This patch refactors RDT packet header parsing so that it can be used in

rtsp.c to detect the ID of the packet source also in case of TCP streams.
This allows proper playback of RDT streams with multiple stream types, e.g.
audio + video. Accepted by LucaB in "RDT/Realmedia patches #2" thread on ML.

Originally committed as revision 15496 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 20 insertions, 16 deletions

diff --git a/libavformat/rdt.c b/libavformat/rdt.c
index c1238b2d46..0dd9a6ef87 100644
--- a/libavformat/rdt.c
+++ b/libavformat/rdt.c
@@ -140,27 +140,25 @@ rdt_load_mdpr (rdt_data *rdt, AVStream *st, int rule_nr)
  * Actual data handling.
  */
 
-static int rdt_parse_header(struct RTPDemuxContext *s, const uint8_t *buf,
-                            int len, int *seq, uint32_t *timestamp, int *flags)
+int
+ff_rdt_parse_header(const uint8_t *buf, int len,
+                    int *sn, int *seq, int *rn, uint32_t *ts)
 {
-    rdt_data *rdt = s->dynamic_protocol_context;
-    int consumed = 0, sn;
+    int consumed = 10;
 
-    if (buf[0] < 0x40 || buf[0] > 0x42) {
+    if (len > 0 && (buf[0] < 0x40 || buf[0] > 0x42)) {
         buf += 9;
         len -= 9;
         consumed += 9;
     }
-    sn = (buf[0]>>1) & 0x1f;
-    *seq = AV_RB16(buf+1);
-    *timestamp = AV_RB32(buf+4);
-    if (!(buf[3] & 1) && (sn != rdt->prev_sn || *timestamp != rdt->prev_ts)) {
-        *flags |= PKT_FLAG_KEY;
-        rdt->prev_sn = sn;
-        rdt->prev_ts = *timestamp;
-    }
+    if (len < 10)
+        return -1;
+    if (sn)  *sn  = (buf[0]>>1) & 0x1f;
+    if (seq) *seq = AV_RB16(buf+1);
+    if (ts)  *ts  = AV_RB32(buf+4);
+    if (rn)  *rn  = buf[3] & 0x3f;
 
-    return consumed + 10;
+    return consumed;
 }
 
 /**< return 0 on packet, no more left, 1 on packet, 1 on partial packet... */
@@ -208,7 +206,8 @@ int
 ff_rdt_parse_packet(RTPDemuxContext *s, AVPacket *pkt,
                     const uint8_t *buf, int len)
 {
-    int seq, flags = 0;
+    rdt_data *rdt = s->dynamic_protocol_context;
+    int seq, flags = 0, rule, sn;
     uint32_t timestamp;
     int rv= 0;
 
@@ -221,9 +220,14 @@ ff_rdt_parse_packet(RTPDemuxContext *s, AVPacket *pkt,
 
     if (len < 12)
         return -1;
-    rv = rdt_parse_header(s, buf, len, &seq, &timestamp, &flags);
+    rv = ff_rdt_parse_header(buf, len, &sn, &seq, &rule, &timestamp);
     if (rv < 0)
         return rv;
+    if (!(rule & 1) && (sn != rdt->prev_sn || timestamp != rdt->prev_ts)) {
+        flags |= PKT_FLAG_KEY;
+        rdt->prev_sn = sn;
+        rdt->prev_ts = timestamp;
+    }
     buf += rv;
     len -= rv;
     s->seq = seq;