feat: 封装一层接口，方便使用

CMakeLists.txt

@@ -28,11 +28,34 @@ elseif(CMAKE_SYSTEM_NAME MATCHES Linux)
     ADD_DEFINITIONS(-DWEBRTC_LINUX)
 endif()
 
-
 add_subdirectory(third_party/abseil-cpp)
 add_subdirectory(api)
 add_subdirectory(audio)
 add_subdirectory(modules)
 add_subdirectory(common_audio)
 add_subdirectory(rtc_base)
-add_subdirectory(system_wrappers)
+add_subdirectory(system_wrappers)
+
+if(BUILD_SHARED)
+set(LIBRARY_TYPE SHARED)
+else()
+set(LIBRARY_TYPE STATIC)
+endif(BUILD_DYNAMIC)
+
+add_library(ts_mixer ${LIBRARY_TYPE} MixerImpl.cpp 
+$<TARGET_OBJECTS:modules_audio_mixer>
+$<TARGET_OBJECTS:rtc_base>
+$<TARGET_OBJECTS:api>
+$<TARGET_OBJECTS:audio>
+$<TARGET_OBJECTS:modules_audio_process>
+$<TARGET_OBJECTS:system_wrappers>
+$<TARGET_OBJECTS:common_audio>
+)
+
+target_link_libraries(ts_mixer PRIVATE absl::throw_delegate absl::strings)
+
+target_include_directories(ts_mixer PRIVATE ${CMAKE_CURRENT_SOURCE_DIR})
+target_include_directories(ts_mixer PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/third_party/abseil-cpp)
+
+INSTALL ( TARGETS ts_mixer						DESTINATION lib )
+

IMixer.h

@@ -0,0 +1,25 @@
+#include <iostream>
+
+namespace ts{
+
+class IMixer {
+public:
+    static IMixer* Create(int sampleRate, int channelCount);
+    static void deleteMixer(IMixer*);
+public:
+    /**
+     * @brief 
+     * 
+     * @param streamCount 流的数量
+     * @param data 混音数据，每个流取一帧
+     * @param lineSize 每个音频帧，一共有多少采样
+     * @param mixData 混音之后的输出数据，需要外部开辟好内存
+     */
+    virtual int Mix(int streamCount, uint16_t* data[], int sampleCount, uint16_t* mixData) = 0;
+protected:
+    IMixer() = default;
+    virtual ~IMixer() = default;
+    IMixer(const IMixer&) = default;
+};
+
+}

MixerImpl.cpp

@@ -0,0 +1,119 @@
+#include <mutex>
+
+#include "MixerImpl.h"
+
+namespace ts{
+
+    class AudioSourceWrap : public ::webrtc::AudioMixer::Source {
+
+    struct AudioData{
+        AudioData(uint16_t* a, int b): data(a),sampleCount(b){}
+        uint16_t* data{nullptr};
+        int sampleCount{0};
+    };
+
+    public:
+        ~AudioSourceWrap() {
+        }
+        explicit AudioSourceWrap(int sampleRate, int channelCount)
+            : sample_rate_hz_(sampleRate)
+            , samples_per_channel_(sample_rate_hz_ / 50)
+            , number_of_channels_(channelCount)
+        {
+        }
+
+        AudioFrameInfo GetAudioFrameWithInfo(int target_rate_hz, ::webrtc::AudioFrame* frame) override {
+            if(dataPool.empty()){
+                frame->Mute();
+                return AudioFrameInfo::kError;
+            }
+            dataLock.lock();
+            auto audioData = dataPool.front();
+            dataPool.pop_front();
+            dataLock.unlock();
+
+            memcpy(frame->mutable_data(),audioData.data, audioData.sampleCount * sizeof(audioData.data[0]));
+            frame->samples_per_channel_ = samples_per_channel_;
+            frame->num_channels_ = number_of_channels_;
+            frame->sample_rate_hz_ = target_rate_hz;
+            return AudioFrameInfo::kNormal;
+        }
+
+        int Ssrc() const override { return 0; }
+
+        int PreferredSampleRate() const override { return sample_rate_hz_; }
+
+        void pushData(uint16_t* data, int sampleCount) {
+            std::lock_guard<std::mutex> lk(dataLock);
+            //这里可能需要有一个专门的构造
+            dataPool.push_back({data,sampleCount});
+        }
+
+    private:
+        int sample_rate_hz_;
+        int samples_per_channel_;
+        int number_of_channels_;
+        std::mutex dataLock;
+        //这里也许不需要list
+        std::list<AudioData> dataPool;
+    };
+
+
+    IMixer* IMixer::Create(int sampleRate, int channelCount){
+        return new MixerImpl(sampleRate, channelCount);
+    }
+
+    void IMixer::deleteMixer(IMixer* ptr){
+        assert(ptr);
+        if (ptr) {
+            delete ptr;
+        }
+    }
+
+    MixerImpl::MixerImpl(int sampleRate, int channelCount)
+        : m_sampleRate(sampleRate)
+        , m_channelCount(channelCount)
+    {
+        m_mixer = ::webrtc::AudioMixerImpl::Create(
+        std::unique_ptr<::webrtc::OutputRateCalculator>(new ::webrtc::DefaultOutputRateCalculator()), true);
+    }
+
+    MixerImpl::~MixerImpl(){
+    }
+
+    int MixerImpl::Mix(int streamCount ,uint16_t* data[], int sampleCount, uint16_t* mixData){
+        int diff = streamCount - m_sources.size();
+        //balance source
+        if(diff > 0){
+            for (int i = 0; i < diff; i++) {
+                auto source = std::make_shared<AudioSourceWrap>(m_sampleRate, m_channelCount);
+                m_sources.emplace_back(source);
+                m_mixer->AddSource(source.get());
+            }
+        }else{
+            for (int i = diff; i < 0; i++) {
+                auto source = m_sources.back();
+                m_sources.pop_back();
+                m_mixer->RemoveSource(source.get());
+            }
+        }
+        // 填充音频数据
+        assert(streamCount == m_sources.size());
+        auto it = m_sources.begin();
+        for (size_t i = 0; i < streamCount; i++) {
+            if(it != m_sources.end()){
+                (*it)->pushData(data[i],sampleCount);
+                it++;
+            }
+        }
+        //执行混音
+        ::webrtc::AudioFrame frame;
+        m_mixer->Mix(m_channelCount, &frame);
+        if (frame.muted()) {
+            return -1;
+        }
+        memcpy(mixData, frame.data(), sampleCount * 2);
+        return 0;
+    }
+
+}

MixerImpl.h

@@ -0,0 +1,27 @@
+#include <memory>
+#include <list>
+#include "IMixer.h"
+
+#include "modules/audio_mixer/audio_mixer_impl.h"
+#include "modules/audio_mixer/default_output_rate_calculator.h"
+
+namespace ts{
+
+class AudioSourceWrap;
+
+class MixerImpl final: public IMixer{
+public:
+    MixerImpl(int sampleRate, int channelCount);
+    ~MixerImpl();
+public:
+    int Mix(int streamCount, uint16_t* data[], int sampleCount, uint16_t* mixData) override;
+
+private:
+    int m_sampleRate{0};
+    int m_channelCount{0};
+    rtc::scoped_refptr<::webrtc::AudioMixerImpl> m_mixer;
+    using AudioSourcePtr = std::shared_ptr<AudioSourceWrap>;
+    std::list<AudioSourcePtr> m_sources;
+};
+
+}

README.md

@@ -0,0 +1,25 @@
+# 项目简介
+该项目主要为了将webrtc中的音频处理模块提取成单独的代码库，以独立的库提供。目前，以完成混音模块的提取。后续会继续完成aec、ns、agc等模块的提取。main分之最低要求cpp17，如果需要使用cpp11版本需要切换到cpp11分之。但是，cpp11分之性能会稍稍降低。
+
+# 使用方式
+## submodule方式
+```
+cd 'SomeDir' //in your project
+git submodule add https://github.com/lowkeywx/webrtc_mixer.git
+
+```
+> 需要主项目也使用cmake方式组织
+
+## 编译成库
+```
+git clone https://github.com/lowkeywx/webrtc_mixer.git
+cd webrtc_mixer
+mkdir build && cd build
+cmake .. && cmake --build .
+or
+cmake .. -DBUILD_SHARED=ON && cmake --build .
+```
+
+> 默认每帧，支持10ms。建议使用单声道、16000hz采样率。
+> 如果需要增大每帧到20ms，需要修改 modules/audio_mixer/audio_mixer_impl.h 中 kFrameDurationInMs = 20; modules/audio_mixer/frame_combiner.cc 中       limiter_(static_cast<size_t>(24000), data_dumper_.get(), "AudioMixer")；modules/audio_processing/agc2/agc2_common.h 中 kFrameDurationMs = 20;
+

api/CMakeLists.txt

@@ -1,15 +1,15 @@
 cmake_minimum_required(VERSION 3.10)
 project(MediaEngine_Api)
 
-add_library(api STATIC 
+add_library(api OBJECT 
 stats_types.cc
 audio/channel_layout.cc
 audio/audio_frame.cc
 task_queue/task_queue_base.cc
 )
 
-target_include_directories(api PRIVATE ${CMAKE_SOURCE_DIR})
-target_include_directories(api PUBLIC ${CMAKE_SOURCE_DIR}/third_party/abseil-cpp)
+target_include_directories(api PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/..)
+target_include_directories(api PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/../third_party/abseil-cpp)
 
 #target_link_libraries(api PRIVATE rtc_base)
 

audio/CMakeLists.txt

@@ -1,12 +1,12 @@
 cmake_minimum_required(VERSION 3.10)
 project(MediaEngine_Audio)
 
-add_library(audio STATIC 
+add_library(audio OBJECT 
 utility/channel_mixer.cc
 utility/audio_frame_operations.cc
 utility/channel_mixing_matrix.cc
 )
 
-target_include_directories(audio PRIVATE ${CMAKE_SOURCE_DIR})
-target_include_directories(audio PUBLIC ${CMAKE_SOURCE_DIR}/third_party/abseil-cpp)
+target_include_directories(audio PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/../)
+target_include_directories(audio PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/../third_party/abseil-cpp)
 

common_audio/CMakeLists.txt

@@ -1,11 +1,11 @@
 cmake_minimum_required(VERSION 3.10)
 project(MediaEngine_CommonAudio)
 
-add_library(common_audio STATIC 
+add_library(common_audio OBJECT 
 wav_file.cc
 audio_util.cc
 wav_header.cc
 )
 
-target_include_directories(common_audio PRIVATE ${CMAKE_SOURCE_DIR})
-target_include_directories(common_audio PUBLIC ${CMAKE_SOURCE_DIR}/third_party/abseil-cpp)
+target_include_directories(common_audio PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/../)
+target_include_directories(common_audio PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/../third_party/abseil-cpp)

modules/audio_mixer/CMakeLists.txt

@@ -3,17 +3,18 @@ project(MediaEngine_Modules_AudioMixer)
 
 set(TARGET_NAME modules_audio_mixer)
 
-add_library(${TARGET_NAME} SHARED
+add_library(${TARGET_NAME} OBJECT
 ./audio_frame_manipulator.cc
 ./audio_mixer_impl.cc
 ./default_output_rate_calculator.cc
 ./frame_combiner.cc
 )
 
-target_include_directories(${TARGET_NAME} PUBLIC ${CMAKE_SOURCE_DIR})
-target_include_directories(${TARGET_NAME} PUBLIC ${CMAKE_SOURCE_DIR}/third_party/abseil-cpp)
-target_link_libraries(${TARGET_NAME} PRIVATE rtc_base api audio modules_audio_process system_wrappers common_audio)
+target_include_directories(${TARGET_NAME} PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/../../)
+target_include_directories(${TARGET_NAME} PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/../../third_party/abseil-cpp)
+
 target_link_libraries(${TARGET_NAME} PRIVATE absl::flags_parse)
+target_compile_definitions(${TARGET_NAME} PRIVATE WEBRTC_APM_DEBUG_DUMP=0)
 
 if(ANDROID)
         find_library(ANDROID_LOG_LIB log)

modules/audio_processing/CMakeLists.txt

@@ -1,7 +1,7 @@
 cmake_minimum_required(VERSION 3.10)
 project(MediaEngine_Modules_AudioProcess)
 
-add_library(modules_audio_process STATIC 
+add_library(modules_audio_process OBJECT 
 logging/apm_data_dumper.cc
 agc2/limiter.cc
 agc2/interpolated_gain_curve.cc
@@ -10,6 +10,6 @@ agc2/fixed_digital_level_estimator.cc
 
 target_compile_definitions(modules_audio_process PUBLIC WEBRTC_APM_DEBUG_DUMP=0)
 
-target_include_directories(modules_audio_process PRIVATE ${CMAKE_SOURCE_DIR})
-target_include_directories(modules_audio_process PUBLIC ${CMAKE_SOURCE_DIR}/third_party/abseil-cpp)
+target_include_directories(modules_audio_process PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/../..)
+target_include_directories(modules_audio_process PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/../../third_party/abseil-cpp)
 

rtc_base/CMakeLists.txt

@@ -1,7 +1,7 @@
 cmake_minimum_required(VERSION 3.10)
 project(MediaEngine_AudioMixer_RtcBase)
 
-add_library(rtc_base STATIC 
+add_library(rtc_base OBJECT 
 checks.cc
 logging.cc
 time_utils.cc
@@ -14,9 +14,9 @@ strings/string_builder.cc
 synchronization/sequence_checker_internal.cc
 )
 
-target_include_directories(rtc_base PRIVATE ${CMAKE_SOURCE_DIR})
-target_include_directories(rtc_base PUBLIC ${CMAKE_SOURCE_DIR}/third_party/abseil-cpp)
-target_link_libraries(rtc_base PRIVATE absl::throw_delegate absl::strings)
+target_include_directories(rtc_base PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/..)
+target_include_directories(rtc_base PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/../third_party/abseil-cpp)
+
 if(CMAKE_SYSTEM_NAME MATCHES Windows)
     target_link_libraries(rtc_base PRIVATE winmm)
 endif()

system_wrappers/CMakeLists.txt

@@ -1,10 +1,10 @@
 cmake_minimum_required(VERSION 3.10)
 project(MediaEngine_SystemWrappers)
 
-add_library(system_wrappers STATIC 
+add_library(system_wrappers OBJECT 
 source/metrics.cc
 source/field_trial.cc
 )
 
-target_include_directories(system_wrappers PRIVATE ${CMAKE_SOURCE_DIR})
-target_include_directories(system_wrappers PUBLIC ${CMAKE_SOURCE_DIR}/third_party/abseil-cpp)
+target_include_directories(system_wrappers PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/..)
+target_include_directories(system_wrappers PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/../third_party/abseil-cpp)