Re: Redundancy/Survival

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From	TheLastSysop <thelastsysop@dev.null>
Newsgroups	comp.os.linux.misc
Subject	Re: Redundancy/Survival
Date	Mon, 01 Jun 2026 04:57:37 GMT
Organization	The Null Device Restoration Society
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>On Mon, 1 Jun 2026 00:49:48 -0400, c186282 <c186282@nnada.net> wrote:
>On 5/31/26 03:14, TheLastSysop wrote:
>>> On Sun, 31 May 2026 03:10:57 -0400, c186282 <c186282@nnada.net> wrote:
>>> On 5/31/26 01:09, TheLastSysop wrote:
>>>
>>>    Good advice.
>>>
>>>    My humble intent was to just do a still-frame capture
>>>    every few seconds, re-name and stash somewhere. Easy
>>>    with lots of webcam apps, but not with ......
>>>
>>>    I think I *can* do that basic trick now. But do I
>>>    want to ??? Better off with little web-cams. Look
>>>    for "Spinel" ... they USED to have a micro-boxed
>>>    board, but of late only bare boards. Easy to use
>>>    and cope with and highly sensitive. DID fit one of
>>>    those microboxes AND a Pi3 into a little weatherproof
>>>    box ... it's now on a screen porch. IR sensitive
>>> [...trimmed...]
>>>    But all that's a different "survival" theme ...
>>> [...trimmed...]
>>
>> If the goal is only "one JPEG every few seconds", I would skip VLC and the
>> streaming path entirely.  Let the camera program write stills directly.
>
>
>   A very simple Python daemon can do that nicely.
>
>   I have another PI with 'motion' on it, but it's
>   a Python daemon that grabs a frame and stashes
>   it (also keeps track of too-old pix).
>
>> On newer Raspberry Pi OS images the names may be rpicam-* rather than
>> libcamera-*; on older ones it is the other way around.  So check both:
>>
>>      command -v rpicam-still libcamera-still
>>
>> The usual package is the Raspberry Pi camera apps package, called rpicam-apps
>> on
>> newer installs and libcamera-apps on some older ones.
>>
>> For a simple timed capture, the shape is roughly:
>>
>>      rpicam-still -n -t 0 --timelapse 5000 -o frame%06d.jpg
>>
>> or, on older installs:
>>
>>      libcamera-still -n -t 0 --timelapse 5000 -o frame%06d.jpg
>
>   Yep, the first one works on my Pi4, most recent distro.
>   Haven't used the "timelapse" yet however. Resembles
>   the ffmpeg automatic naming approach (the app may be
>   BUILT using ffmpeg as its core).
>
>   Still a bit vague on where/how the ribbon-cable cams
>   deliver stuff. "Network" port - "localhost:1234" ???
>   Something weirder ??? Gotta check some more.
>
>> That avoids preview windows, VNC, h264 elementary streams, and VLC guessing.
>> Then a separate cron job or shell loop can move/rename/compress/prune files.
>>
>> For 1 FPS video without duplicated frames, ffmpeg is often easier if you feed
>> it
>> an actual 1 FPS image sequence rather than a 30 FPS camera stream, e.g.
>> capture
>> JPEGs first, then encode the sequence later.  That is less elegant, but a lot
>> more predictable on small Pis.
>
>   I wrote an app using OpenCV2 commands - can grab webcam frames
>   at 1 fps and assembles them into (silent) movies.
>
>   Ffmpeg ... had some good experiences and a few bad. The doc
>   seems all over the place. My final working param set was much
>   smaller than many of the docs suggested. Do have it making
>   RTSP movies at 1-fps, resized, but with continuous sound.
>   Works well EXCEPT kinda in the middle of the day - very odd.
>   It's almost like somebody subtly screwed up the time calx in
>   some deep hidden subroutine, the movies almost always
>   terminate early from about 10am-4pm.
>
>   The trick with movies is keeping the SIZE down. Has to be
>   enough rez and FPS for 'security' doc purposes, but that
>   can be less than most think. 2k movies at 30fps and you'll
>   use up a whole hard disk real quick (and I don't think
>   a PI has enough speed for that anyway).

For the ribbon cable cameras there usually is not a network port involved. They
sit on the Pi's CSI connector and the kernel/libcamera stack exposes them
locally.  So the first sanity check I would do is just:

    rpicam-hello --list-cameras

or, on older installs:

    libcamera-hello --list-cameras

If that sees the module, rpicam-still/rpicam-vid talk to it directly.  No
localhost:1234 unless you deliberately start some server or streamer on top of
it.  The old raspistill/raspivid world was different enough that stale web pages
can be actively unhelpful here.

For USB webcams the path is more like /dev/video*, and then v4l2-ctl is useful:

    v4l2-ctl --list-devices
    v4l2-ctl -d /dev/video0 --list-formats-ext

For CSI/libcamera cameras, the rpicam/libcamera tools are the better first
probe.

On the midday ffmpeg weirdness, I would first check whether it is really a
clock/time-of-day problem or just the camera/source wedging under heat/light. If
the camera is in sun during those hours, thermal throttling, exposure changes,
or an RTSP source timeout can look very much like "ffmpeg went odd". A parallel
still-image capture during that window is a cheap way to separate camera trouble
from encoder trouble.

-- 
TheLastSysop <thelastsysop@dev.null>
"I survived the great rm -rf / rehearsal and all I got was this .signature."

Thread

Redundancy/Survival c186282 <c186282@nnada.net> - 2026-05-26 02:21 -0400
  Re: Redundancy/Survival "Carlos E.R." <robin_listas@es.invalid> - 2026-05-26 08:46 +0200
    Re: Redundancy/Survival Marco Moock <mm@dorfdsl.de> - 2026-05-26 09:49 +0200
      Re: Redundancy/Survival c186282 <c186282@nnada.net> - 2026-05-26 04:47 -0400
      Re: Redundancy/Survival "Carlos E.R." <robin_listas@es.invalid> - 2026-05-26 11:25 +0200
      Re: Redundancy/Survival Rich <rich@example.invalid> - 2026-05-26 09:53 +0000
    Re: Redundancy/Survival c186282 <c186282@nnada.net> - 2026-05-26 04:38 -0400
      Re: Redundancy/Survival "Carlos E.R." <robin_listas@es.invalid> - 2026-05-26 11:35 +0200
      Re: Redundancy/Survival Rich <rich@example.invalid> - 2026-05-26 22:09 +0000
        Re: Redundancy/Survival John Ames <commodorejohn@gmail.com> - 2026-05-26 16:17 -0700
          Re: Redundancy/Survival Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2026-05-27 00:02 +0000
            Re: Redundancy/Survival c186282 <c186282@nnada.net> - 2026-05-27 00:11 -0400
              Re: Redundancy/Survival Marco Moock <mm@dorfdsl.de> - 2026-05-28 10:32 +0200
            Re: Redundancy/Survival Nuno Silva <nunojsilva@invalid.invalid> - 2026-05-27 08:41 +0100
              Re: Redundancy/Survival "Carlos E.R." <robin_listas@es.invalid> - 2026-05-27 11:04 +0200
                Re: Redundancy/Survival c186282 <c186282@nnada.net> - 2026-05-28 03:31 -0400
                Re: Redundancy/Survival The Natural Philosopher <tnp@invalid.invalid> - 2026-05-28 09:18 +0100
                Re: Redundancy/Survival "Carlos E.R." <robin_listas@es.invalid> - 2026-05-28 13:42 +0200
                Re: Redundancy/Survival The Natural Philosopher <tnp@invalid.invalid> - 2026-05-28 15:01 +0100
                Re: Redundancy/Survival c186282 <c186282@nnada.net> - 2026-05-28 21:34 -0400
                Re: Redundancy/Survival The Natural Philosopher <tnp@invalid.invalid> - 2026-05-29 11:07 +0100
                Re: Redundancy/Survival "Carlos E.R." <robin_listas@es.invalid> - 2026-05-29 12:55 +0200
                Re: Redundancy/Survival The Natural Philosopher <tnp@invalid.invalid> - 2026-05-29 12:14 +0100
                Re: Redundancy/Survival "Carlos E.R." <robin_listas@es.invalid> - 2026-05-29 13:36 +0200
                Re: Redundancy/Survival The Natural Philosopher <tnp@invalid.invalid> - 2026-05-29 13:26 +0100
                Re: Redundancy/Survival "Carlos E.R." <robin_listas@es.invalid> - 2026-05-29 19:36 +0200
                Re: Redundancy/Survival Richard Kettlewell <invalid@invalid.invalid> - 2026-05-29 17:24 +0100
                Re: Redundancy/Survival "Carlos E.R." <robin_listas@es.invalid> - 2026-05-29 19:37 +0200
                Re: Redundancy/Survival The Natural Philosopher <tnp@invalid.invalid> - 2026-05-29 19:36 +0100
                Re: Redundancy/Survival Richard Kettlewell <invalid@invalid.invalid> - 2026-05-29 22:34 +0100
                Re: Redundancy/Survival c186282 <c186282@nnada.net> - 2026-05-30 04:29 -0400
                Re: Redundancy/Survival "Carlos E.R." <robin_listas@es.invalid> - 2026-05-30 13:09 +0200
                Re: Redundancy/Survival c186282 <c186282@nnada.net> - 2026-05-30 23:29 -0400
                Re: Redundancy/Survival InterLinked <usenet@phreaknet.org> - 2026-05-31 21:45 -0400
                Re: Redundancy/Survival "Carlos E.R." <robin_listas@es.invalid> - 2026-06-01 12:15 +0200
                Re: Redundancy/Survival Rich <rich@example.invalid> - 2026-05-29 04:30 +0000
                Re: Redundancy/Survival c186282 <c186282@nnada.net> - 2026-05-29 01:34 -0400
                Re: Redundancy/Survival rbowman <bowman@montana.com> - 2026-05-29 06:36 +0000
                Re: Redundancy/Survival c186282 <c186282@nnada.net> - 2026-05-31 00:38 -0400
                Re: Redundancy/Survival TheLastSysop <thelastsysop@dev.null> - 2026-05-31 05:09 +0000
                Re: Redundancy/Survival c186282 <c186282@nnada.net> - 2026-05-31 03:10 -0400
                Re: Redundancy/Survival TheLastSysop <thelastsysop@dev.null> - 2026-05-31 07:14 +0000
                Re: Redundancy/Survival c186282 <c186282@nnada.net> - 2026-06-01 00:49 -0400
                Re: Redundancy/Survival TheLastSysop <thelastsysop@dev.null> - 2026-06-01 04:57 +0000
                Re: Redundancy/Survival Rich <rich@example.invalid> - 2026-06-01 03:20 +0000
                Re: Redundancy/Survival "Carlos E.R." <robin_listas@es.invalid> - 2026-06-01 19:45 +0200
                Re: Redundancy/Survival Rich <rich@example.invalid> - 2026-06-01 18:30 +0000
                Re: Redundancy/Survival "Carlos E.R." <robin_listas@es.invalid> - 2026-06-01 22:27 +0200
                Re: Redundancy/Survival c186282 <c186282@nnada.net> - 2026-05-29 02:17 -0400
                Re: Redundancy/Survival Rich <rich@example.invalid> - 2026-06-01 03:50 +0000
                Re: Redundancy/Survival c186282 <c186282@nnada.net> - 2026-06-01 01:07 -0400
                Re: Redundancy/Survival "Carlos E.R." <robin_listas@es.invalid> - 2026-06-01 12:47 +0200
                Re: Redundancy/Survival Rich <rich@example.invalid> - 2026-06-01 17:36 +0000
                Re: Redundancy/Survival "Carlos E.R." <robin_listas@es.invalid> - 2026-06-01 22:33 +0200
                Re: Redundancy/Survival The Natural Philosopher <tnp@invalid.invalid> - 2026-06-01 12:26 +0100
                Re: Redundancy/Survival Rich <rich@example.invalid> - 2026-06-01 17:31 +0000
                Re: Redundancy/Survival "Carlos E.R." <robin_listas@es.invalid> - 2026-06-01 22:49 +0200
                Re: Redundancy/Survival not@telling.you.invalid (Computer Nerd Kev) - 2026-05-30 09:09 +1000
                Re: Redundancy/Survival "Carlos E.R." <robin_listas@es.invalid> - 2026-05-30 13:17 +0200
                Re: Redundancy/Survival not@telling.you.invalid (Computer Nerd Kev) - 2026-05-31 07:33 +1000
                Re: Redundancy/Survival c186282 <c186282@nnada.net> - 2026-05-31 00:14 -0400
                Re: Redundancy/Survival The Natural Philosopher <tnp@invalid.invalid> - 2026-05-31 12:09 +0100
                Re: Redundancy/Survival c186282 <c186282@nnada.net> - 2026-06-01 00:51 -0400
                Re: Redundancy/Survival The Natural Philosopher <tnp@invalid.invalid> - 2026-06-01 12:28 +0100
                Re: Redundancy/Survival "Carlos E.R." <robin_listas@es.invalid> - 2026-05-31 12:58 +0200
              Re: Redundancy/Survival Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2026-05-27 20:51 +0000
                Re: Redundancy/Survival John Ames <commodorejohn@gmail.com> - 2026-05-27 14:02 -0700
                Re: Redundancy/Survival not@telling.you.invalid (Computer Nerd Kev) - 2026-05-28 08:54 +1000
                Re: Redundancy/Survival Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2026-05-28 05:04 +0000
                Re: Redundancy/Survival c186282 <c186282@nnada.net> - 2026-05-28 03:54 -0400
                Re: Redundancy/Survival Andy Burns <usenet@andyburns.uk> - 2026-05-28 09:15 +0100
                Re: Redundancy/Survival Rich <rich@example.invalid> - 2026-06-01 12:29 +0000
                Re: Redundancy/Survival "Carlos E.R." <robin_listas@es.invalid> - 2026-05-28 13:45 +0200
                Re: Redundancy/Survival Robert Riches <spamtrap42@jacob21819.net> - 2026-05-29 02:50 +0000
                Re: Redundancy/Survival c186282 <c186282@nnada.net> - 2026-05-29 01:17 -0400
                Re: Redundancy/Survival rbowman <bowman@montana.com> - 2026-05-29 06:48 +0000
                Re: Redundancy/Survival c186282 <c186282@nnada.net> - 2026-05-30 04:25 -0400
                Re: Redundancy/Survival "Carlos E.R." <robin_listas@es.invalid> - 2026-05-30 13:20 +0200
                Re: Redundancy/Survival Robert Riches <spamtrap42@jacob21819.net> - 2026-05-30 14:16 +0000
                Re: Redundancy/Survival Robert Riches <spamtrap42@jacob21819.net> - 2026-05-30 04:00 +0000
          Re: Redundancy/Survival c186282 <c186282@nnada.net> - 2026-05-26 23:41 -0400
            Re: Redundancy/Survival The Natural Philosopher <tnp@invalid.invalid> - 2026-05-27 14:09 +0100
              Re: Redundancy/Survival c186282 <c186282@nnada.net> - 2026-05-28 03:51 -0400
                Re: Redundancy/Survival rbowman <bowman@montana.com> - 2026-05-28 17:08 +0000
                Re: Redundancy/Survival c186282 <c186282@nnada.net> - 2026-05-28 22:14 -0400
                Re: Redundancy/Survival rbowman <bowman@montana.com> - 2026-05-29 04:41 +0000
                Re: Redundancy/Survival c186282 <c186282@nnada.net> - 2026-05-29 01:53 -0400
                Re: Redundancy/Survival rbowman <bowman@montana.com> - 2026-05-29 06:32 +0000
                Re: Redundancy/Survival Rich <rich@example.invalid> - 2026-06-01 13:19 +0000
                Re: Redundancy/Survival "Carlos E.R." <robin_listas@es.invalid> - 2026-06-01 22:52 +0200
                Re: Redundancy/Survival Rich <rich@example.invalid> - 2026-06-01 13:08 +0000
                Re: Redundancy/Survival "Carlos E.R." <robin_listas@es.invalid> - 2026-06-01 22:55 +0200
        Re: Redundancy/Survival c186282 <c186282@nnada.net> - 2026-05-26 22:39 -0400
          Re: Redundancy/Survival The Natural Philosopher <tnp@invalid.invalid> - 2026-05-27 14:10 +0100
            Re: Redundancy/Survival not@telling.you.invalid (Computer Nerd Kev) - 2026-05-28 09:05 +1000
              Re: Redundancy/Survival The Natural Philosopher <tnp@invalid.invalid> - 2026-05-28 08:19 +0100
            Re: Redundancy/Survival c186282 <c186282@nnada.net> - 2026-05-28 03:52 -0400
              Re: Redundancy/Survival The Natural Philosopher <tnp@invalid.invalid> - 2026-05-28 09:20 +0100
                Re: Redundancy/Survival c186282 <c186282@nnada.net> - 2026-05-28 20:34 -0400
                Re: Redundancy/Survival InterLinked <usenet@phreaknet.org> - 2026-05-28 21:07 -0400
                Re: Redundancy/Survival Rich <rich@example.invalid> - 2026-06-01 13:40 +0000
                Re: Redundancy/Survival rbowman <bowman@montana.com> - 2026-05-29 01:21 +0000
                Re: Redundancy/Survival c186282 <c186282@nnada.net> - 2026-05-29 02:08 -0400
                Re: Redundancy/Survival rbowman <bowman@montana.com> - 2026-05-29 06:41 +0000
              Re: Redundancy/Survival Rich <rich@example.invalid> - 2026-06-01 13:23 +0000
                Re: Redundancy/Survival "Carlos E.R." <robin_listas@es.invalid> - 2026-06-01 23:00 +0200
  Re: Redundancy/Survival Marco Moock <mm@dorfdsl.de> - 2026-05-26 09:44 +0200
    Re: Redundancy/Survival c186282 <c186282@nnada.net> - 2026-05-26 04:45 -0400
    Re: Redundancy/Survival "Carlos E.R." <robin_listas@es.invalid> - 2026-05-26 11:38 +0200
  Re: Redundancy/Survival "Worst Case" <fritz@spamexpire-202605.rodent.frell.theremailer.net> - 2026-05-26 17:21 +0200

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