test/test_pcm: add unit test for pcm_mix()

test/test_pcm_mix.cxx

@@ -0,0 +1,84 @@
+/*
+ * Copyright (C) 2003-2013 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "config.h"
+#include "test_pcm_all.hxx"
+#include "test_pcm_util.hxx"
+#include "PcmMix.hxx"
+
+#include <glib.h>
+
+template<typename T, sample_format format, typename G=GlibRandomInt<T>>
+void
+TestPcmMix(G g=G())
+{
+	constexpr unsigned N = 256;
+	const auto src1 = TestDataBuffer<T, N>(g);
+	const auto src2 = TestDataBuffer<T, N>(g);
+
+	/* portion1=1.0: result must be equal to src1 */
+	auto result = src1;
+	bool success = pcm_mix(result.begin(), src2.begin(), sizeof(result),
+			       format, 1.0);
+	g_assert(success);
+	AssertEqualWithTolerance(result, src1, 1);
+
+	/* portion1=0.0: result must be equal to src2 */
+	result = src1;
+	success = pcm_mix(result.begin(), src2.begin(), sizeof(result),
+			  format, 0.0);
+	g_assert(success);
+	AssertEqualWithTolerance(result, src2, 1);
+
+	/* portion1=0.5 */
+	result = src1;
+	success = pcm_mix(result.begin(), src2.begin(), sizeof(result),
+			  format, 0.5);
+	g_assert(success);
+
+	auto expected = src1;
+	for (unsigned i = 0; i < N; ++i)
+		expected[i] = (int64_t(src1[i]) + int64_t(src2[i])) / 2;
+
+	AssertEqualWithTolerance(result, expected, 1);
+}
+
+void
+test_pcm_mix_8()
+{
+	TestPcmMix<int8_t, SAMPLE_FORMAT_S8>();
+}
+
+void
+test_pcm_mix_16()
+{
+	TestPcmMix<int16_t, SAMPLE_FORMAT_S16>();
+}
+
+void
+test_pcm_mix_24()
+{
+	TestPcmMix<int32_t, SAMPLE_FORMAT_S24_P32>(GlibRandomInt24());
+}
+
+void
+test_pcm_mix_32()
+{
+	TestPcmMix<int32_t, SAMPLE_FORMAT_S32>();
+}