[Live-devel] problem by changing the framerate

[Ottavio Campana]

Ross Finlayson ha scritto:
>> I have a program that I use to stream PAL video encoded with H.264. 
>> Everything works fine, but if I try to halve the framerate the player 
>> VLC crashes, while mplayer works (but I think it does some form of 
>> concealment).
> 
> I can't help you with VLC; this is not a VLC mailing list.

well, I used VLC because it makes use of live555.

> However, you should - as always - make sure that each of your H.264 NAL 
> units (coming from your "H264VideoStreamFramer" subclass)
> 1/ Have an accurate "fPresentationTime" (which is aligned with the 'wall 
> clock' time that you'd get by calling "gettimeofday()", and
> 2/ Have accurate "fDurationInMicroseconds" values
> 
> Since the only thing you've changed is the frame rate, perhaps one or 
> both of these things didn't get changed correctly?

is it normal that fDurationInMicroseconds is set to 0 each time 
deliverFrame is called?

> You shouldn't have to know or care about RTP timestamps; these will get 
> set automatically by the code, provided that the "fPresentationTime"s 
> are correct.  (H.264-over-RTP always uses a 90000 Hz RTP timestamp 
> frequency.)  (Therefore any future questions about RTP timestamps will 
> be ignored.)

ok, I'll dig into fPresentationTime.

I'm sorry to bother you, but I have a quick question, I'd like you just 
to tell me yes or no: when the framerate changes, am I correct to expect 
that the delta in terms of timestamps between rtp packets varies? 
Because if this is true, it means that I'm making a mistake somewhere 
else, right?

Thanks for your help,

Ottavio