2

I am looking for the simplest way to do alpha fading between two video channels and control it with physical buttons.

I am comfortable with Python (but I can also do some C++ and Bash scripting).

I have tested the videos with OMXPlayer, and they are good (both on codec, resolution, file size, duration, fps, etc.), but I don't know how to make the fade between two videos.

How can I do it?

Edit:

there are some different ways to do it. I have actually tried with gstreamer wrapper (the one in openframeworks) but it is super slow and does not keep the right framerate. So I need a solution tailored to rasberrypi.

Community
  • 1
nkint
  • 215
  • 3
  • 9
  • You need to use graphics engine to do this. It can be done with CPU but it will be very choppy. It is quite complex code either way. This is not an easy topic. – Piotr Kula Sep 04 '13 at 08:25
  • 1
    It just has nothing to do with Pi, Linux or any thing relating. Maybe programming. – Piotr Kula Sep 04 '13 at 08:25
  • to moderators: please see the edit. I need a solution tailored to the rasberrypi because I've done it in a normal desktop pc in various ways. – nkint Sep 04 '13 at 11:49
  • You need something that will use the GPU of the Pi. At the moment that is ... nothing. And now it does make more sense actually. – Piotr Kula Sep 04 '13 at 12:21
  • @nkint: You have an existing solution that is "super slow" on your 700Mhz single core CPU. Do you think the problem is A) The existing solution obviously involves poorly written, inefficient software, or B) Your machine cannot handle this task quickly using existing methods. If (A), look for a better solution, it does not need to be "tailored to the pi", it needs to be available for linux (and this is not a general linux site). If (B), well, there you go... – goldilocks Sep 04 '13 at 14:39
  • I am documenting on it. So.. the problem is that my gstreamer wrapper doesn't use OpenMax for hardware acceleration. While omxplayer does it automatically. – nkint Sep 04 '13 at 15:07
  • Anyway, @goldilocks I don't think it is "poorly written, inefficient software" (and it is not my code, anyway), and I don't think you last comment is constructive in anyway. – nkint Sep 04 '13 at 15:13
  • My first point was: if you do not think it is poorly written or inefficient software, then the problem is probably (B). I suppose it may also be that (C) you need help getting the most out of the software, which relates to my second point which was intended to be helpful: there are better places to look for answers to general linux questions, and plain and simple this is a general linux question and not a raspberry pi specific issue. If you want to disregard that helpful piece of advice, you are of course free to do so! We're not being mean, we're just letting you know how it is. – goldilocks Sep 04 '13 at 15:22
  • To be fair, I'll qualify that by adding that you might hit upon a raspberry pi specific question in the course of your research, in which case this is a good place to ask ;) – goldilocks Sep 04 '13 at 15:26
  • 1
    yes :) Anyway, I'm almost there, I've found a repository where there is an implementation of the OpenMax harware accelleration inside the frameworks I've found. Just time to test it and I'll post the results! – nkint Sep 04 '13 at 15:36
  • @nkint any luck? I'd love to hear more about this – João Pereira Nov 28 '13 at 15:24

0 Answers0