New format suggestion .oma

[lars-unimelb]

Hi, Jesse Dyer and I (Lars Alvik) from the University of Melbourne have been working on a signature file for .oma files.

Format Name:

• Sony Open MG Audio

Extension(s):

• .oma

Mime type: audio/ATRAC-ADVANCED-LOSSLESS

Classification (e.g. Audio):

• Audio

Description:

• Sony ATRAC3 audio files, mostly used for Minidisc players. The file it self can have different audio codecs (mp3 etc) but apparently ATRAC is the most common. The files can be opened with FFMPEG and these files can have DRM protection.

File format identification signatures:

00000000010F5000 9 1 4 3 2 454133010060 65613303 5 4 3 2 1

Relevant links: https://wiki.multimedia.cx/index.php/Oma https://www.ffmpeg.org/doxygen/0.11/omadec_8c.html https://wiki.videolan.org/SoC_2011/OMA/Atrac_Improvements/

Attribution: University of Melbourne

OMA-ATRAC3-1.0-signature-file.txt

[jessedyer-uma]

The xml snippet from the signature file we made is not diplaying properly in the above comment, but here are the sequences and location in a different form (or see the xml signature file attached to the above comment, thanks): BOF; offset: 0; sequence: 65613303 BOF; offset variable (1000-4000); sequence: 454133010060????00000000010F5000

[thorsted]

Testing your signature and found some of my OMA files have the sequence "454133030060" so 03 instead of 01.

I also have quite a few OMG and AEA formats which are also ATRAC types. I will see if I can add a signature to go along with this one.

[jessedyer-uma]

Thanks for testing this with your OMA files, given what you've found we should replace that byte with a wildcard in the signature we submitted. ie: BOF; offset: 0; sequence: 65613303 BOF; offset variable (1000-4000); sequence: 454133??0060????00000000010F5000