pcm/SoxrResampler: implement method Reset()

NEWS

@@ -1,4 +1,6 @@
 ver 0.20.15 (not yet released)
+* resampler
+  - soxr: clear internal state after manual song change
 * state file
   - make mount point restore errors non-fatal
   - fix crash when restoring mounts with incompatible database plugin

src/pcm/SoxrResampler.cxx

@@ -139,6 +139,14 @@ SoxrPcmResampler::Close()
 	soxr_delete(soxr);
 }
 
+void
+SoxrPcmResampler::Reset()
+{
+#if SOXR_THIS_VERSION >= SOXR_VERSION(0,1,2)
+	soxr_clear(soxr);
+#endif
+}
+
 ConstBuffer<void>
 SoxrPcmResampler::Resample(ConstBuffer<void> src)
 {

src/pcm/SoxrResampler.hxx

@@ -41,6 +41,7 @@ class SoxrPcmResampler final : public PcmResampler {
 public:
 	AudioFormat Open(AudioFormat &af, unsigned new_sample_rate) override;
 	void Close() override;
+	void Reset() override;
 	ConstBuffer<void> Resample(ConstBuffer<void> src) override;
 };