Android AudioTrack source

I've been doing a lot of work optimising our audio playback on Tub Thumper Pro for Android this week and I constantly find myself referring back to the C++ source for the OS to help solve latency issues.

For anyone doing work with the AudioTrack object, it's worthwhile bookmarking the source online so that you can browse it whenever you hit a problem.

Here's two links I find really useful:

• AudioTrack.cpp
• AudioFlinger.cpp

Incidentally, I've found that the best way of getting low-latency polyphonic audio is to subclass AudioTrack and call finalize() yourself after you're done playing; I was seeing more "write blocked for xx seconds" messages before I did this, although it may be co-incidental.

MIDI Playback in Android Cupcake

If, like me, you've been wondering why the audio support in Android was so poor, you'll be pleased to hear that Android 1.5 (Cupcake) addresses some of the issues.

I'll write a more in-depth post once I've gone through some real world examples, but one thing which I'm currently reading up on is the in-built MIDI support.

Rather than just stick a bog-standard MIDI engine in Android, the Google engineers have chosen to include a JET playback engine, which allows musical synchronisation of clips and seamless playback. It's mainly tailored towards game playing as it allows you to script the clips about to played back to tie in with the gameplay, but I'm already thinking up some cool musical ideas for it.

Have a read of the documentation on Android.com, at http://developer.android.com/guide/topics/media/jet/jetcreator_manual.html

UK G1 Owners - Get Android Cupcake early!

The rumour mill has been in full swing with regards to the early push out of Android 1.5 "Cupcake" to UK T-Mobile G1 users. Whether or not they really have started the push remains to be seen (I've not had it) but the folks over at Andblogs.net have posted how you can get it early.

First things first, grab the update: UK 1.5 Cupcake Update (CRB17) (5)

Save it to the sd card, named “update.zip”. (If you use windows, be sure you aren’t naming it something like “update.zip.zip”.) Reboot your phone in recovery mode (hold down ‘home’ while booting until you see the diamond warning.)

Now time to update! Press Alt-L. (This will turn on logging, so you can see what is going on.) Then Alt-S will apply the update.zip from the sd card. When it finishes, it’ll reboot.

I'm just trying, fingers crossed!

Oh, and don't blame me if you brick your phone, like I said - I've not tried it yet! Don't know if this works for countries other than the UK either, I'd suspect not but feel free to comment if you know otherwise.

Update!

My phone exploded in a huge fireball! Just kidding, after a nerve wracking few reboots with some cryptic logos I finally got a shiny new animating silver Android logo and I'm now smothered in delicious Cupcake.

Here are a couple of money shots:

The much-talked about touchscreen keyboard.


New homescreen icons (and check out my sweet (get it?) NIN Downward Spiral wallpaper, in your face iPhone!):


In the inimitable words of fake James Hetfield, sprinkles GOOD!