avconv set really slow frame rate

Question

I have just a couple of images ( 20-40 ) and I want make movie which plays with frame rate 1-2 fps ( i.e. each image should be visible for 0.5-1 second ) ... so the whole movie should take ~20-40 seconds to play. It seem that video generated using avconv with option -r 1 or -r 2 does not do this job :-( .

If I generate the movie in this way:

avconv -i ./relief_%04d.png -force_fps -r 1 -vf "scale=320:240" test.avi

I also tried option -force_fps it has no effect

it does strange things:

1. the movie plays just ~2 seconds ( instead of 20-40 seconds )
2. it does not show every images ( just 1-2 )
3. it is like very laggy

( and it is also a bit dependent on the player. mplayer do the strange things described above, vlc shows just black screen )

Solution

I have not tested this but try specifying the framerate before you specify the input file:

avconv -r 1 -i ./relief_%04d.png \
   -vf "scale=320:240" \
   test.avi

This may be enough to get you moving hopefully, if not there are many more hints on this page:

Create a video slideshow from images

Note especially the method of specifying the framerate twice which would bear some experimentation with in your case.

This is aimed at FFmpeg rather than avconv but should hopefully work with both...

Comments

[andrew.46]

Linux often leaves the safety catch off :)