[FFmpeg-devel] ATRAC3+ samples and specifications

[Adrian Glaubitz]

Hi,

since last years' September, ffmpeg has	support	for decoding ATRAC1
audio files besides to the back then already existing ATRAC3+ decoding
support. ATRAC codecs are the main codec used on all Sony MiniDisc
devices and as such it's nice to be able to decode such	ATRAC files
once they have been uploaded to	the PC.

Together with some very	talented programmers I have started a small
project called linux-minidisc to write a software to connect to
MiniDisc Walkman with USB connectors on	Linux and other
non-Windows operating systems. Thanks to ffmpeg and mplayer, the audio tracks
which are uploaded to the PC with our software can be decoded and
converted into other audio formats.

Unfortunately for the community, with the latest MiniDisc devices,
Sony introduced	ATRAC3+	which doesn't seem to be compatible
with ATRAC3 in a way such that ATRAC3+ files cannot be decoded with the
existing free decoder in ffmpeg. Thus, any recordings made with the
latest generation of MiniDisc devices (so-called HiMD) and uploaded
with our software cannot be decoded without the	help of proprietary
Windows	software.

Luckily, one of	our main developers is very endowed when it comes to
reverse engineering and	thus he has already dug deeply into the
ATRAC3+ decoder	from Sony and wrote a lot of documentation to help
clean-room implementing an ATRAC3+ decoder for ffmpeg/mplayer.

The (yet incomplete) documentation can be found here:

<https://wiki.physik.fu-berlin.de/linux-minidisc/doku.php?id=atrac3p:start>

While some ATRAC3+ sample files can be found here:

<http://samples.mplayerhq.hu/A-codecs/ATRAC3%2b/>

So, just wanted to let you know there is something to start with ;).

Adrian