Monday, 11 June 2012

Random stuff

So I spent the last couple of days playing with a few random things.

Beat detection
Interest in this goes way back, probably to when a few lads and I did some graphics at a rave in the early 90s ... anyway I thought i'd have another look. I started here with this rather badly formatted word 'processed' document, but ended up trying to implement a wavelet algorithm based on this paper.

I played with it a bit but didn't really get good results (as far as i could tell, and my testing code wasn't great). Next time I revisit it i will probably look at the simpler spectrum-based algorithms from the first article but with a variation on the cycle detection.

Oh that DLNA crap again. Mostly because there doesn't seem a simple video player that lets one access a DLNA server from Linux in a simple way. I started with cling, and after waiting for about 20 minutes for maven to compile it decided that there really is a build tool worse than ant (surprising as that is), and then proceeded to split the project up into a pattern that netbeans can work with. I eventually got it to run and started work on a jjmpeg media renderer, got the android browser working and so on. But really wtf - it's a huge fucking pile of code just to retrieve a URL to a file on a HTTP server ...

Then this morning I read this post from the developer of libdlna (which seems to be abandoned now), and decided it was just a world of pain I wanted nothing to do with.

IF I ever bother with this again I will probably just write my own protocol but today I can't be stuffed.

jjmpeg build
And finally today I poked at the jjmpeg build. Looking at using the current android branch as the main code-base. The native stuff isn't that difficult (just making a decision and sticking with it is the main problem), but ant and netbeans either makes it impractical or impossible to support cross-platform development in the same project.

So I will probably need to create 3 side-by-side projects, although for various reasons this isn't terribly ideal either.

  • jjmpeg-core would contain the main binding classes, native generators and so on. Probably a copy of the ffmpeg sources.
  • jjmpeg-java would contain the java-specific i/o and display classes. I guess this would also build the native code.
  • jjmpeg-android would contain the android-specific i/o and display classes and android native build, and probably be configured as an android library project so it can be re-used.

I didn't actually get that far, I was working on re-arranging the native build and platform-specific stuff in order to fit it in with the android build and clean it up. But I didn't really come up with great solutions, and in the end I think I solved nothing so might have to try again from scratch another time.

Just not switched on today, so might go find somewhere warm to read ...

1 comment:

johndrinkwater said...

DLNA is horrible, but all my devices now want to use it… my TV, PS3, hell even my Android device supports it.

Which makes it bloody funny that totem dropped support for it last year, and VLC has it buried in the playlist section of the GUI.