[SOLVED] ffmpeg fails to run in cron but ok from command line

Liquid_Squelch · 02-09-2013, 03:57 PM

I'm trying to grab a RTSP stream from my CCTV system. Right now, I am only interested in a single camera source.

The RTSP string works fine in VLC.
The command line to connect to the CCTV Camera using ffmpeg and save a jpg image also works fine.

HOWEVER, once i put the same command into my users' cron, or into the root's cron, I get the following error (again, this error doesn't exist if I run the same command from shell)

Code:

ffmpeg: relocation error: /usr/lib/libswresample.so.0: symbol av_get_packed_sample_fmt, version LIBAVUTIL_51 not defined in file libavutil.so.51 with link time reference

Running in shell, this is how the output works

Code:

Phil@linux-zitz:~/CCTV/Snapshots> bash -x capture.sh
++ date +%Y%m%d%H%M
+ DATETIME=201302091640
++ date +%Y%m%d
+ DATE=20130209
+ echo='WE BE RUNNING!'
+ ffmpeg -i 'rtsp://<ip>:<port>/cam/realmonitor?channel=1&subtype=00&authbasic=<hash>' -ss 0 -vframes 1 -f image2 /<path>/CCTV/Snapshots/cam01/201302091640.jpg
ffmpeg version 0.8.3, Copyright (c) 2000-2011 the FFmpeg developers
  built on Sep 20 2011 19:40:02 with gcc 4.5.1 20101208 [gcc-4_5-branch revision 167585]
  configuration: --enable-shared
  libavutil    51.  9. 1 / 51.  9. 1
  libavcodec   53.  7. 0 / 53.  7. 0
  libavformat  53.  4. 0 / 53.  4. 0
  libavdevice  53.  1. 1 / 53.  1. 1
  libavfilter   2. 23. 0 /  2. 23. 0
  libswscale    2.  0. 0 /  2.  0. 0
[rtsp @ 0x9367340] Estimating duration from bitrate, this may be inaccurate

Seems stream 0 codec frame rate differs from container frame rate: 180000.00 (180000/1) -> 100.00 (100/1)
Input #0, rtsp, from 'rtsp://<ip>:<port>/cam/realmonitor?channel=1&subtype=00&authbasic=<hash>':
  Metadata:
    title           : h264.mp4
  Duration: N/A, start: 0.120000, bitrate: N/A
    Stream #0.0: Video: h264 (Constrained Baseline), yuv420p, 704x480, 100 tbr, 90k tbn, 180k tbc
Incompatible pixel format 'yuv420p' for codec 'mjpeg', auto-selecting format 'yuvj420p'
[buffer @ 0x9369020] w:704 h:480 pixfmt:yuv420p tb:1/1000000 sar:0/1 sws_param:
[buffersink @ 0x952fd00] auto-inserting filter 'auto-inserted scaler 0' between the filter 'src' and the filter 'out'
[scale @ 0x9530a40] w:704 h:480 fmt:yuv420p -> w:704 h:480 fmt:yuvj420p flags:0x4
Output #0, image2, to '/<path>/CCTV/Snapshots/cam01/201302091640.jpg':
  Metadata:
    title           : h264.mp4
    encoder         : Lavf53.4.0
    Stream #0.0: Video: mjpeg, yuvj420p, 704x480, q=2-31, 200 kb/s, 90k tbn, 100 tbc
Stream mapping:
  Stream #0.0 -> #0.0
Press [q] to stop, [?] for help
frame=    1 fps=  0 q=7.1 Lsize=      -0kB time=00:00:00.01 bitrate= -17.6kbits/s    
video:34kB audio:0kB global headers:0kB muxing overhead -100.063075%
Phil@linux-zitz:~/CCTV/Snapshots>

This is a OpenSUSE 12.2 system

Any ideas as to why this will work fine via a command prompt, but fail in cron? My goal here is to take 1 minute snapshots and create a time lapse video.

Please keep in mind, I'm not a linux expert. I'm still a 'work in progress'

Again, the command works fine in shell, it just doesn't want to run in cron..

Thanks

Snark1994 · 02-09-2013, 04:16 PM

Whose crontab is it in? If it's in root's crontab, can you run the ffmpeg command successfully as root?

Liquid_Squelch · 02-09-2013, 04:29 PM

It is my user's crontab. My user can run the ffmpeg command fine, and it saves the image as expected. However, when I put the same command in cron, it fails with the error.

To see if it was a permission's issue, I ran the same command as SU and it works fine. So I added the command into root's crontab, and again, it failed with the same error as the users/my crontab.

Habitual · 02-09-2013, 05:20 PM

Quote:

Originally Posted by Liquid_Squelch

Any ideas as to why this will work fine via a command prompt, but fail in cron?

sure do, environment. What is "the command" exactly?

Liquid_Squelch · 02-10-2013, 04:17 PM

Here is the script <with minor edits for security>
cat capture.sh

Code:

#!/bin/sh
DATETIME=`date +%Y%m%d%H%M`
DATE=`date +%Y%m%d`

echo="WE BE RUNNING!"



ffmpeg -i "rtsp://<ip>:<port>/cam/realmonitor?channel=1&subtype=00&authbasic=<user/pass_hash>" -ss 0 -vframes 1 -f image2 /<path>/Snapshots/cam01/$DATETIME.jpg

#EOF

This is executed as my main user (non-root) and will work fine if I type ./capture.sh from command line.

chrism01 · 02-10-2013, 10:21 PM

Here's a few things that might help

1. the default env in cron is minimal. Usually we recommend using absolute full paths to all cmds (unless they are built-in shell cmds) and also for all files used.
You can get around this by setting/sourcing the correct env near the top of the script.

2. Try putting the script in cron and saving the output and stderr, inc full debugging 'set -xv'

Code:

min hr dayofmth mth dayofwk /path/to/script >/tmp/script.log 2>&1

Code:

#top of script
#!/bin/bash
set -xv

3. it looks like it might be a library setting; can you check LD_LIBRARY and ensure its set the same in the script

4. does ffmpeg cmd require/expect the presence of a terminal/screen ? (never used it myself)

haertig · 02-11-2013, 12:09 AM

As a test, to prove to yourself that it is an environment issue, change your current cron job from "capture.sh" to ". /home/username/.bash_profile; capture.sh" and see if it works with this. Obviously, /home/username/.bash_profile will have to be replaced with the correct fully qualified pathname to your specific profile.

Liquid_Squelch · 02-11-2013, 04:29 PM

Thank you everyone for the help..

I had to add the following into my capture.sh file

Code:

#Set Path for ffmpeg Libraries
export LD_LIBRARY_PATH=/usr/lib/

Thank you all for the help!