Pandora - The Music Player


Just my $0.02: Rhythmbox & other desktop-oriented music players don't sound like fun on a tiny device that should be easy to manipulate without a mouse. Maybe a skin/GUI for mplayer would do the trick. Something that will let me pick songs and play them with my finger on the touchscreen or with the game control nubs.

OTOH, Rockbox has been optimized for small screens and batteries. Yes, I think it basically provides a full OS. No, I've never actually seen it in action. But reading about it has made me consider buying a portable music player (before I'd ordered a Pandora). So it could be pretty sweet if it one was to port over the application-level portions of Rockbox to the Pandora. Even if it was a fork, it could provide a good starting place and, I'm assuming, a well-tested, well-thought-out GUI for a handheld device.

Sadly, it won't be me porting it over...

--Todd
 
It doesn't have the eye candy everyone seems to be looking for(I'm currently trying to work on that), but I will be bringing over ommpc from the gp2x world. As a frontend for mpd it's much better suited to dealing with audio than something like mplayer, and having been designed for a handheld, it's also better suited than a rhythmbox or xmms...IMHO. If I was looking at something from the desktop world, I would look for some of the media center apps designed to be controlled with a remote...they should work well without dragging out a stylus as well...however the music sections in such apps are usually fairly sparse.

Elisa looks pretty sweet, but very, very heavy being python based and dependent on OpenGL...

Anyway, just thought I'd throw yet another option out there...
 
Amarok is easily my favorite linux music playing app, and i would love to have it on the pandora (although 2.0 looks so terrible, i smell a fork). Maybe someone could trim the fat from amarok to make it run well on the pandora (or other low-powered pc's for that matter, like an 'Amarok Lite').
 
How about making the two analog nubs produce a "scratch" sound when you turn them? :D :D :D (they do look like two teeny tiny turntables, don't you think?) ;)
 
It might be worth mentioning again, here, that whilst the 100 hours is fairly realistic, it would rely on packing a music player, SD access, and button-drivers into whatever size the memory of the power-saving/audio chip is.

I.e. the 100h prediction, if I understand it right, assumes that the 3530 itself is effectively off. I may, of course, not be undrstanding it right.

I imagine a music player of that description would have a map something like:
- Interface on OMAP when top is open. Main CPU runs this, lets you set up playlists and displays things like current position, etc. when screen is open.
- When play is selected, the respective data gets passed to the mini-audio player on the ultra-low-power chip.
- When the lid is closed, the OMAP goes into it's lowest standby state. The other processor keeps running though. Songs could be skipped with shoulder buttons or some such. Volume, obviously, is a non-issue given the hardware volume control (yay). Seeing as the screen and CPU are both off, the audio is the only major drain remaining.
- When the lid is opened again, the OMAP checks the current file being played and goes to the respective point on the playlist, showing current data.

I'm guessing that a player behaving in this manner might very well need to be custom-written, though, if only because of the interactions between the sound/power-saving chip and the main processor. We'll see though.
 
QUOTE
When play is selected, the respective data gets passed to the mini-audio player on the ultra-low-power chip.


Are you talking about the DSP?

If so, this is probably not the best way to do things; the DSP can be completely switched off, but the ARM obviously can't. My understanding is that there are better power savings doing it this way (and using the SIMD-style instructions in the Cortex to produce power savings in the ARM) than by keeping the ARM running (at whatever speed - presumably the clock rates are linked anyway?) and decoding on the DSP.
 
lardman said:
QUOTE
When play is selected, the respective data gets passed to the mini-audio player on the ultra-low-power chip.
Click to expand...
Are you talking about the DSP?

If so, this is probably not the best way to do things; the DSP can be completely switched off, but the ARM obviously can't. My understanding is that there are better power savings doing it this way (and using the SIMD-style instructions in the Cortex to produce power savings in the ARM) than by keeping the ARM running (at whatever speed - presumably the clock rates are linked anyway?) and decoding on the DSP.


He doesn't mean the DSP. There is another separate chip on the PCB, that can decode mp3. It's mentioned somewhere in the thread about the PCB blog post, I think.

Edit:
Notaz posted this link:
http://focus.ti.com/general/docs/wtbu/wtbu...templateId=6123
 
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If anyone's used a Creative Zen, a fullscreen gui like that with a few more features and more responsiveness would be wonderful.
 
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Okay, a quick roundup.

Rockbox is spot on. This is what i'm looking for, a fullscreen view of everything, just like any other music player. It just needs controls on the screen and it's perfect for the Pandora.

The alternative Quasar MP is not a bad option either, and is probably simpler to adapt. Shame it doesn't cover the entire screen though.

Elisa has the eye candy, but as said above, is unfortunately a bloated media center application. We just need music.

SonyEricsson and their Walkman series did it right, if you ask me. If there's an app like that out there, it'd be perfect.
 
Quasar looks like a fantastic app.

There is only one special feature (or, function) I'd like to have in a music player; the ability to quickly seek through a track with an analog stick. Either XBMC style (by leaning to the left or right), or iPod style (by rotating the nub).

I mostly listen to live/DJ sets, which tend to be single MP3 files up to two hours long. So good seeking is essential. I'd offer unspeakable things to see it done, and I'd never ask for another feature again.
 
A sorta track bookmarking/indexing feature would be cool for long tracks like that also. Any of the players mentioned have that feature?
 
lardman said:
QUOTE
He doesn't mean the DSP. There is another separate chip on the PCB, that can decode mp3. It's mentioned somewhere in the thread about the PCB blog post, I think.

Edit:
Notaz posted this link:
http://focus.ti.com/general/docs/wtbu/wtbu...templateId=6123


That can't decode mp3 afaict, do you have a link to the thread?

The thread is here:
http://www.gp32x.de/board/index.php?showt...44779&st=60

Mp3 isn't mentioned there. But what are those audio codecs integrated in that chip, then?

Edit:
Scratch that, I have obviously got it wrong.
Here is a quote from Mweston, the main hardware designer of the Pandora:
QUOTE
This is sort of the idea I had in mind when suggesting to Craig we could get 100 hours of battery life just playing music.

What I thought would be ideal is to suspend Linux to SDRAM and then put the external memory to sleep. Then, using the internal scratch pad RAM, and maybe using the DSP core and its RAM, a low power, low speed music player could be run to just play music and use the shoulder buttons to change tracks. It would be pretty basic, but most of the time, I don't even look at the display when playing music. I just put the player on random shuffle so this seems like a great idea for when you don't need any of the Pandora's other capabilities.

The alternative is to see just how little power we can use with the screen off, unnecessary features powered down, the clock speed reduced way down to whatever minimum keeps required external interfaces working, and still running Linux (since it has so many codecs supported already). This will take a while to master because I don't think current OMAP3 kernels even turn Smart Reflex features on yet.
Click to expand...
 
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QUOTE
Mp3 isn't mentioned there. But what are those audio codecs integrated in that chip, then?


Probably alaw/ulaw. Codec is simply an encoder/decoder, in this case a hardware codec which transforms pretty simply encoded digital audio to a analogue audio output and vice versa.

QUOTE
The alternative is to see just how little power we can use with the screen off, unnecessary features powered down, the clock speed reduced way down to whatever minimum keeps required external interfaces working, and still running Linux (since it has so many codecs supported already). This will take a while to master because I don't think current OMAP3 kernels even turn Smart Reflex features on yet.


Will be interesting to see what the difference is (or might be). I imagine it won't be worth the effort to shut down the ARM and just use the DSP, but we'll see :)
 
Technically, just how much playing time could we get if all we left running were the display, the player and the necessary hardware?

This could be named the 'Pandora Music Mode'. Maybe even build a boot selection for it. Turns the Pandora into a simple media player, like all the others are.
 
lardman said:
QUOTE
Mp3 isn't mentioned there. But what are those audio codecs integrated in that chip, then?
Click to expand...
Probably alaw/ulaw. Codec is simply an encoder/decoder, in this case a hardware codec which transforms pretty simply encoded digital audio to a analogue audio output and vice versa.

QUOTE
The alternative is to see just how little power we can use with the screen off, unnecessary features powered down, the clock speed reduced way down to whatever minimum keeps required external interfaces working, and still running Linux (since it has so many codecs supported already). This will take a while to master because I don't think current OMAP3 kernels even turn Smart Reflex features on yet.


Will be interesting to see what the difference is (or might be). I imagine it won't be worth the effort to shut down the ARM and just use the DSP, but we'll see :)


I'm really happy, that you chose to buy the Pandora and want to code for it :)
Optimizing the use of the OMAPs goodies is crucial for Pandoras success.
I hope that maciek succeeds in hacking the SGX.
 
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