrate, channels)));
+    }
+  }
+}
+
+TEST(AudioDecoderFactoryTest, CreateG722) {
+  std::unique_ptr<AudioDecoderFactory> adf = CreateBuiltinAudioDecoderFactory();
+  ASSERT_TRUE(adf);
+  EXPECT_FALSE(adf->MakeAudioDecoder(SdpAudioFormat("g722", 8000, 0)));
+  EXPECT_TRUE(adf->MakeAudioDecoder(SdpAudioFormat("g722", 8000, 1)));
+  EXPECT_TRUE(adf->MakeAudioDecoder(SdpAudioFormat("g722", 8000, 2)));
+  EXPECT_FALSE(adf->MakeAudioDecoder(SdpAudioFormat("g722", 8000, 3)));
+  EXPECT_FALSE(adf->MakeAudioDecoder(SdpAudioFormat("g722", 16000, 1)));
+  EXPECT_FALSE(adf->MakeAudioDecoder(SdpAudioFormat("g722", 32000, 1)));
+}
+
+TEST(AudioDecoderFactoryTest, CreateOpus) {
+  std::unique_ptr<AudioDecoderFactory> adf = CreateBuiltinAudioDecoderFactory();
+  ASSERT_TRUE(adf);
+  EXPECT_FALSE(adf->MakeAudioDecoder(SdpAudioFormat("opus", 48000, 0)));
+  EXPECT_TRUE(adf->MakeAudioDecoder(SdpAudioFormat("opus", 48000, 1)));
+  EXPECT_TRUE(adf->MakeAudioDecoder(SdpAudioFormat("opus", 48000, 2)));
+  EXPECT_FALSE(adf->MakeAudioDecoder(SdpAudioFormat("opus", 48000, 3)));
+  EXPECT_FALSE(adf->MakeAudioDecoder(SdpAudioFormat("opus", 8000, 1)));
+  EXPECT_FALSE(adf->MakeAudioDecoder(SdpAudioFormat("opus", 16000, 1)));
+  EXPECT_FALSE(adf->MakeAudioDecoder(SdpAudioFormat("opus", 32000, 1)));
+}
+
+}  // namespace webrtc