[Live-devel] RE: Windows Media Player compatibility

Fri Apr 16 12:48:43 PDT 2004

Hi Ross,

You can access my web page to download the MMRTPClient.zip. I forgot where I
got it but it works on Windows OS.
	http://www.cool.giti.waseda.ac.jp/~dixonsiu/RTP/
The following is the RR packets generated by WMP and QuickTime Player. You
can take a look. Perhaps you can find something useful. I am totally lost
with NTP and RTP conversion. :P

// BEGINNING of messages I got using WMP
Play this stream using the URL "rtsp://192.168.0.243/testStream"
Beginning streaming...
Beginning to read from file...
RTCP RR data (received at 1082082536.855000): lossStats 0xff000000,
lastPacketNu
mReceived 0x0000a943, jitter 0x00000d53, lastSRTime 0xc36836c8,
diffSR_RRTime 0x
0000a419
=> round-trip delay: 0x0000 (== 0.000000 seconds)
RTCP RR data (received at 1082082537.326000): lossStats 0xfe00000b,
lastPacketNu
mReceived 0x0000fe42, jitter 0x000000c8, lastSRTime 0xc368c666,
diffSR_RRTime 0x
00008d0e
=> round-trip delay: 0x0001 (== 0.000015 seconds)
RTCP RR data (received at 1082082540.300000): lossStats 0x0000000b,
lastPacketNu
mReceived 0x0000fff3, jitter 0x0000015a, lastSRTime 0xc368c666,
diffSR_RRTime 0x
000386a8
=> round-trip delay: 0xffffffbf (== 65535.999008 seconds)
RTCP RR data (received at 1082082541.692000): lossStats 0x00000000,
lastPacketNu
mReceived 0x0000a9a7, jitter 0x00000b90, lastSRTime 0xc36bc24d,
diffSR_RRTime 0x
0001eed9
=> round-trip delay: 0x0001 (== 0.000015 seconds)
RTCP RR data (received at 1082082546.199000): lossStats 0x0000000b,
lastPacketNu
mReceived 0x00010436, jitter 0x00000472, lastSRTime 0xc371a0c4,
diffSR_RRTime 0x
0000922d
=> round-trip delay: 0x0001 (== 0.000015 seconds)
RTCP RR data (received at 1082082547.210000): lossStats 0x00000000,
lastPacketNu
mReceived 0x0000aa1b, jitter 0x00000b98, lastSRTime 0xc36f5062,
diffSR_RRTime 0x
0003e51f
=> round-trip delay: 0x0042 (== 0.001007 seconds)
RTCP RR data (received at 1082082550.204000): lossStats 0x0000000b,
lastPacketNu
mReceived 0x00010693, jitter 0x000003b3, lastSRTime 0xc371a0c4,
diffSR_RRTime 0x
000493b6
=> round-trip delay: 0xffffffbf (== 65535.999008 seconds)
RTCP RR data (received at 1082082552.788000): lossStats 0x00000000,
lastPacketNu
mReceived 0x0000aa8f, jitter 0x00000c28, lastSRTime 0xc3755020,
diffSR_RRTime 0x
0003799a
=> round-trip delay: 0x0000 (== 0.000000 seconds)
RTCP RR data (received at 1082082553.519000): lossStats 0x00000000,
lastPacketNu
mReceived 0x0000aa9f, jitter 0x00000c0f, lastSRTime 0xc3755020,
diffSR_RRTime 0x
000434bc
=> round-trip delay: 0x0001 (== 0.000015 seconds)
RTCP RR data (received at 1082082553.549000): lossStats 0x0000000b,
lastPacketNu
mReceived 0x0001088b, jitter 0x00000301, lastSRTime 0xc37722d0,
diffSR_RRTime 0x
0002624e
=> round-trip delay: 0x076d (== 0.029007 seconds)
RTCP RR data (received at 1082082554.360000): lossStats 0x00000000,
lastPacketNu
mReceived 0x0000aab0, jitter 0x000007a2, lastSRTime 0x00000000,
diffSR_RRTime 0x
00000000
=> round-trip delay: 0x0000 (== 0.000000 seconds)
RTCP RR data (received at 1082082554.380000): lossStats 0x00000000,
lastPacketNu
mReceived 0x00000904, jitter 0x00000000, lastSRTime 0x00000000,
diffSR_RRTime 0x
00000000
=> round-trip delay: 0x0000 (== 0.000000 seconds)
// END of messages I got using WMP

If you verify the messages, the 3rd and the 7th RTTs are 65535.999008
seconds. The message is generated by viewing the stream with WMP.

If I use QuickTime Player, I also receive the wrong RTTs but with different
values.

// BEGINNING of messages I got using QuickTime
Play this stream using the URL "rtsp://192.168.0.243/testStream"
Beginning streaming...
Beginning to read from file...
RTCP RR data (received at 1082082981.985000): lossStats 0x06000001,
lastPacketNu
mReceived 0x00004a34, jitter 0x00000000, lastSRTime 0x00000000,
diffSR_RRTime 0x
43bb1361
=> round-trip delay: 0x0000 (== 0.000000 seconds)
RTCP RR data (received at 1082082982.426000): lossStats 0x00000001,
lastPacketNu
mReceived 0x000003f0, jitter 0x00000000, lastSRTime 0x00000000,
diffSR_RRTime 0x
43bb82ff
=> round-trip delay: 0x0000 (== 0.000000 seconds)
RTCP RR data (received at 1082082987.063000): lossStats 0x00000001,
lastPacketNu
mReceived 0x00004a9b, jitter 0x00000000, lastSRTime 0xc5272083,
diffSR_RRTime 0x
43c02611
=> round-trip delay: 0xbc43c98d (== 48195.787308 seconds)
RTCP RR data (received at 1082082987.453000): lossStats 0x00000001,
lastPacketNu
mReceived 0x000006c8, jitter 0x00000000, lastSRTime 0xc5276312,
diffSR_RRTime 0x
43c08b71
=> round-trip delay: 0xbc438575 (== 48195.521317 seconds)
RTCP RR data (received at 1082082992.100000): lossStats 0x00000001,
lastPacketNu
mReceived 0x00004b06, jitter 0x00000000, lastSRTime 0xc52f7d2f,
diffSR_RRTime 0x
43ba03de
=> round-trip delay: 0xbc46988d (== 48198.595901 seconds)
RTCP RR data (received at 1082082992.460000): lossStats 0x00000001,
lastPacketNu
mReceived 0x00000a5f, jitter 0x00000000, lastSRTime 0xc53028f5,
diffSR_RRTime 0x
43b97193
=> round-trip delay: 0xbc46db3b (== 48198.856369 seconds)
RTCP RR data (received at 1082082997.127000): lossStats 0x00000001,
lastPacketNu
mReceived 0x00004b6f, jitter 0x00000000, lastSRTime 0xc53367ae,
diffSR_RRTime 0x
43b9ad21
=> round-trip delay: 0xbc480bb4 (== 48200.045715 seconds)
RTCP RR data (received at 1082082997.498000): lossStats 0x00000001,
lastPacketNu
mReceived 0x00000e30, jitter 0x00000000, lastSRTime 0xc5352083,
diffSR_RRTime 0x
43b7ad88
=> round-trip delay: 0xbc48b172 (== 48200.693146 seconds)
RTCP RR data (received at 1082083002.745000): lossStats 0x00000001,
lastPacketNu
mReceived 0x000010ca, jitter 0x00000000, lastSRTime 0xc537ca7e,
diffSR_RRTime 0x
43ba40c8
=> round-trip delay: 0xbc48b372 (== 48200.700958 seconds)
RTCP RR data (received at 1082083002.765000): lossStats 0x00000001,
lastPacketNu
mReceived 0x00004bc8, jitter 0x00000000, lastSRTime 0xc5384fdf,
diffSR_RRTime 0x
43b98880
=> round-trip delay: 0xbc48eb78 (== 48200.919800 seconds)
// END of messages I got using QuickTime

This afternoon, I will try to use VLC to see if the RTT is still not
correctly calculated. I suspected the MMRTPClient maybe using different
implementation so that if affects the RTT calculation.

Anyway, thank you very much for your promptly replies. I just started
reading RTP document 2 weeks ago. So I am new to this technology.

Dixon

Date: Thu, 15 Apr 2004 06:20:55 -0700
From: Ross Finlayson <finlayson at live.com>
Subject: Re: [Live-devel] Windows Media Player compatibility
To: "LIVE.COM Streaming Media - development & use"
	<live-devel at ns.live.com>
Message-ID: <6.0.1.1.1.20040415061544.023c9120 at localhost>
Content-Type: text/plain; charset="us-ascii"; format=flowed

>I used Windows Media Player Series 9 (WMP) series at the receiver ends. And
>the test program is testMPEG1or2AudioVideoStreamer. However, WMP didn't
work
>at the beginning. I have to install a MMRTPClient so that somehow WMP will
>start to speak correct RTP/RTCP.

What is a "MMRTPClient"?  I'm really curious as to how people are able to
access RTSP/RTP streams using Windows Medis Player.

>The RTT problem I got, I have closely verified it. Actually the big number
I
>got is 0xfffffd72. I think somehow the RTT becomes a negative number. Not
>sure if it is the WMP problem or not. But I did have the same problem with
>Quick Time (Version 6.5).

It would be nice to know exactly why this is happening - i.e., what are the
values in the incoming RR packet that are causing "roundTripDelay()" to
return this negative number (perhaps there's a bug in the LIVE.COM code
here??).

	Ross Finlayson
	LIVE.COM
	<http://www.live.com/>

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