SD Card file format

[jukingeo]

Hello all,

I been away from the forums for a bit and I have been reading up on the new AP-16+.  I am seriously considering purchasing one as it would greatly simply a project I am working on for this Halloween.  However, after reading the documentation, I have a couple questions in regards to buying and setting up the SD card.

Can the AP-16+ can also read cards labeled SDHD?

The SD card HAS to be formated to either FAT16 or FAT32, nothing else, correct?

In stand alone mode, would I be correct in assuming that you would set up the files directly onto the SD card without being in a folder?   

For example, within Windows you would just have to name the files like so:

AMBIENT.wav
SFX00.wav
SFX01.wav
SFX02.wav
~
SFX14.wav
SFX15.wav
AUX01.wav
AUX02.wav
~
AUX07.wav
AUX08.wav

Would that be all you have to do?

Thank You,

Geo

[bsnut]

It looks like you are on the right from what I can see. To answer this question

Can the AP-16+ can also read cards labeled SDHD?

I don't think so.

[JonnyMac]

We've only used standard SD cards (class 4 and higher is best), so we honestly don't know if SDHD card will work.  You can try formatting it (FAT16 or FAT32) and put your audio files in the root (folders are not supported).

What usually catches people out is metadata in the file -- REMOVE IT.  When the AP-16+ encounters metadata in the file it stops at that point.  Using Audacity you can easily "scrub" the metadata from your files, and convert to mono if you choose (the latest firmware supports stereo or mono files, up to 44.1kHz).

Final note: the maximum file size is 2G; this has to do with 32-bit values (sign + 31 bits) in the Propeller.

[jukingeo]

We've only used standard SD cards (class 4 and higher is best), so we honestly don't know if SDHD card will work.  You can try formatting it (FAT16 or FAT32) and put your audio files in the root (folders are not supported).

Ok, so then then file structure I presented would be the correct way to go for a stand alone operation.   But when using a controller, you can use the DOS 8.3 standard for naming right?

What usually catches people out is metadata in the file -- REMOVE IT.  When the AP-16+ encounters metadata in the file it stops at that point.  Using Audacity you can easily "scrub" the metadata from your files, and convert to mono if you choose (the latest firmware supports stereo or mono files, up to 44.1kHz).

What is metadata?  How does it get in the file in the first place?

I actually like the idea of stereo file support.  One thing I had in mind of doing is using a stereo file to have a filtered low end channel to drive a subwoofer and use the remaining channel for the main audio.  Stereo is just one huge advantage to upgrading my AP-8.   But true, it isn't something I would do all the time.

Would I be correct in saying that converting a file to mono would cut the file size in half?

Final note: the maximum file size is 2G; this has to do with 32-bit values (sign + 31 bits) in the Propeller.

I seriously doubt I would have a single file that big but I would keep that point in mind.

Many thanx for the info.

Geo

[JackMan]

jukingeo,
     What is an SDHD card? I think you may have meant SDHC which is a high capacity card. I doubt it will work in the AP-16+ as they usually need a USB adapter for computer use. You really don't need such high capacity anyway.

[JonnyMac]

But when using a controller, you can use the DOS 8.3 standard for naming right?

You must use 8.3 naming, for files that can play locally as well as those that are accessed via the serial connection.

What is metadata?  How does it get in the file in the first place?

It's additional, non-audio data that can be included in the file. 

Would I be correct in saying that converting a file to mono would cut the file size in half?

Yes. The AP-16+ will play a mono file from both speakers.  You can adjust the balance (via channel volume controls) through the serial link.

[JonnyMac]

Just a follow-up.  I needed to unload the files from my camera's SD card and noted that it was marked SDHC -- is this what you mean?  After saving the images/video onto my media storage drive I reformatted the card (FAT32), dropped some audio files onto it, and popped it into my AP-16+.  Worked just fine.

[jukingeo]

Just a follow-up.  I needed to unload the files from my camera's SD card and noted that it was marked SDHC -- is this what you mean?  After saving the images/video onto my media storage drive I reformatted the card (FAT32), dropped some audio files onto it, and popped it into my AP-16+.  Worked just fine.

Yes, that is what I meant.  The HC in SDHC stands for "High Capacity".  I think all cards 4 gig or more have the SDHC designation.   I wasn't sure if the AP-16+ could handle them or not, which is why I initially asked, but it looks like they can.   At any rate, thank you for testing it out.

Geo

[JonnyMac]

BTW, the detail I left out was that test was done with a 32G SDHC card.