audioconvert: add volume ops

Add volume helpers and use this for the monitor output ports so
that we can add volumes to the monitor output signal as well.

spa/plugins/audioconvert/volume-ops.c

@@ -0,0 +1,79 @@
+/* Spa
+ *
+ * Copyright © 2021 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/param/audio/format-utils.h>
+#include <spa/support/cpu.h>
+#include <spa/support/log.h>
+#include <spa/utils/defs.h>
+
+#include "volume-ops.h"
+
+typedef void (*volume_func_t) (struct volume *vol, void * SPA_RESTRICT dst,
+			const void * SPA_RESTRICT src, float volume, uint32_t n_samples);
+
+static const struct volume_info {
+	volume_func_t process;
+	uint32_t cpu_flags;
+} volume_table[] =
+{
+#if defined (HAVE_SSE)
+	{ volume_f32_sse, SPA_CPU_FLAG_SSE },
+#endif
+	{ volume_f32_c, 0 },
+};
+
+#define MATCH_CPU_FLAGS(a,b)	((a) == 0 || ((a) & (b)) == a)
+
+static const struct volume_info *find_volume_info(uint32_t cpu_flags)
+{
+	size_t i;
+	for (i = 0; i < SPA_N_ELEMENTS(volume_table); i++) {
+		if (!MATCH_CPU_FLAGS(volume_table[i].cpu_flags, cpu_flags))
+			continue;
+		return &volume_table[i];
+	}
+	return NULL;
+}
+
+static void impl_volume_free(struct volume *vol)
+{
+	vol->process = NULL;
+}
+
+int volume_init(struct volume *vol)
+{
+	const struct volume_info *info;
+
+	info = find_volume_info(vol->cpu_flags);
+	if (info == NULL)
+		return -ENOTSUP;
+
+	vol->free = impl_volume_free;
+	vol->process = info->process;
+	return 0;
+}