[FFmpeg-user] multiple instances of segmenter

[Joe Konecny]

On 06/12/2017 10:03 AM, Moritz Barsnick wrote:
> On Mon, Jun 12, 2017 at 09:22:17 -0400, Joe Konecny wrote:
>> I'm calling ffmpeg from crontab and using the segmenter.  Two instances
>> of ffmpeg are running at once.  One of the instances uses the segmenter
>> properly the other creates one large file.
> 
>> 0 6     * * *   root    timeout 5h ffmpeg -i
> 
> Sorry for being a bit blunt, but who in their right mind would execute
> an arbitrary command as user "root"?
> 
>> "http://192.168.1.230/videostream.cgi?user=admin&pwd=blah&resolution=32&rate=0"
>> "http://192.168.1.8/videostream.cgi?user=admin&pwd=blah&resolution=32&rate=0"
> 
> Hmm, I can't reproduce. Could it be that your second stream avoids
> creating keyframes, or does it much less often than the first stream?
> The segmenter doesn't cut until it encounters the next keyframe.
> 
> For us to understand the issue better, it may be necessary to update
> your ffmpeg to latest git master (or at least 3.3.2), and to include
> the full, uncut console output of the misbehaving command. (If you
> can't redirect to a file from crontab, use the "-report" option, but
> check for the size of the file first before posting here - it implies
> an increased loglevel unless you set options using the environment
> variable FFREPORT. Also, if your two ffmpegs launch simultaneously from
> crontab, their report log file names will clash unless changed by such
> an option.)
> 
> Moritz

After researching this I think the issue is the frame rate.  I don't 
understand how the frame rate relates to time and how to adjust it
with ffmpeg.  The frames come in maybe slower than ffmpeg thinks they
are.  So the result is that ffmpeg thinks not as much time has passed
as really has.  The video also plays back faster than real time.  Any
tips on how to make the stream and ffmpeg agree on the frame rate?