codecs: Add Codec 2 mode 2400.

ASTERISK-26217 #close

Change-Id: I1e45d8084683fab5f2b272bf35f4a149cea8b8d6

codecs/ex_codec2.h

@@ -0,0 +1,32 @@
+/*! \file
+ * \brief 8-bit raw data
+ *
+ * Copyright (C) 2016, Alexander Traud
+ *
+ * Distributed under the terms of the GNU General Public License
+ *
+ */
+
+#include "asterisk/format_cache.h"      /* for ast_format_codec2    */
+#include "asterisk/frame.h"             /* for ast_frame, etc       */
+
+static uint8_t ex_codec2[] = {
+	0xea, 0xca, 0x14, 0x85, 0x91, 0x78,
+};
+
+static struct ast_frame *codec2_sample(void)
+{
+	static struct ast_frame f = {
+		.frametype = AST_FRAME_VOICE,
+		.datalen = sizeof(ex_codec2),
+		.samples = CODEC2_SAMPLES,
+		.mallocd = 0,
+		.offset = 0,
+		.src = __PRETTY_FUNCTION__,
+		.data.ptr = ex_codec2,
+	};
+
+	f.subclass.format = ast_format_codec2;
+
+	return &f;
+}