[MEncoder-users] Problem with generating video from image files

[Reimar Döffinger]

On Sun, Dec 18, 2011 at 12:01:48PM +0100, Torbjörn Rathsman wrote:
> 
> 
> > -----Ursprungligt meddelande-----
> > Från: mencoder-users-bounces at mplayerhq.hu
> > [mailto:mencoder-users-bounces at mplayerhq.hu]För Lobster
> > Skickat: den 18 december 2011 06:45
> > Till: MEncoder usage discussions
> > Ämne: Re: [MEncoder-users] Problem with generating video from image
> > files
> >
> >
> > On 18/12/2011 9:04 a.m., Torbjörn Rathsman wrote:
> > > I am trying to create a video file from a set of image file using the
> > > following command:
> > >
> > > mencoder mf://../frames/%d.png -mf fps=25 -o ../video/new-video.avi -ovc
> > > lavc -lavcopts
> > >
> > vcodec=mpeg4:mbd=2:mv0:trell:v4mv:cbp:last_pred=3:predia=2:dia=2:v
> > max_b_fram
> > > es=2:vb_strategy=1:precmp=2:subcmp=2:preme=2:qns=2:vbitrate=30000000
> > >
> > > After it comes to a completly black frame it says
> > >
> > > "The selected video_out device is incompatible with this codec."
> > >
> > > and aborts without generating a valid video file. If I remove the black
> > > frame, everything works fine. How should I deal with this?
> >
> > It sounds to me like that black frame has been created with different
> > colour settings
> > than the other frames, or some thing similar.
> >
> > if I was you I would compare the colour depth and mode of the black png
> > compared
> > to the other ones, and then try to make the black png with the same
> > settings as the
> > other png's.
> >
> 
> This frame was 1 bit per pixel black/white while the other was rgb24. What I
> am doing is the following
> 
> mogrify -resize x720 ..\frames\*.png
> mogrify -crop 1280x720+128+0 ..\frames\*.png
> mencoder mf://../frames/%%d.png -mf fps=25 -o ../video/new-video.avi -ovc
> lavc -lavcopts
> vcodec=mpeg4:mbd=2:mv0:trell:v4mv:cbp:last_pred=3:predia=2:dia=2:vmax_b_fram
> es=2:vb_strategy=1:precmp=2:subcmp=2:preme=2:qns=2:vbitrate=30000000
> 
> It looks like mogrify changes color type to save space when it can. However,
> I guess I could do the resample and crop in the mencoder command. How?
> First the frame should be resampled to a height of 720 pixels. Then the
> width should be cropped to 1280 pixels preserving the center of the image.

-vf scale=-1:720,crop=1280:720
as a starting point (not sure about the -1).