TT#30404 initial support for adding codecs for transcoding

Change-Id: I58474ac2daee213d9f11157f61c2a3df90818fbe

daemon/.gitignore

@@ -7,3 +7,4 @@ core.*
 auxlib.c
 loglib.c
 rtplib.c
+codeclib.c

daemon/Makefile

@@ -57,7 +57,7 @@ SRCS=		main.c kernel.c poller.c aux.c control_tcp.c streambuf.c call.c control_u
 		crypto.c rtp.c call_interfaces.c dtls.c log.c cli.c graphite.c ice.c socket.c \
 		media_socket.c homer.c recording.c statistics.c cdr.c ssrc.c iptables.c tcp_listener.c \
 		codec.c
-LIBSRCS=	loglib.c auxlib.c rtplib.c
+LIBSRCS=	loglib.c auxlib.c rtplib.c codeclib.c
 OBJS=		$(SRCS:.c=.o) $(LIBSRCS:.c=.o)
 
 

daemon/call.c

@@ -1450,92 +1450,6 @@ static void __dtls_logic(const struct sdp_ng_flags *flags,
 		MEDIA_SET(other_media, DTLS);
 }
 
-static void __rtp_payload_type_add(struct call_media *media, struct call_media *other_media,
-		struct rtp_payload_type *pt)
-{
-	struct call *call = media->call;
-
-	if (g_hash_table_lookup(media->codecs, &pt->payload_type)) {
-		// collision/duplicate - ignore
-		__payload_type_free(pt);
-		return;
-	}
-	/* we must duplicate the contents */
-	call_str_cpy(call, &pt->encoding_with_params, &pt->encoding_with_params);
-	call_str_cpy(call, &pt->encoding, &pt->encoding);
-	call_str_cpy(call, &pt->encoding_parameters, &pt->encoding_parameters);
-	call_str_cpy(call, &pt->format_parameters, &pt->format_parameters);
-	g_hash_table_replace(media->codecs, &pt->payload_type, pt);
-
-	GQueue *q = g_hash_table_lookup_queue_new(media->codec_names, &pt->encoding);
-	g_queue_push_tail(q, GUINT_TO_POINTER(pt->payload_type));
-
-	g_queue_push_tail(&media->codecs_prefs_recv, pt);
-
-	// for the other side, we need a new 'pt' struct
-	struct rtp_payload_type *pt_copy = g_slice_alloc(sizeof(*pt));
-	*pt_copy = *pt; // contents are allocated from the 'call'
-	g_queue_push_tail(&other_media->codecs_prefs_send, pt_copy);
-
-	// make sure we have at least an empty queue here to indicate support for this code.
-	// don't add anything to the queue as we don't know the reverse RTP payload type.
-	g_hash_table_lookup_queue_new(other_media->codec_names, &pt->encoding);
-}
-
-static void __payload_queue_free(void *qq) {
-	GQueue *q = qq;
-	g_queue_free_full(q, __payload_type_free);
-}
-static void __rtp_payload_types(struct call_media *media, struct call_media *other_media,
-		GQueue *types, GHashTable *strip,
-		const GQueue *offer)
-{
-	// 'media' = receiver of this offer/answer; 'other_media' = sender of this offer/answer
-	struct rtp_payload_type *pt;
-	static const str str_all = STR_CONST_INIT("all");
-	GHashTable *removed = g_hash_table_new_full(str_hash, str_equal, NULL, __payload_queue_free);
-	int remove_all = 0;
-
-	// start fresh
-	g_queue_clear(&media->codecs_prefs_recv);
-	g_queue_clear_full(&other_media->codecs_prefs_send, __payload_type_free);
-	g_hash_table_remove_all(media->codecs);
-	g_hash_table_remove_all(media->codec_names);
-
-	if (strip && g_hash_table_lookup(strip, &str_all))
-		remove_all = 1;
-
-	/* we steal the entire list to avoid duplicate allocs */
-	while ((pt = g_queue_pop_head(types))) {
-		// codec stripping
-		if (strip) {
-			if (remove_all || g_hash_table_lookup(strip, &pt->encoding)) {
-				GQueue *q = g_hash_table_lookup_queue_new(removed, &pt->encoding);
-				g_queue_push_tail(q, pt);
-				continue;
-			}
-		}
-		__rtp_payload_type_add(media, other_media, pt);
-	}
-
-	if (offer) {
-		// now restore codecs that have been removed, but should be offered
-		for (GList *l = offer->head; l; l = l->next) {
-			str *codec = l->data;
-			GQueue *q = g_hash_table_lookup(removed, codec);
-			if (!q)
-				continue;
-			g_hash_table_steal(removed, codec);
-			for (GList *l = q->head; l; l = l->next) {
-				pt = l->data;
-				__rtp_payload_type_add(media, other_media, pt);
-			}
-			g_queue_free(q);
-		}
-	}
-
-	g_hash_table_destroy(removed);
-}
 
 static void __ice_start(struct call_media *media) {
 	if (MEDIA_ISSET(media, PASSTHRU)) {
@@ -1658,8 +1572,8 @@ int monologue_offer_answer(struct call_monologue *other_ml, GQueue *streams,
 		}
 
 		// codec and RTP payload types handling
-		__rtp_payload_types(media, other_media, &sp->rtp_payload_types,
-				flags->codec_strip, &flags->codec_offer);
+		codec_rtp_payload_types(media, other_media, &sp->rtp_payload_types,
+				flags->codec_strip, &flags->codec_offer, &flags->codec_transcode);
 		codec_handlers_update(media, other_media);
 
 		/* send and recv are from our POV */

daemon/call_interfaces.c

@@ -618,6 +618,11 @@ static void call_ng_flags_flags(struct sdp_ng_flags *out, str *s, void *dummy) {
 			return;
 		if (call_ng_flags_prefix(out, s, "codec-offer-", call_ng_flags_codec_list, &out->codec_offer))
 			return;
+		if (call_ng_flags_prefix(out, s, "transcode-", call_ng_flags_codec_list, &out->codec_transcode))
+			return;
+		if (call_ng_flags_prefix(out, s, "codec-transcode-", call_ng_flags_codec_list,
+					&out->codec_transcode))
+			return;
 
 		ilog(LOG_WARN, "Unknown flag encountered: '" STR_FORMAT "'",
 				STR_FMT(s));
@@ -693,11 +698,13 @@ static void call_ng_process_flags(struct sdp_ng_flags *out, bencode_item_t *inpu
 		/* XXX module still needs to support these */
 		call_ng_flags_list(out, dict, "strip", call_ng_flags_codec_ht, out->codec_strip);
 		call_ng_flags_list(out, dict, "offer", call_ng_flags_codec_list, &out->codec_offer);
+		call_ng_flags_list(out, dict, "transcode", call_ng_flags_codec_list, &out->codec_transcode);
 	}
 }
 static void call_ng_free_flags(struct sdp_ng_flags *flags) {
 	g_hash_table_destroy(flags->codec_strip);
 	g_queue_clear_full(&flags->codec_offer, str_slice_free);
+	g_queue_clear_full(&flags->codec_transcode, str_slice_free);
 }
 
 static const char *call_offer_answer_ng(bencode_item_t *input,

daemon/call_interfaces.h

@@ -33,6 +33,7 @@ struct sdp_ng_flags {
 	str metadata;
 	GHashTable *codec_strip;
 	GQueue codec_offer;
+	GQueue codec_transcode;
 	int asymmetric:1,
 	    no_redis_update:1,
 	    unidirectional:1,

daemon/codec.c

@@ -3,6 +3,7 @@
 #include "call.h"
 #include "log.h"
 #include "rtplib.h"
+#include "codeclib.h"
 
 
 
@@ -128,3 +129,193 @@ void codec_packet_free(void *pp) {
 		p->free_func(p->s.s);
 	g_slice_free1(sizeof(*p), p);
 }
+
+
+
+static struct rtp_payload_type *codec_make_payload_type(const str *codec) {
+	const codec_def_t *dec = codec_find(codec);
+	if (!dec)
+		return NULL;
+	const struct rtp_payload_type *rfc_pt = rtp_get_rfc_codec(codec);
+	if (!rfc_pt)
+		return NULL; // XXX amend for other codecs
+
+	struct rtp_payload_type *ret = g_slice_alloc(sizeof(*ret));
+	*ret = *rfc_pt;
+	ret->codec_def = dec;
+
+	return ret;
+}
+
+
+static struct rtp_payload_type *codec_add_payload_type(const str *codec, struct call_media *media) {
+	struct rtp_payload_type *pt = codec_make_payload_type(codec);
+	if (!pt) {
+		ilog(LOG_WARN, "Codec '" STR_FORMAT "' requested for transcoding is not supported",
+				STR_FMT(codec));
+		return NULL;
+	}
+	// find an unused payload type number
+	if (pt->payload_type < 0)
+		pt->payload_type = 96; // default first dynamic payload type number
+	while (1) {
+		if (!g_hash_table_lookup(media->codecs, &pt->payload_type))
+			break; // OK
+		pt->payload_type++;
+		if (pt->payload_type < 96) // if an RFC type was taken already
+			pt->payload_type = 96;
+		else if (pt->payload_type >= 128) {
+			ilog(LOG_WARN, "Ran out of RTP payload type numbers while adding codec '"
+					STR_FORMAT "' for transcoding",
+				STR_FMT(codec));
+			__payload_type_free(pt);
+			return NULL;
+		}
+	}
+	return pt;
+}
+
+
+
+
+
+
+
+
+
+static void __rtp_payload_type_dup(struct call *call, struct rtp_payload_type *pt) {
+	/* we must duplicate the contents */
+	call_str_cpy(call, &pt->encoding_with_params, &pt->encoding_with_params);
+	call_str_cpy(call, &pt->encoding, &pt->encoding);
+	call_str_cpy(call, &pt->encoding_parameters, &pt->encoding_parameters);
+	call_str_cpy(call, &pt->format_parameters, &pt->format_parameters);
+}
+// consumes 'pt'
+static struct rtp_payload_type *__rtp_payload_type_add_recv(struct call_media *media,
+		struct rtp_payload_type *pt)
+{
+	struct rtp_payload_type *existing_pt;
+	if ((existing_pt = g_hash_table_lookup(media->codecs, &pt->payload_type))) {
+		// collision/duplicate - ignore
+		__payload_type_free(pt);
+		return existing_pt;
+	}
+	g_hash_table_replace(media->codecs, &pt->payload_type, pt);
+
+	GQueue *q = g_hash_table_lookup_queue_new(media->codec_names, &pt->encoding);
+	g_queue_push_tail(q, GUINT_TO_POINTER(pt->payload_type));
+
+	g_queue_push_tail(&media->codecs_prefs_recv, pt);
+
+	return pt;
+}
+// duplicates 'pt'
+static void __rtp_payload_type_add_send(struct call_media *other_media, struct rtp_payload_type *pt) {
+	// for the other side, we need a new 'pt' struct
+	struct rtp_payload_type *pt_copy = g_slice_alloc(sizeof(*pt));
+	*pt_copy = *pt;
+	g_queue_push_tail(&other_media->codecs_prefs_send, pt_copy);
+
+	// make sure we have at least an empty queue here to indicate support for this code.
+	// don't add anything to the queue as we don't know the reverse RTP payload type.
+	g_hash_table_lookup_queue_new(other_media->codec_names, &pt->encoding);
+}
+// consumes 'pt'
+static void __rtp_payload_type_add(struct call_media *media, struct call_media *other_media,
+		struct rtp_payload_type *pt)
+{
+	// if this payload type is already present in the 'codec' table, the _recv
+	// function frees its argument and returns the existing entry instead.
+	// otherwise it returns its argument.
+	pt = __rtp_payload_type_add_recv(media, pt);
+	__rtp_payload_type_add_send(other_media, pt);
+}
+
+static void __payload_queue_free(void *qq) {
+	GQueue *q = qq;
+	g_queue_free_full(q, __payload_type_free);
+}
+static int __revert_codec_strip(GHashTable *removed, const str *codec,
+		struct call_media *media, struct call_media *other_media) {
+	GQueue *q = g_hash_table_lookup(removed, codec);
+	if (!q)
+		return 0;
+	ilog(LOG_DEBUG, "Restoring codec '" STR_FORMAT "' from stripped codecs (%u payload types)",
+			STR_FMT(codec), q->length);
+	g_hash_table_steal(removed, codec);
+	for (GList *l = q->head; l; l = l->next) {
+		struct rtp_payload_type *pt = l->data;
+		__rtp_payload_type_add(media, other_media, pt);
+	}
+	g_queue_free(q);
+	return 1;
+}
+void codec_rtp_payload_types(struct call_media *media, struct call_media *other_media,
+		GQueue *types, GHashTable *strip,
+		const GQueue *offer, const GQueue *transcode)
+{
+	// 'media' = receiver of this offer/answer; 'other_media' = sender of this offer/answer
+	struct call *call = media->call;
+	struct rtp_payload_type *pt;
+	static const str str_all = STR_CONST_INIT("all");
+	GHashTable *removed = g_hash_table_new_full(str_hash, str_equal, NULL, __payload_queue_free);
+	int remove_all = 0;
+
+	// start fresh
+	g_queue_clear(&media->codecs_prefs_recv);
+	g_queue_clear_full(&other_media->codecs_prefs_send, __payload_type_free);
+	g_hash_table_remove_all(media->codecs);
+	g_hash_table_remove_all(media->codec_names);
+
+	if (strip && g_hash_table_lookup(strip, &str_all))
+		remove_all = 1;
+
+	/* we steal the entire list to avoid duplicate allocs */
+	while ((pt = g_queue_pop_head(types))) {
+		__rtp_payload_type_dup(call, pt); // this takes care of string allocation
+
+		// codec stripping
+		if (strip) {
+			if (remove_all || g_hash_table_lookup(strip, &pt->encoding)) {
+				ilog(LOG_DEBUG, "Stripping codec '" STR_FORMAT "'", STR_FMT(&pt->encoding));
+				GQueue *q = g_hash_table_lookup_queue_new(removed, &pt->encoding);
+				g_queue_push_tail(q, pt);
+				continue;
+			}
+		}
+		__rtp_payload_type_add(media, other_media, pt);
+	}
+
+	// now restore codecs that have been removed, but should be offered
+	for (GList *l = offer ? offer->head : NULL; l; l = l->next) {
+		str *codec = l->data;
+		__revert_codec_strip(removed, codec, media, other_media);
+	}
+
+	// add transcode codecs
+	for (GList *l = transcode ? transcode->head : NULL; l; l = l->next) {
+		str *codec = l->data;
+		// if we wish to 'transcode' to a codec that was offered originally,
+		// simply restore it from the original list and handle it the same way
+		// as 'offer'
+		if (__revert_codec_strip(removed, codec, media, other_media))
+			continue;
+		// also check if maybe the codec was never stripped
+		if (g_hash_table_lookup(media->codec_names, codec)) {
+			ilog(LOG_DEBUG, "Codec '" STR_FORMAT "' requested for transcoding is already present",
+					STR_FMT(codec));
+			continue;
+		}
+
+		// create new payload type
+		pt = codec_add_payload_type(codec, media);
+		if (!pt)
+			continue;
+
+		ilog(LOG_DEBUG, "Codec '" STR_FORMAT "' added for transcoding with payload type %u",
+				STR_FMT(codec), pt->payload_type);
+		__rtp_payload_type_add_recv(media, pt);
+	}
+
+	g_hash_table_destroy(removed);
+}

daemon/codec.h

@@ -32,6 +32,10 @@ void codec_handlers_free(struct call_media *);
 
 void codec_packet_free(void *);
 
+void codec_rtp_payload_types(struct call_media *media, struct call_media *other_media,
+		GQueue *types, GHashTable *strip,
+		const GQueue *offer, const GQueue *transcode);
+
 
 
 

lib/codeclib.c

@@ -0,0 +1,53 @@
+#include "codeclib.h"
+#include <libavcodec/avcodec.h>
+#include <glib.h>
+#include "str.h"
+
+
+
+
+#define CODEC_DEF_MULT_NAME(ref, id, mult, name) { \
+	.rtpname = #ref, \
+	.avcodec_id = AV_CODEC_ID_ ## id, \
+	.clockrate_mult = mult, \
+	.avcodec_name = #name, \
+}
+#define CODEC_DEF_MULT(ref, id, mult) CODEC_DEF_MULT_NAME(ref, id, mult, NULL)
+#define CODEC_DEF_NAME(ref, id, name) CODEC_DEF_MULT_NAME(ref, id, 1, name)
+#define CODEC_DEF(ref, id) CODEC_DEF_MULT(ref, id, 1)
+
+static const struct codec_def_s codecs[] = {
+	CODEC_DEF(PCMA, PCM_ALAW),
+	CODEC_DEF(PCMU, PCM_MULAW),
+	CODEC_DEF(G723, G723_1),
+	CODEC_DEF_MULT(G722, ADPCM_G722, 2),
+	CODEC_DEF(QCELP, QCELP),
+	CODEC_DEF(G729, G729),
+	CODEC_DEF(speex, SPEEX),
+	CODEC_DEF(GSM, GSM),
+	CODEC_DEF(iLBC, ILBC),
+	CODEC_DEF_NAME(opus, OPUS, libopus),
+	CODEC_DEF_NAME(vorbis, VORBIS, libvorbis),
+	CODEC_DEF(ac3, AC3),
+	CODEC_DEF(eac3, EAC3),
+	CODEC_DEF(ATRAC3, ATRAC3),
+	CODEC_DEF(ATRAC-X, ATRAC3P),
+#if LIBAVCODEC_VERSION_INT >= AV_VERSION_INT(57, 0, 0)
+	CODEC_DEF(EVRC, EVRC),
+	CODEC_DEF(EVRC0, EVRC),
+	CODEC_DEF(EVRC1, EVRC),
+#endif
+	CODEC_DEF(AMR, AMR_NB),
+	CODEC_DEF(AMR-WB, AMR_WB),
+};
+
+
+
+// XXX use hashtable for quicker lookup
+const codec_def_t *codec_find(const str *name) {
+	for (int i = 0; i < G_N_ELEMENTS(codecs); i++) {
+		if (!str_cmp(name, codecs[i].rtpname))
+			return &codecs[i];
+	}
+	return NULL;
+}

lib/codeclib.h

@@ -0,0 +1,21 @@
+#ifndef __CODECLIB_H__
+#define __CODECLIB_H__
+
+
+#include "str.h"
+
+
+
+struct codec_def_s {
+	const char *rtpname;
+	int clockrate_mult;
+	int avcodec_id;
+	const char *avcodec_name;
+};
+typedef struct codec_def_s codec_def_t;
+
+
+const codec_def_t *codec_find(const str *name);
+
+
+#endif

lib/rtplib.c

@@ -2,6 +2,7 @@
 #include <arpa/inet.h>
 #include "str.h"
 #include "log.h"
+#include "codeclib.h"
 
 
 
@@ -125,3 +126,15 @@ const struct rtp_payload_type *rtp_get_rfc_payload_type(unsigned int type) {
 		return NULL;
 	return rtp_pt;
 }
+
+// XXX use hash table
+const struct rtp_payload_type *rtp_get_rfc_codec(const str *codec) {
+	for (int i = 0; i < num_rfc_rtp_payload_types; i++) {
+		if (!rfc_rtp_payload_types[i].encoding.s)
+			continue;
+		if (str_cmp_str(codec, &rfc_rtp_payload_types[i].encoding))
+			continue;
+		return &rfc_rtp_payload_types[i];
+	}
+	return NULL;
+}

lib/rtplib.h

@@ -3,6 +3,7 @@
 
 #include <stdint.h>
 #include "str.h"
+#include "codeclib.h"
 
 
 struct rtp_header {
@@ -16,12 +17,14 @@ struct rtp_header {
 
 
 struct rtp_payload_type {
-	unsigned int payload_type;
+	int payload_type;
 	str encoding_with_params;
 	str encoding;
 	unsigned int clock_rate;
 	str encoding_parameters;
 	str format_parameters;
+
+	const codec_def_t *codec_def;
 };
 
 
@@ -32,6 +35,7 @@ extern const int num_rfc_rtp_payload_types;
 int rtp_payload(struct rtp_header **out, str *p, const str *s);
 int rtp_padding(struct rtp_header *header, str *payload);
 const struct rtp_payload_type *rtp_get_rfc_payload_type(unsigned int type);
+const struct rtp_payload_type *rtp_get_rfc_codec(const str *codec);
 
 
 #endif

recording-daemon/.gitignore

@@ -7,3 +7,4 @@ rtpengine-recording
 auxlib.c
 loglib.c
 rtplib.c
+codeclib.c

recording-daemon/Makefile

@@ -26,7 +26,7 @@ include ../lib/lib.Makefile
 
 SRCS=		epoll.c garbage.c inotify.c main.c metafile.c stream.c recaux.c packet.c \
 		decoder.c output.c mix.c resample.c db.c log.c forward.c
-LIBSRCS=	loglib.c auxlib.c rtplib.c
+LIBSRCS=	loglib.c auxlib.c rtplib.c codeclib.c
 OBJS=		$(SRCS:.c=.o) $(LIBSRCS:.c=.o)
 
 

recording-daemon/decoder.c

@@ -15,6 +15,7 @@
 #include "output.h"
 #include "mix.h"
 #include "resample.h"
+#include "codeclib.h"
 
 
 struct decoder_s {
@@ -33,67 +34,12 @@ struct decoder_s {
 };
 
 
-struct decoder_def_s {
-	const char *rtpname;
-	int clockrate_mult;
-	int avcodec_id;
-	const char *avcodec_name;
-};
-
-
-#define DECODER_DEF_MULT_NAME(ref, id, mult, name) { \
-	.rtpname = #ref, \
-	.avcodec_id = AV_CODEC_ID_ ## id, \
-	.clockrate_mult = mult, \
-	.avcodec_name = #name, \
-}
-#define DECODER_DEF_MULT(ref, id, mult) DECODER_DEF_MULT_NAME(ref, id, mult, NULL)
-#define DECODER_DEF_NAME(ref, id, name) DECODER_DEF_MULT_NAME(ref, id, 1, name)
-#define DECODER_DEF(ref, id) DECODER_DEF_MULT(ref, id, 1)
-
-static const struct decoder_def_s decoders[] = {
-	DECODER_DEF(PCMA, PCM_ALAW),
-	DECODER_DEF(PCMU, PCM_MULAW),
-	DECODER_DEF(G723, G723_1),
-	DECODER_DEF_MULT(G722, ADPCM_G722, 2),
-	DECODER_DEF(QCELP, QCELP),
-	DECODER_DEF(G729, G729),
-	DECODER_DEF(speex, SPEEX),
-	DECODER_DEF(GSM, GSM),
-	DECODER_DEF(iLBC, ILBC),
-	DECODER_DEF_NAME(opus, OPUS, libopus),
-	DECODER_DEF_NAME(vorbis, VORBIS, libvorbis),
-	DECODER_DEF(ac3, AC3),
-	DECODER_DEF(eac3, EAC3),
-	DECODER_DEF(ATRAC3, ATRAC3),
-	DECODER_DEF(ATRAC-X, ATRAC3P),
-#if LIBAVCODEC_VERSION_INT >= AV_VERSION_INT(57, 0, 0)
-	DECODER_DEF(EVRC, EVRC),
-	DECODER_DEF(EVRC0, EVRC),
-	DECODER_DEF(EVRC1, EVRC),
-#endif
-	DECODER_DEF(AMR, AMR_NB),
-	DECODER_DEF(AMR-WB, AMR_WB),
-};
-typedef struct decoder_def_s decoder_def_t;
-
-
 
 
 int resample_audio;
 
 
 
-
-static const decoder_def_t *decoder_find(const str *name) {
-	for (int i = 0; i < G_N_ELEMENTS(decoders); i++) {
-		if (!str_cmp(name, decoders[i].rtpname))
-			return &decoders[i];
-	}
-	return NULL;
-}
-
-
 decoder_t *decoder_new(const char *payload_str) {
 	const char *err = NULL;
 
@@ -115,7 +61,7 @@ decoder_t *decoder_new(const char *payload_str) {
 			channels = 1;
 	}
 
-	const decoder_def_t *def = decoder_find(&name);
+	const codec_def_t *def = codec_find(&name);
 	if (!def) {
 		ilog(LOG_WARN, "No decoder for payload %s", payload_str);
 		return NULL;

recording-daemon/output.c

@@ -201,7 +201,7 @@ int output_config(output_t *output, const format_t *requested_format, format_t *
 	avcodec_parameters_from_context(output->avst->codecpar, output->avcctx);
 #endif
 
-	char full_fn[PATH_MAX];
+	char full_fn[PATH_MAX*2];
 	char suff[16] = "";
 	for (int i = 1; i < 20; i++) {
 		snprintf(full_fn, sizeof(full_fn), "%s%s.%s", output->full_filename, suff, output->file_format);

utils/rtpengine-ng-client

@@ -47,6 +47,7 @@ GetOptions(
 	'media-address=s'		=> \$options{'media address'},
 	'codec-strip=s@'		=> \$options{'codec-strip'},
 	'codec-offer=s@'		=> \$options{'codec-offer'},
+	'codec-transcode=s@'		=> \$options{'codec-transcode'},
 	'flags=s@'			=> \$options{'flags'},
 ) or die;
 
@@ -74,11 +75,10 @@ if (defined($options{direction})) {
 	$options{direction} =~ /(.*),(.*)/ or die;
 	$packet{direction} = [$1,$2];
 }
-if ($options{'codec-strip'} && @{$options{'codec-strip'}}) {
-	$packet{codec}{strip} = $options{'codec-strip'};
-}
-if ($options{'codec-offer'} && @{$options{'codec-offer'}}) {
-	$packet{codec}{offer} = $options{'codec-offer'};
+for my $x (qw(strip offer transcode)) {
+	if ($options{'codec-'.$x} && @{$options{'codec-'.$x}}) {
+		$packet{codec}{$x} = $options{'codec-'.$x};
+	}
 }
 if ($options{'flags'} && @{$options{'flags'}}) {
 	push(@{$packet{flags}}, @{$options{'flags'}});