so I want to code a ddream replacement since its website died

[Patashu]

RIP www.ddreamstudio.com . If you need DDReam download it here: http://www.mediafire.com/?82al94e5ot6sfy2

Aside from the site for it being down, there are some core flaws with the program that don't prevent me from stepping with it but introduce unnecessary barriers and irritants.
Major problems:
-No mac or linux build
-No downscroll
-(at least on my laptop) when not focused on DDReam consumes as many cpu cycles as it can
-Can't say B, other unwanted capturing of input, etc
Minor problems:
-Support of stops incomplete
-(at least on my laptop) changing the resolution crashes DDReam
-The keybinding for changing music rate is ctrl+shift+left/right: at least on my laptop this rotates the screen then crashes DDReam
-You can't erase notes you pass over by creating a hold, and other oddities of using holds
-Working with bpms instead of beats is difficult
-Miscellaneous parsing errors

That said, my reasons for wanting to code a replacement are multifold:
1) I really, really need some practice with an actual program - yes, this will be my first serious programming project, and that's really sad
2) I want something that works like ddream but is crossplatform, open source and will have constant development possible on it
3) I'd love to be able to port it as a webpage embedded java applet and/or as an android app

I am intending on writing it in java so I can do 3), using the swing library for window management.
-Does anyone know good java libraries for music file manipulation, e.g. for ddream's waveform display, waveform filtering and ability to change the music rate while playing? How would I do all this?
-Anyone interested in helping out? I could set up a repository for it or something.
-(from Silvuh) growing with subbeats between beats, finding the average/min/max/other stats? bpm of a range of beats

Features I want:
-To be able to step with beats or with bpms and mix the two models on the go depending on what's more appropriate, and to have stops at the same time.
-To be able to look at the chart through cmod or xmod goggles
-Automatic offset and BPM detection using the waveform - this would be sooo useful if I could make it work. Worst case have a sync wizard that'll guide you through doing it by hand.
-Customizable snaps - e.g. if I want to step a file with 64th swing, I'd change to 16th swing, open 'customize snap', untick the yellows and tick the greens immediately after them, then hitting up/down or scrolling the mousewheel would move only to those locations. because moving down to 64ths destroys your mobility
-Swingifier/unswingifier - select a part of the chart, and enter in how much I want to force down each offbeat (or each second beat) and it'll expand/contract every section to compensate. Or I can go the other way, and say how far down I want to reach and pick that up and make it the new midpoint.
-Maybe make the song-long scrollbar have a waveform mimicing the one under the chart and a tiny scale preview of the chart? (might show note densities and clusters instead of the patterns b/c it'd be so shrunken)

Less important features:
-Some kind of hold management techniques - e.g. when laying down taps I want each one to be a hold that lasts to the next tap, or to the tap after that, or half way between the two, or X distance after the first, and if it's going to collide with another note leave a gap of X... things like that could eliminate a lot of tedium
-Automatic shuffling or lateral rearranging techniques, aka what I do automatically to keep stuff from being boring. also pattern suggesters, but this is really low priority because I'd only put this kind of thing to allow me to be really lazy lmao, plus it'd probably be more effort to code than to actually do normally
-A doublestep detector, but this is kind of meh because there are lots of patterns that can be hit using footswitches or doublesteps fine and when jumps are added to the mix it gets ambiguous fast
-Dumping your chart to multimedia formats like: png (aka bemanistyle's simfile preview), animated gif, avi, mp3 with assist tick and beat tick on top of it (maybe separate sounds for chords, holds, mines passing and so on? could be kinda interesting lmao). maybe putting it on ftp/imgur/sendspace?
-Being able to view someone else's chart and comment on it (chat room?) in real time. This would be super cool but I have no idea how to do this and don't want to think 'I HAVE to do this'. It could be very basic, e.g. you attach the program to a port, and when someone else connects with their program to that ip and port it sends the sm and mp3 as it was when they connected, and you can chat back and forth and request a resend.