[MEncoder-users] encoding multiple jpeg files to avi, with strange results.

[Nicholas Mistry]

I recently purchased a dlink dcs-900w wireless webcam with hopes to create
timelapse videos from the captured images.   I have used mencoder in the past to
make timelapse videos, so i figured this was a great tool for the job. 

I wrote a simple script to grab a jpeg image from the camera every minute and
store it with a filename that is in the 'date +%s' format.  (for those who dont
know:  %s  = seconds since '00:00:00 1970-01-01 UTC').   This way i dont have to
worry about the frame numbering.

when i run mencoder with the following commandline:

mencoder  "mf://*.jpg" -mf fps=4:type=jpeg -o output.avi -ovc lavc -lavcopts
vcodec=mpeg4

I get an avi that seems to "flicker" back and forth beteween the first frame and
black.   There are also some artifacts that start showing up in the top of the
image.   

Trolling through the docs, mailing lists, etc.. i could not configure mencoder
to work.  Every time the output was the same.   DIVX, XVID, MPEG1, MJPEG, etc... 

Just out of blind luck, i accidentially made a typeo in my script and managed to
use imagemagic's convert utility to convert the jpegs into new jpegs.   The
script then ran mencoder on the NEW jpegs and the movie came out fine.    It
seems at this point that the problem was how mencoder was reading the jpegs, and
not the encoding side..   

I am wondering if anyone here has experienced a similar problem when trying to
encode a series of jpegs.   Could this be a bug with mencoder?  

I am using: MEncoder 1.0pre7try2-3.4.4  compiled from source.

As a side note, i have tried to open the jpeg with all sorts of image programs
(command line, and otherwise), and no program reports any errors when opening
the original source images. 

Thanks in advance.

-N