--- alsa-utils-1.1.8/axfer/test/generator.h
+++ alsa-utils-1.1.8/axfer/test/generator.h
@@ -0,0 +1,47 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// generator.c - a generator for test with buffers of PCM frames.
+//
+// Copyright (c) 2018 Takashi Sakamoto <o-takashi@sakamocchi.jp>
+//
+// Licensed under the terms of the GNU General Public License, version 2.
+
+#ifndef __ALSA_UTILS_AXFER_TEST_GENERATOR__H_
+#define __ALSA_UTILS_AXFER_TEST_GENERATOR__H_
+
+#include <stdint.h>
+#include <alsa/asoundlib.h>
+
+struct test_generator;
+typedef int (*generator_cb_t)(struct test_generator *gen,
+			      snd_pcm_access_t access,
+			      snd_pcm_format_t sample_format,
+			      unsigned int samples_per_frame,
+			      void *frame_buffer, unsigned int frame_count);
+
+struct test_generator {
+	int fd;
+	uint64_t access_mask;
+	uint64_t sample_format_mask;
+	unsigned int min_samples_per_frame;
+	unsigned int max_samples_per_frame;
+	unsigned int min_frame_count;
+	unsigned int max_frame_count;
+	unsigned int step_frame_count;
+
+	generator_cb_t cb;
+	void *private_data;
+};
+
+int generator_context_init(struct test_generator *gen,
+			   uint64_t access_mask, uint64_t sample_format_mask,
+			   unsigned int min_samples_per_frame,
+			   unsigned int max_samples_per_frame,
+			   unsigned int min_frame_count,
+			   unsigned int max_frame_count,
+			   unsigned int step_frame_count,
+			   unsigned int private_size);
+int generator_context_run(struct test_generator *gen, generator_cb_t cb);
+void generator_context_destroy(struct test_generator *gen);
+
+#endif