Make sure that full video frames are sent whenever the 15 bit timestamp rolls over.

(closes issue #11923)
Reported by: mihai
Patches:
      asterisk-fullvideo.patch uploaded by mihai (license 94)

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.4@111014 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/channels/chan_iax2.c b/channels/chan_iax2.c
index 67a0ba03bae1cdf202257b2941b1f41100e5ea8b..b6d683204056732926779d3e85df9f243957e330 100644 (file)
--- a/channels/chan_iax2.c
+++ b/channels/chan_iax2.c
@@ -480,6 +480,8 @@ struct chan_iax2_pvt {
        unsigned int last;
        /*! Last sent timestamp - never send the same timestamp twice in a single call */
        unsigned int lastsent;
+       /*! Timestamp of the last video frame sent */
+       unsigned int lastvsent;
        /*! Next outgoing timestamp if everything is good */
        unsigned int nextpred;
        /*! True if the last voice we transmitted was not silence/CNG */
@@ -3785,6 +3787,17 @@ static unsigned int calc_timestamp(struct chan_iax2_pvt *p, unsigned int ts, str
                                p->nextpred = ms;
                                p->notsilenttx = 1;
                        }
+               } else if ( f->frametype == AST_FRAME_VIDEO ) {
+                       /*
+                       * IAX2 draft 03 says that timestamps MUST be in order.
+                       * It does not say anything about several frames having the same timestamp
+                       * When transporting video, we can have a frame that spans multiple iax packets
+                       * (so called slices), so it would make sense to use the same timestamp for all of
+                       * them
+                       * We do want to make sure that frames don't go backwards though
+                       */
+                       if ( (unsigned int)ms < p->lastsent )
+                               ms = p->lastsent;
                } else {
                        /* On a dataframe, use last value + 3 (to accomodate jitter buffer shrinking) if appropriate unless
                           it's a genuine frame */
@@ -4154,11 +4167,22 @@ static int iax2_send(struct chan_iax2_pvt *pvt, struct ast_frame *f, unsigned in
                        /* Mark that mini-style frame is appropriate */
                        sendmini = 1;
        }
-       if (((fts & 0xFFFF8000L) == (lastsent & 0xFFFF8000L)) && 
-               (f->frametype == AST_FRAME_VIDEO) &&
-               ((f->subclass & ~0x1) == pvt->svideoformat)) {
+       if ( f->frametype == AST_FRAME_VIDEO ) {
+               /*
+                * If the lower 15 bits of the timestamp roll over, or if
+                * the video format changed then send a full frame.
+                * Otherwise send a mini video frame
+                */
+               if (((fts & 0xFFFF8000L) == (pvt->lastvsent & 0xFFFF8000L)) &&
+                   ((f->subclass & ~0x1) == pvt->svideoformat)
+                  ) {
                        now = 1;
                        sendmini = 1;
+               } else {
+                       now = 0;
+                       sendmini = 0;
+               }
+               pvt->lastvsent = fts;
        }
        /* Allocate an iax_frame */
        if (now) {