New interface (AudioDecoderFactory), with an implementation
This is a first draft of what we're hoping to use to create all
AudioDecoder instances. Follow-up CLs will start using this internally
in NetEq instead of calling constructors manually.
BUG=webrtc:5801
Review-Url: https://codereview.webrtc.org/1917163002
Cr-Commit-Position: refs/heads/master@{#12548}
diff --git a/webrtc/modules/audio_coding/BUILD.gn b/webrtc/modules/audio_coding/BUILD.gn
index 3797818..a51a73a 100644
--- a/webrtc/modules/audio_coding/BUILD.gn
+++ b/webrtc/modules/audio_coding/BUILD.gn
@@ -39,6 +39,33 @@
audio_codec_deps += [ ":red" ]
}
+source_set("audio_decoder_factory_interface") {
+ sources = [
+ "codecs/audio_decoder_factory.h",
+ "codecs/audio_format.cc",
+ "codecs/audio_format.h",
+ ]
+ configs += [ "../..:common_config" ]
+ public_configs = [ "../..:common_inherited_config" ]
+ deps = [
+ "../..:webrtc_common",
+ ]
+}
+
+source_set("builtin_audio_decoder_factory") {
+ sources = [
+ "codecs/builtin_audio_decoder_factory.cc",
+ "codecs/builtin_audio_decoder_factory.h",
+ ]
+ configs += [ "../..:common_config" ]
+ public_configs = [ "../..:common_inherited_config" ]
+ deps = [
+ "../..:webrtc_common",
+ ":audio_decoder_factory_interface",
+ ] + audio_codec_deps
+ defines = audio_codec_defines
+}
+
source_set("rent_a_codec") {
sources = [
"acm2/acm_codec_database.cc",
diff --git a/webrtc/modules/audio_coding/audio_coding.gypi b/webrtc/modules/audio_coding/audio_coding.gypi
index e460853..af2cb3c 100644
--- a/webrtc/modules/audio_coding/audio_coding.gypi
+++ b/webrtc/modules/audio_coding/audio_coding.gypi
@@ -69,6 +69,50 @@
},
'targets': [
{
+ 'target_name': 'audio_decoder_factory_interface',
+ 'type': 'static_library',
+ 'dependencies': [
+ '<(webrtc_root)/common.gyp:webrtc_common',
+ ],
+ 'include_dirs': [
+ '<(webrtc_root)',
+ ],
+ 'direct_dependent_settings': {
+ 'include_dirs': [
+ '<(webrtc_root)',
+ ],
+ },
+ 'sources': [
+ 'codecs/audio_decoder_factory.h',
+ 'codecs/audio_format.cc',
+ 'codecs/audio_format.h',
+ ],
+ },
+ {
+ 'target_name': 'builtin_audio_decoder_factory',
+ 'type': 'static_library',
+ 'defines': [
+ '<@(audio_codec_defines)',
+ ],
+ 'dependencies': [
+ '<(webrtc_root)/common.gyp:webrtc_common',
+ '<@(audio_codec_dependencies)',
+ 'audio_decoder_factory_interface',
+ ],
+ 'include_dirs': [
+ '<(webrtc_root)',
+ ],
+ 'direct_dependent_settings': {
+ 'include_dirs': [
+ '<(webrtc_root)',
+ ],
+ },
+ 'sources': [
+ 'codecs/builtin_audio_decoder_factory.cc',
+ 'codecs/builtin_audio_decoder_factory.h',
+ ],
+ },
+ {
'target_name': 'rent_a_codec',
'type': 'static_library',
'defines': [
diff --git a/webrtc/modules/audio_coding/codecs/audio_decoder_factory.h b/webrtc/modules/audio_coding/codecs/audio_decoder_factory.h
new file mode 100644
index 0000000..12b9778
--- /dev/null
+++ b/webrtc/modules/audio_coding/codecs/audio_decoder_factory.h
@@ -0,0 +1,36 @@
+/*
+ * 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.
+ */
+
+#ifndef WEBRTC_MODULES_AUDIO_CODING_CODECS_AUDIO_DECODER_FACTORY_H_
+#define WEBRTC_MODULES_AUDIO_CODING_CODECS_AUDIO_DECODER_FACTORY_H_
+
+#include <memory>
+#include <vector>
+
+#include "webrtc/modules/audio_coding/codecs/audio_decoder.h"
+#include "webrtc/modules/audio_coding/codecs/audio_format.h"
+
+namespace webrtc {
+
+// A factory that creates AudioDecoders.
+// NOTE: This class is still under development and may change without notice.
+class AudioDecoderFactory {
+ public:
+ virtual ~AudioDecoderFactory() = default;
+
+ virtual std::vector<SdpAudioFormat> GetSupportedFormats() = 0;
+
+ virtual std::unique_ptr<AudioDecoder> MakeAudioDecoder(
+ const SdpAudioFormat& format) = 0;
+};
+
+} // namespace webrtc
+
+#endif // WEBRTC_MODULES_AUDIO_CODING_CODECS_AUDIO_DECODER_FACTORY_H_
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 0000000..a1ae05d
--- /dev/null
+++ b/webrtc/modules/audio_coding/codecs/audio_decoder_factory_unittest.cc
@@ -0,0 +1,117 @@
+/*
+ * 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);
+ // PCMu supports 8 kHz, and any number of channels.
+ EXPECT_FALSE(adf->MakeAudioDecoder(SdpAudioFormat("pcmu", 8000, 0)));
+ 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);
+ // PCMa supports 8 kHz, and any number of channels.
+ 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);
+ // iLBC supports 8 kHz, 1 channel.
+ 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)));
+
+ // iLBC actually uses a 16 kHz sample rate instead of the nominal 8 kHz.
+ // TODO(kwiberg): Uncomment this once AudioDecoder has a SampleRateHz method.
+ // std::unique_ptr<AudioDecoder> dec =
+ // adf->MakeAudioDecoder(SdpAudioFormat("ilbc", 8000, 1));
+ // EXPECT_EQ(16000, dec->SampleRateHz());
+}
+
+TEST(AudioDecoderFactoryTest, CreateIsac) {
+ std::unique_ptr<AudioDecoderFactory> adf = CreateBuiltinAudioDecoderFactory();
+ ASSERT_TRUE(adf);
+ // iSAC supports 16 kHz, 1 channel. The float implementation additionally
+ // supports 32 kHz, 1 channel.
+ 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)));
+#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);
+ // L16 supports any clock rate, any number of channels.
+ const int clockrates[] = {8000, 16000, 32000, 48000};
+ const int num_channels[] = {1, 2, 3, 4711};
+ for (int clockrate : clockrates) {
+ EXPECT_FALSE(adf->MakeAudioDecoder(SdpAudioFormat("l16", clockrate, 0)));
+ for (int channels : num_channels) {
+ EXPECT_TRUE(
+ adf->MakeAudioDecoder(SdpAudioFormat("l16", clockrate, channels)));
+ }
+ }
+}
+
+TEST(AudioDecoderFactoryTest, CreateG722) {
+ std::unique_ptr<AudioDecoderFactory> adf = CreateBuiltinAudioDecoderFactory();
+ ASSERT_TRUE(adf);
+ // g722 supports 8 kHz, 1-2 channels.
+ 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);
+ // Opus supports 48 kHz, 1-2 channels.
+ 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
diff --git a/webrtc/modules/audio_coding/codecs/audio_format.cc b/webrtc/modules/audio_coding/codecs/audio_format.cc
new file mode 100644
index 0000000..b2acf09
--- /dev/null
+++ b/webrtc/modules/audio_coding/codecs/audio_format.cc
@@ -0,0 +1,50 @@
+/*
+ * 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 "webrtc/modules/audio_coding/codecs/audio_format.h"
+
+namespace webrtc {
+
+SdpAudioFormat::SdpAudioFormat() = default;
+SdpAudioFormat::SdpAudioFormat(const SdpAudioFormat&) = default;
+SdpAudioFormat::SdpAudioFormat(SdpAudioFormat&&) = default;
+
+SdpAudioFormat::SdpAudioFormat(const char* name,
+ int clockrate_hz,
+ int num_channels)
+ : name(name), clockrate_hz(clockrate_hz), num_channels(num_channels) {}
+
+SdpAudioFormat::~SdpAudioFormat() = default;
+SdpAudioFormat& SdpAudioFormat::operator=(const SdpAudioFormat&) = default;
+SdpAudioFormat& SdpAudioFormat::operator=(SdpAudioFormat&&) = default;
+
+void swap(SdpAudioFormat& a, SdpAudioFormat& b) {
+ using std::swap;
+ swap(a.name, b.name);
+ swap(a.clockrate_hz, b.clockrate_hz);
+ swap(a.num_channels, b.num_channels);
+ swap(a.parameters, b.parameters);
+}
+
+std::ostream& operator<<(std::ostream& os, const SdpAudioFormat& saf) {
+ os << "{name: " << saf.name;
+ os << ", clockrate_hz: " << saf.clockrate_hz;
+ os << ", num_channels: " << saf.num_channels;
+ os << ", parameters: {";
+ const char* sep = "";
+ for (const auto& kv : saf.parameters) {
+ os << sep << kv.first << ": " << kv.second;
+ sep = ", ";
+ }
+ os << "}}";
+ return os;
+}
+
+} // namespace webrtc
diff --git a/webrtc/modules/audio_coding/codecs/audio_format.h b/webrtc/modules/audio_coding/codecs/audio_format.h
new file mode 100644
index 0000000..7ad7edd
--- /dev/null
+++ b/webrtc/modules/audio_coding/codecs/audio_format.h
@@ -0,0 +1,48 @@
+/*
+ * 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.
+ */
+
+#ifndef WEBRTC_MODULES_AUDIO_CODING_CODECS_AUDIO_FORMAT_H_
+#define WEBRTC_MODULES_AUDIO_CODING_CODECS_AUDIO_FORMAT_H_
+
+#include <map>
+#include <ostream>
+#include <string>
+#include <utility>
+
+namespace webrtc {
+
+// SDP specification for a single audio codec.
+// NOTE: This class is still under development and may change without notice.
+struct SdpAudioFormat {
+ // TODO(kwiberg): Get rid of the default constructor when rtc::Optional no
+ // longer requires it.
+ SdpAudioFormat();
+ SdpAudioFormat(const SdpAudioFormat&);
+ SdpAudioFormat(SdpAudioFormat&&);
+ SdpAudioFormat(const char* name, int clockrate_hz, int num_channels);
+ ~SdpAudioFormat();
+
+ SdpAudioFormat& operator=(const SdpAudioFormat&);
+ SdpAudioFormat& operator=(SdpAudioFormat&&);
+
+ using Parameters = std::map<std::string, std::string>;
+ std::string name;
+ int clockrate_hz;
+ int num_channels;
+ Parameters parameters;
+ // Parameters feedback_parameters; ??
+};
+
+void swap(SdpAudioFormat& a, SdpAudioFormat& b);
+std::ostream& operator<<(std::ostream& os, const SdpAudioFormat& saf);
+
+} // namespace webrtc
+
+#endif // WEBRTC_MODULES_AUDIO_CODING_CODECS_AUDIO_FORMAT_H_
diff --git a/webrtc/modules/audio_coding/codecs/builtin_audio_decoder_factory.cc b/webrtc/modules/audio_coding/codecs/builtin_audio_decoder_factory.cc
new file mode 100644
index 0000000..12a6afe
--- /dev/null
+++ b/webrtc/modules/audio_coding/codecs/builtin_audio_decoder_factory.cc
@@ -0,0 +1,140 @@
+/*
+ * 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 "webrtc/modules/audio_coding/codecs/builtin_audio_decoder_factory.h"
+
+#include <vector>
+
+#include "webrtc/base/checks.h"
+#include "webrtc/common_types.h"
+#include "webrtc/modules/audio_coding/codecs/cng/webrtc_cng.h"
+#include "webrtc/modules/audio_coding/codecs/g711/audio_decoder_pcm.h"
+#ifdef WEBRTC_CODEC_G722
+#include "webrtc/modules/audio_coding/codecs/g722/audio_decoder_g722.h"
+#endif
+#ifdef WEBRTC_CODEC_ILBC
+#include "webrtc/modules/audio_coding/codecs/ilbc/audio_decoder_ilbc.h"
+#endif
+#ifdef WEBRTC_CODEC_ISACFX
+#include "webrtc/modules/audio_coding/codecs/isac/fix/include/audio_decoder_isacfix.h"
+#endif
+#ifdef WEBRTC_CODEC_ISAC
+#include "webrtc/modules/audio_coding/codecs/isac/main/include/audio_decoder_isac.h"
+#endif
+#ifdef WEBRTC_CODEC_OPUS
+#include "webrtc/modules/audio_coding/codecs/opus/audio_decoder_opus.h"
+#endif
+#include "webrtc/modules/audio_coding/codecs/pcm16b/audio_decoder_pcm16b.h"
+
+namespace webrtc {
+
+namespace {
+
+struct NamedDecoderConstructor {
+ const char* name;
+ std::unique_ptr<AudioDecoder> (*constructor)(int clockrate_hz,
+ int num_channels);
+};
+
+std::unique_ptr<AudioDecoder> Unique(AudioDecoder* d) {
+ return std::unique_ptr<AudioDecoder>(d);
+}
+
+// TODO(kwiberg): These factory functions should probably be moved to each
+// decoder.
+NamedDecoderConstructor decoder_constructors[] = {
+ {"pcmu",
+ [](int clockrate_hz, int num_channels) {
+ return clockrate_hz == 8000 && num_channels >= 1
+ ? Unique(new AudioDecoderPcmU(num_channels))
+ : nullptr;
+ }},
+ {"pcma",
+ [](int clockrate_hz, int num_channels) {
+ return clockrate_hz == 8000 && num_channels >= 1
+ ? Unique(new AudioDecoderPcmA(num_channels))
+ : nullptr;
+ }},
+#ifdef WEBRTC_CODEC_ILBC
+ {"ilbc",
+ [](int clockrate_hz, int num_channels) {
+ return clockrate_hz == 8000 && num_channels == 1
+ ? Unique(new AudioDecoderIlbc)
+ : nullptr;
+ }},
+#endif
+#if defined(WEBRTC_CODEC_ISACFX)
+ {"isac",
+ [](int clockrate_hz, int num_channels) {
+ return clockrate_hz == 16000 && num_channels == 1
+ ? Unique(new AudioDecoderIsacFix)
+ : nullptr;
+ }},
+#elif defined(WEBRTC_CODEC_ISAC)
+ {"isac",
+ [](int clockrate_hz, int num_channels) {
+ return (clockrate_hz == 16000 || clockrate_hz == 32000) &&
+ num_channels == 1
+ ? Unique(new AudioDecoderIsac)
+ : nullptr;
+ }},
+#endif
+ {"l16",
+ [](int clockrate_hz, int num_channels) {
+ return num_channels >= 1 ? Unique(new AudioDecoderPcm16B(num_channels))
+ : nullptr;
+ }},
+#ifdef WEBRTC_CODEC_G722
+ {"g722",
+ [](int clockrate_hz, int num_channels) {
+ if (clockrate_hz == 8000) {
+ if (num_channels == 1)
+ return Unique(new AudioDecoderG722);
+ if (num_channels == 2)
+ return Unique(new AudioDecoderG722Stereo);
+ }
+ return Unique(nullptr);
+ }},
+#endif
+#ifdef WEBRTC_CODEC_OPUS
+ {"opus",
+ [](int clockrate_hz, int num_channels) {
+ return clockrate_hz == 48000 && (num_channels == 1 || num_channels == 2)
+ ? Unique(new AudioDecoderOpus(num_channels))
+ : nullptr;
+ }},
+#endif
+};
+
+class BuiltinAudioDecoderFactory : public AudioDecoderFactory {
+ public:
+ std::vector<SdpAudioFormat> GetSupportedFormats() override {
+ FATAL() << "Not implemented yet!";
+ }
+
+ std::unique_ptr<AudioDecoder> MakeAudioDecoder(
+ const SdpAudioFormat& format) override {
+ for (const auto& dc : decoder_constructors) {
+ if (STR_CASE_CMP(format.name.c_str(), dc.name) == 0) {
+ return std::unique_ptr<AudioDecoder>(
+ dc.constructor(format.clockrate_hz, format.num_channels));
+ }
+ }
+ return nullptr;
+ }
+};
+
+} // namespace
+
+std::unique_ptr<AudioDecoderFactory> CreateBuiltinAudioDecoderFactory() {
+ return std::unique_ptr<AudioDecoderFactory>(new BuiltinAudioDecoderFactory);
+}
+
+} // namespace webrtc
diff --git a/webrtc/modules/audio_coding/codecs/builtin_audio_decoder_factory.h b/webrtc/modules/audio_coding/codecs/builtin_audio_decoder_factory.h
new file mode 100644
index 0000000..7234c16
--- /dev/null
+++ b/webrtc/modules/audio_coding/codecs/builtin_audio_decoder_factory.h
@@ -0,0 +1,26 @@
+/*
+ * 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.
+ */
+
+#ifndef WEBRTC_MODULES_AUDIO_CODING_CODECS_BUILTIN_AUDIO_DECODER_FACTORY_H_
+#define WEBRTC_MODULES_AUDIO_CODING_CODECS_BUILTIN_AUDIO_DECODER_FACTORY_H_
+
+#include <memory>
+
+#include "webrtc/modules/audio_coding/codecs/audio_decoder_factory.h"
+
+namespace webrtc {
+
+// Creates a new factory that can create the built-in types of audio decoders.
+// NOTE: This function is still under development and may change without notice.
+std::unique_ptr<AudioDecoderFactory> CreateBuiltinAudioDecoderFactory();
+
+} // namespace webrtc
+
+#endif // WEBRTC_MODULES_AUDIO_CODING_CODECS_BUILTIN_AUDIO_DECODER_FACTORY_H_