[FFmpeg-user] syncing live streams when mosaicing

[Daniel Oberhoff]

On 2013-02-06 22:10:24 +0000, Stefano Sabatini <stefasab at gmail.com> said:

> On date Wednesday 2013-02-06 16:10:11 +0100, Daniel Oberhoff wrote:
> [...]
>> Ok, I must confess I am not so proficient in timestamps and video
>> format internals. I am currenlty under the impression, that the
>> problem cannot be solved the way I hoped. The streams nor the rtsp
>> commnunication do not seem to contain any absolute time values (the
>> pts seems to be relative to the stream start). So the only hope
>> would be that ffmpeg somehow measures the stream start delays and
>> compensates them. Until then we will just hope the delay is constant
>> and compensate it manually.
>> 
>> Any better ideas?
> 
> setpts=PTS-STARTPTS
> 
>> Best, and thanks for the attention

Thanks for that. Though I would really need the absolute start time of 
the stream. According to the documentation this would be 
RTCSTART/(1000000*TB), but this is no longer supported. The 
documentation says something obscure about "use time(0) instead", but 
just writing time(0) does not work, and I cannot find any further 
documentation or code regarding this. Can anyone point me in the right 
direction here.