On Sunday 23 October 2011, Kevin Cosgrove wrote: > > On 23 October 2011 at 17:38, Fons Adriaensen <fons@xxxxxxxxxxxxxx> wrote: > > > On Sun, Oct 23, 2011 at 08:13:24AM -0700, Kevin Cosgrove wrote: > > > > > The subject line says it all. I'm looking for a Linux solution to > > > watermarking audio. Thanks... > > > > I've never seen any. The amount of work to develop such a thing > > would depend on your exact requirements. Important parameters > > are: > > I never thought much about requirements, as I wasn't thinking of > creating one. > > > * Which operations should leave the watermark intact. If this > > includes lossy encoding/decoding things get more difficult. > > Maybe version 0.5 would work with lossless and version 2.X would > work with lossy? > > > * The minium duration of a fragment that allows the mark to be > > detected. > > However long is easiest I suppose. 1 sec? 10 sec? Repeated in > spots through the file X times, where 1 < X < (length in minutes)? > > > * How strong the 'provability' should be. > > Maybe version 0.5 is 10% chance of proving, and version 2.X would be > better? > > > * Operational requirements. For example, should it be possible > > to verify the mark without having the information necessary > > to remove it ? > > Some operations would be: > > - Mark > - Un-mark > - Re-mark > - Remove > - Verify signature > - Verify content > > In a later version maybe the tool could be able to use some of the > above tools, in cooperation with other sound file tools, to preserve > a watermark across sound file format conversions, between lossless > forms and crossing between lossy/lossless domains. > > For version 0.01 even just being able to attach an md5 sum of an > audio file along with a gpg signature would be cool. > > I use a subset of GNUPG's capability. Maybe you can see that in > my above requirements? ;-) > > Is that a useful start on a start? This reminds me when the SDMI (Secure Digital Music Initiative) [1] tried to use audio watermarks among other technologies trying to stop piracy. AFAIK, the initiative was not a success [2]. Regards, Pedro [1] http://en.wikipedia.org/wiki/Secure_Digital_Music_Initiative [2] http://cryptome.org/sdmi-attack.htm _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx http://lists.linuxaudio.org/listinfo/linux-audio-user
