[FFmpeg-devel] Legal status of MLP decoder/encoder + MLP DVD-Audio headers

[fabrice nicol]

Hi there,

I'm Fabrice Nicol, the developer of the free software dvda-author, which 
creates DVD-Audio discs (http://dvd-audio.sourceforge.net/)

1. With the help of Jai Luthra, the MLP encoder maintainer, I've been 
implementing DVD-Audio authoring for MLP files using libavcodec. This 
will be an important step forward, as MLP makes it possible to implement 
full 5.1 High res audio on DVDs, a long-awaited feature in the free 
world (plus there is no longer any maintained commercial software that 
offers it either, the only two ones that did it have be retrieved from 
the market).

I was wondering whether the ffmpeg team has investigated the potential 
legal issues with the MLP decoder/encoder, as it was originally created 
under proprietary licensing terms. In particular, I'm wary that 
uploading to Sourceforge servers hosted in the US may involve potential 
risks in this respect. Do you think it necessary to refrain from posting 
on SF and sticking to European-hosted servers, or is this just unecessary?

2. MLP on DVD-Audio is just MLP files with MPEG-like headers (64 or 43 
bytes long). I've been able to infer and implement 90 % of these headers 
but there are 4 remaining bytes at the end of headers with which I'm 
stuck. They strongly differ from the reference for LPCM DVD-Audio. LPCM 
values are sample rate/size/downmix. MLP values cannot be that. I was 
wondering if the ffmpeg specialists who worked on MLP or possibly MPEG 
could have an idea. Issue is referenced in lines 577-582 of this blob : 
https://sourceforge.net/p/dvd-audio/dev/ci/master/tree/src/ats.c

Best,

Fabrice Nicol