external: tinycompress: add support for compress plugins

Add plugin support to use vendor specific compress implementation

Bug: 166667071
Test: manual offload playback test
Test: cts AudioTrackOffloadTest

CRs-Fixed: 2563258
Change-Id: I71f588b9ed84b62d3b1b08dae7ce65f8fa649e6a
diff --git a/snd_utils.h b/snd_utils.h
new file mode 100644
index 0000000..d00f7f2
--- /dev/null
+++ b/snd_utils.h
@@ -0,0 +1,72 @@
+/* snd_utils.h
+**
+** Copyright (c) 2019, The Linux Foundation. All rights reserved.
+**
+** Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above
+**     copyright notice, this list of conditions and the following
+**     disclaimer in the documentation and/or other materials provided
+**     with the distribution.
+**   * Neither the name of The Linux Foundation nor the names of its
+**     contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+** THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
+** WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+** MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
+** ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
+** BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+** CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+** SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+** BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+** WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
+** OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
+** IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+**/
+
+#ifndef __SND_CARD_UTILS_H__
+#define __SND_CARD_UTILS_H__
+
+#include <dlfcn.h>
+
+struct snd_node {
+	void *card_node;
+	void *dev_node;
+	void *dl_hdl;
+
+	void* (*get_card) (unsigned int card);
+	void (*put_card) (void *card);
+	void* (*get_node) (void *card, unsigned int id,
+				int type);
+	int (*get_int) (void *node, const char *prop, int *val);
+	int (*get_str) (void *node, const char *prop, char **val);
+};
+
+enum {
+	NODE_PCM,
+	NODE_MIXER,
+	NODE_COMPRESS,
+};
+
+enum snd_node_type {
+	SND_NODE_TYPE_HW = 0,
+	SND_NODE_TYPE_PLUGIN,
+	SND_NODE_TYPE_INVALID,
+};
+
+struct snd_node *snd_utils_get_dev_node(unsigned int card,
+		unsigned int device, int dev_type);
+
+void snd_utils_put_dev_node(struct snd_node *node);
+
+enum snd_node_type snd_utils_get_node_type(struct snd_node *node);
+
+int snd_utils_get_int(struct snd_node *node, const char *prop, int *val);
+
+int snd_utils_get_str(struct snd_node *node, const char *prop, char **val);
+
+#endif /* end of __SND_CARD_UTILS_H__ */