diff --git a/src/pcm/Dop.hxx b/src/pcm/Dop.hxx
index c6b6d2947..92fa0ae72 100644
--- a/src/pcm/Dop.hxx
+++ b/src/pcm/Dop.hxx
@@ -46,6 +46,20 @@ public:
 		rest_buffer.Reset();
 	}
 
+	/**
+	 * @return the size of one input block in bytes
+	 */
+	size_t GetInputBlockSize() const noexcept {
+		return rest_buffer.GetInputBlockSize();
+	}
+
+	/**
+	 * @return the size of one output block in bytes
+	 */
+	size_t GetOutputBlockSize() const noexcept {
+		return 2 * GetInputBlockSize();
+	}
+
 	ConstBuffer<uint32_t> Convert(ConstBuffer<uint8_t> src) noexcept;
 };
 
diff --git a/src/pcm/Dsd16.hxx b/src/pcm/Dsd16.hxx
index 18b31b83a..6e00f4039 100644
--- a/src/pcm/Dsd16.hxx
+++ b/src/pcm/Dsd16.hxx
@@ -44,6 +44,20 @@ public:
 		rest_buffer.Reset();
 	}
 
+	/**
+	 * @return the size of one input block in bytes
+	 */
+	size_t GetInputBlockSize() const noexcept {
+		return rest_buffer.GetInputBlockSize();
+	}
+
+	/**
+	 * @return the size of one output block in bytes
+	 */
+	size_t GetOutputBlockSize() const noexcept {
+		return GetInputBlockSize();
+	}
+
 	ConstBuffer<uint16_t> Convert(ConstBuffer<uint8_t> src) noexcept;
 };
 
diff --git a/src/pcm/Dsd32.hxx b/src/pcm/Dsd32.hxx
index f6036c527..6a9afb5d4 100644
--- a/src/pcm/Dsd32.hxx
+++ b/src/pcm/Dsd32.hxx
@@ -44,6 +44,20 @@ public:
 		rest_buffer.Reset();
 	}
 
+	/**
+	 * @return the size of one input block in bytes
+	 */
+	size_t GetInputBlockSize() const noexcept {
+		return rest_buffer.GetInputBlockSize();
+	}
+
+	/**
+	 * @return the size of one output block in bytes
+	 */
+	size_t GetOutputBlockSize() const noexcept {
+		return GetInputBlockSize();
+	}
+
 	ConstBuffer<uint32_t> Convert(ConstBuffer<uint8_t> src) noexcept;
 };
 
diff --git a/src/pcm/Export.cxx b/src/pcm/Export.cxx
index f70fe8064..ad087d0d8 100644
--- a/src/pcm/Export.cxx
+++ b/src/pcm/Export.cxx
@@ -144,6 +144,52 @@ PcmExport::GetOutputFrameSize() const noexcept
 	return GetInputFrameSize();
 }
 
+size_t
+PcmExport::GetInputBlockSize() const noexcept
+{
+#ifdef ENABLE_DSD
+	switch (dsd_mode) {
+	case DsdMode::NONE:
+		break;
+
+	case DsdMode::U16:
+		return dsd16_converter.GetInputBlockSize();
+
+	case DsdMode::U32:
+		return dsd32_converter.GetInputBlockSize();
+		break;
+
+	case DsdMode::DOP:
+		return dop_converter.GetInputBlockSize();
+	}
+#endif
+
+	return GetInputFrameSize();
+}
+
+size_t
+PcmExport::GetOutputBlockSize() const noexcept
+{
+#ifdef ENABLE_DSD
+	switch (dsd_mode) {
+	case DsdMode::NONE:
+		break;
+
+	case DsdMode::U16:
+		return dsd16_converter.GetOutputBlockSize();
+
+	case DsdMode::U32:
+		return dsd32_converter.GetOutputBlockSize();
+		break;
+
+	case DsdMode::DOP:
+		return dop_converter.GetOutputBlockSize();
+	}
+#endif
+
+	return GetOutputFrameSize();
+}
+
 unsigned
 PcmExport::Params::CalcOutputSampleRate(unsigned sample_rate) const noexcept
 {
diff --git a/src/pcm/Export.hxx b/src/pcm/Export.hxx
index 251576e60..b4a8ae9b9 100644
--- a/src/pcm/Export.hxx
+++ b/src/pcm/Export.hxx
@@ -198,6 +198,18 @@ public:
 	gcc_pure
 	size_t GetOutputFrameSize() const noexcept;
 
+	/**
+	 * @return the size of one input block in bytes
+	 */
+	gcc_pure
+	size_t GetInputBlockSize() const noexcept;
+
+	/**
+	 * @return the size of one output block in bytes
+	 */
+	gcc_pure
+	size_t GetOutputBlockSize() const noexcept;
+
 	/**
 	 * Export a PCM buffer.
 	 *
diff --git a/src/pcm/RestBuffer.hxx b/src/pcm/RestBuffer.hxx
index ddcfdfcf8..47ce87903 100644
--- a/src/pcm/RestBuffer.hxx
+++ b/src/pcm/RestBuffer.hxx
@@ -48,6 +48,13 @@ public:
 		size = 0;
 	}
 
+	/**
+	 * @return the size of one input block in #T samples
+	 */
+	size_t GetInputBlockSize() const noexcept {
+		return capacity;
+	}
+
 	unsigned GetChannelCount() const noexcept {
 		return capacity / n_frames;
 	}