5 files changed, 70 insertions, 7 deletions
diff --git a/src/pcm/PcmResample.cxx b/src/pcm/PcmResample.cxx
index 318181e15..b30e01407 100644
--- a/src/pcm/PcmResample.cxx
+++ b/src/pcm/PcmResample.cxx
@@ -148,3 +148,26 @@ PcmResampler::Resample32(unsigned channels, unsigned src_rate,
 					src_rate, src_buffer, src_size,
 					dest_rate, dest_size_r);
 }
+
+const int32_t *
+PcmResampler::Resample24(unsigned channels, unsigned src_rate,
+			 const int32_t *src_buffer, size_t src_size,
+			 unsigned dest_rate, size_t *dest_size_r,
+			 Error &error_r)
+{
+#ifdef HAVE_LIBSAMPLERATE
+	if (pcm_resample_lsr_enabled())
+		return pcm_resample_lsr_24(this, channels,
+					   src_rate, src_buffer, src_size,
+					   dest_rate, dest_size_r,
+					   error_r);
+#else
+	(void)error_r;
+#endif
+
+	/* reuse the 32 bit code - the resampler code doesn't care if
+	   the upper 8 bits are actually used */
+	return pcm_resample_fallback_32(buffer, channels,
+					src_rate, src_buffer, src_size,
+					dest_rate, dest_size_r);
+}
diff --git a/src/pcm/PcmResample.hxx b/src/pcm/PcmResample.hxx
index 8a740744a..e839d6ecd 100644
--- a/src/pcm/PcmResample.hxx
+++ b/src/pcm/PcmResample.hxx
@@ -124,13 +124,7 @@ struct PcmResampler {
 	const int32_t *Resample24(unsigned channels, unsigned src_rate,
 				  const int32_t *src_buffer, size_t src_size,
 				  unsigned dest_rate, size_t *dest_size_r,
-				  Error &error_r)
-	{
-		/* reuse the 32 bit code - the resampler code doesn't care if
-		   the upper 8 bits are actually used */
-		return Resample32(channels, src_rate, src_buffer, src_size,
-				  dest_rate, dest_size_r, error_r);
-	}
+				  Error &error_r);
 };
 
 bool
diff --git a/src/pcm/PcmResampleInternal.hxx b/src/pcm/PcmResampleInternal.hxx
index 4219b22ed..94cef94ff 100644
--- a/src/pcm/PcmResampleInternal.hxx
+++ b/src/pcm/PcmResampleInternal.hxx
@@ -69,6 +69,15 @@ pcm_resample_lsr_32(PcmResampler *state,
 		    unsigned dest_rate, size_t *dest_size_r,
 		    Error &error);
 
+const int32_t *
+pcm_resample_lsr_24(PcmResampler *state,
+		    unsigned channels,
+		    unsigned src_rate,
+		    const int32_t *src_buffer,
+		    size_t src_size,
+		    unsigned dest_rate, size_t *dest_size_r,
+		    Error &error);
+
 #endif
 
 const int16_t *
diff --git a/src/pcm/PcmResampleLibsamplerate.cxx b/src/pcm/PcmResampleLibsamplerate.cxx
index 1986e8821..9eac2d545 100644
--- a/src/pcm/PcmResampleLibsamplerate.cxx
+++ b/src/pcm/PcmResampleLibsamplerate.cxx
@@ -19,6 +19,7 @@
 
 #include "config.h"
 #include "PcmResampleInternal.hxx"
+#include "PcmUtils.hxx"
 #include "util/ASCII.hxx"
 #include "util/Error.hxx"
 #include "util/Domain.hxx"
@@ -283,3 +284,27 @@ pcm_resample_lsr_32(PcmResampler *state,
 
 	return dest_buffer;
 }
+
+const int32_t *
+pcm_resample_lsr_24(PcmResampler *state,
+		    unsigned channels,
+		    unsigned src_rate,
+		    const int32_t *src_buffer, size_t src_size,
+		    unsigned dest_rate, size_t *dest_size_r,
+		    Error &error)
+{
+	const auto result = pcm_resample_lsr_32(state, channels,
+						src_rate, src_buffer, src_size,
+						dest_rate, dest_size_r,
+						error);
+	if (result != nullptr)
+		/* src_float_to_int_array() clamps for 32 bit
+		   integers; now make sure everything's fine for 24
+		   bit */
+		/* TODO: eliminate the 32 bit clamp to reduce overhead */
+		PcmClampN<int32_t, int32_t, 24>(const_cast<int32_t *>(result),
+						result,
+						*dest_size_r / sizeof(*result));
+
+	return result;
+}
diff --git a/src/pcm/PcmUtils.hxx b/src/pcm/PcmUtils.hxx
index 108ba85ae..febe12d7b 100644
--- a/src/pcm/PcmUtils.hxx
+++ b/src/pcm/PcmUtils.hxx
@@ -63,4 +63,16 @@ PcmClamp(U x)
 	return T(x);
 }
 
+/**
+ * Check if the values in this buffer are within the range of the
+ * provided bit size, and clamps them whenever necessary.
+ */
+template<typename T, typename U, unsigned bits>
+static inline void
+PcmClampN(T *dest, const U *src, unsigned n)
+{
+	while (n-- > 0)
+		*dest++ = PcmClamp<T, U, bits>(*src++);
+}
+
 #endif