Possibility to calculate resampe ratio per channel in adapter to avoid delay buildup

common/JackAudioAdapterInterface.cpp

@@ -67,8 +67,8 @@ namespace Jack
         fprintf(file, "set xlabel \"audio cycles\"\n");
         fprintf(file, "set ylabel \"frames\"\n");
         fprintf(file, "plot ");
-        fprintf(file, "\"JackAudioAdapter.log\" using 2 title \"Ringbuffer error\" with lines,");
-        fprintf(file, "\"JackAudioAdapter.log\" using 3 title \"Ringbuffer error with timing correction\" with lines");
+        fprintf(file, "\"JackAudioAdapter.log\" using 2 title \"Ringbuffer error\" with dots,");
+        fprintf(file, "\"JackAudioAdapter.log\" using 3 title \"Ringbuffer error with timing correction\" with dots");
 
         fprintf(file, "\n unset multiplot\n");
         fprintf(file, "set output 'AdapterTiming1.svg\n");
@@ -81,8 +81,8 @@ namespace Jack
         fprintf(file, "set xlabel \"audio cycles\"\n");
         fprintf(file, "set ylabel \"frames\"\n");
         fprintf(file, "plot ");
-        fprintf(file, "\"JackAudioAdapter.log\" using 2 title \"Consumer interrupt period\" with lines,");
-        fprintf(file, "\"JackAudioAdapter.log\" using 3 title \"Producer interrupt period\" with lines\n");
+        fprintf(file, "\"JackAudioAdapter.log\" using 2 title \"Consumer interrupt period\" with dots,");
+        fprintf(file, "\"JackAudioAdapter.log\" using 3 title \"Producer interrupt period\" with dots\n");
         fprintf(file, "unset multiplot\n");
         fprintf(file, "unset output\n");
 
@@ -97,8 +97,8 @@ namespace Jack
         fprintf(file, "set xlabel \"audio cycles\"\n");
         fprintf(file, "set ylabel \"resampling ratio\"\n");
         fprintf(file, "plot ");
-        fprintf(file, "\"JackAudioAdapter.log\" using 4 title \"Ratio 1\" with lines,");
-        fprintf(file, "\"JackAudioAdapter.log\" using 5 title \"Ratio 2\" with lines");
+        fprintf(file, "\"JackAudioAdapter.log\" using 4 title \"Ratio 1\" with dots,");
+        fprintf(file, "\"JackAudioAdapter.log\" using 5 title \"Ratio 2\" with dots");
 
         fprintf(file, "\n unset multiplot\n");
         fprintf(file, "set output 'AdapterTiming2.svg\n");
@@ -111,8 +111,8 @@ namespace Jack
         fprintf(file, "set xlabel \"audio cycles\"\n");
         fprintf(file, "set ylabel \"resampling ratio\"\n");
         fprintf(file, "plot ");
-        fprintf(file, "\"JackAudioAdapter.log\" using 4 title \"Ratio 1\" with lines,");
-        fprintf(file, "\"JackAudioAdapter.log\" using 5 title \"Ratio 2\" with lines\n");
+        fprintf(file, "\"JackAudioAdapter.log\" using 4 title \"Ratio 1\" with dots,");
+        fprintf(file, "\"JackAudioAdapter.log\" using 5 title \"Ratio 2\" with dots\n");
         fprintf(file, "unset multiplot\n");
         fprintf(file, "unset output\n");
 
@@ -127,8 +127,8 @@ namespace Jack
          fprintf(file, "set xlabel \"audio cycles\"\n");
         fprintf(file, "set ylabel \"frames\"\n");
         fprintf(file, "plot ");
-        fprintf(file, "\"JackAudioAdapter.log\" using 6 title \"Frames position in consumer ringbuffer\" with lines,");
-        fprintf(file, "\"JackAudioAdapter.log\" using 7 title \"Frames position in producer ringbuffer\" with lines");
+        fprintf(file, "\"JackAudioAdapter.log\" using 6 title \"Frames position in consumer ringbuffer\" with dots,");
+        fprintf(file, "\"JackAudioAdapter.log\" using 7 title \"Frames position in producer ringbuffer\" with dots");
 
         fprintf(file, "\n unset multiplot\n");
         fprintf(file, "set output 'AdapterTiming3.svg\n");
@@ -141,8 +141,8 @@ namespace Jack
         fprintf(file, "set xlabel \"audio cycles\"\n");
         fprintf(file, "set ylabel \"frames\"\n");
         fprintf(file, "plot ");
-        fprintf(file, "\"JackAudioAdapter.log\" using 6 title \"Frames position in consumer ringbuffer\" with lines,");
-        fprintf(file, "\"JackAudioAdapter.log\" using 7 title \"Frames position in producer ringbuffer\" with lines\n");
+        fprintf(file, "\"JackAudioAdapter.log\" using 6 title \"Frames position in consumer ringbuffer\" with dots,");
+        fprintf(file, "\"JackAudioAdapter.log\" using 7 title \"Frames position in producer ringbuffer\" with dots\n");
         fprintf(file, "unset multiplot\n");
         fprintf(file, "unset output\n");
 
@@ -173,9 +173,11 @@ namespace Jack
 
         for (int i = 0; i < fCaptureChannels; i++) {
             fCaptureRingBuffer[i]->Reset(fRingbufferCurSize);
+            fPIControllerCapture[i]->Reset();
         }
         for (int i = 0; i < fPlaybackChannels; i++) {
             fPlaybackRingBuffer[i]->Reset(fRingbufferCurSize);
+            fPIControllerPlayback[i]->Reset();
         }
     }
 
@@ -191,9 +193,11 @@ namespace Jack
 #else
     void JackAudioAdapterInterface::Create()
     {
-        //ringbuffers
         fCaptureRingBuffer = new JackResampler*[fCaptureChannels];
+        fPIControllerCapture = new JackPIController*[fCaptureChannels];
+
         fPlaybackRingBuffer = new JackResampler*[fPlaybackChannels];
+        fPIControllerPlayback = new JackPIController*[fPlaybackChannels];
 
         if (fAdaptative) {
             AdaptRingBufferSize();
@@ -205,13 +209,22 @@ namespace Jack
             jack_info("Fixed ringbuffer size = %d frames", fRingbufferCurSize);
         }
 
+        if (fResampleRatioPerChannel){
+            jack_info("Resample ratio tracked independently for each capture and playback channel");
+        } else {
+            jack_info("Shared resample ratio tracking for all capture and playback channels");
+        }
+
+
         for (int i = 0; i < fCaptureChannels; i++ ) {
             fCaptureRingBuffer[i] = new JackLibSampleRateResampler(fQuality);
             fCaptureRingBuffer[i]->Reset(fRingbufferCurSize);
+            fPIControllerCapture[i] = new JackPIController(double(fHostSampleRate) / double(fAdaptedSampleRate));
         }
         for (int i = 0; i < fPlaybackChannels; i++ ) {
             fPlaybackRingBuffer[i] = new JackLibSampleRateResampler(fQuality);
             fPlaybackRingBuffer[i]->Reset(fRingbufferCurSize);
+            fPIControllerPlayback[i] = new JackPIController(double(fHostSampleRate) / double(fAdaptedSampleRate));
         }
 
         if (fCaptureChannels > 0) {
@@ -227,40 +240,79 @@ namespace Jack
     {
         for (int i = 0; i < fCaptureChannels; i++) {
             delete(fCaptureRingBuffer[i]);
+            delete(fPIControllerCapture[i]);
         }
         for (int i = 0; i < fPlaybackChannels; i++) {
             delete (fPlaybackRingBuffer[i]);
+            delete(fPIControllerPlayback[i]);
         }
 
         delete[] fCaptureRingBuffer;
+        delete [] fPIControllerCapture;
         delete[] fPlaybackRingBuffer;
+        delete [] fPIControllerPlayback;
+    }
+
+    double JackAudioAdapterInterface::GetSharedRatio(int delta_frames)
+    {
+        if (0 < fCaptureChannels) {
+            return fPIControllerCapture[0]->GetRatio(fCaptureRingBuffer[0]->GetReadBalance() - delta_frames);
+        }
+        else if (0 < fPlaybackChannels) {
+            return fPIControllerPlayback[0]->GetRatio(fPlaybackRingBuffer[0]->GetReadBalance() - delta_frames);
+        }
+        return 1;
     }
 
     int JackAudioAdapterInterface::PushAndPull(float** inputBuffer, float** outputBuffer, unsigned int frames)
     {
+        // Most of the time we can use a shared ratio calculated on a single input or output channel ringbuffer and apply this ratio also to all other channels.
+        // In some situations we see that there is a drift between the channels coming from or going to the same device.
+        // On those devices we need to activate the fResampleRatioPerChannel option so that every channel will calculate and keep track of its own resample ratio
+        // in order to keep his ringbuffer in a good balance which is half used for reading and half used for writing.
+        // Not using this option when it is needed will result in buffer errors followed by resets for all the buffers.
+        // cfr. https://github.com/jackaudio/jack2/issues/534
+
         bool failure = false;
         fRunning = true;
 
         // Finer estimation of the position in the ringbuffer
         int delta_frames = (fPullAndPushTime > 0) ? (int)((float(long(GetMicroSeconds() - fPullAndPushTime)) * float(fAdaptedSampleRate)) / 1000000.f) : 0;
 
-        double ratio = 1;
-
-        // TODO : done like this just to avoid crash when input only or output only...
-        if (fCaptureChannels > 0) {
-            ratio = fPIControler.GetRatio(fCaptureRingBuffer[0]->GetError() - delta_frames);
-        } else if (fPlaybackChannels > 0) {
-            ratio = fPIControler.GetRatio(fPlaybackRingBuffer[0]->GetError() - delta_frames);
+        double ratioC[fCaptureChannels];
+        double ratioP[fPlaybackChannels];
+        if(!fResampleRatioPerChannel) {
+            double shared_ratio = GetSharedRatio(delta_frames);
+            for (int i = 0; i < fCaptureChannels; i++) {
+                ratioC[i] = shared_ratio;
+            }
+            for (int i = 0; i < fPlaybackChannels; i++) {
+                ratioP[i] = shared_ratio;
+            }
+#ifdef JACK_MONITOR
+            if (fCaptureRingBuffer && fCaptureRingBuffer[0] != NULL) {
+                fTable.Write(fCaptureRingBuffer[0]->GetReadBalance(), fCaptureRingBuffer[0]->GetReadBalance() - delta_frames, shared_ratio, 1/shared_ratio, fCaptureRingBuffer[0]->ReadSpace(), fCaptureRingBuffer[0]->ReadSpace());
+            }
+#endif // JACK_MONITOR
+        }
+        else {
+            for (int i = 0; i < fCaptureChannels; i++) {
+                ratioC[i] = fPIControllerCapture[i]->GetRatio(fCaptureRingBuffer[i]->GetReadBalance() - delta_frames);
+            }
+            for (int i = 0; i < fPlaybackChannels; i++) {
+                ratioP[i] = fPIControllerPlayback[i]->GetRatio(fPlaybackRingBuffer[i]->GetWriteBalance() + delta_frames);
+            }
+#ifdef JACK_MONITOR
+            if (fCaptureRingBuffer && fCaptureRingBuffer[0] != NULL) {
+                fTable.Write(fCaptureRingBuffer[0]->GetReadBalance(), fCaptureRingBuffer[0]->GetReadBalance() - delta_frames, ratioC[0], 1/ratioC[0], fCaptureRingBuffer[0]->ReadSpace(), fCaptureRingBuffer[0]->ReadSpace());
+            }
+#endif // JACK_MONITOR
         }
 
-    #ifdef JACK_MONITOR
-        if (fCaptureRingBuffer && fCaptureRingBuffer[0] != NULL)
-            fTable.Write(fCaptureRingBuffer[0]->GetError(), fCaptureRingBuffer[0]->GetError() - delta_frames, ratio, 1/ratio, fCaptureRingBuffer[0]->ReadSpace(), fCaptureRingBuffer[0]->ReadSpace());
-    #endif
 
         // Push/pull from ringbuffer
         for (int i = 0; i < fCaptureChannels; i++) {
-            fCaptureRingBuffer[i]->SetRatio(ratio);
+            fCaptureRingBuffer[i]->SetRatio(ratioC[i]);
             if (inputBuffer[i]) {
                 if (fCaptureRingBuffer[i]->WriteResample(inputBuffer[i], frames) < frames) {
                     failure = true;
@@ -269,7 +321,7 @@ namespace Jack
         }
 
         for (int i = 0; i < fPlaybackChannels; i++) {
-            fPlaybackRingBuffer[i]->SetRatio(1/ratio);
+            fPlaybackRingBuffer[i]->SetRatio(1 / ratioP[i]);
             if (outputBuffer[i]) {
                 if (fPlaybackRingBuffer[i]->ReadResample(outputBuffer[i], frames) < frames) {
                      failure = true;
@@ -347,14 +399,32 @@ namespace Jack
     int JackAudioAdapterInterface::SetHostSampleRate(jack_nframes_t sample_rate)
     {
         fHostSampleRate = sample_rate;
-        fPIControler.Init(double(fHostSampleRate) / double(fAdaptedSampleRate));
+        if (NULL != fPIControllerCapture) {
+            for (int i = 0; i < fCaptureChannels; i++) {
+                fPIControllerCapture[i]->Init(double(fHostSampleRate) / double(fAdaptedSampleRate));
+            }
+        }
+        if (NULL != fPIControllerPlayback) {
+            for (int i = 0; i < fPlaybackChannels; i++) {
+                fPIControllerPlayback[i]->Init(double(fHostSampleRate) / double(fAdaptedSampleRate));
+            }
+        }
         return 0;
     }
 
     int JackAudioAdapterInterface::SetAdaptedSampleRate(jack_nframes_t sample_rate)
     {
         fAdaptedSampleRate = sample_rate;
-        fPIControler.Init(double(fHostSampleRate) / double(fAdaptedSampleRate));
+        if (NULL != fPIControllerCapture) {
+            for (int i = 0; i < fCaptureChannels; i++) {
+                fPIControllerCapture[i]->Init(double(fHostSampleRate) / double(fAdaptedSampleRate));
+            }
+        }
+        if (NULL != fPIControllerPlayback) {
+            for (int i = 0; i < fPlaybackChannels; i++ ) {
+                fPIControllerPlayback[i]->Init(double(fHostSampleRate) / double(fAdaptedSampleRate));
+            }
+        }
         return 0;
     }
 

common/JackAudioAdapterInterface.h

@@ -82,9 +82,9 @@ namespace Jack
         jack_nframes_t fAdaptedBufferSize;
         jack_nframes_t fAdaptedSampleRate;
 
-        //PI controller
-        JackPIControler fPIControler;
-
+        //PI controler
+        JackPIController** fPIControllerCapture;
+        JackPIController** fPIControllerPlayback;
         JackResampler** fCaptureRingBuffer;
         JackResampler** fPlaybackRingBuffer;
 
@@ -94,6 +94,7 @@ namespace Jack
 
         bool fRunning;
         bool fAdaptative;
+        bool fResampleRatioPerChannel;
 
         void ResetRingBuffers();
         void AdaptRingBufferSize();
@@ -108,13 +109,14 @@ namespace Jack
                                 fHostSampleRate(sample_rate),
                                 fAdaptedBufferSize(buffer_size),
                                 fAdaptedSampleRate(sample_rate),
-                                fPIControler(sample_rate / sample_rate, 256),
+                                fPIControllerCapture(NULL), fPIControllerPlayback(NULL),
                                 fCaptureRingBuffer(NULL), fPlaybackRingBuffer(NULL),
                                 fQuality(0),
                                 fRingbufferCurSize(ring_buffer_size),
                                 fPullAndPushTime(0),
                                 fRunning(false),
-                                fAdaptative(true)
+                                fAdaptative(true),
+                                fResampleRatioPerChannel(false)
         {}
 
         JackAudioAdapterInterface(jack_nframes_t host_buffer_size,
@@ -128,12 +130,14 @@ namespace Jack
                                 fHostSampleRate(host_sample_rate),
                                 fAdaptedBufferSize(adapted_buffer_size),
                                 fAdaptedSampleRate(adapted_sample_rate),
-                                fPIControler(host_sample_rate / host_sample_rate, 256),
+                                fPIControllerCapture(NULL), fPIControllerPlayback(NULL),
+                                fCaptureRingBuffer(NULL), fPlaybackRingBuffer(NULL),
                                 fQuality(0),
                                 fRingbufferCurSize(ring_buffer_size),
                                 fPullAndPushTime(0),
                                 fRunning(false),
-                                fAdaptative(true)
+                                fAdaptative(true),
+                                fResampleRatioPerChannel(false)
         {}
 
         virtual ~JackAudioAdapterInterface()
@@ -168,6 +172,7 @@ namespace Jack
         virtual int GetInputLatency(int port_index) { return 0; }
         virtual int GetOutputLatency(int port_index) { return 0; }
 
+        double GetSharedRatio(int delta_frames);
         int PushAndPull(jack_default_audio_sample_t** inputBuffer, jack_default_audio_sample_t** outputBuffer, unsigned int frames);
         int PullAndPush(jack_default_audio_sample_t** inputBuffer, jack_default_audio_sample_t** outputBuffer, unsigned int frames);
 

common/JackFilters.h

@@ -220,102 +220,44 @@ namespace Jack
 #endif
 
     /*
-    Torben Hohn PI controller from JACK1
+    Torben Hohn PI controler from JACK1
     */
 
-    struct JackPIControler {
+    struct JackPIController {
 
-        double resample_mean;
         double static_resample_factor;
-
-        double* offset_array;
-        double* window_array;
-        int offset_differential_index;
-
         double offset_integral;
-
         double catch_factor;
         double catch_factor2;
-        double pclamp;
-        double controlquant;
-        int smooth_size;
 
         double hann(double x)
         {
             return 0.5 * (1.0 - cos(2 * M_PI * x));
         }
 
-        JackPIControler(double resample_factor, int fir_size)
+        JackPIController(double resample_factor)
         {
-            resample_mean = resample_factor;
             static_resample_factor = resample_factor;
-            offset_array = new double[fir_size];
-            window_array = new double[fir_size];
-            offset_differential_index = 0;
             offset_integral = 0.0;
-            smooth_size = fir_size;
-
-            for (int i = 0; i < fir_size; i++) {
-                offset_array[i] = 0.0;
-                window_array[i] = hann(double(i) / (double(fir_size) - 1.0));
-            }
 
             // These values could be configurable
             catch_factor = 100000;
             catch_factor2 = 10000;
-            pclamp = 15.0;
-            controlquant = 10000.0;
         }
 
-        ~JackPIControler()
+        ~JackPIController()
         {
-            delete[] offset_array;
-            delete[] window_array;
         }
 
         void Init(double resample_factor)
         {
-            resample_mean = resample_factor;
             static_resample_factor = resample_factor;
         }
 
-        /*
-        double GetRatio(int fill_level)
+        void Reset()
         {
-            double offset = fill_level;
-
-            // Save offset.
-            offset_array[(offset_differential_index++) % smooth_size] = offset;
-
-            // Build the mean of the windowed offset array basically fir lowpassing.
-            double smooth_offset = 0.0;
-            for (int i = 0; i < smooth_size; i++) {
-                smooth_offset += offset_array[(i + offset_differential_index - 1) % smooth_size] * window_array[i];
-            }
-            smooth_offset /= double(smooth_size);
-
-            // This is the integral of the smoothed_offset
-            offset_integral += smooth_offset;
-
-            // Clamp offset : the smooth offset still contains unwanted noise which would go straight onto the resample coeff.
-            // It only used in the P component and the I component is used for the fine tuning anyways.
-            if (fabs(smooth_offset) < pclamp)
-                smooth_offset = 0.0;
-
-            // Ok, now this is the PI controller.
-            // u(t) = K * (e(t) + 1/T \int e(t') dt')
-            // Kp = 1/catch_factor and T = catch_factor2  Ki = Kp/T
-            double current_resample_factor
-                = static_resample_factor - smooth_offset / catch_factor - offset_integral / catch_factor / catch_factor2;
-
-            // Now quantize this value around resample_mean, so that the noise which is in the integral component doesn't hurt.
-            current_resample_factor = floor((current_resample_factor - resample_mean) * controlquant + 0.5) / controlquant + resample_mean;
-
-            // Calculate resample_mean so we can init ourselves to saner values.
-            resample_mean = 0.9999 * resample_mean + 0.0001 * current_resample_factor;
-            return current_resample_factor;
+            offset_integral = 0.0;
         }
-        */
 
         double GetRatio(int error)
         {
@@ -329,20 +271,6 @@ namespace Jack
             // Kp = 1/catch_factor and T = catch_factor2 Ki = Kp/T
             return static_resample_factor - smooth_offset/catch_factor - offset_integral/catch_factor/catch_factor2;
         }
-
-        void OurOfBounds()
-        {
-            int i;
-            // Set the resample_rate... we need to adjust the offset integral, to do this.
-            // first look at the PI controller, this code is just a special case, which should never execute once
-            // everything is swung in.
-            offset_integral = - (resample_mean - static_resample_factor) * catch_factor * catch_factor2;
-            // Also clear the array. we are beginning a new control cycle.
-            for (i = 0; i < smooth_size; i++) {
-                offset_array[i] = 0.0;
-            }
-        }
-
     };
 
 }

common/JackNetAPI.cpp

@@ -995,9 +995,11 @@ struct JackNetAdapter : public JackAudioAdapterInterface {
 
         if (fCaptureChannels > 0) {
             fCaptureRingBuffer = new JackResampler*[fCaptureChannels];
+            fPIControllerCapture = new JackPIController*[fCaptureChannels];
         }
         if (fPlaybackChannels > 0) {
             fPlaybackRingBuffer = new JackResampler*[fPlaybackChannels];
+            fPIControllerPlayback = new JackPIController*[fPlaybackChannels];
         }
 
         if (fAdaptative) {
@@ -1013,10 +1015,12 @@ struct JackNetAdapter : public JackAudioAdapterInterface {
         for (int i = 0; i < fCaptureChannels; i++ ) {
             fCaptureRingBuffer[i] = new JackResampler();
             fCaptureRingBuffer[i]->Reset(fRingbufferCurSize);
+            fPIControllerCapture[i] = new JackPIController(double(fHostSampleRate) / double(fAdaptedSampleRate));
         }
         for (int i = 0; i < fPlaybackChannels; i++ ) {
             fPlaybackRingBuffer[i] = new JackResampler();
             fPlaybackRingBuffer[i]->Reset(fRingbufferCurSize);
+            fPIControllerPlayback[i] = new JackPIController(double(fHostSampleRate) / double(fAdaptedSampleRate));
         }
 
         if (fCaptureChannels > 0) {
@@ -1036,9 +1040,11 @@ struct JackNetAdapter : public JackAudioAdapterInterface {
     {
         for (int i = 0; i < fCaptureChannels; i++ ) {
             fCaptureRingBuffer[i]->Reset(fRingbufferCurSize);
+            fPIControllerCapture[i]->Reset();
         }
         for (int i = 0; i < fPlaybackChannels; i++ ) {
             fPlaybackRingBuffer[i]->Reset(fRingbufferCurSize);
+            fPIControllerPlayback[i]->Reset();
         }
     }
 

common/JackNetAdapter.cpp

@@ -124,6 +124,9 @@ namespace Jack
                     fRingbufferCurSize = param->value.ui;
                     fAdaptative = false;
                     break;
+                case 'R':
+                    fResampleRatioPerChannel = true;
+                    break;
              }
         }
 
@@ -462,6 +465,10 @@ extern "C"
         value.i = false;
         jack_driver_descriptor_add_parameter(desc, &filler, "auto-connect", 'c', JackDriverParamBool, &value, NULL, "Auto connect netadapter to system ports", NULL);
 
+        value.i  = false;
+        jack_driver_descriptor_add_parameter(desc, &filler, "multi-ratios", 'R', JackDriverParamBool, &value, NULL, "Calculate resample ratio per channel"
+                    , "Calculate resample ratio per channel in case of repeated ringbuffer errors because of clock drift between the channels from the same device.");
+
         return desc;
     }
 

common/JackResampler.h

@@ -65,10 +65,14 @@ class JackRingBuffer
         virtual unsigned int ReadSpace();
         virtual unsigned int WriteSpace();
 
-        unsigned int GetError()
+        unsigned int GetReadBalance()
         {
             return (jack_ringbuffer_read_space(fRingBuffer) / sizeof(float)) - (fRingBufferSize / 2);
         }
+        unsigned int GetWriteBalance()
+        {
+            return (jack_ringbuffer_write_space(fRingBuffer) / sizeof(float)) - (fRingBufferSize / 2);
+        }
 
 };
 

linux/alsa/JackAlsaAdapter.cpp

@@ -86,6 +86,9 @@ namespace Jack
                     fRingbufferCurSize = param->value.ui;
                     fAdaptative = false;
                     break;
+                case 'R':
+                    fResampleRatioPerChannel = true;
+                    break;
             }
         }
 
@@ -228,6 +231,9 @@ extern "C"
         value.ui = 32768;
         jack_driver_descriptor_add_parameter(desc, &filler, "ring-buffer", 'g', JackDriverParamUInt, &value, NULL, "Fixed ringbuffer size", "Fixed ringbuffer size (if not set => automatic adaptative)");
 
+        value.i  = false;
+        jack_driver_descriptor_add_parameter(desc, &filler, "multi-ratios", 'R', JackDriverParamBool, &value, NULL, "Calculate resample ratio per channel"
+                   , "Calculate resample ratio per channel in case of repeated ringbuffer errors because of clock drift between the channels from the same device.");
         return desc;
     }
 

macosx/coreaudio/JackCoreAudioAdapter.mm

@@ -409,6 +409,10 @@ JackCoreAudioAdapter::JackCoreAudioAdapter(jack_nframes_t buffer_size, jack_nfra
             case 's':
                 fClockDriftCompensate = true;
                 break;
+
+            case 'R':
+                fResampleRatioPerChannel = true;
+                break;
         }
     }
 
@@ -1745,6 +1749,10 @@ extern "C"
         value.i = false;
         jack_driver_descriptor_add_parameter(desc, &filler, "auto-connect", 'c', JackDriverParamBool, &value, NULL, "Auto connect audioadapter to system ports", NULL);
 
+        value.i  = false;
+        jack_driver_descriptor_add_parameter(desc, &filler, "multi-ratios", 'R', JackDriverParamBool, &value, NULL, "Calculate resample ratio per channel"
+                      , "Calculate resample ratio per channel in case of repeated ringbuffer errors because of clock drift between the channels from the same device.");
+
         return desc;
     }
 

solaris/oss/JackOSSAdapter.cpp

@@ -187,6 +187,10 @@ JackOSSAdapter::JackOSSAdapter(jack_nframes_t buffer_size, jack_nframes_t sample
                 fAdaptative = false;
                 break;
 
+            case 'R':
+                fResampleRatioPerChannel = true;
+                break;
+
            }
     }
 
@@ -674,6 +678,10 @@ extern "C"
         value.i = 32768;
         jack_driver_descriptor_add_parameter(desc, &filler, "ring-buffer", 'g', JackDriverParamInt, &value, NULL, "Fixed ringbuffer size", "Fixed ringbuffer size (if not set => automatic adaptative)");
 
+        value.i  = false;
+        jack_driver_descriptor_add_parameter(desc, &filler, "multi-ratios", 'R', JackDriverParamBool, &value, NULL, "Calculate resample ratio per channel"
+                    , "Calculate resample ratio per channel in case of repeated ringbuffer errors because of clock drift between the channels from the same device.");
+
         return desc;
     }
 

windows/portaudio/JackPortAudioAdapter.cpp

@@ -92,6 +92,9 @@ namespace Jack
                 fRingbufferCurSize = param->value.ui;
                 fAdaptative = false;
                 break;
+            case 'R':
+                fResampleRatioPerChannel = true;
+                break;
             }
         }
 
@@ -235,6 +238,10 @@ extern "C"
         value.ui = 32768;
         jack_driver_descriptor_add_parameter(desc, &filler, "ring-buffer", 'g', JackDriverParamUInt, &value, NULL, "Fixed ringbuffer size", "Fixed ringbuffer size (if not set => automatic adaptative)");
 
+        value.i  = false;
+        jack_driver_descriptor_add_parameter(desc, &filler, "multi-ratios", 'R', JackDriverParamBool, &value, NULL, "Calculate resample ratio per channel"
+                   , "Calculate resample ratio per channel in case of repeated ringbuffer errors because of clock drift between the channels from the same device.");
+
         return desc;
     }