[gst-devel] use of videorate plugin and gnonlin

[Henry Gomersall]

Hi,

I have spent some time (spread out over the last year or so) trying to
make a slide show application in Gstreamer. I have received some help in
the past from Edward Hervey, but I think I am in a better position to
ask a more direct question.

The aim of the project is to generate a photo slide show based on a set
of jpeg images. The idea is that using gstreamer will allow easy and
elegant insertion of interesting transition effects and allow simple
export to a video file. My current idea is to use gnonlin, with a
composition set up to handle each jpeg load/decode bin, and then a
gnloperation to handle the transition effects.

The 2 questions I have are as follows:

- A filesrc ! jpegdec type pipeline just pushes out a single frame (if I
use timeoverlay it seems to have a timestamp of 0). I assume that I need
to push some more frames with increasing time stamps. I am hoping that
the videorate plugin will solve my problem. Any advice on how to use it
in this context is much appreciated. Reading the docs, it seems to
depend on the frame rate of the source, which in this case is of course
1 frame (ever!). Do I need to adjust the source caps or similar?

- I only ever care about 2 photos at an instant (and only then during
transitions). Is the idea that each each photo should have its own
load/decode bin correct? Should I instead have a single or two bins and
change their parameters? Any advice on the best way to source lots of
photos would be appreciated.

Many thanks,

Henry Gomersall