access: rtp: flag discontinuity on TS sessions

modules/access/rtp/rtp.c

@@ -473,6 +473,16 @@ static void stream_destroy (demux_t *demux, void *data)
     }
 }
 
+static void stream_header (demux_t *demux, void *data, block_t *block)
+{
+    VLC_UNUSED(demux);
+    VLC_UNUSED(data);
+    if(block->p_buffer[1] & 0x80) /* TS M-bit == discontinuity (RFC 2250, 2.1) */
+    {
+        block->i_flags |= BLOCK_FLAG_DISCONTINUITY;
+    }
+}
+
 /* Send a packet to a chained demuxer */
 static bool stream_decode (demux_t *demux, void *data, block_t *block)
 {
@@ -652,6 +662,7 @@ void rtp_autodetect (demux_t *demux, rtp_session_t *session,
     rtp_pt_t pt = {
         .init = NULL,
         .destroy = codec_destroy,
+        .header = NULL,
         .decode = codec_decode,
         .frequency = 0,
         .number = ptype,
@@ -714,6 +725,7 @@ void rtp_autodetect (demux_t *demux, rtp_session_t *session,
         msg_Dbg (demux, "detected MPEG2 TS");
         pt.init = ts_init;
         pt.destroy = stream_destroy;
+        pt.header = stream_header;
         pt.decode = stream_decode;
         pt.frequency = 90000;
         break;

modules/access/rtp/rtp.h

@@ -30,6 +30,7 @@ struct rtp_pt_t
 {
     void   *(*init) (demux_t *);
     void    (*destroy) (demux_t *, void *);
+    void    (*header) (demux_t *, void *, block_t *);
     bool    (*decode) (demux_t *, void *, block_t *);
     uint32_t  frequency; /* RTP clock rate (Hz) */
     uint8_t   number;

modules/access/rtp/session.c

@@ -124,6 +124,7 @@ int rtp_add_type (demux_t *demux, rtp_session_t *ses, const rtp_pt_t *pt)
     ppt->init = pt->init ? pt->init : no_init;
     ppt->destroy = pt->destroy ? pt->destroy : no_destroy;
     ppt->decode = pt->decode ? pt->decode : no_decode;
+    ppt->header = NULL;
     ppt->frequency = pt->frequency;
     ppt->number = pt->number;
     msg_Dbg (demux, "added payload type %"PRIu8" (f = %"PRIu32" Hz)",
@@ -518,6 +519,9 @@ rtp_decode (demux_t *demux, const rtp_session_t *session, rtp_source_t *src)
         goto drop;
     }
 
+    if(pt->header)
+        pt->header(demux, pt_data, block);
+
     /* Computes the PTS from the RTP timestamp and payload RTP frequency.
      * DTS is unknown. Also, while the clock frequency depends on the payload
      * format, a single source MUST only use payloads of a chosen frequency.