pcm/PcmConvert: move code to new class PcmFormatConverter

5 files changed, 244 insertions, 68 deletions

diff --git a/Makefile.am b/Makefile.am
index 6aeb69ea3..b74d5fbb7 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -337,6 +337,7 @@ libpcm_a_SOURCES = \
 	src/pcm/PcmChannels.cxx src/pcm/PcmChannels.hxx \
 	src/pcm/PcmPack.cxx src/pcm/PcmPack.hxx \
 	src/pcm/PcmFormat.cxx src/pcm/PcmFormat.hxx \
+	src/pcm/FormatConverter.cxx src/pcm/FormatConverter.hxx \
 	src/pcm/PcmResample.cxx src/pcm/PcmResample.hxx \
 	src/pcm/PcmResampleFallback.cxx \
 	src/pcm/PcmResampleInternal.hxx \
diff --git a/src/pcm/FormatConverter.cxx b/src/pcm/FormatConverter.cxx
new file mode 100644
index 000000000..f3f9c8685
--- /dev/null
+++ b/src/pcm/FormatConverter.cxx
@@ -0,0 +1,104 @@
+/*
+ * Copyright (C) 2003-2013 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 "FormatConverter.hxx"
+#include "PcmFormat.hxx"
+#include "PcmConvert.hxx"
+#include "util/ConstBuffer.hxx"
+#include "util/Error.hxx"
+
+#include <assert.h>
+
+bool
+PcmFormatConverter::Open(SampleFormat _src_format, SampleFormat _dest_format,
+			 gcc_unused Error &error)
+{
+	assert(_src_format != SampleFormat::UNDEFINED);
+	assert(_dest_format != SampleFormat::UNDEFINED);
+
+	src_format = _src_format;
+	dest_format = _dest_format;
+	return true;
+}
+
+void
+PcmFormatConverter::Close()
+{
+#ifndef NDEBUG
+	src_format = SampleFormat::UNDEFINED;
+	dest_format = SampleFormat::UNDEFINED;
+#endif
+}
+
+ConstBuffer<void>
+PcmFormatConverter::Convert(ConstBuffer<void> src, Error &error)
+{
+	const void *result = nullptr;
+	size_t result_size = 0;
+
+	switch (dest_format) {
+	case SampleFormat::UNDEFINED:
+		assert(false);
+		gcc_unreachable();
+
+	case SampleFormat::S8:
+	case SampleFormat::DSD:
+		result = nullptr;
+		break;
+
+	case SampleFormat::S16:
+		result = pcm_convert_to_16(buffer, dither,
+					   src_format,
+					   src.data, src.size,
+					   &result_size);
+		break;
+
+	case SampleFormat::S24_P32:
+		result = pcm_convert_to_24(buffer,
+					   src_format,
+					   src.data, src.size,
+					   &result_size);
+		break;
+
+	case SampleFormat::S32:
+		result = pcm_convert_to_32(buffer,
+					   src_format,
+					   src.data, src.size,
+					   &result_size);
+		break;
+
+	case SampleFormat::FLOAT:
+		result = pcm_convert_to_float(buffer,
+					      src_format,
+					      src.data, src.size,
+					      &result_size);
+		break;
+	}
+
+	if (result == nullptr) {
+		error.Format(pcm_convert_domain,
+			     "PCM conversion from %s to %s is not implemented",
+			     sample_format_to_string(src_format),
+			     sample_format_to_string(dest_format));
+		return nullptr;
+	}
+
+	return { result, result_size };
+}
diff --git a/src/pcm/FormatConverter.hxx b/src/pcm/FormatConverter.hxx
new file mode 100644
index 000000000..f5b13a0b0
--- /dev/null
+++ b/src/pcm/FormatConverter.hxx
@@ -0,0 +1,84 @@
+/*
+ * Copyright (C) 2003-2013 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_FORMAT_CONVERTER_HXX
+#define MPD_PCM_FORMAT_CONVERTER_HXX
+
+#include "check.h"
+#include "AudioFormat.hxx"
+#include "PcmBuffer.hxx"
+#include "PcmDither.hxx"
+
+#ifndef NDEBUG
+#include <assert.h>
+#endif
+
+class Error;
+template<typename T> struct ConstBuffer;
+
+/**
+ * A class that converts samples from one format to another.
+ */
+class PcmFormatConverter {
+	SampleFormat src_format, dest_format;
+
+	PcmBuffer buffer;
+	PcmDither dither;
+
+public:
+#ifndef NDEBUG
+	PcmFormatConverter()
+		:src_format(SampleFormat::UNDEFINED),
+		 dest_format(SampleFormat::UNDEFINED) {}
+
+	~PcmFormatConverter() {
+		assert(src_format == SampleFormat::UNDEFINED);
+		assert(dest_format == SampleFormat::UNDEFINED);
+	}
+#endif
+
+	/**
+	 * Opens the object, prepare for Convert().
+	 *
+	 * @param src_format the sample format of incoming data
+	 * @param dest_format the sample format of outgoing data
+	 * @param error location to store the error
+	 * @return true on success
+	 */
+	bool Open(SampleFormat src_format, SampleFormat dest_format,
+		  Error &error);
+
+	/**
+	 * Closes the object.  After that, you may call Open() again.
+	 */
+	void Close();
+
+	/**
+	 * Convert a block of PCM data.
+	 *
+	 * @param src the input buffer
+	 * @param error location to store the error
+	 * @return the destination buffer on success,
+	 * ConstBuffer::Null() on error
+	 */
+	gcc_pure
+	ConstBuffer<void> Convert(ConstBuffer<void> src, Error &error);
+};
+
+#endif
diff --git a/src/pcm/PcmConvert.cxx b/src/pcm/PcmConvert.cxx
index e32a4ba4e..eb9c0e052 100644
--- a/src/pcm/PcmConvert.cxx
+++ b/src/pcm/PcmConvert.cxx
@@ -20,11 +20,11 @@
 #include "config.h"
 #include "PcmConvert.hxx"
 #include "PcmChannels.hxx"
-#include "PcmFormat.hxx"
 #include "AudioFormat.hxx"
 #include "util/ConstBuffer.hxx"
 #include "util/Error.hxx"
 #include "util/Domain.hxx"
+#include "util/ConstBuffer.hxx"
 
 #include <assert.h>
 #include <math.h>
@@ -53,7 +53,7 @@ PcmConvert::~PcmConvert()
 
 bool
 PcmConvert::Open(AudioFormat _src_format, AudioFormat _dest_format,
-		 gcc_unused Error &error)
+		 Error &error)
 {
 	assert(!src_format.IsValid());
 	assert(!dest_format.IsValid());
@@ -63,12 +63,24 @@ PcmConvert::Open(AudioFormat _src_format, AudioFormat _dest_format,
 	src_format = _src_format;
 	dest_format = _dest_format;
 
+	AudioFormat format = src_format;
+	if (format.format == SampleFormat::DSD)
+		format.format = SampleFormat::FLOAT;
+
+	if (format.format != dest_format.format &&
+	    !format_converter.Open(format.format, dest_format.format, error))
+		return false;
+	format.format = dest_format.format;
+
 	return true;
 }
 
 void
 PcmConvert::Close()
 {
+	if (src_format.format != dest_format.format)
+		format_converter.Close();
+
 	dsd.Reset();
 	resampler.Reset();
 
@@ -79,23 +91,14 @@ PcmConvert::Close()
 }
 
 inline ConstBuffer<int16_t>
-PcmConvert::Convert16(ConstBuffer<void> src, AudioFormat format, Error &error)
+PcmConvert::Convert16(ConstBuffer<int16_t> src, AudioFormat format,
+		      Error &error)
 {
-	const int16_t *buf;
-	size_t len;
-
+	assert(format.format == SampleFormat::S16);
 	assert(dest_format.format == SampleFormat::S16);
 
-	buf = pcm_convert_to_16(format_buffer, dither,
-				format.format,
-				src.data, src.size,
-				&len);
-	if (buf == nullptr) {
-		error.Format(pcm_convert_domain,
-			     "Conversion from %s to 16 bit is not implemented",
-			     sample_format_to_string(format.format));
-		return nullptr;
-	}
+	auto buf = src.data;
+	size_t len = src.size * sizeof(*src.data);
 
 	if (format.channels != dest_format.channels) {
 		buf = pcm_convert_channels_16(channels_buffer,
@@ -125,22 +128,14 @@ PcmConvert::Convert16(ConstBuffer<void> src, AudioFormat format, Error &error)
 }
 
 inline ConstBuffer<int32_t>
-PcmConvert::Convert24(ConstBuffer<void> src, AudioFormat format, Error &error)
+PcmConvert::Convert24(ConstBuffer<int32_t> src, AudioFormat format,
+		      Error &error)
 {
-	const int32_t *buf;
-	size_t len;
-
+	assert(format.format == SampleFormat::S24_P32);
 	assert(dest_format.format == SampleFormat::S24_P32);
 
-	buf = pcm_convert_to_24(format_buffer,
-				format.format,
-				src.data, src.size, &len);
-	if (buf == nullptr) {
-		error.Format(pcm_convert_domain,
-			     "Conversion from %s to 24 bit is not implemented",
-			     sample_format_to_string(format.format));
-		return nullptr;
-	}
+	auto buf = src.data;
+	size_t len = src.size * sizeof(*src.data);
 
 	if (format.channels != dest_format.channels) {
 		buf = pcm_convert_channels_24(channels_buffer,
@@ -170,22 +165,14 @@ PcmConvert::Convert24(ConstBuffer<void> src, AudioFormat format, Error &error)
 }
 
 inline ConstBuffer<int32_t>
-PcmConvert::Convert32(ConstBuffer<void> src, AudioFormat format, Error &error)
+PcmConvert::Convert32(ConstBuffer<int32_t> src, AudioFormat format,
+		      Error &error)
 {
-	const int32_t *buf;
-	size_t len;
-
+	assert(format.format == SampleFormat::S32);
 	assert(dest_format.format == SampleFormat::S32);
 
-	buf = pcm_convert_to_32(format_buffer,
-				format.format,
-				src.data, src.size, &len);
-	if (buf == nullptr) {
-		error.Format(pcm_convert_domain,
-			     "Conversion from %s to 32 bit is not implemented",
-			     sample_format_to_string(format.format));
-		return nullptr;
-	}
+	auto buf = src.data;
+	size_t len = src.size * sizeof(*src.data);
 
 	if (format.channels != dest_format.channels) {
 		buf = pcm_convert_channels_32(channels_buffer,
@@ -215,23 +202,14 @@ PcmConvert::Convert32(ConstBuffer<void> src, AudioFormat format, Error &error)
 }
 
 inline ConstBuffer<float>
-PcmConvert::ConvertFloat(ConstBuffer<void> src, AudioFormat format,
+PcmConvert::ConvertFloat(ConstBuffer<float> src, AudioFormat format,
 			 Error &error)
 {
+	assert(format.format == SampleFormat::FLOAT);
 	assert(dest_format.format == SampleFormat::FLOAT);
 
-	/* convert to float now */
-
-	size_t size;
-	const float *buffer = pcm_convert_to_float(format_buffer,
-						   format.format,
-						   src.data, src.size, &size);
-	if (buffer == nullptr) {
-		error.Format(pcm_convert_domain,
-			     "Conversion from %s to float is not implemented",
-			     sample_format_to_string(format.format));
-		return nullptr;
-	}
+	auto buffer = src.data;
+	size_t size = src.size * sizeof(*src.data);
 
 	/* convert channels */
 
@@ -288,21 +266,33 @@ PcmConvert::Convert(const void *src, size_t src_size,
 		format.format = SampleFormat::FLOAT;
 	}
 
+	if (format.format != dest_format.format) {
+		buffer = format_converter.Convert(buffer, error);
+		if (buffer.IsNull())
+			return nullptr;
+
+		format.format = dest_format.format;
+	}
+
 	switch (dest_format.format) {
 	case SampleFormat::S16:
-		buffer = Convert16(buffer, format, error).ToVoid();
+		buffer = Convert16(ConstBuffer<int16_t>::FromVoid(buffer),
+				   format, error).ToVoid();
 		break;
 
 	case SampleFormat::S24_P32:
-		buffer = Convert24(buffer, format, error).ToVoid();
+		buffer = Convert24(ConstBuffer<int32_t>::FromVoid(buffer),
+				   format, error).ToVoid();
 		break;
 
 	case SampleFormat::S32:
-		buffer = Convert32(buffer, format, error).ToVoid();
+		buffer = Convert32(ConstBuffer<int32_t>::FromVoid(buffer),
+				   format, error).ToVoid();
 		break;
 
 	case SampleFormat::FLOAT:
-		buffer = ConvertFloat(buffer, format, error).ToVoid();
+		buffer = ConvertFloat(ConstBuffer<float>::FromVoid(buffer),
+				      format, error).ToVoid();
 		break;
 
 	default:
diff --git a/src/pcm/PcmConvert.hxx b/src/pcm/PcmConvert.hxx
index 12c4b26f3..d78d72214 100644
--- a/src/pcm/PcmConvert.hxx
+++ b/src/pcm/PcmConvert.hxx
@@ -20,10 +20,10 @@
 #ifndef PCM_CONVERT_HXX
 #define PCM_CONVERT_HXX
 
-#include "PcmDither.hxx"
 #include "PcmDsd.hxx"
 #include "PcmResample.hxx"
 #include "PcmBuffer.hxx"
+#include "FormatConverter.hxx"
 #include "AudioFormat.hxx"
 
 #include <stddef.h>
@@ -42,10 +42,7 @@ class PcmConvert {
 
 	PcmResampler resampler;
 
-	PcmDither dither;
-
-	/** the buffer for converting the sample format */
-	PcmBuffer format_buffer;
+	PcmFormatConverter format_converter;
 
 	/** the buffer for converting the channel count */
 	PcmBuffer channels_buffer;
@@ -85,16 +82,16 @@ public:
 			    Error &error);
 
 private:
-	ConstBuffer<int16_t> Convert16(ConstBuffer<void> src,
+	ConstBuffer<int16_t> Convert16(ConstBuffer<int16_t> src,
 				       AudioFormat format,
 				       Error &error);
-	ConstBuffer<int32_t> Convert24(ConstBuffer<void> src,
+	ConstBuffer<int32_t> Convert24(ConstBuffer<int32_t> src,
 				       AudioFormat format,
 				       Error &error);
-	ConstBuffer<int32_t> Convert32(ConstBuffer<void> src,
+	ConstBuffer<int32_t> Convert32(ConstBuffer<int32_t> src,
 				       AudioFormat format,
 				       Error &error);
-	ConstBuffer<float> ConvertFloat(ConstBuffer<void> src,
+	ConstBuffer<float> ConvertFloat(ConstBuffer<float> src,
 					AudioFormat format,
 					Error &error);
 };