I am speaking as an individual and am not a lawyer.
On 11/11/2016 02:32 PM, Yaakov Selkowitz wrote:
Also, for the sake of clarity, what is the status of:
* MPEG-1 Audio Layer II (MP2) encoding (e.g. twolame)?
* MPEG-1 video decoding (e.g. smpeg, which also includes MP3 decoding)?
These are probably patent free, just by virtue of age. As in patents in the US have to be
filed within one year of the technique being published, and last 20 years after filing, or
for patents filed before June 8, 1995, can last 17 years after the grant date. There is
the possibility of patent term extension if the patent office takes too long to process
ISO 11172-2 which defines MPEG-1 video decoding came out in 1993-08-01 (August 8, 1993)
ISO 11172-3 which defines MPEG-1 audio decoding (including Layer II) came out in
1993-08-01 (August 8, 1993)
So, doing the math, 1993+1+20 = 2014 (1993 + 1 year after publication + 20 years to
and 1995 + 3 + 17 = 2015 (1995 + 3 years to get patent granted + 17 years to expire)
so patents on anything in ISO 11172 are highly likely to be expired.
I have some more detail on this at:
That said, the rest of MPEG-1 is much less common than MPEG-1 layer III audio, so there is
much less research in this part. (Also, the last time I saw a new MPEG-1 video was in
2009, so the format is not getting used much.)
Oh, and also:
* MPEG-2 video decoding (e.g. libmpeg2)?
Rob Glidden looked at this in 2011, and his conclusion at the time was that the last
MPEG-2 patent he was aware of expired on 2018-Feb-14th. He posted about this, but the
links to the spreadsheets are broken (but he has been emailed about the url problems, so
hopefully it gets fixed soon.)
So MPEG-2 is still probably patented, but this is worth looking at in 2018.