[Ffmpeg-devel] H264 RTP + quicktime

Jerry Johns jerry.johns
Fri Nov 3 16:46:58 CET 2006


Your brilliant! Thanks derk, it worked like a charm
They key phrase in your email was the encoding of the SPS+PPS in the sdp

Now I seem to see one problem with my stream - when I play with VLC, I've
set the RTSP latency to about 150ms, and on a 4Mb/s stream it has no dropped
frames and its very smooth and 'real time'

With quicktime, even though I adjusted the streaming settings to the lowest
latency, it still has about a 4 second latency when playing it back!

Is it something to do with my SDP? I'm using payloadformatype of 96
Does the type affect this?

This is my SDP

m=video 16666 RTP/AVP 96
c=IN IP4 232.197.14.24/255
a=rtpmap:96 H264/90000
a=fmtp:96
packetization-mode=1;profile-level-id=42801E;sprop-parameteter-sets=Z0KAHo2M
QFoeiA==,aM44gA==

Thanks


-----Original Message-----
From: Derk-Jan Hartman [mailto:hartman at videolan.org] 
Sent: Thursday, November 02, 2006 4:52 PM
To: FFmpeg development discussions and patches
Cc: Jerry Johns
Subject: Re: [Ffmpeg-devel] H264 RTP + quicktime


On 2-nov-2006, at 22:15, Jerry Johns wrote:

> My Framer that I developed follows the RFC spec for H264 closely  
> (using non
> interleaved, FUA Fragmenting, chopping up on NAL units)
>
> However, I cant even get my base H264 file without streaming on to  
> play in
> quicktime; the only way I can play it is if I wrap it in MP4 using  
> mp4box,
> And then it plays like a charm

Well, then it's not a RTP stream anymore is it ? It's a file.

> I have tried opening my stream with quicktime, doesn't work neither
>
> The only way around is it to use MP4 RTP streaming, in which case  
> I'll have
> to wrap my data into mdat, moov, etc. atoms in the container and  
> that's
> where I need the help

Non-sense. such a thing does not exist. There is something called QT  
RTP streaming, but I wouldn't advice on using it. It only works on  
mp4 and mov files. The documentation for QuickTime RTP framing is  
available somewhere on the Apple developers site. But I reiterate,  
there is no reason why you would need to use this, FU-A H264  
streaming to QuickTime works just fine.

I suspect you are not properly reporting the SPS/PPS in the SDP.
This is the a=packetization-mode=1,profile-level-id=######,sprop- 
parameter-sets=binarydata
lines in your SDP.

This is CRITICAL in getting your RTSP/RTP stream to work in QuickTime.

> I need to know how the MP4 file is chopped up into RTP packets (I  
> wish there
> was an RFC spec for this that shows it as clearly as the H264 spec)
> -----Original Message-----
> From: Derk-Jan Hartman [mailto:hartman at videolan.org]
> Sent: Thursday, November 02, 2006 4:08 PM
> To: FFmpeg development discussions and patches
> Cc: Jerry Johns
> Subject: Re: [Ffmpeg-devel] H264 RTP + quicktime
>
> On 2-nov-2006, at 16:42, Jerry Johns wrote:
>> I've already gotten a H264 Framer + RTP packetizer working, and it
>> streams
>> absolutely well to a VLC Client, and plays without a hitch;
>>
>> My next step is to get this to work in quicktime, and that's where
>> I need
>> the mp4 container to work
>
> Why? RTP has nothing to do with mp4 file muxing. If you can stream to
> VLC, you should be able to stream to QuickTime.
> That is:
>
> 1 as long as you don't use any of the h.264 codec options that QT
> doesn't support (QT doesn't support H264 very well)
> 2 you write the SPS/PPS to the SDP file
> 3 you only use 1 slice (at least i haven't been able to use more than
> 1 slice when doing VLC h264 RTSP to quicktime. If someone figures out
> why, i'm all ears).
>
>> The ISO files you mention, I cant seem to download them as I don't
>> have
>> access to them
>
> Then you'll just have to look around very hard for someone who
> accidently left them somewhere, or pay up the fee that is required to
> read/use this standard.
>
>> What I now need to do is a)find out general info on the MP4
>> container and
>> b)how it relates to the H264 stream and c)streaming MP4 over RTP
>
> See above.
>
> DJ
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