Before I knew of flac, I converted 2 cd's to LPAC. When I got to know of FLAC I reconverted the cd's to flac, but they got bigger in size, so I deleted them.
Now when I am reorganizing my music folder I saw them. I have foobar set to not accept lpac files, so I didn't have it in my foobar library. I converted them to flac, and they got the same size as the lpac files. Then I re-ripped the cd, and the flac-files from the cd got bigger than the flac-files converted from the lpac files, even with the same options.

Is LPAC really loseless?

Well, first, how much bigger? And did you encode the files at the same compression level? A good way to test this also would be to rip a track from the cd, compress it lpac and the extract the wav and compare it to the original. The only reason A flac converted from a lossless source would be bigger than another flac of the same file would be a different compression level/tag padding.

Just use foobars bit comparator.

How much bigger? About 500kb. I have padding @ 4098 bytes, so that's not it. Also, same compression level.
I will try bit-comparing later.

Just a few quick tests with LPAC and MD5 seem to suggest that it is indeed lossless. If you could post a sample that is bigger when encoded LPAC->FLAC than straight to FLAC it would be very interesting.

Those files that did get smaller when converting from lpac than from cd are about 30 mb each. And..I can't upload them due to copyright and stuff.
I will try to make some short samples and see if it is loseless.

As far as I know, the man who developed LPAC is also the primary person behind developing the new MPEG 4 ALS (Lossless Audio) International standard. His name is Tilman Liebchen and he wrote me the other day answering some of my questions about the new MPEG 4 ALS standard. The reason he stopped (froze) work on developing LPAC lossless codec was to wait until the specs for MPEG 4 ALS were worked out.

Tilman informed me the following statement concerning the lossless ALS standard's status:
I really hope that by next spring standardization has proceeded such
that all file format issues are fixed and products can be released.

So it looks like Spring '05 will be the time you see lossless .ALS files start appearing along with software to encode/decode them. LPAC is dead as far as I know and Tilman will be providing a tool to convert LPAC files to ALS files (according to his web site). His web site says LPAC files are lossless.

Hope this answers you questions as to whether LPAC files are lossless or not.

For more information about the new MPEG 4 ALS (Lossless Audio) format see his web site at (also check out under Links for LPAC info):
http://www.nue.tu-berlin.de/forschung/proj...ess/mp4als.html

What does this have to do with the current discussion?

I was just trying to answer the original poster's question, namely:

Is LPAC really loseless?

I gave him some background on the author of LPAC and provided a link to find out more about LPAC and its new derivative ALS. If the poster has a problem with LPAC not being lossless I suggest he contact the LPAC author, Mr. Liebchen.

before bothering the author with seemingly trival questions (i.e. "is your lossless codec realy lossless?"), it might be a good idea to do some selftesting it _then_ the problem isn't solved, maybe try to get some further help form the community, or contact the authors involved.