Pass host sample rate into jack

Signed-off-by: falkTX <falktx@falktx.com>
mod-audio · Mar 11, 2024 · 3952104 · 3952104
1 parent 819c537
commit 3952104
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Showing 2 changed files with 39 additions and 10 deletions.
diff --git a/src/plugin/DesktopAudioDriver.cpp b/src/plugin/DesktopAudioDriver.cpp
@@ -246,16 +246,35 @@ SERVER_EXPORT jack_driver_desc_t* driver_get_descriptor()
 {
     printf("%03d:%s\n", __LINE__, __FUNCTION__);
     jack_driver_desc_filler_t filler;
-    return jack_driver_descriptor_construct("desktop", JackDriverMaster, "MOD Desktop plugin audio backend", &filler);
+    jack_driver_param_value_t value;
+
+    jack_driver_desc_t* const desc = jack_driver_descriptor_construct("desktop", JackDriverMaster, "MOD Desktop plugin audio backend", &filler);
+
+    value.ui = 48000U;
+    jack_driver_descriptor_add_parameter(desc, &filler, "rate", 'r', JackDriverParamUInt, &value, NULL, "Sample rate", NULL);
+
+    return desc;
 }
 
 SERVER_EXPORT Jack::JackDriverClientInterface* driver_initialize(Jack::JackLockedEngine* engine, Jack::JackSynchro* table, const JSList* params)
 {
-    printf("zzz %03d:%s\n", __LINE__, __FUNCTION__);
+    jack_nframes_t srate = 48000;
+
+    for (const JSList* node = params; node; node = jack_slist_next(node))
+    {
+        const jack_driver_param_t* const param = (const jack_driver_param_t *) node->data;
+
+        switch (param->character)
+        {
+        case 'r':
+            srate = param->value.ui;
+            break;
+        }
+    }
+
     Jack::JackDriverClientInterface* driver = new Jack::DesktopAudioDriver("system", "mod-desktop", engine, table);
-    printf("zzz %03d:%s\n", __LINE__, __FUNCTION__);
 
-    if (driver->Open(128, 48000, true, true, 2, 2, false, "", "", 0, 0) == 0)
+    if (driver->Open(128, srate, true, true, 2, 2, false, "", "", 0, 0) == 0)
     {
         printf("%03d:%s OK\n", __LINE__, __FUNCTION__);
         return driver;

diff --git a/src/plugin/DesktopPlugin.cpp b/src/plugin/DesktopPlugin.cpp
@@ -190,12 +190,14 @@ class ChildProcess
           stop();
     }
 
-    bool start()
+    bool start(const uint32_t sampleRate)
     {
+        const String sampleRateStr(sampleRate);
+
         #define P "/home/falktx/Source/MOD/mod-app/build"
 
-        static constexpr const char* const args[] = {
-            "jackd", "-R", "-S", "-n", "mod-desktop", "-C", P "/jack/jack-session.conf", "-d", "desktop", nullptr
+        const char* const args[] = {
+            "jackd", "-R", "-S", "-n", "mod-desktop", "-C", P "/jack/jack-session.conf", "-d", "desktop", "-r", sampleRateStr.buffer(), nullptr
         };
 
         // FIXME
@@ -314,11 +316,10 @@ class DesktopPlugin : public Plugin
         if (isDummyInstance())
             return;
 
-        if (shm.init() && jackd.start())
+        if (shm.init() && jackd.start(getSampleRate()))
         {
-            shm.getAudioData(fInBuffers);
             processing = true;
-
+            shm.getAudioData(fInBuffers);
             bufferSizeChanged(getBufferSize());
         }
     }
@@ -551,6 +552,15 @@ class DesktopPlugin : public Plugin
         std::memset(fOutBuffers[1], 0, sizeof(float) * (bufferSize + 256));
     }
 
+    void sampleRateChanged(const double sampleRate) override
+    {
+        if (processing)
+        {
+            jackd.stop();
+            jackd.start(sampleRate);
+        }
+    }
+
     // -------------------------------------------------------------------------------------------------------
 
    /**