Support for Sony Atrac .oma files codec ?

[Ysl]

Hi

First of all thank you to all involved in this great project !!!

I would like to know if there will be a possibility to listen to all those .oma files I recorded from vinyl to my Minidisc recorder.

I use Rockbox on my Iaudio X5 and would be even more happy if there was a atrac codec !

Thanks again

Ysl

[TexasRockbox]

I notice in the later builds (r22761, for example) there is an atrac3_rm.codec.  I think this was implemented a few weeks ago.  I do not know if it will work for your files.

There have been various flavors of ATRAC over the years, ATRAC 1, LP/SP, ATRAC 3+.  I do not know if the codec makes any distinction and it all seems to be backward compatible.

[saratoga]

I would like to know if there will be a possibility to listen to all those .oma files I recorded from vinyl to my Minidisc recorder.

According to Google, OMA files are encrypted and so are not playable in devices that do not support Sony's DRM format, and so cannot be used in rockbox (nor can you discuss removing that DRM as per our forum rules).

This thread has some info:

http://forum.dbpoweramp.com/showthread.php?t=7532

Your best bet is to see if the Sony software will let you remove the DRM, or failing that to rerecord them into a less restrictive format.

[Ysl]

Thanks for your reply

As already mentioned, the recorded tracks came from vinyl records, I do not think they is any DRM in them.
Proof that there are no DRM is that I can easily convert those .oma files to mp3/flac/ogg etc with Himd Renderer (http://marcnetsystem.co.uk/) but I would like to avoid the re-compression which cause lost of quality.

Where can I find more info about the Atrac codec in the latest builds. The decoding of Atrac files in rockbox doesn't seem to very well documented..(?)

Thanks again

Ysl

[saratoga]

Proof that there are no DRM is that I can easily convert those .oma files to mp3/flac/ogg etc with Himd Renderer (http://marcnetsystem.co.uk/) but I would like to avoid the re-compression which cause lost of quality.

According to the link I gave above that software requires the files to be authorized to decode before you can convert them.  Could you try copying the files and converting them on a PC that does not have the Sony DRM software installed?   Should give you a good idea if they're encrypted or not.

Where can I find more info about the Atrac codec in the latest builds. The decoding of Atrac files in rockbox doesn't seem to very well documented..(?)

What documentation exactly are you looking for?  Theres some here on the RealMedia page:

http://www.rockbox.org/wiki/RealMediaSupport

If you want to know more about ATRAC3 itself, the codec is from ffmpeg, who have some technical information about how it works.

[saratoga]

Looking into this more, it looks like these files can be in either protected or unprotected form, and the unprotected ones have an ffmpeg parser:

http://git.ffmpeg.org/?p=ffmpeg;a=blob;f=libavformat/oma.c;h=cc512cae7648ca548ab68088038d835c6b90474a;hb=HEAD

So at very least the unencrypted ones should be convertible to RM using ffmpeg, but I've never tried.

[Ysl]

Thanks again for your reply

I will try Himd renderer on another PC tommorow to be 100% sure there is no DRM.

The documentation I'm looking for is about the kind of Atrac3 files that are supposedly decoded by rockbox on my Iaudio X5.

Ysl

[saratoga]

The documentation I'm looking for is about the kind of Atrac3 files that are supposedly decoded by rockbox on my Iaudio X5.

All atrac3 in RA files should work.  If not, its a bug.

[Ysl]

Well, no they doesn't work...

What I do not understand is that my .oma files do not even have a music icon in front of them in rockbox.It should mean that they aren't recognized..?

Thank

Ysl

[saratoga]

Well, no they doesn't work...

Because they are OMA and not RM.  As I said above you will need to convert them to RM before you can play them.

It should mean that they aren't recognized..?

Correct.  Rockbox has no idea what to do with an OMA file.

[sirdan]

I would like to know if there will be a possibility to listen to all those .oma files I recorded from vinyl to my Minidisc recorder.

From http://ffmpeg.org/

September 23, 2009

In 1992 Sony introduced the first Minidisc player. 17 years later it is now possible to transfer and play back the raw ATRAC data from the actual digital disc with the help of FFmpeg, tools developed by the Linux Minidisc project ( https://wiki.physik.fu-berlin.de/linux-minidisc/doku.php ) official hardware (MZ-RH1). So if you have lots of digital recordings stored on Minidisc now is the time to archive it all.

Maybe that is helpful?

[Ysl]

Thanks

Does someone know :

1) if there is an executable of ffmpeg for download somewhere

2) if this program re-compress .oma files or is it lossless

[saratoga]

Maybe that is helpful?

Thats ATRAC1 not ATRAC3, and its not related to his problem (OMA vs. RM format).  And yes we know about ffmpeg, its where we got the ATRAC3 decoder from in the first place

if this program re-compress .oma files or is it lossless

Changing containers should be lossless if you do it correctly.

[Ysl]

Great ! Thanks Saratoga !

So I just have to found an executable of ffmpeg because unfortunately I can do nothing with source code...