static GstFlowReturn
gst_rdt_depay_chain (GstPad * pad, GstBuffer * buf)
{
GstRDTDepay *rdtdepay;
GstFlowReturn ret;
GstClockTime timestamp;
gboolean more;
GstRDTPacket packet;
rdtdepay = GST_RDT_DEPAY (GST_PAD_PARENT (pad));
if (GST_BUFFER_IS_DISCONT (buf)) {
GST_LOG_OBJECT (rdtdepay, "received discont");
rdtdepay->discont = TRUE;
}
if (rdtdepay->header) {
GstBuffer *out;
out = rdtdepay->header;
rdtdepay->header = NULL;
/* push header data first */
ret = gst_rdt_depay_push (rdtdepay, out);
}
/* save timestamp */
timestamp = GST_BUFFER_TIMESTAMP (buf);
ret = GST_FLOW_OK;
GST_LOG_OBJECT (rdtdepay, "received buffer timestamp %" GST_TIME_FORMAT,
GST_TIME_ARGS (timestamp));
/* data is in RDT format. */
more = gst_rdt_buffer_get_first_packet (buf, &packet);
while (more) {
GstRDTType type;
type = gst_rdt_packet_get_type (&packet);
GST_DEBUG_OBJECT (rdtdepay, "Have packet of type %04x", type);
if (GST_RDT_IS_DATA_TYPE (type)) {
GST_DEBUG_OBJECT (rdtdepay, "We have a data packet");
ret = gst_rdt_depay_handle_data (rdtdepay, timestamp, &packet);
} else {
switch (type) {
default:
GST_DEBUG_OBJECT (rdtdepay, "Ignoring packet");
break;
}
}
if (ret != GST_FLOW_OK)
break;
more = gst_rdt_packet_move_to_next (&packet);
}
return ret;
}
static GstFlowReturn
gst_rdt_depay_handle_data (GstRDTDepay * rdtdepay, GstClockTime outtime,
GstRDTPacket * packet)
{
GstFlowReturn ret;
GstBuffer *outbuf;
GstMapInfo outmap;
guint8 *data, *outdata;
guint size;
guint16 stream_id;
guint32 timestamp;
gint gap;
guint16 seqnum;
guint8 flags;
guint16 outflags;
/* get pointers to the packet data */
data = gst_rdt_packet_data_map (packet, &size);
outbuf = gst_buffer_new_and_alloc (12 + size);
GST_BUFFER_TIMESTAMP (outbuf) = outtime;
GST_DEBUG_OBJECT (rdtdepay, "have size %u", size);
/* copy over some things */
stream_id = gst_rdt_packet_data_get_stream_id (packet);
timestamp = gst_rdt_packet_data_get_timestamp (packet);
flags = gst_rdt_packet_data_get_flags (packet);
seqnum = gst_rdt_packet_data_get_seq (packet);
GST_DEBUG_OBJECT (rdtdepay, "stream_id %u, timestamp %u, seqnum %d, flags %d",
stream_id, timestamp, seqnum, flags);
if (rdtdepay->next_seqnum != -1) {
gap = gst_rdt_buffer_compare_seqnum (seqnum, rdtdepay->next_seqnum);
/* if we have no gap, all is fine */
if (G_UNLIKELY (gap != 0)) {
GST_LOG_OBJECT (rdtdepay, "got packet %u, expected %u, gap %d", seqnum,
rdtdepay->next_seqnum, gap);
if (gap < 0) {
/* seqnum > next_seqnum, we are missing some packets, this is always a
* DISCONT. */
GST_LOG_OBJECT (rdtdepay, "%d missing packets", gap);
rdtdepay->discont = TRUE;
} else {
/* seqnum < next_seqnum, we have seen this packet before or the sender
* could be restarted. If the packet is not too old, we throw it away as
* a duplicate, otherwise we mark discont and continue. 100 misordered
* packets is a good threshold. See also RFC 4737. */
if (gap < 100)
goto dropping;
GST_LOG_OBJECT (rdtdepay,
"%d > 100, packet too old, sender likely restarted", gap);
rdtdepay->discont = TRUE;
}
}
}
rdtdepay->next_seqnum = (seqnum + 1);
if (rdtdepay->next_seqnum == 0xff00)
rdtdepay->next_seqnum = 0;
if ((flags & 1) == 0)
outflags = 2;
else
outflags = 0;
gst_buffer_map (outbuf, &outmap, GST_MAP_WRITE);
outdata = outmap.data;
GST_WRITE_UINT16_BE (outdata + 0, 0); /* version */
GST_WRITE_UINT16_BE (outdata + 2, size + 12); /* length */
GST_WRITE_UINT16_BE (outdata + 4, stream_id); /* stream */
GST_WRITE_UINT32_BE (outdata + 6, timestamp); /* timestamp */
GST_WRITE_UINT16_BE (outdata + 10, outflags); /* flags */
memcpy (outdata + 12, data, size);
gst_buffer_unmap (outbuf, &outmap);
gst_buffer_resize (outbuf, 0, 12 + size);
gst_rdt_packet_data_unmap (packet);
GST_DEBUG_OBJECT (rdtdepay, "Pushing packet, outtime %" GST_TIME_FORMAT,
GST_TIME_ARGS (outtime));
ret = gst_rdt_depay_push (rdtdepay, outbuf);
return ret;
/* ERRORS */
dropping:
{
GST_WARNING_OBJECT (rdtdepay, "%d <= 100, dropping old packet", gap);
return GST_FLOW_OK;
}
}
