[vlc] Re: vlc stop when playing H.264 RTP stream

[jogging song]

I have saved the RTP payloads in file and vlc can play the file without
problem. So the RTP payloads is ok.
But when payloads are sent to vlc in RTP packets, vlc fails to play the
stream.
Now the stream consists of one I frame and 299 P frames. We find that if I
frame is repeated in the stream, vlc encounters the second
I frame and will play normally.

First, i think the sps and pps in the sdp file is different from the sps and
pps in rtp packet streams. vlc receives the sps and pps again and think the
new ones are used to update the old ones. But I review the sps and pps in
sdp file and am sure they are  correct.

And I have downloaded the vlc source code from the websites and find vlc is
very complex to understand and it is difficult to find the process for RTP
packet operations.

Thanks
jogging

On 3/9/07, Chris Dobbs <chris_dobbs at dobbscr.karoo.co.uk> wrote:
>
>  Can u verify without using VLC that your H264 frames are ok? i.e play it
> from file or something. VLC will play h264 from file so maby try that first.
>
> Your SDP looks ok although I'm not familiar with the specific h263 fmtp
> options, try just having
> fmtp:96
>
> your SDP states you are streaming to port 1100 so make sure your streamer
> is in fact doing this (obvious I know but...)
>
> Run up ethereal and capture the first couple of packet and see if they
> look ok. Check that your RTP header payload type is in fact 96 and not the
> non-dynamic one (forget which number this is for H264...35?)
>
> -Chris
>
> ----- Original Message -----
> *From:* jogging song <joggingsong at gmail.com>
> *To:* vlc at videolan.org
> *Sent:* Friday, March 09, 2007 2:54 AM
> *Subject:* [vlc] Re: vlc stop when playing H.264 RTP stream
>
> Thanks, Chris
>       Payload type in RTP header is 96.
>   Before it is about to receive RTP stream, vlc need a SDP.  I'm not sure
> whether the sdp file is right.
> v=0
> m=video 1100 RTP/AVP 96
> b=AS:247
> a=rtpmap:96 H264/90000
> a=fmtp:96 packetization-mode=1;profile-level-id=42001E;
>
> I read the RFC3984, and change it to the following.
>
> v=0
> m=video 1100 RTP/AVP 96
> b=AS:247
> a=rtpmap:96 H264/90000
> a=fmtp:96
> packetization-mode=0;profile-level-id=42001E;sprop-parameteter-sets=Z0IAHpZ0Ficg,aM44gA==
>
>
> It still doesn't work.
>
> The RTP stream consists of RTP of 300 frames. And only the first frame is
> an IDR frame(I frame), which has a sps and pps.
> All other frame is P frame.
>
> But VLC stops after printing the following things:
> packetizer_h264 debug: found NAL_SPS
> packetizer_h264 debug: found NAL_PPS
> I don't know why it stops after recognizing sps and pps.
>
>
> And i think sps and pps already are in sdp file, so I don't send sps and
> pps.
> Vlc will print "waiting for sps".
>
> Thanks
> jogging
>
>
> On 3/8/07, chris.2.dobbs at bt.com <chris.2.dobbs at bt.com > wrote:
> >
> >  Not sure what that erro msg means but here are a few quick things to
> > check:
> > 1. Are you setting the RTP payload to 96 in your stream?
> > 2. Are you setting correct timestamp framing intervals in your stream ,
> > think u need to increment rtp timestamp by 30Ms every time u start sending a
> > new frame. Keep this timestamp constant for frames spanning several packets.
> > 3. Are you keeping the RTP SSRC at constant value all the way through?
> >
> > Can you post the first few packets here?- use ethereal or something to
> > capture and I'll take a look.
> > -Chris
> >
> >  ------------------------------
> > *From:* vlc-bounce at videolan.org [mailto:vlc-bounce at videolan.org] *On
> > Behalf Of *jogging song
> > *Sent:* 08 March 2007 12:52
> > *To:* vlc at videolan.org
> > *Subject:* [vlc] vlc stop when playing H.264 RTP stream
> >
> >  hi,
> >     Now I use VLC to play H.264 RTP stream.I encounter some problems.
> > Before it is about to receive RTP streams,  VLC read a SDP like this,
> > v=0
> > m=video 1100 RTP/AVP 96
> > b=AS:247
> > a=rtpmap:96 H264/90000
> > a=fmtp:96 packetization-mode=1;profile-level-id=42001E;
> >
> > Then I send RTP packets, and VLC recieve them.But VLC stops after
> > printing the following things:
> > packetizer_h264 debug: found NAL_SPS
> > packetizer_h264 debug: found NAL_PPS
> >
> > Can anyone help me?Thanks
> > Best Regards
> > jogging
> >
> >
> >
> >
>
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