[Live-devel] [live555] same spspps in sdp for different video size for H264 streaming

[Ross Finlayson]

> On Oct 24, 2019, at 7:35 PM, Zhang Qian（张倩） <qianzhang at asrmicro.com> wrote:
> 
> Hi Ross,
>  
> I found the spspps value are same in sprop-parameter-sets for SDP when there are two H264 streaming wth different video resolution. (ie, 720p and 1080p).
>  
> For example.
> If I start H264 rtsp streaming with 720p resolution for the first time, the spspps value in sprop-parameter-sets is right.
> Then I start another H264 rtsp streaming with 1080p resolution, the spspps value in sprop-parameter-sets is same with 720p spspps value. It is reused and doesn’t update it for this rtsp negotiation.
>  
> Is it normal for this behavior?

Yes, probably.  If you change the resolution (and/or aspect ratio) of your video stream, then you should probably use a different “ServerMediaSubsession” object in your server.  I.e., destroy the old one; then create a new one in its place.

Ross Finlayson
Live Networks, Inc.
http://www.live555.com/