audioconvert: move peaks functions to separate file

Make a peaks finder helper and use it in the peaks resampler.

spa/plugins/audioconvert/peaks-ops-c.c

@@ -0,0 +1,50 @@
+/* Spa
+ *
+ * Copyright © 2022 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 <math.h>
+
+#include "peaks-ops.h"
+
+void peaks_min_max_c(struct peaks *peaks, const float * SPA_RESTRICT src,
+		uint32_t n_samples, float *min, float *max)
+{
+	uint32_t n;
+	float t, mi = *min, ma = *max;
+	for (n = 0; n < n_samples; n++) {
+		t = src[n];
+		mi = fminf(mi, t);
+		ma = fmaxf(ma, t);
+	}
+	*min = mi;
+	*max = ma;
+}
+
+float peaks_abs_max_c(struct peaks *peaks, const float * SPA_RESTRICT src,
+		uint32_t n_samples, float max)
+{
+	uint32_t n;
+	for (n = 0; n < n_samples; n++)
+		max = fmaxf(fabsf(src[n]), max);
+	return max;
+}