Add support for changing Opus encoder bitrate. #11

include/mumlib.hpp

@@ -10,6 +10,8 @@
 
 namespace mumlib {
 
+    constexpr int DEFAULT_OPUS_ENCODER_BITRATE = 16000;
+
     using namespace std;
     using namespace boost::asio;
 
@@ -18,6 +20,11 @@ namespace mumlib {
         MumlibException(string message) : runtime_error(message) { }
     };
 
+    struct MumlibConfiguration {
+        int opusEncoderBitrate = DEFAULT_OPUS_ENCODER_BITRATE;
+        // additional fields will be added in the future
+    };
+
     struct _Mumlib_Private;
 
 
@@ -27,6 +34,10 @@ namespace mumlib {
 
         Mumlib(Callback &callback, io_service &ioService);
 
+        Mumlib(Callback &callback, MumlibConfiguration &configuration);
+
+        Mumlib(Callback &callback, io_service &ioService, MumlibConfiguration &configuration);
+
         virtual ~Mumlib();
 
         void connect(string host, int port, string user, string password);

include/mumlib/Audio.hpp

@@ -28,7 +28,7 @@ namespace mumlib {
 
     class Audio : boost::noncopyable {
     public:
-        Audio();
+        Audio(int opusEncoderBitrate = DEFAULT_OPUS_ENCODER_BITRATE);
 
         virtual ~Audio();
 
@@ -46,6 +46,10 @@ namespace mumlib {
                 uint8_t *outputBuffer,
                 int outputBufferSize = MAX_UDP_LENGTH);
 
+        void setOpusEncoderBitrate(int bitrate);
+
+        int getOpusEncoderBitrate();
+
         void resetEncoder();
 
     private:

mumlib_example.cpp

@@ -48,7 +48,9 @@ int main(int argc, char *argv[]) {
 
     while (true) {
         try {
-            mumlib::Mumlib mum(myCallback);
+            mumlib::MumlibConfiguration conf;
+            conf.opusEncoderBitrate = 32000;
+            mumlib::Mumlib mum(myCallback, conf);
             myCallback.mum = &mum;
             mum.connect(argv[1], 64738, "mumlib_example", argv[2]);
             mum.run();

src/Audio.cpp

@@ -4,7 +4,7 @@
 
 static boost::posix_time::seconds RESET_SEQUENCE_NUMBER_INTERVAL(5);
 
-mumlib::Audio::Audio()
+mumlib::Audio::Audio(int opusEncoderBitrate)
         : logger(log4cpp::Category::getInstance("mumlib.Audio")),
           opusDecoder(nullptr),
           opusEncoder(nullptr),
@@ -24,6 +24,8 @@ mumlib::Audio::Audio()
 
     opus_encoder_ctl(opusEncoder, OPUS_SET_VBR(0));
 
+    setOpusEncoderBitrate(opusEncoderBitrate);
+
     resetEncoder();
 }
 
@@ -37,6 +39,23 @@ mumlib::Audio::~Audio() {
     }
 }
 
+void mumlib::Audio::setOpusEncoderBitrate(int bitrate) {
+    int error = opus_encoder_ctl(opusEncoder, OPUS_SET_BITRATE(bitrate));
+    if (error != OPUS_OK) {
+        throw AudioException((boost::format("failed to initialize transmission bitrate to %d B/s: %s")
+                              % bitrate % opus_strerror(error)).str());
+    }
+}
+
+int mumlib::Audio::getOpusEncoderBitrate() {
+    opus_int32 bitrate;
+    int error = opus_encoder_ctl(opusEncoder, OPUS_GET_BITRATE(&bitrate));
+    if (error != OPUS_OK) {
+        throw AudioException((boost::format("failed to read Opus bitrate: %s") % opus_strerror(error)).str());
+    }
+    return bitrate;
+}
+
 std::pair<int, bool>  mumlib::Audio::decodeOpusPayload(uint8_t *inputBuffer,
                                                        int inputLength,
                                                        int16_t *pcmBuffer,
@@ -166,3 +185,5 @@ mumlib::IncomingAudioPacket mumlib::Audio::decodeIncomingAudioPacket(uint8_t *in
 
     return incomingAudioPacket;
 }
+
+

src/mumlib.cpp

@@ -33,17 +33,20 @@ namespace mumlib {
         int sessionId = 0;
         int channelId = 0;
 
-        _Mumlib_Private(Callback &callback)
-                : _Mumlib_Private(callback, *(new io_service())) {
+        _Mumlib_Private(Callback &callback, MumlibConfiguration &configuration)
+                : _Mumlib_Private(callback, *(new io_service()), configuration) {
             externalIoService = false;
         }
 
-        _Mumlib_Private(Callback &callback, io_service &ioService)
+        _Mumlib_Private(Callback &callback, io_service &ioService, MumlibConfiguration &configuration)
                 : callback(callback),
                   ioService(ioService),
                   externalIoService(true),
                   transport(ioService, boost::bind(&_Mumlib_Private::processIncomingTcpMessage, this, _1, _2, _3),
-                            boost::bind(&_Mumlib_Private::processAudioPacket, this, _1, _2, _3)) { }
+                            boost::bind(&_Mumlib_Private::processAudioPacket, this, _1, _2, _3)) {
+
+            audio.setOpusEncoderBitrate(configuration.opusEncoderBitrate);
+        }
 
         virtual ~_Mumlib_Private() {
             if (not externalIoService) {
@@ -334,12 +337,21 @@ namespace mumlib {
 
     };
 
-    Mumlib::Mumlib(Callback &callback)
-            : impl(new _Mumlib_Private(callback)) {
+    Mumlib::Mumlib(Callback &callback) {
+        MumlibConfiguration conf;
+        impl = new _Mumlib_Private(callback, conf);
     }
 
-    Mumlib::Mumlib(Callback &callback, io_service &ioService)
-            : impl(new _Mumlib_Private(callback, ioService)) { }
+    Mumlib::Mumlib(Callback &callback, io_service &ioService) {
+        MumlibConfiguration conf;
+        impl = new _Mumlib_Private(callback, ioService, conf);
+    }
+
+    Mumlib::Mumlib(Callback &callback, MumlibConfiguration &configuration)
+            : impl(new _Mumlib_Private(callback, configuration)) { }
+
+    Mumlib::Mumlib(Callback &callback, io_service &ioService, MumlibConfiguration &configuration)
+            : impl(new _Mumlib_Private(callback, ioService, configuration)) { }
 
     Mumlib::~Mumlib() {
         disconnect();