Config: add section "resampler"

12 files changed, 333 insertions, 192 deletions

diff --git a/Makefile.am b/Makefile.am
index 349e00e14..1bbf9d2b1 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -1951,14 +1951,17 @@ test_run_normalize_LDADD = \
 	$(GLIB_LIBS)
 
 test_run_convert_SOURCES = test/run_convert.cxx \
-	src/config/ConfigError.cxx \
 	src/Log.cxx src/LogBackend.cxx \
 	src/AudioFormat.cxx \
 	src/CheckAudioFormat.cxx \
 	src/AudioParser.cxx
 test_run_convert_LDADD = \
 	$(PCM_LIBS) \
+	libconf.a \
+	$(FS_LIBS) \
+	libsystem.a \
 	libutil.a \
+	$(ICU_LDADD) \
 	$(GLIB_LIBS)
 
 test_run_output_LDADD = $(MPD_LIBS) \
diff --git a/NEWS b/NEWS
index b8a460938..a1e57d65a 100644
--- a/NEWS
+++ b/NEWS
@@ -18,6 +18,9 @@ ver 0.20 (not yet released)
   - recorder: allow dynamic file names
 * mixer
   - null: new plugin
+* resampler
+  - new block "resampler" in configuration file
+    replacing the old "samplerate_converter" setting
 * reset song priority on playback
 * write database and state file atomically
 * remove dependency on GLib
diff --git a/doc/mpdconf.example b/doc/mpdconf.example
index 7a2db5d16..73a71f1f4 100644
--- a/doc/mpdconf.example
+++ b/doc/mpdconf.example
@@ -325,13 +325,6 @@ input {
 #	mixer_type      "none"			# optional
 #}
 #
-# If MPD has been compiled with libsamplerate support, this setting specifies 
-# the sample rate converter to use.  Possible values can be found in the 
-# mpd.conf man page or the libsamplerate documentation. By default, this is
-# setting is disabled.
-#
-#samplerate_converter		"Fastest Sinc Interpolator"
-#
 ###############################################################################
 
 
diff --git a/doc/user.xml b/doc/user.xml
index 914a89620..310b50d53 100644
--- a/doc/user.xml
+++ b/doc/user.xml
@@ -771,150 +771,9 @@ systemctl start mpd.socket</programlisting>
 
         <para>
           Check the <link linkend="resampler_plugins">resampler plugin
-          reference</link> for a list of resamplers.
+          reference</link> for a list of resamplers and how to
+          configure them.
         </para>
-
-        <para>
-          The setting <varname>samplerate_converter</varname> controls
-          how <application>MPD</application> shall resample music.
-          Possible values:
-        </para>
-
-        <informaltable>
-          <tgroup cols="2">
-            <thead>
-              <row>
-                <entry>
-                  Value
-                </entry>
-                <entry>
-                  Description
-                </entry>
-              </row>
-            </thead>
-            <tbody>
-              <row>
-                <entry>
-                  "<parameter>internal</parameter>"
-                </entry>
-                <entry>
-                  The internal resampler.  Low CPU usage, but very
-                  poor quality.
-                </entry>
-              </row>
-
-              <row>
-                <entry>
-                  "<parameter>soxr very high</parameter>"
-                </entry>
-                <entry>
-                  Use <application>libsoxr</application> with "Very
-                  High Quality" setting.
-                </entry>
-              </row>
-
-              <row>
-                <entry>
-                  "<parameter>soxr high</parameter>" or
-                  "<parameter>soxr</parameter>"
-                </entry>
-                <entry>
-                  Use <application>libsoxr</application> with "High
-                  Quality" setting.
-                </entry>
-              </row>
-
-              <row>
-                <entry>
-                  "<parameter>soxr medium</parameter>"
-                </entry>
-                <entry>
-                  Use <application>libsoxr</application> with "Medium
-                  Quality" setting.
-                </entry>
-              </row>
-
-              <row>
-                <entry>
-                  "<parameter>soxr low</parameter>"
-                </entry>
-                <entry>
-                  Use <application>libsoxr</application> with "Low
-                  Quality" setting.
-                </entry>
-              </row>
-
-              <row>
-                <entry>
-                  "<parameter>soxr quick</parameter>"
-                </entry>
-                <entry>
-                  Use <application>libsoxr</application> with "Quick"
-                  setting.
-                </entry>
-              </row>
-
-              <row>
-                <entry>
-                  "<parameter>Best Sinc Interpolator</parameter>" or
-                  "<parameter>0</parameter>"
-                </entry>
-                <entry>
-                  <application>libsamplerate</application>: Band
-                  limited sinc interpolation, best quality, 97dB SNR,
-                  96% BW.
-                </entry>
-              </row>
-
-              <row>
-                <entry>
-                  "<parameter>Medium Sinc Interpolator</parameter>" or
-                  "<parameter>1</parameter>"
-                </entry>
-                <entry>
-                  <application>libsamplerate</application>: Band
-                  limited sinc interpolation, medium quality, 97dB
-                  SNR, 90% BW.
-                </entry>
-              </row>
-
-              <row>
-                <entry>
-                  "<parameter>Fastest Sinc Interpolator</parameter>" or
-                  "<parameter>2</parameter>"
-                </entry>
-                <entry>
-                  <application>libsamplerate</application>: Band
-                  limited sinc interpolation, fastest, 97dB SNR, 80%
-                  BW.
-                </entry>
-              </row>
-
-              <row>
-                <entry>
-                  "<parameter>ZOH Sinc Interpolator</parameter>" or
-                  "<parameter>3</parameter>"
-                </entry>
-                <entry>
-                  <application>libsamplerate</application>: Zero order
-                  hold interpolator, very fast, very poor quality with
-                  audible distortions.
-                </entry>
-              </row>
-
-              <row>
-                <entry>
-                  "<parameter>Linear Interpolator</parameter>" or
-                  "<parameter>4</parameter>"
-                </entry>
-                <entry>
-                  <application>libsamplerate</application>: Linear
-                  interpolator, very fast, poor quality.
-                </entry>
-              </row>
-            </tbody>
-          </tgroup>
-        </informaltable>
       </section>
     </section>
 
@@ -2308,6 +2167,46 @@ buffer_size: 16384</programlisting>
     <section id="resampler_plugins">
       <title>Resampler plugins</title>
 
+      <para>
+        The resampler can be configured in a block named
+        <varname>resampler</varname>, for example:
+      </para>
+
+      <programlisting>resampler {
+  plugin "soxr"
+  quality "very high"
+}</programlisting>
+
+      <para>
+        The following table lists the <varname>resampler</varname>
+        options valid for all plugins:
+      </para>
+
+      <informaltable>
+        <tgroup cols="2">
+          <thead>
+            <row>
+              <entry>
+                Name
+              </entry>
+              <entry>
+                Description
+              </entry>
+            </row>
+          </thead>
+          <tbody>
+            <row>
+              <entry>
+                <varname>plugin</varname>
+              </entry>
+              <entry>
+                The name of the plugin.
+              </entry>
+            </row>
+          </tbody>
+        </tgroup>
+      </informaltable>
+
       <section id="internal_resampler">
         <title><varname>internal</varname></title>
 
@@ -2327,6 +2226,107 @@ buffer_size: 16384</programlisting>
           url="http://www.mega-nerd.com/SRC/"><application>libsamplerate</application></ulink>
           a.k.a. Secret Rabbit Code (SRC).
         </para>
+
+        <informaltable>
+          <tgroup cols="2">
+            <thead>
+              <row>
+                <entry>
+                  Name
+                </entry>
+                <entry>
+                  Description
+                </entry>
+              </row>
+            </thead>
+            <tbody>
+              <row>
+                <entry>
+                  <varname>type</varname>
+                </entry>
+                <entry>
+                  The interpolator type.  See below for a list of
+                  known types.
+                </entry>
+              </row>
+            </tbody>
+          </tgroup>
+        </informaltable>
+
+        <para>
+          The following converter types are provided by
+          <application>libsamplerate</application>:
+        </para>
+
+        <informaltable>
+          <tgroup cols="2">
+            <thead>
+              <row>
+                <entry>
+                  Type
+                </entry>
+                <entry>
+                  Description
+                </entry>
+              </row>
+            </thead>
+            <tbody>
+              <row>
+                <entry>
+                  "<parameter>Best Sinc Interpolator</parameter>" or
+                  "<parameter>0</parameter>"
+                </entry>
+                <entry>
+                  Band limited sinc interpolation, best quality, 97dB
+                  SNR, 96% BW.
+                </entry>
+              </row>
+
+              <row>
+                <entry>
+                  "<parameter>Medium Sinc Interpolator</parameter>" or
+                  "<parameter>1</parameter>"
+                </entry>
+                <entry>
+                  Band limited sinc interpolation, medium quality,
+                  97dB SNR, 90% BW.
+                </entry>
+              </row>
+
+              <row>
+                <entry>
+                  "<parameter>Fastest Sinc Interpolator</parameter>" or
+                  "<parameter>2</parameter>"
+                </entry>
+                <entry>
+                  Band limited sinc interpolation, fastest, 97dB SNR,
+                  80% BW.
+                </entry>
+              </row>
+
+              <row>
+                <entry>
+                  "<parameter>ZOH Sinc Interpolator</parameter>" or
+                  "<parameter>3</parameter>"
+                </entry>
+                <entry>
+                  Zero order hold interpolator, very fast, very poor
+                  quality with audible distortions.
+                </entry>
+              </row>
+
+              <row>
+                <entry>
+                  "<parameter>Linear Interpolator</parameter>" or
+                  "<parameter>4</parameter>"
+                </entry>
+                <entry>
+                  Linear interpolator, very fast, poor quality.
+                </entry>
+              </row>
+            </tbody>
+          </tgroup>
+        </informaltable>
       </section>
 
       <section id="soxr_resampler">
@@ -2337,6 +2337,64 @@ buffer_size: 16384</programlisting>
           url="http://sourceforge.net/projects/soxr/"><application>libsoxr</application></ulink>,
           the SoX Resampler library
         </para>
+
+        <informaltable>
+          <tgroup cols="2">
+            <thead>
+              <row>
+                <entry>
+                  Name
+                </entry>
+                <entry>
+                  Description
+                </entry>
+              </row>
+            </thead>
+            <tbody>
+              <row>
+                <entry>
+                  <varname>quality</varname>
+                </entry>
+                <entry>
+                  The <application>libsoxr</application> quality
+                  setting.  Valid values are:
+
+                  <itemizedlist>
+                    <listitem>
+                      <para>
+                        "<parameter>very high</parameter>"
+                      </para>
+                    </listitem>
+
+                    <listitem>
+                      <para>
+                        "<parameter>high</parameter>" (the default)
+                      </para>
+                    </listitem>
+
+                    <listitem>
+                      <para>
+                        "<parameter>medium</parameter>"
+                      </para>
+                    </listitem>
+
+                    <listitem>
+                      <para>
+                        "<parameter>low</parameter>"
+                      </para>
+                    </listitem>
+
+                    <listitem>
+                      <para>
+                        "<parameter>quick</parameter>"
+                      </para>
+                    </listitem>
+                  </itemizedlist>
+                </entry>
+              </row>
+            </tbody>
+          </tgroup>
+        </informaltable>
       </section>
     </section>
 
diff --git a/src/config/ConfigOption.hxx b/src/config/ConfigOption.hxx
index 8cc0d42d5..5acd6fd49 100644
--- a/src/config/ConfigOption.hxx
+++ b/src/config/ConfigOption.hxx
@@ -86,6 +86,7 @@ enum class ConfigBlockOption {
 	DECODER,
 	INPUT,
 	PLAYLIST_PLUGIN,
+	RESAMPLER,
 	AUDIO_FILTER,
 	DATABASE,
 	NEIGHBORS,
diff --git a/src/config/ConfigTemplates.cxx b/src/config/ConfigTemplates.cxx
index 1ceef9119..6fbf025fc 100644
--- a/src/config/ConfigTemplates.cxx
+++ b/src/config/ConfigTemplates.cxx
@@ -86,6 +86,7 @@ const ConfigTemplate config_block_templates[] = {
 	{ "decoder", true },
 	{ "input", true },
 	{ "playlist_plugin", true },
+	{ "resampler", false },
 	{ "filter", true },
 	{ "database", false },
 	{ "neighbors", true },
diff --git a/src/pcm/ConfiguredResampler.cxx b/src/pcm/ConfiguredResampler.cxx
index bf6ea58ee..30cb801c7 100644
--- a/src/pcm/ConfiguredResampler.cxx
+++ b/src/pcm/ConfiguredResampler.cxx
@@ -23,6 +23,8 @@
 #include "config/ConfigGlobal.hxx"
 #include "config/ConfigOption.hxx"
 #include "config/ConfigError.hxx"
+#include "config/Block.hxx"
+#include "config/Param.hxx"
 #include "util/Error.hxx"
 
 #ifdef ENABLE_LIBSAMPLERATE
@@ -49,34 +51,119 @@ enum class SelectedResampler {
 
 static SelectedResampler selected_resampler = SelectedResampler::FALLBACK;
 
+static const ConfigBlock *
+MakeResamplerDefaultConfig(ConfigBlock &block)
+{
+	assert(block.IsEmpty());
+
+#ifdef ENABLE_LIBSAMPLERATE
+	block.AddBlockParam("plugin", "libsamplerate");
+#elif defined(ENABLE_SOXR)
+	block.AddBlockParam("plugin", "soxr");
+#else
+	block.AddBlockParam("plugin", "internal");
+#endif
+	return &block;
+}
+
+/**
+ * Convert the old "samplerate_converter" setting to a new-style
+ * "resampler" block.
+ */
+static const ConfigBlock *
+MigrateResamplerConfig(const config_param &param, ConfigBlock &block)
+{
+	assert(block.IsEmpty());
+
+	block.line = param.line;
+
+	const char *converter = param.value.c_str();
+	if (*converter == 0 || strcmp(converter, "internal") == 0) {
+		block.AddBlockParam("plugin", "internal");
+		return &block;
+	}
+
+#ifdef ENABLE_SOXR
+	if (strcmp(converter, "soxr") == 0) {
+		block.AddBlockParam("plugin", "soxr");
+		return &block;
+	}
+
+	if (memcmp(converter, "soxr ", 5) == 0) {
+		block.AddBlockParam("plugin", "soxr");
+		block.AddBlockParam("quality", converter + 5);
+		return &block;
+	}
+#endif
+
+	block.AddBlockParam("plugin", "libsamplerate");
+	block.AddBlockParam("type", converter);
+	return &block;
+}
+
+static const ConfigBlock *
+MigrateResamplerConfig(const config_param *param, ConfigBlock &buffer)
+{
+	assert(buffer.IsEmpty());
+
+	return param == nullptr
+		? MakeResamplerDefaultConfig(buffer)
+		: MigrateResamplerConfig(*param, buffer);
+}
+
+static const ConfigBlock *
+GetResamplerConfig(ConfigBlock &buffer, Error &error)
+{
+	const auto *old_param =
+		config_get_param(ConfigOption::SAMPLERATE_CONVERTER);
+	const auto *block = config_get_block(ConfigBlockOption::RESAMPLER);
+	if (block == nullptr)
+		return MigrateResamplerConfig(old_param, buffer);
+
+	if (old_param != nullptr) {
+		error.Format(config_domain,
+			     "Cannot use both 'resampler' (line %d) and 'samplerate_converter' (line %d)",
+			     block->line, old_param->line);
+		return nullptr;
+	}
+
+	return block;
+}
+
 bool
 pcm_resampler_global_init(Error &error)
 {
-	const char *converter =
-		config_get_string(ConfigOption::SAMPLERATE_CONVERTER, "");
+	ConfigBlock buffer;
+	const auto *block = GetResamplerConfig(buffer, error);
+	if (block == nullptr)
+		return false;
+
+	const char *plugin_name = block->GetBlockValue("plugin");
+	if (plugin_name == nullptr) {
+		error.Format(config_domain,
+			     "'plugin' missing in line %d", block->line);
+		return false;
+	}
 
-	if (strcmp(converter, "internal") == 0)
+	if (strcmp(plugin_name, "internal") == 0) {
+		selected_resampler = SelectedResampler::FALLBACK;
 		return true;
-
 #ifdef ENABLE_SOXR
-	if (memcmp(converter, "soxr", 4) == 0) {
+	} else if (strcmp(plugin_name, "soxr") == 0) {
 		selected_resampler = SelectedResampler::SOXR;
-		return pcm_resample_soxr_global_init(converter, error);
-	}
+		return pcm_resample_soxr_global_init(*block, error);
 #endif
-
 #ifdef ENABLE_LIBSAMPLERATE
-	selected_resampler = SelectedResampler::LIBSAMPLERATE;
-	return pcm_resample_lsr_global_init(converter, error);
+	} else if (strcmp(plugin_name, "libsamplerate") == 0) {
+		selected_resampler = SelectedResampler::LIBSAMPLERATE;
+		return pcm_resample_lsr_global_init(*block, error);
 #endif
-
-	if (*converter == 0)
-		return true;
-
-	error.Format(config_domain,
-		     "The samplerate_converter '%s' is not available",
-		     converter);
-	return false;
+	} else {
+		error.Format(config_domain,
+			     "No such resampler plugin: %s",
+			     plugin_name);
+		return false;
+	}
 }
 
 PcmResampler *
diff --git a/src/pcm/LibsamplerateResampler.cxx b/src/pcm/LibsamplerateResampler.cxx
index 73ed33644..cc6f3d43f 100644
--- a/src/pcm/LibsamplerateResampler.cxx
+++ b/src/pcm/LibsamplerateResampler.cxx
@@ -19,6 +19,7 @@
 
 #include "config.h"
 #include "LibsamplerateResampler.hxx"
+#include "config/Block.hxx"
 #include "util/ASCII.hxx"
 #include "util/Error.hxx"
 #include "util/Domain.hxx"
@@ -63,8 +64,9 @@ lsr_parse_converter(const char *s)
 }
 
 bool
-pcm_resample_lsr_global_init(const char *converter, Error &error)
+pcm_resample_lsr_global_init(const ConfigBlock &block, Error &error)
 {
+	const char *converter = block.GetBlockValue("type", "2");
 	if (!lsr_parse_converter(converter)) {
 		error.Format(libsamplerate_domain,
 			     "unknown samplerate converter '%s'", converter);
diff --git a/src/pcm/LibsamplerateResampler.hxx b/src/pcm/LibsamplerateResampler.hxx
index 1ae70ef71..f19dc19eb 100644
--- a/src/pcm/LibsamplerateResampler.hxx
+++ b/src/pcm/LibsamplerateResampler.hxx
@@ -27,6 +27,8 @@
 
 #include <samplerate.h>
 
+struct ConfigBlock;
+
 /**
  * A resampler using libsamplerate.
  */
@@ -51,6 +53,6 @@ private:
 };
 
 bool
-pcm_resample_lsr_global_init(const char *converter, Error &error);
+pcm_resample_lsr_global_init(const ConfigBlock &block, Error &error);
 
 #endif
diff --git a/src/pcm/SoxrResampler.cxx b/src/pcm/SoxrResampler.cxx
index 878c95337..3c271261b 100644
--- a/src/pcm/SoxrResampler.cxx
+++ b/src/pcm/SoxrResampler.cxx
@@ -20,6 +20,7 @@
 #include "config.h"
 #include "SoxrResampler.hxx"
 #include "AudioFormat.hxx"
+#include "config/Block.hxx"
 #include "util/ASCII.hxx"
 #include "util/Error.hxx"
 #include "util/Domain.hxx"
@@ -62,18 +63,11 @@ soxr_quality_name(unsigned long recipe)
 
 gcc_pure
 static unsigned long
-soxr_parse_converter(const char *converter)
+soxr_parse_quality(const char *quality)
 {
-	assert(converter != nullptr);
-
-	assert(memcmp(converter, "soxr", 4) == 0);
-	if (converter[4] == '\0')
+	if (quality == nullptr)
 		return SOXR_DEFAULT_RECIPE;
-	if (converter[4] != ' ')
-		return SOXR_INVALID_RECIPE;
 
-	// converter example is "soxr very high", we want the "very high" part
-	const char *quality = converter + 5;
 	if (strcmp(quality, "very high") == 0)
 		return SOXR_VHQ;
 	else if (strcmp(quality, "high") == 0)
@@ -89,12 +83,16 @@ soxr_parse_converter(const char *converter)
 }
 
 bool
-pcm_resample_soxr_global_init(const char *converter, Error &error)
+pcm_resample_soxr_global_init(const ConfigBlock &block, Error &error)
 {
-	unsigned long recipe = soxr_parse_converter(converter);
+	const char *quality_string = block.GetBlockValue("quality");
+	unsigned long recipe = soxr_parse_quality(quality_string);
 	if (recipe == SOXR_INVALID_RECIPE) {
+		assert(quality_string != nullptr);
+
 		error.Format(soxr_domain,
-			     "unknown samplerate converter '%s'", converter);
+			     "unknown quality setting '%s' in line %d",
+			     quality_string, block.line);
 		return false;
 	}
 
diff --git a/src/pcm/SoxrResampler.hxx b/src/pcm/SoxrResampler.hxx
index 7756bcea8..6c31ca45a 100644
--- a/src/pcm/SoxrResampler.hxx
+++ b/src/pcm/SoxrResampler.hxx
@@ -25,6 +25,7 @@
 #include "Compiler.h"
 
 struct AudioFormat;
+struct ConfigBlock;
 
 /**
  * A resampler using soxr.
@@ -46,6 +47,6 @@ public:
 };
 
 bool
-pcm_resample_soxr_global_init(const char *converter, Error &error);
+pcm_resample_soxr_global_init(const ConfigBlock &block, Error &error);
 
 #endif
diff --git a/test/run_convert.cxx b/test/run_convert.cxx
index 7673c25ca..1929d6c02 100644
--- a/test/run_convert.cxx
+++ b/test/run_convert.cxx
@@ -27,7 +27,6 @@
 #include "AudioParser.hxx"
 #include "AudioFormat.hxx"
 #include "pcm/PcmConvert.hxx"
-#include "config/ConfigGlobal.hxx"
 #include "util/ConstBuffer.hxx"
 #include "util/StaticFifoBuffer.hxx"
 #include "util/Error.hxx"
@@ -39,13 +38,6 @@
 #include <stdlib.h>
 #include <unistd.h>
 
-const char *
-config_get_string(gcc_unused enum ConfigOption option,
-		  const char *default_value)
-{
-	return default_value;
-}
-
 int main(int argc, char **argv)
 {
 	AudioFormat in_audio_format, out_audio_format;