DPF

commit 4f981c5336c48052cdffeb463572365bf2315c37
parent ad3c5dae30b548134635873ee05e021d18da2e5e
Author: falkTX <falktx@falktx.com>
Date:   Fri, 22 Jul 2022 15:37:47 +0100

Implement buffer size changes in RtAudio native audio fallback

Diffstat:
M
distrho/src/jackbridge/RtAudioBridge.hpp
 | 
44
+++++++++++++++++++++++++++++++++++++++++++-

1 file changed, 43 insertions(+), 1 deletion(-)
diff --git a/distrho/src/jackbridge/RtAudioBridge.hpp b/distrho/src/jackbridge/RtAudioBridge.hpp
@@ -42,6 +42,7 @@
 # include "rtaudio/RtAudio.h"
 # undef Point
 # include "../../extra/ScopedPointer.hpp"
+# include "../../extra/String.hpp"
 
 using DISTRHO_NAMESPACE::ScopedPointer;
 
@@ -49,6 +50,10 @@ struct RtAudioBridge : NativeBridge {
     // pointer to RtAudio instance
     ScopedPointer<RtAudio> handle;
 
+    // for buffer size changes
+    String name;
+    uint nextBufferSize = 512;
+
     const char* getVersion() const noexcept
     {
         return RTAUDIO_VERSION;
@@ -62,7 +67,7 @@ struct RtAudioBridge : NativeBridge {
             rtAudio = new RtAudio(RtAudio::RTAUDIO_API_TYPE);
         } DISTRHO_SAFE_EXCEPTION_RETURN("new RtAudio()", false);
 
-        uint rtAudioBufferFrames = 512;
+        uint rtAudioBufferFrames = nextBufferSize;
 
        #if DISTRHO_PLUGIN_NUM_INPUTS > 0
         RtAudio::StreamParameters inParams;
@@ -94,6 +99,7 @@ struct RtAudioBridge : NativeBridge {
             return false;
         } DISTRHO_SAFE_EXCEPTION_RETURN("rtAudio->openStream()", false);
 
+        name = clientName;
         handle = rtAudio;
         bufferSize = rtAudioBufferFrames;
         sampleRate = handle->getStreamSampleRate();
@@ -137,6 +143,42 @@ struct RtAudioBridge : NativeBridge {
         return true;
     }
 
+    /* RtAudio in macOS uses a different than usual way to handle audio block size,
+     * where RTAUDIO_MINIMIZE_LATENCY makes CoreAudio use very low latencies (around 15 samples).
+     * As such, dynamic buffer sizes are meaningless there.
+     */
+   #ifndef DISTRHO_OS_MAC
+    bool supportsBufferSizeChanges() const override
+    {
+        return true;
+    }
+
+    bool requestBufferSizeChange(const uint32_t newBufferSize) override
+    {
+        // stop audio first
+        deactivate();
+        close();
+
+        // try to open with new buffer size
+        nextBufferSize = newBufferSize;
+
+        const bool ok = open(name);
+
+        if (!ok)
+        {
+            // revert to old buffer size if new one failed
+            nextBufferSize = bufferSize;
+            open(name);
+        }
+
+        if (bufferSizeCallback != nullptr)
+            bufferSizeCallback(bufferSize, jackBufferSizeArg);
+
+        activate();
+        return ok;
+    }
+   #endif
+
     static int RtAudioCallback(void* const outputBuffer,
                               #if DISTRHO_PLUGIN_NUM_INPUTS > 0
                                void* const inputBuffer,