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Get rid of SS - a call for samples

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Hello everyone,

first of all - there is a partial alternative to SS: the ffmpeg project: http://ffmpeg.mplayerhq.hu/ has now a support for unencrypted Sony's OpenMG files (.oma, .aa3). Currently only the ATRAC3 codec is supported, but there will be a support for ATRAC3+ files soon.

Now you can easily play back and transcode (convert in any other format, including PCM) ATRAC3 encoded oma files without Sonic Stage. The only restriction - files may not contain DRm encryption.

I know that OMA files can contain MP3 and WMA encoded music also. I would very appreciated if someone could provide me with samples in these formats - I'll try to add a support for them to ffmpeg also.

Please PM me if you had WMA/MP3 encoded OMA files... WITHOUT DRM!!!



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Err, how hard is it to encode those yourself?

Thanks for your reply!

Hmm, unfortunately I'm able to encode files with ATRAC codec only. I'm using the atrac plugin for Vegas. It produces only .aa3 files; they have the same format as oma ones but don't contain any DRM encryption. This plugin supports neither MP3 nor WMA.

Probably one must have specific Sony devices supporting the formats mentioned above. Then it would be possible to encode samples using the SS. I don't own any Sony device being able to produce OMA files containing WMA or Mp3 tracks, so I cannot encode my own test samples. That's why I asked here...

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Let's back up. How do you know that .oma can contain MP3 or WMA? That could just be an Atrac file transcoded from MP3/WMA.

Ok, I looked into the OmgUtils.dll - this is a library SS use for parcing .oma files. Among some other things it contains a code that extracts codec_id and codec specific parameters from the .oma container. Each .oma file has a header starting with "EA3" - this is the sony specific header that will be recognized by devices. The byte at the offset +32 from the start of this header tell which codec was used to encode the context. Here a small list of the ids I was able to extract from this code:

0 - ATRAC3 (94Kbps, 105Kbps, 132Kbps)

1 - ATRAC3Plus

2 - unknown

3 - MP3 (see below)

4 - LPCM (linear PCM, not compressed)

5 - Windows Media Audio (WMA)

32/33/34 - ATRAC Advanced Lossless

I'm one of the maintainers of the ffmpeg's parser for the .oma files (see http://svn.mplayerhq.hu/ffmpeg/trunk/libav...oma.c?view=log). While playing around with oma files in order to test my code I accidentally came across an .oma file that contains a MP3 encoded track, so I was able to figure out the codec_id and codec specific parameters. Now I can play this file back using the ffmpeg's mp3 decoder.

That's why I proceed on the assumtion that Sony has introduced some devices are capable of decoding WMA and MP3 also. The most oma files I have were encoded using ATRAC/ATRAC+. I have only one sample with MP3, but no one with WMA and LPCM.

I just add a support for the codecs mentioned above to our parcer for completeness. But it's not very necessary because the most of files were encoded using ATRAC...

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