[FFmpeg-devel] AVFilter for watermarking DCTELEM MPEG2 blocks

[Luca Barbato]

On 11/16/2010 04:40 PM, Vladimir Pantelic wrote:
> Carl Eugen Hoyos wrote:
>> Roger Pau Monn?<royger<at>  gmail.com>  writes:
>>
>>>  I've done a modification to the ffmpeg source code, to add a watermark
>>>  in MPEG2 DCTELEM luminance blocks
>>
>> Even if your patch doesn't make it into svn, please post it here for
>> people
>> having the same need.
> 
> but then people would know how the watermarking
> works and it would be useless, no?

Good Watermarking as a subset of steganography should work even if you
know the algorithm. Since it should be nearly seamless, depending on
some external key to be meaningful and robust to a number of conversion
procedures (think about fair use, low qual encoding or small sampling
deletes the watermark, doing high quality reencoding preserves it)

lu

-- 

Luca Barbato
Gentoo/linux
http://dev.gentoo.org/~lu_zero