mixer: Move floatmix to the audio mixer plugin

Move floatmix to the audiomixer plugin and change the name to
AUDIO_MIXER_DSP.
Add runtime selectable sse and sse2 optimizations.
Load the port mixer plugin dynamically based on the factory_name.
Add some more debug

spa/plugins/audiomixer/mix-ops-c.c

@@ -0,0 +1,69 @@
+/* Spa
+ *
+ * Copyright © 2019 Wim Taymans
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+#include <string.h>
+#include <stdio.h>
+#include <math.h>
+
+#include <spa/utils/defs.h>
+
+#include "mix-ops.h"
+
+void
+mix_f32_c(struct mix_ops *ops, void * SPA_RESTRICT dst, const void * SPA_RESTRICT src[],
+		uint32_t n_src, uint32_t n_samples)
+{
+	uint32_t i, n;
+	float *d = dst;
+
+	if (n_src == 0)
+		memset(dst, 0, n_samples * sizeof(float));
+	else if (dst != src[0])
+		memcpy(dst, src[0], n_samples * sizeof(float));
+
+	for (i = 1; i < n_src; i++) {
+		const float *s = src[i];
+		for (n = 0; n < n_samples; n++)
+			d[n] += s[n];
+	}
+}
+
+void
+mix_f64_c(struct mix_ops *ops, void * SPA_RESTRICT dst, const void * SPA_RESTRICT src[],
+		uint32_t n_src, uint32_t n_samples)
+{
+	uint32_t i, n;
+	double *d = dst;
+
+	if (n_src == 0)
+		memset(dst, 0, n_samples * sizeof(double));
+	else if (dst != src[0])
+		memcpy(dst, src[0], n_samples * sizeof(double));
+
+	for (i = 1; i < n_src; i++) {
+		const double *s = src[i];
+		for (n = 0; n < n_samples; n++)
+			d[n] += s[n];
+	}
+}