[FFmpeg-user] How to slow down video playback?

[Virgil Stokes]

On 28-Dec-2014 19:01, Simon Thelen wrote:
> On 14-12-28 at 18:33, Virgil Stokes wrote:
>> I have used FFmpeg to extract PNG images for each frame of some short AVI files.
>> These AVIs were created for a research project in which a person's movements
>> were recorded over about 2 seconds at 25 fps.  These extracted images are then
>> processed and graphical objects are often superimposed on them; but, the PNG
>> images are always kept at the same size (720 x 576 Px).
>>
>> I use FFmpeg to merge these new PNG images back into an AVI file; then use Miro
>> to convert the AVI to an MP4.The problem that I have been unable to solve is
>> that when I playback this MP4 file in an HTML5 video player with FireFox (or
>> Chrome or IE) they are so short that the viewer has little chance to examine
>> them.  I would like to be able to show them frame-by-frame; but, this apparently
>> is a rather difficult problem for the HTML5 video player.
>>
>> Is it possible to use FFmpeg to create a very slow AVI (e.g. 1 frame per second)
>> or an MP4 file directly, that would allow the user to study the individual
>> images? I would be glad to provide one of these short AVIs for testing purposes
>> if needed.
> https://trac.ffmpeg.org/wiki/Create%20a%20video%20slideshow%20from%20images
>
> Has examples and everything.
>
Yes, thanks for the line :-)