Revert "pcm/Convert: add option to enable the integer-only dsd2pcm implementation"

This reverts commit c84bae739a.  A
configuration option is not necessary, because the PcmConvert
constructor knows already whether integer or floating point is needed.

NEWS

@@ -22,7 +22,6 @@ ver 0.22 (not yet released)
   - ffmpeg: new plugin based on FFmpeg's libavfilter library
   - hdcd: new plugin based on FFmpeg's "af_hdcd" for HDCD playback
   - volume: convert S16 to S24 to preserve quality and reduce dithering noise
-  - dsd: add integer-only DSD to PCM converter
 * output
   - jack: add option "auto_destination_ports"
   - jack: report error details

doc/user.rst

@@ -568,26 +568,6 @@ Sometimes, music needs to be resampled before it can be played; for example, CDs
 Check the :ref:`resampler_plugins` reference for a list of resamplers
 and how to configure them.
 
-DSD
-^^^
-
-There are three ways to play back DSD (Direct Stream Digital):
-
-- natively if your output supports it (ALSA only and requires a sound
-  card with native DSD support)
-- `DSD over PCM <http://dsd-guide.com/dop-open-standard>`_: wrapped
-  inside fake 24 bit PCM samples (ALSA and OSX only and requires an
-  external DAC with DoP support)
-- for everything else, MPD automatically converts DSD to PCM
-
-For the last option, the setting ``dsd2pcm_converter`` selects a
-conversion method.  The default is ``float`` which converts to
-floating point samples.  For CPUs with a weak floating point unit
-(e.g. some ARMs like the one in the Raspberry Pi), it may be faster to
-use ``integer``, which is an integer-only implementation of the
-conversion algorithm.
-
-
 Client Connections
 ------------------
 

src/config/Option.hxx

@@ -79,7 +79,6 @@ enum class ConfigOption {
 	DESPOTIFY_USER,
 	DESPOTIFY_PASSWORD,
 	DESPOTIFY_HIGH_BITRATE,
-	DSD2PCM_CONVERTER,
 	MAX
 };
 

src/config/Templates.cxx

@@ -75,7 +75,6 @@ const ConfigTemplate config_param_templates[] = {
 	{ "despotify_user", false, true },
 	{ "despotify_password", false, true },
 	{ "despotify_high_bitrate", false, true },
-	{ "dsd2pcm_converter" },
 };
 
 static constexpr unsigned n_config_param_templates =

src/pcm/Convert.cxx

@@ -19,35 +19,16 @@
 
 #include "Convert.hxx"
 #include "ConfiguredResampler.hxx"
-#include "config/Data.hxx"
 #include "util/ConstBuffer.hxx"
-#include "util/StringAPI.hxx"
 
 #include <stdexcept>
 
 #include <assert.h>
 
-#ifdef ENABLE_DSD
-static bool dsd2pcm_integer = false;
-#endif
-
 void
 pcm_convert_global_init(const ConfigData &config)
 {
 	pcm_resampler_global_init(config);
-
-#ifdef ENABLE_DSD
-	dsd2pcm_integer = config.With(ConfigOption::DSD2PCM_CONVERTER, [](const char *s){
-		if (s == nullptr)
-			return false;
-		else if (StringIsEqual(s, "float"))
-			return false;
-		else if (StringIsEqual(s, "integer"))
-			return true;
-		else
-			throw std::runtime_error("Unrecognized value");
-	});
-#endif
 }
 
 PcmConvert::PcmConvert(const AudioFormat _src_format,