alaw16_pass_through.patch

--- include/asterisk/format_cache.h	(Asterisk 13.13.1)
+++ include/asterisk/format_cache.h	(working copy)
@@ -234,2 +234,7 @@ extern struct ast_format *ast_format_sil
 /*!
+ * \brief Built-in PCMA 16 format.
+ */
+extern struct ast_format *ast_format_alaw16;
+
+/*!
  * \brief Initialize format cache support within the core.
--- main/codec_builtin.c	(Asterisk 13.13.1)
+++ main/codec_builtin.c	(working copy)
@@ -169,2 +169,16 @@ static struct ast_codec alaw = {
 
+static struct ast_codec alaw16 = {
+	.name = "alaw16",
+	.description = "PCMA 16",
+	.type = AST_MEDIA_TYPE_AUDIO,
+	.sample_rate = 16000,
+	.minimum_ms = 10,
+	.maximum_ms = 150,
+	.default_ms = 10,
+	.minimum_bytes = 160,
+	.samples_count = ulaw_samples,
+	.get_length = ulaw_length,
+	.smooth = 1,
+};
+
 static int gsm_samples(struct ast_frame *frame)
@@ -887,2 +901,4 @@ int ast_codec_builtin_init(void)
 	res |= CODEC_REGISTER_AND_CACHE(codec2);
+	res |= CODEC_REGISTER_AND_CACHE(alaw16);
+
 	res |= CODEC_REGISTER_AND_CACHE(g723);
--- main/format_cache.c	(Asterisk 13.13.1)
+++ main/format_cache.c	(working copy)
@@ -220,2 +220,7 @@ struct ast_format *ast_format_opus;
 /*!
+ * \brief Built-in cached PCMA 16 format.
+ */
+struct ast_format *ast_format_alaw16;
+
+/*!
  * \brief Built-in cached t140 format.
@@ -302,2 +307,4 @@ static void format_cache_shutdown(void)
 
+	ao2_replace(ast_format_alaw16, NULL);
+
 	ao2_replace(ast_format_g723, NULL);
@@ -368,2 +375,4 @@ static void set_cached_format(const char
 		ao2_replace(ast_format_alaw, format);
+	} else if (!strcmp(name, "alaw16")) {
+		ao2_replace(ast_format_alaw16, format);
 	} else if (!strcmp(name, "gsm")) {
--- main/rtp_engine.c	(Asterisk 13.13.1)
+++ main/rtp_engine.c	(working copy)
@@ -2264,2 +2264,4 @@ int ast_rtp_engine_init(void)
 
+	set_next_mime_type(ast_format_alaw16, 0,  "audio", "PCMA", 16000);
+
 	/* Define the static rtp payload mappings */
@@ -2307,2 +2309,4 @@ int ast_rtp_engine_init(void)
 	add_static_payload(107, ast_format_opus, 0);
+
+	add_static_payload(-1, ast_format_alaw16, 0);