Add getProcessSizeLimit

rubberband/RubberBandStretcher.h

@@ -805,10 +805,10 @@ public:
      *
      * Despite the existence of this call and its use of a size_t
      * argument, there is an internal limit to the maximum process
-     * buffer size that can be requested. This is currently 524288 (or
-     * 2^19). The Rubber Band API is essentially block-based and is
-     * not designed to process an entire signal within a single
-     * process cycle.
+     * buffer size that can be requested. Call getProcessSizeLimit()
+     * to query that limit. The Rubber Band API is essentially
+     * block-based and is not designed to process an entire signal
+     * within a single process cycle.
      *
      * Note that the value of "samples" refers to the number of audio
      * sample frames, which may be multi-channel, not the number of
@@ -818,6 +818,16 @@ public:
      */
     void setMaxProcessSize(size_t samples);
 
+    /**
+     * Obtain the overall maximum supported process buffer size in
+     * sample frames, which is also the maximum acceptable value to
+     * pass to setMaxProcessSize(). This value is fixed across
+     * instances and configurations. As of Rubber Band v3.3 it is
+     * always 524288 (or 2^19), but in principle it may change in
+     * future releases.
+     */
+    size_t getProcessSizeLimit() const;
+    
     /**
      * Ask the stretcher how many audio sample frames should be
      * provided as input in order to ensure that some more output

src/RubberBandStretcher.cpp

@@ -226,6 +226,13 @@ public:
         else m_r3->setMaxProcessSize(samples);
     }
 
+    size_t
+    getProcessSizeLimit() const
+    {
+        if (m_r2) return m_r2->getProcessSizeLimit();
+        else return m_r3->getProcessSizeLimit();
+    }
+
     void
     setKeyFrameMap(const std::map<size_t, size_t> &mapping)
     {
@@ -492,6 +499,12 @@ RubberBandStretcher::setMaxProcessSize(size_t samples)
     m_d->setMaxProcessSize(samples);
 }
 
+size_t
+RubberBandStretcher::getProcessSizeLimit() const
+{
+    return m_d->getProcessSizeLimit();
+}
+
 void
 RubberBandStretcher::setKeyFrameMap(const std::map<size_t, size_t> &mapping)
 {

src/faster/R2Stretcher.cpp

@@ -316,6 +316,12 @@ R2Stretcher::setMaxProcessSize(size_t samples)
     reconfigure();
 }
 
+size_t
+R2Stretcher::getProcessSizeLimit() const
+{
+    return 524288;
+}
+
 void
 R2Stretcher::setKeyFrameMap(const std::map<size_t, size_t> &mapping)
 {

src/faster/R2Stretcher.h

@@ -73,6 +73,7 @@ public:
 
     void setExpectedInputDuration(size_t samples);
     void setMaxProcessSize(size_t samples);
+    size_t getProcessSizeLimit() const;
     void setKeyFrameMap(const std::map<size_t, size_t> &);
 
     size_t getSamplesRequired() const;

src/finer/R3Stretcher.cpp

@@ -652,6 +652,12 @@ R3Stretcher::setMaxProcessSize(size_t requested)
     ensureOutbuf(n * 8, false);
 }
 
+size_t
+R3Stretcher::getProcessSizeLimit() const
+{
+    return m_limits.overallMaxProcessSize;
+}
+
 void
 R3Stretcher::ensureInbuf(int required, bool warn)
 {

src/finer/R3Stretcher.h

@@ -93,6 +93,7 @@ public:
 
     void setExpectedInputDuration(size_t samples);
     void setMaxProcessSize(size_t samples);
+    size_t getProcessSizeLimit() const;
     
     void setDebugLevel(int level) {
         m_log.setDebugLevel(level);

src/test/TestStretcher.cpp

@@ -46,8 +46,10 @@ BOOST_AUTO_TEST_CASE(engine_version)
 {
     RubberBandStretcher s2(44100, 1, RubberBandStretcher::OptionEngineFaster);
     BOOST_TEST(s2.getEngineVersion() == 2);
+    BOOST_TEST(s2.getProcessSizeLimit() == 524288);
     RubberBandStretcher s3(44100, 1, RubberBandStretcher::OptionEngineFiner);
     BOOST_TEST(s3.getEngineVersion() == 3);
+    BOOST_TEST(s3.getProcessSizeLimit() == 524288);
 }
 
 BOOST_AUTO_TEST_CASE(sinusoid_unchanged_offline_faster)