[vlc-devel] [PATCH] access: live555: fix spurious PCR_RESET on RTCP clock synchronization

[Rémi Denis-Courmont]

Le 2016-08-08 15:58, Ludovic Fauvet a écrit :
> On Mon, Aug 8, 2016, at 15:35, Rémi Denis-Courmont wrote:
>> Le 2016-08-08 14:58, Ludovic Fauvet a écrit :
>> > On Fri, Aug 5, 2016, at 23:41, Francois Cartegnie wrote:
>> >> ---
>> >>  modules/access/live555.cpp | 61
>> >>  +++++++++++++++++++++++++++++++++-------------
>> >>  1 file changed, 44 insertions(+), 17 deletions(-)
>> >
>> > Hello François,
>> >
>> > I was quite doubtful at first but this patch indeed fixes the 
>> issue
>> > of
>> > the PCR RESET on RTCP sync that can be reproduced with the Axis
>> > camera I
>> > have in my office. I cannot challenge what has been said by Rémi 
>> but
>> > still, I see this patch as an improvement over the initial code 
>> which
>> > is
>> > wrong and partially broken.
>> >
>> > So except if someone has a strong opinion, I would be in favor of
>> > pushing it.
>>
>> There are basically two cases. If you have a single ES, then this 
>> patch
>> is overkill. You just need to "stitch" the PTS from before the first
>> RTCP-SR with those after it. I am not sure if live555 provides the
>> necessary infos, but if it does not, you can't really make it up 
>> anywya.
>
> That was what my first naive implementation was doing (see attached
> patch). But obviously that won't work for multiple ES.  Maybe this 
> idea
> can be extended to keep all the ES in sync?

You have multiple first degree equations to solve, with only one 
unknown. In general, that is a mathematical impossibility.

-- 
Rémi Denis-Courmont
Looking for a job
http://www.remlab.net/