Re #1970: Implement function pjmedia_rtp_decode_rtp2().

git-svn-id: http://svn.pjsip.org/repos/pjproject/trunk@5460 74dad513-b988-da41-8d7b-12977e46ad98

2 files changed, 72 insertions, 5 deletions

diff --git a/pjmedia/include/pjmedia/rtp.h b/pjmedia/include/pjmedia/rtp.h
index 66983d81..7a360f9d 100644
--- a/pjmedia/include/pjmedia/rtp.h
+++ b/pjmedia/include/pjmedia/rtp.h
@@ -113,7 +113,7 @@ typedef struct pjmedia_rtp_hdr pjmedia_rtp_hdr;
 
 
 /**
- * RTP extendsion header.
+ * RTP extension header.
  */
 struct pjmedia_rtp_ext_hdr
 {
@@ -126,6 +126,21 @@ struct pjmedia_rtp_ext_hdr
  */
 typedef struct pjmedia_rtp_ext_hdr pjmedia_rtp_ext_hdr;
 
+/**
+ * This will contain the RTP header decode output.
+ */
+struct pjmedia_rtp_dec_hdr
+{
+    /* RTP extension header output decode */
+    pjmedia_rtp_ext_hdr *ext_hdr;
+    pj_uint32_t *ext;
+    unsigned ext_len;
+};
+
+/**
+ * @see pjmedia_rtp_dec_hdr
+ */
+typedef struct pjmedia_rtp_dec_hdr pjmedia_rtp_dec_hdr;
 
 #pragma pack(1)
 
@@ -321,6 +336,38 @@ PJ_DECL(pj_status_t) pjmedia_rtp_decode_rtp( pjmedia_rtp_session *ses,
 					     const void **payload,
 					     unsigned *payloadlen);
 
+
+/**
+ * This function decodes incoming packet into RTP header and payload.
+ * The decode function is guaranteed to point the payload to the correct
+ * position regardless of any options present in the RTP packet.
+ *
+ * Note that this function does not modify the returned RTP header to
+ * host byte order.
+ *
+ * @param ses		The session.
+ * @param pkt		The received RTP packet.
+ * @param pkt_len	The length of the packet.
+ * @param hdr		Upon return will point to the location of the RTP
+ *			header inside the packet. Note that the RTP header
+ *			will be given back as is, meaning that the fields
+ *			will be in network byte order.
+ * @param dec_hdr	Upon return will point to the location of the 
+ *			additional RTP header inside the packet, if any.
+ * @param payload	Upon return will point to the location of the
+ *			payload inside the packet.
+ * @param payloadlen	Upon return will indicate the size of the payload.
+ *
+ * @return		PJ_SUCCESS if successfull.
+ */
+PJ_DECL(pj_status_t) pjmedia_rtp_decode_rtp2(
+				    pjmedia_rtp_session *ses,
+				    const void *pkt, int pkt_len,
+				    const pjmedia_rtp_hdr **hdr,
+				    pjmedia_rtp_dec_hdr *dec_hdr,
+				    const void **payload,
+				    unsigned *payloadlen);
+
 /**
  * Call this function everytime an RTP packet is received to check whether 
  * the packet can be received and to let the RTP session performs its internal
diff --git a/pjmedia/src/pjmedia/rtp.c b/pjmedia/src/pjmedia/rtp.c
index 5a19c37e..3aa13e92 100644
--- a/pjmedia/src/pjmedia/rtp.c
+++ b/pjmedia/src/pjmedia/rtp.c
@@ -149,6 +149,21 @@ PJ_DEF(pj_status_t) pjmedia_rtp_decode_rtp( pjmedia_rtp_session *ses,
 					    const void **payload,
 					    unsigned *payloadlen)
 {
+    pjmedia_rtp_dec_hdr dec_hdr;
+
+    return pjmedia_rtp_decode_rtp2(ses, pkt, pkt_len, hdr, &dec_hdr, 
+				   payload, payloadlen);
+}
+
+
+PJ_DEF(pj_status_t) pjmedia_rtp_decode_rtp2(
+					    pjmedia_rtp_session *ses,
+					    const void *pkt, int pkt_len,
+					    const pjmedia_rtp_hdr **hdr,
+					    pjmedia_rtp_dec_hdr *dec_hdr,
+					    const void **payload,
+					    unsigned *payloadlen)
+{
     int offset;
 
     PJ_UNUSED_ARG(ses);
@@ -164,11 +179,16 @@ PJ_DEF(pj_status_t) pjmedia_rtp_decode_rtp( pjmedia_rtp_session *ses,
     /* Payload is located right after header plus CSRC */
     offset = sizeof(pjmedia_rtp_hdr) + ((*hdr)->cc * sizeof(pj_uint32_t));
 
-    /* Adjust offset if RTP extension is used. */
+    /* Decode RTP extension. */
     if ((*hdr)->x) {
-	pjmedia_rtp_ext_hdr *ext = (pjmedia_rtp_ext_hdr*) 
-				    (((pj_uint8_t*)pkt) + offset);
-	offset += ((pj_ntohs(ext->length)+1) * sizeof(pj_uint32_t));
+        dec_hdr->ext_hdr = (pjmedia_rtp_ext_hdr*)(((pj_uint8_t*)pkt) + offset);
+        dec_hdr->ext = (pj_uint32_t*)(dec_hdr->ext_hdr + 1);
+        dec_hdr->ext_len = pj_ntohs((dec_hdr->ext_hdr)->length);
+        offset += ((dec_hdr->ext_len + 1) * sizeof(pj_uint32_t));
+    } else {
+	dec_hdr->ext_hdr = NULL;
+	dec_hdr->ext = NULL;
+	dec_hdr->ext_len = 0;
     }
 
     /* Check that offset is less than packet size */