[FFmpeg-devel] Realmedia patch

Luca Abeni lucabe72
Wed Sep 10 13:42:14 CEST 2008


Hi Ronald,

Ronald S. Bultje wrote:
>> Are you sure
>> that in youy last example the server was sending you RTP
>> packets, and not RDT (just double-checking)?
>> If yes, a real server is not even compliant with documents
>> from real.com...
> 
> Very positive. Byte[4] (i.e. byte 5), after $, stream-nr and size of
> the TCP stream is 0x80 for RTP (version 1 << 6, no padding).

I just tried
ffmpeg -i rtsp://streamr.hitpops.jp/ngc/mov/m0609.mov
(the server resolves to 218.45.142.19) and after the first RTSP
packets needed for setting up the stream I got a TCP packet whit
payload
0x24 0x00 0x04 0x6a    0x84 0xff 0x08 ...
the first byte is '$', then I have the channel id (0), then the
packet len (1130), and then the transport protocol packet. Which
starts with 0x84 (wireshark says this is an RDT "latency report"
packet After 9 bytes, it sees an RDT "data" packet, starting with
0x40). This could be an RTP packet...

But the next packet is
0x24 0x00 0x04 0xbf    0x40 0x00 0x01 ...
Here, the first byte in the transport protocol packet is 0x40,
which cannot be an RTP packet... So, this traffic does not look
like RTP.


				Luca




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