[Ffmpeg-devel] RTP patches & RFC

Michael Niedermayer michaelni
Fri Oct 13 03:02:21 CEST 2006


On Thu, Oct 12, 2006 at 07:11:47PM -0500, Ryan Martell wrote:
> On Oct 12, 2006, at 4:29 PM, Ryan Martell wrote:
> >On Oct 12, 2006, at 5:29 AM, Michael Niedermayer wrote:
> >>Hi
> >>
> >>On Wed, Oct 11, 2006 at 10:41:36PM -0500, Ryan Martell wrote:
> >>[...]
> >>>>
> >>>>either way you should set AVStream->need_parsing=1 and leave the
> >>>>merging
> >>>>of packets to the AVParser
> >>>
> >>>Okay, sorry to be dense about this, but I'm still confused.  The
> >>>packets that come over rtp have their size indicated in various  
> >>>ways,
> >>>depending on the packet.  That information is NOT in the NAL, and  
> >>>the
> >>>NAL is NOT preceeded by the start sequence.  So what I was doing was
> >>>converting them to AvC style (preceded by length) packets.  This is
> >>
> >>iam more in favor of adding the startcode prefix instead of the  
> >>length
> >>i dont think the avc style length stuff is supported by our AVParser
> >>
> >
> >I changed the code, so that in my init routine you can specify if  
> >you want the bitstream version or the avcc version.  Both work, as  
> >long as I don't set needs_parse= 1 for the stream.  When I do that,  
> >I never get past the setup code (I don't know why).  (Maybe it's  
> >because I only had 001 instead of 0001 on the sps/pps packets, from  
> >derk above?).  This is the same issue i was having when i first  
> >started this, where there was no data in the extradata field, it  
> >wouldn't get to the point where it showed the stream types.
> >
> >>
> >>it doesnt need the pts for this, it will analize the nal units
> >
> >This doesn't work for me; probably because I am not using the  
> >AVParser yet?
> Okay, if i change the code a bit, I can get the AVParser to do my  
> conglomeration of packets for a given frame.
> As the code stands, it can generate either AVCC style or Bytestream  
> style streams.
> It didn't look like the AVParser knew how to handle AVCC style  
> streams, so if I change the code, it will break the AVCC stuff.
> So, should i leave it as is (where it works for both), or modify it  
> to use the AVParser, which reduces code size (it gets rid of  
> put_packet_at_head_of_queue and create_frame_packet)?

IMHO reduced code size is better, and if needed AVCC support could always
be added to the AVParser ...

Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

In the past you could go to a library and read, borrow or copy any book
Today you'd get arrested for mere telling someone where the library is

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