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Wireshark-users: Re: [Wireshark-users] MPEG2TS over UPD not decoded

From: "Jake Peavy" <djstunks@xxxxxxxxx>
Date: Thu, 29 Nov 2007 18:07:29 -0700
Thanks Jaap,

So why isn't the MPEG dissector in the list when I choose "Decode As.." for a UDP encapsulated stream?  That was the OP's question I believe.

-jp


On Nov 29, 2007 3:11 PM, Jaap Keuter <jaap.keuter@xxxxxxxxx> wrote:
Hi,

No, the intelligence isn't put into the RTP dissector, it's the other
way around. The MPEG2TS dissectors registers itself with the RTP
dissector, for payload type 33 (PT_MP2T, RFC 2250). If the RTP dissector
gets such a payload it's passed to the MPEG2TS dissector.

What could be done is adding a preference to the MPEG2TS dissector to
set a UDP port number to register on, so that ETH/IP/UDP/MPEG2TS is
possible.

Thanx,
Jaap

Jake Peavy wrote:
> Yes, I also noticed this.  With an RTP encapsulated video stream, the
> PIDs are decoded.  With a UDP encapsulated video stream, no decocde is
> possible.
>
> Does this mean this intelligence was built into the RTP module?  That
> seems to go against the whole point of encapsulation.  It would be far
> better to have a separate MPEGTS dissector - to apply against any type
> of stream.
>
> -jp
>
>
> On Nov 29, 2007 11:06 AM, maurizio simoni <mau2000.sim@xxxxxxxxx
> <mailto: mau2000.sim@xxxxxxxxx>> wrote:
>
>     HI,
>
>     MPEG2 Transport Streams packets are not decoded if they are
>     transported directly over UDP (i.e. if RTP is not present).
>     Moreover MPEG2TS is not present in the list of protocols in "Decode
>     As" list, so there is no way to decode MPEG2TS over UDP neither
>     automatically ( i.e. by automatically detect that the UDP payload is
>     MPEG2TS) nor manually (that means to add MPEG2TS to "Decode As" list)
>
>     Mau.
>     _______________________________________________
>     Wireshark-users mailing list
>     Wireshark-users@xxxxxxxxxxxxx <mailto:Wireshark-users@xxxxxxxxxxxxx>
>     http://www.wireshark.org/mailman/listinfo/wireshark-users
>
>
>
>
> --
> -jp
>
>

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--
-jp


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