fix double promotions

Found with -Wdouble-promotion

Signed-off-by: Rosen Penev <rosenp@gmail.com>

src/pcm/FloatConvert.hxx

@@ -53,7 +53,7 @@ struct IntegerToFloatSampleConvert {
 	typedef typename SrcTraits::value_type SV;
 	typedef typename DstTraits::value_type DV;
 
-	static constexpr DV factor = 1.0 / FloatToIntegerSampleConvert<F, Traits>::factor;
+	static constexpr DV factor = 1.0f / FloatToIntegerSampleConvert<F, Traits>::factor;
 	static_assert(factor > 0, "Wrong factor");
 
 	static constexpr DV Convert(SV src) noexcept {

src/pcm/PcmMix.cxx

@@ -26,6 +26,8 @@
 
 #include "PcmDither.cxx" // including the .cxx file to get inlined templates
 
+#include <cmath>
+
 #include <assert.h>
 
 template<SampleFormat F, class Traits=SampleTraits<F>>
@@ -221,7 +223,7 @@ pcm_mix(PcmDither &dither, void *buffer1, const void *buffer2, size_t size,
 	if (portion1 < 0)
 		return pcm_add(buffer1, buffer2, size, format);
 
-	s = sin(M_PI_2 * portion1);
+	s = std::sin((float)M_PI_2 * portion1);
 	s *= s;
 
 	int vol1 = lround(s * PCM_VOLUME_1S);

src/pcm/SoxrResampler.cxx

@@ -122,7 +122,7 @@ SoxrPcmResampler::Open(AudioFormat &af, unsigned new_sample_rate)
 	ratio = float(new_sample_rate) / float(af.sample_rate);
 	FormatDebug(soxr_domain,
 		    "samplerate conversion ratio to %.2lf",
-		    ratio);
+		    double(ratio));
 
 	/* libsoxr works with floating point samples */
 	af.format = SampleFormat::FLOAT;

src/pcm/Volume.hxx

@@ -48,7 +48,7 @@ static constexpr int PCM_VOLUME_1S = PCM_VOLUME_1;
 static constexpr inline int
 pcm_float_to_volume(float volume) noexcept
 {
-	return volume * PCM_VOLUME_1 + 0.5;
+	return int(volume * PCM_VOLUME_1 + 0.5f);
 }
 
 static constexpr inline float