Config: add section "resampler"

src/config/ConfigOption.hxx

@@ -86,6 +86,7 @@ enum class ConfigBlockOption {
 	DECODER,
 	INPUT,
 	PLAYLIST_PLUGIN,
+	RESAMPLER,
 	AUDIO_FILTER,
 	DATABASE,
 	NEIGHBORS,

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 },

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;
 
-bool
-pcm_resampler_global_init(Error &error)
+static const ConfigBlock *
+MakeResamplerDefaultConfig(ConfigBlock &block)
 {
-	const char *converter =
-		config_get_string(ConfigOption::SAMPLERATE_CONVERTER, "");
+	assert(block.IsEmpty());
 
-	if (strcmp(converter, "internal") == 0)
-		return true;
+#ifdef ENABLE_LIBSAMPLERATE
+	block.AddBlockParam("plugin", "libsamplerate");
+#elif defined(ENABLE_SOXR)
+	block.AddBlockParam("plugin", "soxr");
+#else
+	block.AddBlockParam("plugin", "internal");
+#endif
+	return █
+}
+
+/**
+ * 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 █
+	}
 
 #ifdef ENABLE_SOXR
-	if (memcmp(converter, "soxr", 4) == 0) {
-		selected_resampler = SelectedResampler::SOXR;
-		return pcm_resample_soxr_global_init(converter, error);
+	if (strcmp(converter, "soxr") == 0) {
+		block.AddBlockParam("plugin", "soxr");
+		return █
+	}
+
+	if (memcmp(converter, "soxr ", 5) == 0) {
+		block.AddBlockParam("plugin", "soxr");
+		block.AddBlockParam("quality", converter + 5);
+		return █
 	}
 #endif
 
-#ifdef ENABLE_LIBSAMPLERATE
-	selected_resampler = SelectedResampler::LIBSAMPLERATE;
-	return pcm_resample_lsr_global_init(converter, error);
-#endif
+	block.AddBlockParam("plugin", "libsamplerate");
+	block.AddBlockParam("type", converter);
+	return █
+}
 
-	if (*converter == 0)
+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)
+{
+	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(plugin_name, "internal") == 0) {
+		selected_resampler = SelectedResampler::FALLBACK;
 		return true;
-
-	error.Format(config_domain,
-		     "The samplerate_converter '%s' is not available",
-		     converter);
-	return false;
+#ifdef ENABLE_SOXR
+	} else if (strcmp(plugin_name, "soxr") == 0) {
+		selected_resampler = SelectedResampler::SOXR;
+		return pcm_resample_soxr_global_init(*block, error);
+#endif
+#ifdef ENABLE_LIBSAMPLERATE
+	} else if (strcmp(plugin_name, "libsamplerate") == 0) {
+		selected_resampler = SelectedResampler::LIBSAMPLERATE;
+		return pcm_resample_lsr_global_init(*block, error);
+#endif
+	} else {
+		error.Format(config_domain,
+			     "No such resampler plugin: %s",
+			     plugin_name);
+		return false;
+	}
 }
 
 PcmResampler *

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);

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

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;
 	}
 

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