diff --git a/libs/unimrcp/libs/mpf/src/mpf_codec_linear.c b/libs/unimrcp/libs/mpf/src/mpf_codec_linear.c
index ceaec016ce..cbe536959d 100644
--- a/libs/unimrcp/libs/mpf/src/mpf_codec_linear.c
+++ b/libs/unimrcp/libs/mpf/src/mpf_codec_linear.c
@@ -14,6 +14,8 @@
  * limitations under the License.
  */
 
+#define APR_WANT_BYTEFUNC
+#include <apr_want.h>
 #include "mpf_codec.h"
 
 /* linear 16-bit PCM (host horder) */
@@ -40,12 +42,12 @@ static apt_bool_t l16_encode(mpf_codec_t *codec, const mpf_codec_frame_t *frame_
 	apr_uint32_t i;
 	const short *buf_in = frame_in->buffer;
 	short *buf_out = frame_out->buffer;
+	apr_size_t samples = frame_in->size / sizeof(short);
 
 	frame_out->size = frame_in->size;
 
-	for(i=0; i<frame_in->size; ) {
+	for(i=0; i<samples; i++) {
 		buf_out[i] = htons(buf_in[i]);
-		i += sizeof(short);
 	}
 
 	return TRUE;
@@ -56,12 +58,12 @@ static apt_bool_t l16_decode(mpf_codec_t *codec, const mpf_codec_frame_t *frame_
 	apr_uint32_t i;
 	const short *buf_in = frame_in->buffer;
 	short *buf_out = frame_out->buffer;
+	apr_size_t samples = frame_in->size / sizeof(short);
 
 	frame_out->size = frame_in->size;
 
-	for(i=0; i<frame_in->size; ) {
+	for(i=0; i<samples; i++) {
 		buf_out[i] = ntohs(buf_in[i]);
-		i += sizeof(short);
 	}
 
 	return TRUE;
diff --git a/libs/unimrcp/libs/mpf/src/mpf_context.c b/libs/unimrcp/libs/mpf/src/mpf_context.c
index 2f261484a5..0b8bc2ed17 100644
--- a/libs/unimrcp/libs/mpf/src/mpf_context.c
+++ b/libs/unimrcp/libs/mpf/src/mpf_context.c
@@ -208,12 +208,12 @@ static mpf_object_t* mpf_context_connection_create(mpf_context_t *context, mpf_t
 				object = mpf_null_bridge_create(source,sink,context->pool);
 			}
 			else {
-				if(rx_codec->attribs->bits_per_samples != BITS_PER_SAMPLE) {
+				if(rx_codec->vtable && rx_codec->vtable->decode) {
 					/* set decoder before bridge */
 					mpf_audio_stream_t *decoder = mpf_decoder_create(source,context->pool);
 					source = decoder;
 				}
-				if(tx_codec->attribs->bits_per_samples != BITS_PER_SAMPLE) {
+				if(tx_codec->vtable && tx_codec->vtable->encode) {
 					/* set encoder after bridge */
 					mpf_audio_stream_t *encoder = mpf_encoder_create(sink,context->pool);
 					sink = encoder;