[MPlayer-users] Creating and playing MPEG stll images

[Giacomo Comes]

On Sun, Feb 05, 2006 at 11:26:24PM -0500, John Brown wrote:
> 
> 
> 
> >From: Philip Walden <pwaldenlinux at pacbell.net>
> 
> >I found that mpeg1 is not valid unless it is 24 or 30 fps. You need to set 
> >-ofps to something. So maybe mpeg2 has the same problem?
> 
> Thanks for your reply.
> 
> I did set the rate, using  fps=30000/1001 as a parameter to -mf. Looking at 
> your command line, I realized that I did not explicitly specifiy everything 
> that is required for an SVCD-compliant MPEG. My modified command:
> /* added keyint=1 in -lavcopts and -ofps 30000/1001 */
> 
> C:\DVD>mencoder mf://menu.jpg -mf type=jpeg:fps=30000/1001 -ovc lavc 
> -lavcopts v
> codec=mpeg2video:vbitrate=2000:vrc_maxrate=2500:vrc_buf_size=917:keyint=1:aspect
> =4/3 -of mpeg -mpegopts format=xsvcd -ofps 30000/1001 -aspect 4/3 -o 
> menu.mpg
> 
> This did not improve the situation either. Remember, though, that I burned 
> a SuperVideo CD that worked using this mpeg, and I can view it in other 
> players. I was just wondering if the MPEG was compliant, or whether the 
> players were just tolerant.
> 
> Anyway, I found this in the MPlayer Docs, in the Frequently Asked Questions 
> (Chapter 4)
> >4.6. DVD playback
> >Q:
> >
> >What about DVD navigation/menus?
> >A:
> >
> >MPlayer does not support DVD menus due to serious architectural 
> >limitations that prevent proper > handling of still images and interactive 
> >content...
> 
> So it seems that MPlayer cannot play MPEG still images. If I increase the 
> number of frames by copying menu jpg to menu2.jpg, menu3.jpg (don't know if 
> there is an easier way), I can view it in Mlayer, but I suppose that it is 
> not an MPEG still mage anymore.

I can confirm that mplayer can not play an mpeg with a single image. If 
the mpeg has n frames you will see the first n-2, the last two are not showed. 
(Actually the sequence will be 1 2 3 ..... n-4 n-3 n-2 n-3)
So you need at least 3 frames in order to see one.
This limitation regards only mpeg. Avi are not affected.

Giacomo