ndoran

Basically, I am looking for ways to conserve space on my 128M SD card. Has anyone tried using PocketMusic to play zipped MP3s? Or, is there any other space-saving method out there?

Thanks,

Neil

ARM Hacker

heh.. a zipped mp3 would probably be a bit larger than the mp3 files itself.

Compressed data, jpg or mp3 doesn't compress well.. The reason is mp3 or jpeg is compressed in a manner that is suited to the type of data it is, jpeg being inverse discreet cosine transform and mp3 being a breakdown of the sound into its components in the frequency domain.

Applying LZ or the pkware compression to that data will result in a slightly larger file because of the overhead needed to store the symbol dictionary and headers for the compression format used.

ndoran

You're right that it appears little space savings will be realized by compressing mp3s. Rather than compressing individual files, I was envisioning zipping several tracks together.

I subsequently tried this to see how much space would be saved...by zipping the nine tracks of Bob Marley's 'Natty Dread' together with maximum compression, the size goes from 37+ megs to about 34.5 megs. Not much savings there.

So, what you're saying is that the file format does not take well to compression. I wonder if there is something I can do during file transfer and/or conversion that will shrink these babies down a bit?

Thanks,

Neil

Double-Trinity

Yeah, you coudl try using .ogg or some other format, but since Pocket Music I've found has the best audio quality of all the PPC players, I would prefer to stick with that (plus MP3 is more universal anyway).

Hm... I thought of an interesting idea for a program, it wouldn't compress songs at all, but perhaps there could be a program that would cycle certain songs on sync. You coudl have a folder, and playlists with a few extra bits added to each song... a probability of the staying on the device.

Then, on synce, it would weigh each file by your given probability (it would be pssible to make it so that some songs would never switch), then, it would randomly cylce in and out some songs from a file on your hardrive, to whatever folder you're storing your playlists in. (or maybe it could go on a folder-by-foldre basis)

but sometyhing like that would be quite cool.. to be able to set it so that say, 20% of your songs change out, and that certain ones have a higher chance of being swapped than others.

I'm thinking, a text log could be genreated with filenames, and an integer variable between say, 1 and 9, with zero being always on PC, and 10 always on PPC. the UI could then translate this into slider-bards, and then there could be the playlist editor for both PPC, PC, and the actaul sync utility on both.

Just a thought for another piece of bloatware to add to my PPC, too bad my programming skills are effectively nil =/

NMkiD

yeah a zip file is as about as compressed as it can be, thats like zipping a zip file :D

ARM Hacker

ndoran, I doubt you even saved that much.. More likely it has to do with how much 'space on disk' those files take up. When the files are seperate on the disk they tend to occupy some extra sectors that they don't when they are all in one big .zip file, thus the difference in the total space of the individual files and the final .zip file.

ndoran

Yeah, that makes sense...

I guess I'll just have to suck it up and buy a bigger card if I want to have more than one or two albums with me. Anybody know the status of Panasonic's one-gig SD card due out this year?:p
Now *that* should do the trick.

Anyhow, thanks for the input, ARM Hacker and others.

_Neil

jbit

I usualy just do a super high quality rencode using lame (128kbps max vbr)
Sounds almost as good as the original at a fractional smaller size
(Most of my mp3s are HQ (160->256) VBR or 192CBR)
I might try to hack active sync ot automagicly use its "convert" feature to reencode on-the-fly, could be quite useful ;)


(i'm using a 64MB MMC card, so space is an issue, especialy since i usualy have a 50Mbyte divxon it lol ;)

--jbit

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