PTS is chasing the server framerate cap when the actual framerate is slightly different

General Discussion
1

I have an rtsp server which is a ip camera. The SDP messages contain:
caps application/x-rtp, .... a-framerate=(string)25, ...

However, the actual frame rate of the camera is 24.98 fps. This slight discrepancy cause the rtspsrc buffer to misbehave slightly.

In buffer-mode=0 and 4, the PTS are spaced exactly 1/25 s apart, which causes the PTS to accumulate errors (~30s over 12 hr).

In buffer-mode=1, the PTS initially try to track 25 fps, until the time error gets too large and then adjust the pts to reduce the error. Unfortunately, it continuously chases the target and the PTS oscillated by a few ms around the correct values but never settles down.

Is there a way to override the advertised cap framerate to the rtspsrc element of the pipeline?

Here’s the pipeline in my python code:

rtspsrc buffer-mode=1 latency=1000 protocols=tcp location="..." ! rtpjitterbuffer latency=1000 mode=1 ! rtph264depay ! h264parse ! avdec_h264 !videoconvert ! appsink ...
2

Framerate in caps is usually not used for timing/scheduling purposes, at best to fill in some default frame duration or so. Are you sure what you’re seeing is related to the framerate in the SDP?

I think the first question would be what are the actual RTP timestamps you get here, and what’s the clock-rate?

3

Thank you for help. I’m not sure what causes the behaviour I observe. Something, somewhere seem to be using the nominal frame rate to space the pts. Looking at the log, I see that the above mentioned SDP message is the first to contain framerate information. But, I don’t know the inner working of GStreamer…

clock-rate=(int)90000

Here’s a extract from the rtpsrc log:


0:00:00.284257808 e[35m15970e[00m      0x9767aa0 e[37mDEBUG  e[00m e[00m             rtspsrc gstrtspsrc.c:7918:gst_rtspsrc_parse_range:<rtspsrc0>e[00m parsed range npt=now-
0:00:00.284284827 e[35m15970e[00m      0x9767aa0 e[37mDEBUG  e[00m e[00m             rtspsrc gstrtspsrc.c:7929:gst_rtspsrc_parse_range:<rtspsrc0>e[00m range: type 1, min 0.000000 - type 2,  max 0.000000 
0:00:00.284306937 e[35m15970e[00m      0x9767aa0 e[37mDEBUG  e[00m e[00m             rtspsrc gstrtspsrc.c:7940:gst_rtspsrc_parse_range:<rtspsrc0>e[00m range: min 0:00:00.000000000
0:00:00.284327233 e[35m15970e[00m      0x9767aa0 e[37mDEBUG  e[00m e[00m             rtspsrc gstrtspsrc.c:7959:gst_rtspsrc_parse_range:<rtspsrc0>e[00m range: max 99:99:99.999999999
0:00:00.284351326 e[35m15970e[00m      0x9767aa0 e[37mDEBUG  e[00m e[00m             rtspsrc gstrtspsrc.c:7983:gst_rtspsrc_parse_range:<rtspsrc0>e[00m not updating existing duration 99:99:99.999999999 from range 99:99:99.999999999
0:00:00.284368900 e[35m15970e[00m      0x9767aa0 e[37mDEBUG  e[00m e[00m             rtspsrc gstrtspsrc.c:5089:gst_rtspsrc_configure_caps:<rtspsrc0>e[00m configuring stream caps
0:00:00.284460176 e[35m15970e[00m      0x9767aa0 e[37mDEBUG  e[00m e[00m             rtspsrc gstrtspsrc.c:5128:gst_rtspsrc_configure_caps:<rtspsrc0>e[00m stream 0x7f30024990, pt 96, caps application/x-rtp, media=(string)video, payload=(int)96, clock-rate=(int)90000, encoding-name=(string)H264, profile-level-id=(string)4d001f, packetization-mode=(string)1, sprop-parameter-sets=(string)"Z00AH5Y1QKALdNwEBAQI\,aO48gA\=\=", a-framerate=(string)25, npt-start=(guint64)0, play-speed=(double)1, play-scale=(double)1, onvif-mode=(boolean)false
0:00:00.284478917 e[35m15970e[00m      0x9767aa0 e[37mDEBUG  e[00m e[00m             rtspsrc gstrtspsrc.c:5139:gst_rtspsrc_configure_caps:<rtspsrc0>e[00m clear session
0:00:00.284819802 e[35m15970e[00m      0x9767aa0 e[37mDEBUG  e[00m e[00m             rtspsrc gstrtspsrc.c:9063:gst_rtspsrc_play:<rtspsrc0>e[00m mark DISCONT, we did a seek to another position
0:00:00.284904727 e[35m15970e[00m      0x9767aa0 e[37mDEBUG  e[00m e[00m             rtspsrc gstrtspsrc.c:9350:gst_rtspsrc_thread:<rtspsrc0>e[00m got command LOOP
0:00:00.284925523 e[35m15970e[00m      0x9767aa0 e[37mDEBUG  e[00m e[00m             rtspsrc gstrtspsrc.c:5435:gst_rtspsrc_connection_flush:<rtspsrc0>e[00m set flushing 0
0:00:00.392813767 e[35m15970e[00m      0x9767aa0 e[37mDEBUG  e[00m e[00m             rtspsrc gstrtspsrc.c:5835:gst_rtspsrc_loop_interleaved:<rtspsrc0>e[00m we received a server message
0:00:00.392859896 e[35m15970e[00m      0x9767aa0 e[37mDEBUG  e[00m e[00m             rtspsrc gstrtspsrc.c:5868:gst_rtspsrc_loop_interleaved:<rtspsrc0>e[00m got data message
0:00:00.392926933 e[35m15970e[00m      0x9767aa0 e[37mDEBUG  e[00m e[00m             rtspsrc gstrtspsrc.c:5634:gst_rtspsrc_handle_data:<rtspsrc0>e[00m pushing data of size 27 on channel 0
0:00:00.393521278 e[35m15970e[00m      0x9767aa0 e[37mDEBUG  e[00m e[00m             rtspsrc gstrtspsrc.c:5032:gst_rtspsrc_activate_streams:<rtspsrc0>e[00m activating streams
0:00:00.393571259 e[35m15970e[00m      0x9767aa0 e[37mDEBUG  e[00m e[00m             rtspsrc gstrtspsrc.c:5731:gst_rtspsrc_handle_data:<rtspsrc0>e[00m first buffer at time 4:06:19.500533118, base 4:06:19.310933759
0:00:00.393689202 e[35m15970e[00m      0x9767aa0 e[37mDEBUG  e[00m e[00m             rtspsrc gstrtspsrc.c:5779:gst_rtspsrc_handle_data:<rtspsrc0>e[00m setting timestamp 0:00:00.189599359
4 
177	46.815860763	192.168.42.51	192.168.42.101	TCP	74	57924 → 554 [SYN] Seq=0 Win=64240 Len=0 MSS=1460 SACK_PERM TSval=3647369797 TSecr=0 WS=128
178	46.816362775	192.168.42.101	192.168.42.51	TCP	74	554 → 57924 [SYN, ACK] Seq=0 Ack=1 Win=28960 Len=0 MSS=1460 SACK_PERM TSval=128402 TSecr=3647369797 WS=8
179	46.816423052	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1 Ack=1 Win=64256 Len=0 TSval=3647369797 TSecr=128402
180	46.817379319	192.168.42.51	192.168.42.101	RTSP	557	OPTIONS rtsp://192.168.42.101:554/user=admin&password=&channel=1&stream=0.sdp/ RTSP/1.1
181	46.819316426	192.168.42.101	192.168.42.51	TCP	66	554 → 57924 [ACK] Seq=1 Ack=492 Win=30032 Len=0 TSval=128403 TSecr=3647369798
182	46.824709956	192.168.42.101	192.168.42.51	RTSP	202	Reply: RTSP/1.0 200 OK
183	46.824780437	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=492 Ack=137 Win=64128 Len=0 TSval=3647369805 TSecr=128403
184	46.826315789	192.168.42.51	192.168.42.101	RTSP	259	DESCRIBE rtsp://192.168.42.101:554/user=admin&password=&channel=1&stream=0.sdp/ RTSP/1.1
185	46.843615700	192.168.42.101	192.168.42.51	RTSP/SDP	704	Reply: RTSP/1.0 200 OK
186	46.846620406	192.168.42.51	192.168.42.101	RTSP	288	SETUP rtsp://192.168.42.101:554/user=admin&password=&channel=1&stream=0.sdp/trackID=3 RTSP/1.1
187	46.855110215	192.168.42.101	192.168.42.51	RTSP	245	Reply: RTSP/1.0 200 OK
188	46.864635234	192.168.42.51	192.168.42.101	RTSP	263	PLAY rtsp://192.168.42.101:554/user=admin&password=&channel=1&stream=0.sdp/ RTSP/1.1
189	46.875944547	192.168.42.101	192.168.42.51	RTSP	150	Reply: RTSP/1.0 200 OK
190	46.919800908	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=1038 Win=64128 Len=0 TSval=3647369901 TSecr=128408
191	46.979370662	192.168.42.101	192.168.42.51	RTP	97	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=0, Time=2080800
192	46.979443883	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=1069 Win=64128 Len=0 TSval=3647369960 TSecr=128419
193	46.979518345	192.168.42.101	192.168.42.51	RTP	86	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=1, Time=2080800
194	46.979538585	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=1089 Win=64128 Len=0 TSval=3647369960 TSecr=128419
195	46.979747213	192.168.42.101	192.168.42.51	RTP	87	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=2, Time=2080800
196	46.979790397	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=1110 Win=64128 Len=0 TSval=3647369960 TSecr=128419
197	46.981388434	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=3, Time=2080800
198	46.981445100	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=2522 Win=64128 Len=0 TSval=3647369962 TSecr=128419
199	46.981484896	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=4, Time=2080800
200	46.981496489	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=3934 Win=62976 Len=0 TSval=3647369962 TSecr=128419
201	46.981607876	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=5, Time=2080800
202	46.981623358	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=5346 Win=61696 Len=0 TSval=3647369962 TSecr=128419
203	46.981727486	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=6, Time=2080800
204	46.981750652	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=6758 Win=60416 Len=0 TSval=3647369962 TSecr=128419
205	46.981847448	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=7, Time=2080800
206	46.981863929	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=8170 Win=59264 Len=0 TSval=3647369963 TSecr=128419
207	46.982115185	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=8, Time=2080800
208	46.982140129	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=9582 Win=57984 Len=0 TSval=3647369963 TSecr=128419
209	46.982291535	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=9, Time=2080800
210	46.982312498	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=10994 Win=56704 Len=0 TSval=3647369963 TSecr=128419
211	46.982403423	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=10, Time=2080800
212	46.982417182	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=12406 Win=55424 Len=0 TSval=3647369963 TSecr=128419
213	46.982559847	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=11, Time=2080800
214	46.982579569	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=13818 Win=54272 Len=0 TSval=3647369963 TSecr=128419
215	46.982722493	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=12, Time=2080800
216	46.982884324	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=13, Time=2080800
217	46.983048045	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=14, Time=2080800
218	46.983168654	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=15, Time=2080800
219	46.983287875	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=16, Time=2080800
220	46.983416318	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=17, Time=2080800
221	46.983526780	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=18, Time=2080800
222	46.983740963	192.168.42.101	192.168.42.51	RTP	1514	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=19, Time=2080800, 
223	46.983858202	192.168.42.101	192.168.42.51	RTP	1514	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=20, Time=2080800
224	46.983980052	192.168.42.101	192.168.42.51	RTP	1514	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=21, Time=2080800
225	46.985211057	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=28046 Win=41600 Len=0 TSval=3647369966 TSecr=128419
226	46.986089398	192.168.42.101	192.168.42.51	RTP	1514	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=22, Time=2080800
227	46.986195490	192.168.42.101	192.168.42.51	RTP	1514	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=23, Time=2080800
228	46.986287007	192.168.42.101	192.168.42.51	RTP	1132	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=24, Time=2080800, Mark
229	46.986508745	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=32008 Win=37888 Len=0 TSval=3647369967 TSecr=128419
230	46.999474780	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=25, Time=2084400
231	46.999558483	192.168.42.101	192.168.42.51	RTP	958	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=26, Time=2084400, Mark
232	46.999595390	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=34312 Win=62976 Len=0 TSval=3647369980 TSecr=128421
233	47.061763891	192.168.42.101	192.168.42.51	RTP	1446	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=27, Time=2088000, Mark
234	47.061830816	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=35692 Win=67072 Len=0 TSval=3647370043 TSecr=128427
235	47.099575619	192.168.42.101	192.168.42.51	RTP	1365	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=28, Time=2091600, Mark
236	47.099653673	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=36991 Win=69888 Len=0 TSval=3647370080 TSecr=128431
237	47.139400231	192.168.42.101	192.168.42.51	RTP	1299	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=29, Time=2095200, Mark
238	47.139472119	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=38224 Win=72832 Len=0 TSval=3647370120 TSecr=128435
239	47.179800262	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=30, Time=2098800
240	47.179865946	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=39636 Win=75776 Len=0 TSval=3647370161 TSecr=128439
241	47.179893890	192.168.42.101	192.168.42.51	RTP	260	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=31, Time=2098800, Mark
242	47.179907686	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=39830 Win=78592 Len=0 TSval=3647370161 TSecr=128439
243	47.198770393	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=32, Time=2102400
244	47.198803412	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=41242 Win=81536 Len=0 TSval=3647370180 TSecr=128441
245	47.198822819	192.168.42.101	192.168.42.51	RTP	206	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=33, Time=2102400, Mark
246	47.198834837	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=41382 Win=84480 Len=0 TSval=3647370180 TSecr=128441
247	47.259379190	192.168.42.101	192.168.42.51	RTP	1248	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=34, Time=2106000, Mark
248	47.259427745	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=42564 Win=87296 Len=0 TSval=3647370240 TSecr=128447
249	47.299445762	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=35, Time=2109600
250	47.299504039	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=43976 Win=90240 Len=0 TSval=3647370280 TSecr=128451
251	47.299528409	192.168.42.101	192.168.42.51	RTP	478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=36, Time=2109600, Mark
252	47.299541428	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=44388 Win=93056 Len=0 TSval=3647370280 TSecr=128451
253	47.340331788	192.168.42.101	192.168.42.51	RTP	1242	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=37, Time=2113200, Mark
254	47.340369324	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=45564 Win=96000 Len=0 TSval=3647370321 TSecr=128455
255	47.379279743	192.168.42.101	192.168.42.51	RTP	1132	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=38, Time=2116800, Mark
256	47.379320243	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=46630 Win=98944 Len=0 TSval=3647370360 TSecr=128459
257	47.398891608	192.168.42.101	192.168.42.51	RTP	1395	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=39, Time=2120400, Mark
258	47.398926145	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=47959 Win=101760 Len=0 TSval=3647370380 TSecr=128461
259	47.459601515	192.168.42.101	192.168.42.51	RTP	1261	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=40, Time=2124000, Mark
260	47.459661588	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=49154 Win=104704 Len=0 TSval=3647370440 TSecr=128467
261	47.501423919	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=41, Time=2127600
262	47.501502344	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=50566 Win=107648 Len=0 TSval=3647370482 TSecr=128471
263	47.501787748	192.168.42.101	192.168.42.51	RTP	409	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=42, Time=2127600, Mark
264	47.501821544	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=50909 Win=110464 Len=0 TSval=3647370483 TSecr=128471
265	47.539535032	192.168.42.101	192.168.42.51	RTP	1261	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=43, Time=2131200, Mark
266	47.539614809	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=52104 Win=113408 Len=0 TSval=3647370520 TSecr=128475
267	47.579546142	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=44, Time=2134800
268	47.579629289	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=53516 Win=116224 Len=0 TSval=3647370560 TSecr=128479
269	47.579657289	192.168.42.101	192.168.42.51	RTP	185	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=45, Time=2134800, Mark
270	47.580132746	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=53635 Win=116224 Len=0 TSval=3647370561 TSecr=128479
271	47.600016738	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=46, Time=2138400
272	47.600042756	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=55047 Win=119168 Len=0 TSval=3647370581 TSecr=128481
273	47.600062089	192.168.42.101	192.168.42.51	RTP	178	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=47, Time=2138400, Mark
274	47.600307382	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=55159 Win=119168 Len=0 TSval=3647370581 TSecr=128481
275	47.659420196	192.168.42.101	192.168.42.51	RTP	1074	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=48, Time=2142000, Mark
276	47.659470640	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=56167 Win=122112 Len=0 TSval=3647370640 TSecr=128487
277	47.699576175	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=49, Time=2145600
278	47.699622378	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=57579 Win=124928 Len=0 TSval=3647370680 TSecr=128491
279	47.699645563	192.168.42.101	192.168.42.51	RTP	140	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=50, Time=2145600, Mark
280	47.700092428	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=57653 Win=124928 Len=0 TSval=3647370681 TSecr=128491
281	47.739399342	192.168.42.101	192.168.42.51	RTP	1197	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=51, Time=2149200, Mark
282	47.739478730	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=58784 Win=127872 Len=0 TSval=3647370720 TSecr=128495
283	47.779299879	192.168.42.101	192.168.42.51	RTP	1124	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=52, Time=2152800, Mark
284	47.779364860	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=59842 Win=130816 Len=0 TSval=3647370760 TSecr=128499
285	47.798710932	192.168.42.101	192.168.42.51	RTP	1333	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=53, Time=2156400, Mark
286	47.798742395	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=61109 Win=133632 Len=0 TSval=3647370779 TSecr=128501
287	47.860136182	192.168.42.101	192.168.42.51	RTP	1070	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=54, Time=2160000, Mark
288	47.860176034	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=62113 Win=136576 Len=0 TSval=3647370841 TSecr=128507
289	47.899554780	192.168.42.101	192.168.42.51	RTP	1210	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=55, Time=2163600, Mark
290	47.899622298	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=63257 Win=139392 Len=0 TSval=3647370880 TSecr=128511
291	47.942123323	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=56, Time=2167200
292	47.942164453	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=64669 Win=142336 Len=0 TSval=3647370923 TSecr=128515
293	47.942186582	192.168.42.101	192.168.42.51	RTP	123	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=57, Time=2167200, Mark
294	47.942481653	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=64726 Win=142336 Len=0 TSval=3647370923 TSecr=128515
295	47.979115894	192.168.42.101	192.168.42.51	RTP	97	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=58, Time=2170800
296	47.979188356	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=64757 Win=142336 Len=0 TSval=3647370960 TSecr=128519
297	47.979277114	192.168.42.101	192.168.42.51	RTP	86	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=59, Time=2170800
298	47.979499853	192.168.42.101	192.168.42.51	RTP	87	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=60, Time=2170800
299	47.979713572	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=64798 Win=142336 Len=0 TSval=3647370960 TSecr=128519
300	47.981057390	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=61, Time=2170800
301	47.981102815	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=66210 Win=145280 Len=0 TSval=3647370962 TSecr=128519
302	47.981168722	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=62, Time=2170800
303	47.981186944	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=67622 Win=148096 Len=0 TSval=3647370962 TSecr=128519
304	47.981287850	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=63, Time=2170800
305	47.981300684	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=69034 Win=151040 Len=0 TSval=3647370962 TSecr=128519
306	47.981510292	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=64, Time=2170800
307	47.981527922	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=70446 Win=153984 Len=0 TSval=3647370962 TSecr=128519
308	47.981753271	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=65, Time=2170800
309	47.981775567	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=71858 Win=156800 Len=0 TSval=3647370962 TSecr=128519
310	47.981929195	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=66, Time=2170800
311	47.981947972	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=73270 Win=159744 Len=0 TSval=3647370963 TSecr=128519
312	47.982049101	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=67, Time=2170800
313	47.982065786	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=74682 Win=162560 Len=0 TSval=3647370963 TSecr=128519
314	47.982168525	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=68, Time=2170800
315	47.982185025	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=76094 Win=165504 Len=0 TSval=3647370963 TSecr=128519
316	47.982370671	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=69, Time=2170800
317	47.982393856	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=77506 Win=168448 Len=0 TSval=3647370963 TSecr=128519
318	47.982566206	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=70, Time=2170800
319	47.982589483	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=78918 Win=171264 Len=0 TSval=3647370963 TSecr=128519
320	47.982684927	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=71, Time=2170800
321	47.982703390	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=80330 Win=174208 Len=0 TSval=3647370963 TSecr=128519
322	47.982836481	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=72, Time=2170800
323	47.982854517	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=81742 Win=177152 Len=0 TSval=3647370964 TSecr=128519
324	47.982998145	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=73, Time=2170800
325	47.983017978	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=83154 Win=179968 Len=0 TSval=3647370964 TSecr=128519
326	47.983234309	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=74, Time=2170800
327	47.983255846	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=84566 Win=182912 Len=0 TSval=3647370964 TSecr=128519
328	47.983388585	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=75, Time=2170800
329	47.983401752	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=85978 Win=185728 Len=0 TSval=3647370964 TSecr=128519
330	47.983511343	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=76, Time=2170800
331	47.983527028	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=87390 Win=188672 Len=0 TSval=3647370964 TSecr=128519
332	47.983670082	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=77, Time=2170800
333	47.983685267	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=88802 Win=191616 Len=0 TSval=3647370964 TSecr=128519
334	47.983833913	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=78, Time=2170800
335	47.983849450	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=90214 Win=194432 Len=0 TSval=3647370965 TSecr=128519
336	47.983997337	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=79, Time=2170800
337	47.984010893	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=91626 Win=197376 Len=0 TSval=3647370965 TSecr=128519
338	47.984199668	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=80, Time=2170800
339	47.984217113	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=93038 Win=200320 Len=0 TSval=3647370965 TSecr=128519
340	47.984319593	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=81, Time=2170800
341	47.984335296	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=94450 Win=203136 Len=0 TSval=3647370965 TSecr=128519
342	47.984411185	192.168.42.101	192.168.42.51	RTP	1122	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=82, Time=2170800, Mark
343	47.984424536	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=95506 Win=205952 Len=0 TSval=3647370965 TSecr=128519
344	47.998977756	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=83, Time=2174400
345	47.999048996	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=96918 Win=208896 Len=0 TSval=3647370980 TSecr=128521
346	47.999082514	192.168.42.101	192.168.42.51	RTP	724	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=84, Time=2174400, Mark
347	47.999099051	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=97576 Win=211712 Len=0 TSval=3647370980 TSecr=128521
348	48.059675015	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=85, Time=2178000
349	48.059676626	192.168.42.101	192.168.42.51	RTP	280	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=86, Time=2178000, Mark
350	48.059835772	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=98988 Win=214656 Len=0 TSval=3647371040 TSecr=128527
351	48.059859198	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=99202 Win=217472 Len=0 TSval=3647371041 TSecr=128527
352	48.099518571	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=87, Time=2181600
353	48.099520145	192.168.42.101	192.168.42.51	RTP	188	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=88, Time=2181600, Mark
354	48.099793105	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=100614 Win=220288 Len=0 TSval=3647371080 TSecr=128531
355	48.100418412	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=100736 Win=220288 Len=0 TSval=3647371081 TSecr=128531
356	48.139435015	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=89, Time=2185200
357	48.139435663	192.168.42.101	192.168.42.51	RTP	129	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=90, Time=2185200, Mark
358	48.139557662	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=102148 Win=223232 Len=0 TSval=3647371120 TSecr=128535
359	48.140193192	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=102211 Win=223232 Len=0 TSval=3647371121 TSecr=128535
360	48.179512439	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=91, Time=2188800
361	48.179513069	192.168.42.101	192.168.42.51	RTP	199	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=92, Time=2188800, Mark
362	48.179630512	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=103623 Win=226048 Len=0 TSval=3647371160 TSecr=128539
363	48.180270486	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=103756 Win=226048 Len=0 TSval=3647371161 TSecr=128539
364	48.198766253	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=93, Time=2192400
365	48.198767290	192.168.42.101	192.168.42.51	RTP	116	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=94, Time=2192400, Mark
366	48.198941899	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=105168 Win=228992 Len=0 TSval=3647371180 TSecr=128541
367	48.199691927	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=105218 Win=228992 Len=0 TSval=3647371180 TSecr=128541
368	48.260124022	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=95, Time=2196000
369	48.260236391	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=106630 Win=231936 Len=0 TSval=3647371241 TSecr=128547
370	48.260295983	192.168.42.101	192.168.42.51	RTP	266	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=96, Time=2196000, Mark
371	48.260313946	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=106830 Win=234752 Len=0 TSval=3647371241 TSecr=128547
372	48.299729803	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=97, Time=2199600
373	48.299822599	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=108242 Win=237568 Len=0 TSval=3647371280 TSecr=128551
374	48.299876080	192.168.42.101	192.168.42.51	RTP	311	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=98, Time=2199600, Mark
375	48.299893190	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=108487 Win=240384 Len=0 TSval=3647371281 TSecr=128551
376	48.339468379	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=99, Time=2203200
377	48.339469509	192.168.42.101	192.168.42.51	RTP	91	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=100, Time=2203200, Mark
378	48.339559786	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=109899 Win=243328 Len=0 TSval=3647371320 TSecr=128555
379	48.340076039	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=109924 Win=243328 Len=0 TSval=3647371321 TSecr=128555
380	48.382046922	192.168.42.101	192.168.42.51	RTP	1278	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=101, Time=2206800, Mark
381	48.382134958	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=111136 Win=246144 Len=0 TSval=3647371363 TSecr=128559
382	48.398691470	192.168.42.101	192.168.42.51	RTP	1179	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=102, Time=2210400, Mark
383	48.398786876	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1104 Ack=112249 Win=248960 Len=0 TSval=3647371379 TSecr=128561
384	48.435830669	192.168.42.51	192.168.42.101	RTCP	154	Receiver Report   Source description   
385	48.459418950	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=103, Time=2214000
386	48.459536356	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1192 Ack=113661 Win=251904 Len=0 TSval=3647371440 TSecr=128567
387	48.459582689	192.168.42.101	192.168.42.51	RTP	539	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=104, Time=2214000, Mark
388	48.459602059	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1192 Ack=114134 Win=254720 Len=0 TSval=3647371440 TSecr=128567
389	48.504471854	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=105, Time=2217600
390	48.504550445	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1192 Ack=115546 Win=257664 Len=0 TSval=3647371485 TSecr=128571
391	48.504580538	192.168.42.101	192.168.42.51	RTP	145	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=106, Time=2217600, Mark
392	48.505054625	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1192 Ack=115625 Win=257664 Len=0 TSval=3647371486 TSecr=128571
393	48.539672982	192.168.42.101	192.168.42.51	RTP	1389	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=107, Time=2221200, Mark
394	48.539754463	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1192 Ack=116948 Win=260480 Len=0 TSval=3647371520 TSecr=128575
395	48.579251782	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=108, Time=2224800
396	48.579252523	192.168.42.101	192.168.42.51	RTP	116	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=109, Time=2224800, Mark
397	48.579333411	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1192 Ack=118360 Win=263296 Len=0 TSval=3647371560 TSecr=128579
398	48.579957237	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1192 Ack=118410 Win=263296 Len=0 TSval=3647371561 TSecr=128579
399	48.600837458	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=110, Time=2228400
400	48.600920420	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1192 Ack=119822 Win=266240 Len=0 TSval=3647371582 TSecr=128581
401	48.600969030	192.168.42.101	192.168.42.51	RTP	675	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=111, Time=2228400, Mark
402	48.600988382	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1192 Ack=120431 Win=269056 Len=0 TSval=3647371582 TSecr=128581
403	48.659865958	192.168.42.101	192.168.42.51	RTP	1478	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=112, Time=2232000
404	48.659936439	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1192 Ack=121843 Win=272000 Len=0 TSval=3647371641 TSecr=128587
405	48.659975160	192.168.42.101	192.168.42.51	RTP	618	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=113, Time=2232000, Mark
406	48.659992086	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1192 Ack=122395 Win=274816 Len=0 TSval=3647371641 TSecr=128587
407	48.699420906	192.168.42.101	192.168.42.51	RTP	1436	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=114, Time=2235600, Mark
408	48.699493961	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1192 Ack=123765 Win=277632 Len=0 TSval=3647371680 TSecr=128591
409	48.739399146	192.168.42.101	192.168.42.51	RTP	1264	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=115, Time=2239200, Mark
410	48.739469590	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1192 Ack=124963 Win=280448 Len=0 TSval=3647371720 TSecr=128595
411	48.779759696	192.168.42.101	192.168.42.51	RTP	1135	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=116, Time=2242800, Mark
412	48.779835010	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1192 Ack=126032 Win=283264 Len=0 TSval=3647371761 TSecr=128599
413	48.798733198	192.168.42.101	192.168.42.51	RTP	1181	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=117, Time=2246400, Mark
414	48.798811660	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1192 Ack=127147 Win=285184 Len=0 TSval=3647371779 TSecr=128601
415	48.859827267	192.168.42.101	192.168.42.51	RTP	1168	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=118, Time=2250000, Mark
416	48.859982247	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1192 Ack=128249 Win=285184 Len=0 TSval=3647371841 TSecr=128607
417	48.900389926	192.168.42.101	192.168.42.51	RTP	1251	PT=DynamicRTP-Type-96, SSRC=0x0, Seq=119, Time=2253600, Mark
418	48.900676830	192.168.42.51	192.168.42.101	TCP	66	57924 → 554 [ACK] Seq=1192 Ack=129434 Win=285184 Len=0 TSval=3647371881 TSecr=128611
5 
|RTP|PT=DynamicRTP-Type-96, SSRC=0x0, Seq=24, Time=2080800, Mark|
|RTP|PT=DynamicRTP-Type-96, SSRC=0x0, Seq=25, Time=2084400          |
|RTP|PT=DynamicRTP-Type-96, SSRC=0x0, Seq=26, Time=2084400, Mark|

2084400 - 2080800 = 3600 (RTP timestamp diff between two frames)

3600 / 90000 (clock rate) = 0.04 = 40ms = 25fps

So looks like it’s the camera that timestamps packets like that? (I didn’t check any other timestamps of course)

6

Yes, you’re right. Darn.

Is that typical, or is the camera misconfigured somehow? It does actually produce ~24.98 fps, which is a weird number.
I’m not sure if it’s a coincidence but 29.976 * 5/6 = 24.98.

We have hundreds of these cheap IP cameras across the world doing meteor observations, and I’m really struggling to get accurate millisecond accuracy out of them. What can we do to bring the timestamps in line with reality?

7

And, yes, all the RTP timestamps are 3600 apart.