Add GSM (libgsm) codec support

configure.ac

@@ -74,8 +74,13 @@ AC_SUBST(SYMBOL_VISIBILITY)
 dnl Generate the output
 AM_CONFIG_HEADER(config.h)
 
-AC_CHECK_LIB([m], [main])
-AC_CHECK_LIB([pthread], [main])
+AC_CHECK_LIB([m], [main], [], [echo "Failed to find lib!" ; exit -1])
+AC_CHECK_LIB([pthread], [main], [], [echo "Failed to find lib!" ; exit -1])
+
+AC_ARG_WITH([gsm], [AS_HELP_STRING([--with-gsm], [compile with GSM codec support @<:@default=check@:>@]) ], [], [with_gsm="check"])
+AS_IF([test "x$with_gsm" != xno], [AC_CHECK_LIB([gsm], [main], [with_gsm="yes"], [with_gsm="no"])])
+AM_CONDITIONAL(HAVE_GSM, test "x$with_gsm" == "xyes" )
+AS_IF([test "x$with_gsm" == "xyes"],[AC_MSG_NOTICE( Compiling with GSM codec support )], [AC_MSG_NOTICE( Compiling without GSM codec not found )])
 
 AC_OUTPUT(
 	src/liboptions/Makefile

src/router/Makefile.am

@@ -24,3 +24,13 @@ osmo_cc_router_LDADD = \
 	../libfilter/libfilter.a \
 	../libwave/libwave.a
 
+if HAVE_GSM
+AM_CPPFLAGS += -DHAVE_GSM
+
+osmo_cc_router_SOURCES += \
+	gsm_codec.c
+
+osmo_cc_router_LDADD += \
+	-lgsm
+endif
+

src/router/call.c

@@ -75,6 +75,9 @@
 #include "call.h"
 #include "audio.h"
 #include "display.h"
+#ifdef HAVE_GSM
+#include "gsm_codec.h"
+#endif
 
 call_t *call_list = NULL;
 struct timer status_timer;
@@ -85,7 +88,11 @@ static struct osmo_cc_helper_audio_codecs codecs_def[] = {
 	{ "PCMA", 8000, 1, g711_encode_alaw, g711_decode_alaw },
 	{ "PCMU", 8000, 1, g711_encode_ulaw, g711_decode_ulaw },
 	{ "telephone-event", 8000, 1, encode_te, decode_te },
+	/* non-default (selectable) codecs */
 	{ "L16", 8000, 1, encode_l16, decode_l16 },
+#ifdef HAVE_GSM
+	{ "GSM", 8000, 1, gsm_fr_encode, gsm_fr_decode },
+#endif
 	{ NULL, 0, 0, NULL, NULL},
 };
 
@@ -282,6 +289,10 @@ static call_relation_t *relation_create(call_t *call)
 	}
 	*relation_p = relation;
 
+#ifdef HAVE_GSM
+	gsm_fr_create(relation);
+#endif
+
 	PDEBUG(DROUTER, DEBUG_DEBUG, "%s Created new endpoint relation instance.\n", relation_name(relation));
 
 	return relation;
@@ -312,6 +323,11 @@ static void relation_destroy(call_relation_t *relation)
 	}
 	*relation_p = relation->next;
 
+#ifdef HAVE_GSM
+	if (relation->gsm_fr_encoder)
+		gsm_fr_destroy(relation);
+#endif
+
 	PDEBUG(DROUTER, DEBUG_DEBUG, "%s Destroyed endpoint relation instance.\n", relation_name(relation));
 
 	free(relation);
@@ -1287,8 +1303,8 @@ static int parse_params(int argc, char *argv[], struct command_def *command_def)
 
 /* routing orders us to activate rtp proxy */
 struct param_def param_rtp_proxy[] = {
-	{ .n = "orig-codecs", .o = param.orig_codecs, .d = "Define allowed codecs to be accepted by originating endpoint." },
-	{ .n = "term-codecs", .t = param.term_codecs, .d = "Define allowed codecs on terminating endpoint in order of preference." },
+	{ .n = "orig-codecs", .o = param.orig_codecs, .d = "Define allowed codecs to be accepted by originating endpoint. (codec1,[codec2[,...]])" },
+	{ .n = "term-codecs", .t = param.term_codecs, .d = "Define allowed codecs on terminating endpoint in order of preference. (codec1,[codec2[,...]])" },
 	{ .n = NULL }
 };
 

src/router/call.h

@@ -37,6 +37,9 @@ typedef struct call_relation {
 	char			id[256];	/* caller ID / dialing*/
 	enum call_state		state;		/* state for status display */
 
+	void			*gsm_fr_encoder;/* instance for FR codec */
+	void			*gsm_fr_decoder;
+
 	osmo_cc_session_t	*cc_session;
 	int			codec_negotiated;
 	struct osmo_cc_helper_audio_codecs orig_codecs[MAX_CODECS + 1];	/* codecs for originator */

src/router/gsm_codec.c

@@ -0,0 +1,81 @@
+#include <errno.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+#include <gsm.h>
+#include "call.h"
+#include "gsm_codec.h"
+#include "../libdebug/debug.h"
+
+
+/* create gsm instance */
+int gsm_fr_create(call_relation_t *relation)
+{
+	int value = 1;
+	gsm encoder, decoder;
+
+	encoder = gsm_create();
+	if (!encoder) {
+		fprintf(stderr, "gsm codec failed to intialize.\n");
+		abort();
+	}
+	gsm_option(encoder, 0/*GSM_OPT_WAV49*/, &value);
+
+	decoder = gsm_create();
+	if (!decoder) {
+		fprintf(stderr, "gsm codec failed to intialize.\n");
+		abort();
+	}
+	gsm_option(decoder, 0/*GSM_OPT_WAV49*/, &value);
+
+	relation->gsm_fr_encoder = encoder;
+	relation->gsm_fr_decoder = decoder;
+
+	return -ENOMEM;
+}
+
+/* free gsm instance */
+void gsm_fr_destroy(call_relation_t *relation)
+{
+	gsm_destroy((gsm)relation->gsm_fr_encoder);
+	gsm_destroy((gsm)relation->gsm_fr_decoder);
+}
+
+/* encode samples into frame */
+void gsm_fr_encode(uint8_t *src_data, int src_len, uint8_t **dst_data, int *dst_len, void *priv)
+{
+	call_relation_t *relation = (call_relation_t *)priv;
+	gsm_signal *src = (gsm_signal *)src_data;
+	gsm_byte *dst;
+
+	dst = malloc(33);
+        if (!dst)
+		return;
+
+	if (src_len / 2 != 160)
+		fprintf(stderr, "GSM encoder requires 160 samples per chunk! Please fix!\n");
+	else
+		gsm_encode((gsm)relation->gsm_fr_encoder, src, dst);
+	*dst_data = (uint8_t *)dst;
+	*dst_len = 33;
+}
+
+/* decode frame into samples */
+void gsm_fr_decode(uint8_t *src_data, int src_len, uint8_t **dst_data, int *dst_len, void *priv)
+{
+	call_relation_t *relation = (call_relation_t *)priv;
+	gsm_byte *src = (gsm_byte *)src_data;
+	gsm_signal *dst;
+
+	dst = malloc(160 * 2);
+        if (!dst)
+		return;
+
+	if (src_len != 33)
+		fprintf(stderr, "GSM decoder requires 33 bytes per chunk! Please fix!\n");
+	else
+		gsm_decode((gsm)relation->gsm_fr_decoder, src, dst);
+	*dst_data = (uint8_t *)dst;
+	*dst_len = 160 * 2;
+}
+

src/router/gsm_codec.h

@@ -0,0 +1,6 @@
+
+int gsm_fr_create(call_relation_t *relation);
+void gsm_fr_destroy(call_relation_t *relation);
+void gsm_fr_encode(uint8_t *src_data, int src_len, uint8_t **dst_data, int *dst_len, void *priv);
+void gsm_fr_decode(uint8_t *src_data, int src_len, uint8_t **dst_data, int *dst_len, void *priv);
+