[FFmpeg-user] Transition between two videos

[Michael Bradshaw]

On Thu, Jul 5, 2012 at 11:26 AM, Roger Pack <rogerdpack2 at gmail.com> wrote:
>>> There are "fade" type filters, though I've never used them.
>>> You can concate files like this:
>>> http://www.ffmpeg.org/faq.html#How-can-I-join-video-files_003f
>> Thanks for replay,I need any other transition the fade in/out.Do we have that in ffmpeg.
>
> I see a "fade" filter:
> http://ffmpeg.org/libavfilter.html#fade
> However I do not know if ffmpeg+libavfilter can "combine + fade" all
> in one step, you may need to first create intermediary files.  Anybody
> else know?

The fade filter can't do that, as it takes one input video and
produces one output video. A "fade from one video to another video"
would require two input videos and one output video (VV->V in ffmpeg
-filters). The only VV->V filter is the "overlay" filter. I wonder if
you could create an intermediate video using the fade filter to fade
to/from completely transparent, and then use that intermediate video
and the second video as input to the overlay filter and if it would
combine everything correctly... I've never tried it, so I can't say.
It would be interesting to know though.

--Michael