Re: [Motion-user] MJPEG palette: Corrupt JPEG data extraneous bytes

[Bob B. <bob...@bi...>]

Hi Corentin

No the interference issue only happens over the WiFi link. I only ever
see it on 2 of the cameras that connect that way!

I can think of a couple of scenarios that might cause it. One will
obviously be a time-out situation where the TCP layer re-sent data is
just ignored. I just haven't delved into the motion netcam code to find
out. Keep in mind too that there isn't much point doing retries over
streaming audio and video generally. For viewing purposes a lost frame
can be pretty well ignored, but of course for motion it ends up as a
changed image detection event.

If I get real excited I may Wireshark the stream to see what's
happening. It may even help to fiddle with frame rates. A general
purpose buffer delay might also fix it. Its not exactly high priority
though. It might even be easier to go and make an acquaintance with the
owner of the interfering system and ask them to set their channel
statically!

I would be extra worried if Wireshark proved the same frame was (say)
being re-sent 20 times. That would explain the latency as well.

Bob

On 04/09/12 23:17, corentin barbu wrote:
> Hi Andrew and Bob,
>
> Thank you so much guys for the details. As for mpg-streamer I had
> tried with the .deb but it doesn't install ... I'll give a shot to the
> compilation from sources.
>
> One thing I don't understand is how you connect the interferences on
> the image with the WiFi. Does it affect even the cam not connected
> through WiFi?
>
> Corentin
>