mgcp: Move Annex A counting out of patch/count method
mgcp_patch_and_count has grown due supporting linearizing timestamps,
ssrc and other things for equipment like the ip.access nanoBTS. Fight
back and move the Annex A code into a dedicated method.
The result is updated as we now count after all the patching and for
the Annex A code no change in SSRC can be detected.
diff --git a/openbsc/src/libmgcp/mgcp_network.c b/openbsc/src/libmgcp/mgcp_network.c
index be8ba1b..888ec6e 100644
--- a/openbsc/src/libmgcp/mgcp_network.c
+++ b/openbsc/src/libmgcp/mgcp_network.c
@@ -331,6 +331,60 @@
*fmtp_extra = endp->bts_end.fmtp_extra;
}
+
+void mgcp_rtp_annex_count(struct mgcp_endpoint *endp, struct mgcp_rtp_state *state,
+ const uint16_t seq, const int32_t transit,
+ const uint32_t ssrc)
+{
+ uint16_t udelta;
+ int32_t d;
+
+ /* initialize or re-initialize */
+ if (!state->stats_initialized || state->stats_ssrc != ssrc) {
+ state->stats_initialized = 1;
+ state->stats_base_seq = seq;
+ state->stats_max_seq = seq - 1;
+ state->stats_ssrc = ssrc;
+ state->stats_jitter = 0;
+ state->stats_transit = transit;
+ state->stats_cycles = 0;
+ }
+
+ /*
+ * The below takes the shape of the validation of
+ * Appendix A. Check if there is something weird with
+ * the sequence number, otherwise check for a wrap
+ * around in the sequence number.
+ * It can't wrap during the initialization so let's
+ * skip it here. The Appendix A probably doesn't have
+ * this issue because of the probation.
+ */
+ udelta = seq - state->stats_max_seq;
+ if (udelta < RTP_MAX_DROPOUT) {
+ if (seq < state->stats_max_seq)
+ state->stats_cycles += RTP_SEQ_MOD;
+ } else if (udelta <= RTP_SEQ_MOD - RTP_MAX_MISORDER) {
+ LOGP(DMGCP, LOGL_NOTICE,
+ "RTP seqno made a very large jump on 0x%x delta: %u\n",
+ ENDPOINT_NUMBER(endp), udelta);
+ }
+
+ /*
+ * Calculate the jitter between the two packages. The TS should be
+ * taken closer to the read function. This was taken from the
+ * Appendix A of RFC 3550. Timestamp and arrival_time have a 1/rate
+ * resolution.
+ */
+ d = transit - state->stats_transit;
+ state->stats_transit = transit;
+ if (d < 0)
+ d = -d;
+ state->stats_jitter += d - ((state->stats_jitter + 8) >> 4);
+ state->stats_max_seq = seq;
+}
+
+
+
/**
* The RFC 3550 Appendix A assumes there are multiple sources but
* some of the supported endpoints (e.g. the nanoBTS) can only handle
@@ -344,8 +398,8 @@
char *data, int len)
{
uint32_t arrival_time;
- int32_t transit, d;
- uint16_t seq, udelta;
+ int32_t transit;
+ uint16_t seq;
uint32_t timestamp, ssrc;
struct rtp_hdr *rtp_hdr;
int payload = rtp_end->codec.payload_type;
@@ -361,13 +415,10 @@
transit = arrival_time - timestamp;
if (!state->initialized) {
+ state->initialized = 1;
state->in_stream.last_seq = seq - 1;
state->in_stream.ssrc = state->orig_ssrc = ssrc;
state->in_stream.last_tsdelta = 0;
- state->base_seq = seq;
- state->initialized = 1;
- state->jitter = 0;
- state->transit = transit;
state->packet_duration = mgcp_rtp_packet_duration(endp, rtp_end);
state->out_stream = state->in_stream;
state->out_stream.last_timestamp = timestamp;
@@ -398,8 +449,6 @@
endp->conn_mode);
state->in_stream.ssrc = ssrc;
- state->jitter = 0;
- state->transit = transit;
if (rtp_end->force_constant_ssrc) {
int16_t delta_seq;
@@ -470,34 +519,7 @@
addr, seq, timestamp, "output",
&state->out_stream.last_tsdelta);
- /*
- * The below takes the shape of the validation from Appendix A. Check
- * if there is something weird with the sequence number, otherwise check
- * for a wrap around in the sequence number.
- *
- * Note that last_seq is used where the appendix mentions max_seq.
- */
- udelta = seq - state->out_stream.last_seq;
- if (udelta < RTP_MAX_DROPOUT) {
- if (seq < state->out_stream.last_seq)
- state->cycles += RTP_SEQ_MOD;
- } else if (udelta <= RTP_SEQ_MOD - RTP_MAX_MISORDER) {
- LOGP(DMGCP, LOGL_NOTICE,
- "RTP seqno made a very large jump on 0x%x delta: %u\n",
- ENDPOINT_NUMBER(endp), udelta);
- }
-
- /*
- * Calculate the jitter between the two packages. The TS should be
- * taken closer to the read function. This was taken from the
- * Appendix A of RFC 3550. Timestamp and arrival_time have a 1/rate
- * resolution.
- */
- d = transit - state->transit;
- state->transit = transit;
- if (d < 0)
- d = -d;
- state->jitter += d - ((state->jitter + 8) >> 4);
+ mgcp_rtp_annex_count(endp, state, seq, transit, ssrc);
/* Save output values */
state->out_stream.last_seq = seq;
@@ -998,10 +1020,10 @@
struct mgcp_rtp_end *end, uint32_t *expected,
int *loss)
{
- *expected = state->cycles + state->out_stream.last_seq;
- *expected = *expected - state->base_seq + 1;
+ *expected = state->stats_cycles + state->stats_max_seq;
+ *expected = *expected - state->stats_base_seq + 1;
- if (!state->initialized) {
+ if (!state->stats_initialized) {
*expected = 0;
*loss = 0;
return;
@@ -1023,7 +1045,7 @@
uint32_t mgcp_state_calc_jitter(struct mgcp_rtp_state *state)
{
- if (!state->initialized)
+ if (!state->stats_initialized)
return 0;
- return state->jitter >> 4;
+ return state->stats_jitter >> 4;
}