diff --git a/Makefile.am b/Makefile.am
index e0202b0cc..b0ac1aa36 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -575,6 +575,7 @@ PCM_LIBS = \
if ENABLE_DSD
libpcm_a_SOURCES += \
+ src/pcm/Dsd16.cxx src/pcm/Dsd16.hxx \
src/pcm/Dsd32.cxx src/pcm/Dsd32.hxx \
src/pcm/PcmDsd.cxx src/pcm/PcmDsd.hxx \
src/pcm/dsd2pcm/dsd2pcm.c src/pcm/dsd2pcm/dsd2pcm.h
diff --git a/src/pcm/Dsd16.cxx b/src/pcm/Dsd16.cxx
new file mode 100644
index 000000000..774a51ecc
--- /dev/null
+++ b/src/pcm/Dsd16.cxx
@@ -0,0 +1,62 @@
+/*
+ * Copyright 2003-2017 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "config.h"
+#include "Dsd16.hxx"
+#include "PcmBuffer.hxx"
+#include "util/ConstBuffer.hxx"
+
+/**
+ * Construct a 16 bit integer from two bytes.
+ */
+static constexpr inline uint16_t
+Construct16(uint8_t a, uint8_t b)
+{
+ /* "a" is the oldest byte, which must be in the most
+ significant byte */
+
+ return uint16_t(b) | (uint16_t(a) << 8);
+}
+
+static constexpr inline uint16_t
+Dsd8To16Sample(const uint8_t *src, unsigned channels)
+{
+ return Construct16(src[0], src[channels]);
+}
+
+ConstBuffer<uint16_t>
+Dsd8To16(PcmBuffer &buffer, unsigned channels, ConstBuffer<uint8_t> _src)
+{
+ const size_t in_frames = _src.size / channels;
+ const size_t out_frames = in_frames / 2;
+ const size_t out_samples = out_frames * channels;
+
+ const uint8_t *src = _src.data;
+ uint16_t *const dest0 = buffer.GetT<uint16_t>(out_samples);
+ uint16_t *dest = dest0;
+
+ for (size_t i = 0; i < out_frames; ++i) {
+ for (size_t c = 0; c < channels; ++c)
+ *dest++ = Dsd8To16Sample(src++, channels);
+
+ src += channels;
+ }
+
+ return {dest0, out_samples};
+}
diff --git a/src/pcm/Dsd16.hxx b/src/pcm/Dsd16.hxx
new file mode 100644
index 000000000..47341868b
--- /dev/null
+++ b/src/pcm/Dsd16.hxx
@@ -0,0 +1,36 @@
+/*
+ * Copyright 2003-2017 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef MPD_PCM_DSD_16_HXX
+#define MPD_PCM_DSD_16_HXX
+
+#include "check.h"
+
+#include <stdint.h>
+
+template<typename T> struct ConstBuffer;
+class PcmBuffer;
+
+/**
+ * Convert DSD_U8 to DSD_U16 (native endian, oldest bits in MSB).
+ */
+ConstBuffer<uint16_t>
+Dsd8To16(PcmBuffer &buffer, unsigned channels, ConstBuffer<uint8_t> src);
+
+#endif
diff --git a/src/pcm/PcmExport.cxx b/src/pcm/PcmExport.cxx
index 6b4f625cc..6738ebada 100644
--- a/src/pcm/PcmExport.cxx
+++ b/src/pcm/PcmExport.cxx
@@ -25,6 +25,7 @@
#include "util/ConstBuffer.hxx"
#ifdef ENABLE_DSD
+#include "Dsd16.hxx"
#include "Dsd32.hxx"
#include "PcmDsd.hxx"
#include "PcmDop.hxx"
@@ -42,9 +43,15 @@ PcmExport::Open(SampleFormat sample_format, unsigned _channels,
: SampleFormat::UNDEFINED;
#ifdef ENABLE_DSD
- assert(!params.dsd_u32 || !params.dop);
+ assert((params.dsd_u16 + params.dsd_u32 + params.dop) <= 1);
assert(!params.dop || audio_valid_channel_count(_channels));
+ dsd_u16 = params.dsd_u16 && sample_format == SampleFormat::DSD;
+ if (dsd_u16)
+ /* after the conversion to DSD_U16, the DSD samples
+ are stuffed inside fake 16 bit samples */
+ sample_format = SampleFormat::S16;
+
dsd_u32 = params.dsd_u32 && sample_format == SampleFormat::DSD;
if (dsd_u32)
/* after the conversion to DSD_U32, the DSD samples
@@ -83,6 +90,9 @@ PcmExport::GetFrameSize(const AudioFormat &audio_format) const
return audio_format.channels * 3;
#ifdef ENABLE_DSD
+ if (dsd_u16)
+ return channels * 2;
+
if (dsd_u32)
return channels * 4;
@@ -101,6 +111,11 @@ unsigned
PcmExport::Params::CalcOutputSampleRate(unsigned sample_rate) const
{
#ifdef ENABLE_DSD
+ if (dsd_u16)
+ /* DSD_U16 combines two 8-bit "samples" in one 16-bit
+ "sample" */
+ sample_rate /= 2;
+
if (dsd_u32)
/* DSD_U32 combines four 8-bit "samples" in one 32-bit
"sample" */
@@ -119,6 +134,9 @@ unsigned
PcmExport::Params::CalcInputSampleRate(unsigned sample_rate) const
{
#ifdef ENABLE_DSD
+ if (dsd_u16)
+ sample_rate *= 2;
+
if (dsd_u32)
sample_rate *= 4;
@@ -137,6 +155,11 @@ PcmExport::Export(ConstBuffer<void> data)
alsa_channel_order, channels);
#ifdef ENABLE_DSD
+ if (dsd_u16)
+ data = Dsd8To16(dop_buffer, channels,
+ ConstBuffer<uint8_t>::FromVoid(data))
+ .ToVoid();
+
if (dsd_u32)
data = Dsd8To32(dop_buffer, channels,
ConstBuffer<uint8_t>::FromVoid(data))
diff --git a/src/pcm/PcmExport.hxx b/src/pcm/PcmExport.hxx
index eb010bf0e..3e801a150 100644
--- a/src/pcm/PcmExport.hxx
+++ b/src/pcm/PcmExport.hxx
@@ -79,6 +79,11 @@ class PcmExport {
SampleFormat alsa_channel_order;
#ifdef ENABLE_DSD
+ /**
+ * Convert DSD (U8) to DSD_U16?
+ */
+ bool dsd_u16;
+
/**
* Convert DSD (U8) to DSD_U32?
*/
@@ -114,6 +119,7 @@ public:
struct Params {
bool alsa_channel_order = false;
#ifdef ENABLE_DSD
+ bool dsd_u16 = false;
bool dsd_u32 = false;
bool dop = false;
#endif
diff --git a/test/test_pcm_all.hxx b/test/test_pcm_all.hxx
index 8a5b83cb6..ace822ab8 100644
--- a/test/test_pcm_all.hxx
+++ b/test/test_pcm_all.hxx
@@ -128,6 +128,7 @@ class PcmExportTest : public CppUnit::TestFixture {
CPPUNIT_TEST(TestPack24);
CPPUNIT_TEST(TestReverseEndian);
#ifdef ENABLE_DSD
+ CPPUNIT_TEST(TestDsdU16);
CPPUNIT_TEST(TestDsdU32);
CPPUNIT_TEST(TestDop);
#endif
@@ -139,6 +140,7 @@ public:
void TestPack24();
void TestReverseEndian();
#ifdef ENABLE_DSD
+ void TestDsdU16();
void TestDsdU32();
void TestDop();
#endif
diff --git a/test/test_pcm_export.cxx b/test/test_pcm_export.cxx
index ba4ef347f..ebbeeaf57 100644
--- a/test/test_pcm_export.cxx
+++ b/test/test_pcm_export.cxx
@@ -126,6 +126,37 @@ PcmExportTest::TestReverseEndian()
#ifdef ENABLE_DSD
+void
+PcmExportTest::TestDsdU16()
+{
+ static constexpr uint8_t src[] = {
+ 0x01, 0x23, 0x45, 0x67,
+ 0x89, 0xab, 0xcd, 0xef,
+ 0x11, 0x22, 0x33, 0x44,
+ 0x55, 0x66, 0x77, 0x88,
+ };
+
+ static constexpr uint16_t expected[] = {
+ 0x0145, 0x2367,
+ 0x89cd, 0xabef,
+ 0x1133, 0x2244,
+ 0x5577, 0x6688,
+ };
+
+ PcmExport::Params params;
+ params.dsd_u16 = true;
+
+ CPPUNIT_ASSERT_EQUAL(params.CalcOutputSampleRate(705600u), 352800u);
+ CPPUNIT_ASSERT_EQUAL(params.CalcInputSampleRate(352800u), 705600u);
+
+ PcmExport e;
+ e.Open(SampleFormat::DSD, 2, params);
+
+ auto dest = e.Export({src, sizeof(src)});
+ CPPUNIT_ASSERT_EQUAL(sizeof(expected), dest.size);
+ CPPUNIT_ASSERT(memcmp(dest.data, expected, dest.size) == 0);
+}
+
void
PcmExportTest::TestDsdU32()
{