Test: Cmocka: Add unit test for A-law encode and decode

Signed-off-by: Seppo Ingalsuo <seppo.ingalsuo@linux.intel.com>

Author: singalsu

test/cmocka/src/math/arithmetic/CMakeLists.txt

@@ -31,3 +31,8 @@ cmocka_test(base_e_logarithm
 	${PROJECT_SOURCE_DIR}/src/math/log_e.c
 	${PROJECT_SOURCE_DIR}/src/math/base2log.c
 )
+
+cmocka_test(a_law_codec
+	a_law_codec.c
+	${PROJECT_SOURCE_DIR}/src/math/a_law.c
+)

test/cmocka/src/math/arithmetic/a_law_codec.c

@@ -0,0 +1,61 @@
+// SPDX-License-Identifier: BSD-3-Clause
+//
+// Copyright(c) 2025 Intel Corporation.
+
+#include <stdio.h>
+#include <stdint.h>
+#include <setjmp.h>
+#include <stdbool.h>
+#include <cmocka.h>
+#include <sof/math/a_law.h>
+
+#include "a_law_codec.h"
+
+static void test_a_law_encode(void **state)
+{
+	(void)state;
+
+	uint8_t a_law_sample, a_law_ref;
+	int i;
+
+	for (i = 0; i < A_LAW_SAMPLES_COUNT; i++) {
+		a_law_sample = sofm_a_law_encode(chirp_8k_s16[i]);
+		a_law_ref = chirp_8k_alaw[i];
+
+		if (a_law_sample != a_law_ref) {
+			printf("%s: difference found at %d, encoded %d, ref %d\n",
+			       __func__, i, a_law_sample, a_law_ref);
+			assert_true(false);
+		}
+	}
+}
+
+static void test_a_law_decode(void **state)
+{
+	(void)state;
+
+	int16_t s16_sample, s16_ref;
+	int i;
+
+	for (i = 0; i < A_LAW_SAMPLES_COUNT; i++) {
+		s16_sample = sofm_a_law_decode(chirp_8k_alaw[i]);
+		s16_ref = chirp_8k_alaw_to_s16[i];
+		if (s16_sample != s16_ref) {
+			printf("%s: difference found at %d, decoded %d, ref %d\n",
+			       __func__, i, s16_sample, s16_ref);
+			assert_true(false);
+		}
+	}
+}
+
+int main(void)
+{
+	const struct CMUnitTest tests[] = {
+		cmocka_unit_test(test_a_law_encode),
+		cmocka_unit_test(test_a_law_decode),
+	};
+
+	cmocka_set_message_output(CM_OUTPUT_TAP);
+
+	return cmocka_run_group_tests(tests, NULL, NULL);
+}