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LPAC development freeze at its current state

Quote from : http://www.nue.tu-berlin.de/wer/liebchen/lpac.html
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The LPAC Homepage
by Tilman Liebchen

Latest update: 6 January 2004

Important notice: An improved version of the LPAC algorithm was recently chosen as reference model for "MPEG-4 Audio Lossless Coding (ALS)", so I decided to freeze the development of LPAC at its current state. Once standardization is completed, I will supply tools to convert LPAC files into MPEG-4 ALS files (which will not require any reencoding). Another good news is that the MPEG-4 ALS format specification as well as reference encoder and decoder software will be publicly available, providing an opportunity for everyone to use this new standard.

More information on MPEG-4 Audio Lossless Coding can be found on the MPEG-4 ALS page.
.halverhahn

LPAC development freeze at its current state

Reply #1
Very interesting news. Is LPAC really that good? (I am not suggesting that it isn't - just asking)



LPAC development freeze at its current state

Reply #4
A small hint about this can be found even here, see C 5

Vital papers will demonstrate their vitality by spontaneously moving from where you left them to where you can't find them.

LPAC development freeze at its current state

Reply #5
Good news. Will this replace FLAC then as a lossless standard? Will it still be in a MPEG 4 conatiner file format and have a .M4A or .MP4 file extension or use something different?

Any time frame for this being "standardized" and finally approved?

LPAC development freeze at its current state

Reply #6
Yes, MPEG-4 loseless will be part of the MPEG-4 standard, and it will be possible to mux it into MP4/M4A containers naturally.

LPAC development freeze at its current state

Reply #7
How does the improved version compare to flac or monkey's encoding- and decoding speed and the compression rate of course?

Is it the same like version 1.41 as shown on speeks comparison page?

LPAC development freeze at its current state

Reply #8
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How does the improved version compare to flac or monkey's encoding- and decoding speed and the compression rate of course?

Is it the same like version 1.41 as shown on speeks comparison page?

Well, Menno said this, but didn't provide any link to the results though.
Juha Laaksonheimo

LPAC development freeze at its current state

Reply #9
How does error correction in LPAC, both in original and new MPEG flavors, compare with FLAC and Monkey's?

That is to say, I appreciate FLAC's ability to play through corrupted spots, and consider Monkey's inability to handle corruption a showstopper. MPEG standard-to-be or not, FLAC's error correction could still make it a better choice for true archival.

LPAC development freeze at its current state

Reply #10
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Any time frame for this being "standardized" and finally approved?

In one of the papers linked to on the MPEG-4 ALS page it says
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MPEG-4 Audio Lossless Coding (ALS) is expected to be an international standard by the end of 2004.
In theory, there is no difference between theory and practice. In practice there is.

LPAC development freeze at its current state

Reply #11
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How does error correction in LPAC, both in original and new MPEG flavors, compare with FLAC and Monkey's?

That is to say, I appreciate FLAC's ability to play through corrupted spots, and consider Monkey's inability to handle corruption a showstopper. MPEG standard-to-be or not, FLAC's error correction could still make it a better choice for true archival.

LPAC is block-based, just like FLAC, so it should be able to act the same way.

-Eugene
The  greatest  programming  project of all took six days;  on the seventh  day  the  programmer  rested.  We've been trying to debug the !@#$%&* thing ever since. Moral: design before you implement.

LPAC development freeze at its current state

Reply #12
I'm wondering what advantages will LPAC have over existing lossless codecs (FLAC, APE) because I'm not very knowledgeable when it comes to LPAC.  Anybody know?

LPAC development freeze at its current state

Reply #13
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I'm wondering what advantages will LPAC have over existing lossless codecs (FLAC, APE) because I'm not very knowledgeable when it comes to LPAC.  Anybody know?

I think the most important one is that it combines a high compression ratio (competitive with APE) to an algorithm that is usable in hardware (like FLAC).

So it combines the best of both worlds.

LPAC development freeze at its current state

Reply #14
Now remains to Apple to add it to iTunes then the iPod.

At last lossless on iPod.... 

Who said useless? 

LPAC development freeze at its current state

Reply #15
Hmmm... that one to iTunes and iPod - must need the HD's to grow a bit to get listened more than one album per 'session' (150-250 megs) - same as having Sony Walkman and a lossless general Audio-CD - just the later case is more simple to organize 

Still - good to hear of new standards - like this one combining FLAC's and APE's good points together and still adding some new to the stack - namely the full MPEG4 standard with container to M4A!

I'm just wondering how far can a lossless compression go in mpeg4 / audio containers, before the real limits are coming towards in coding - just like Zip, Rar and Ace are a bit competiting, who's getting best compression algorhitms for general data (year by year bettered a bit).

I suppose that 1:5 (or even 1:4)) compression could be a huge achievement (for nowadays 1:2 - 1:3 and 0.4 - 0.6++ percentually) and by that way would win for example 320 kbps MP3's, which many are still using as a 'near lossless' saving format (Maybe not knowing that VBR LC / MAIN MPEG4 M4A 192kbps sounds better with much more room to save in HDs!) 

Antsa

LPAC development freeze at its current state

Reply #16
Garf, thanks for the reply.  LPAC certaintly sounds interesting.  I'm going to be looking forward to seeing how it develops.

LPAC development freeze at its current state

Reply #17
Yes ALS sounds good. I presume there aren't any patent licensing issues involved with being able to use it for an encoder/decoder without paying any patent royalties, can anyone confirm this?

BTW I wrote Tilman Liebchen asking about which file extension they planned to use and he wrote that presumably ALS will use the ALS file extension when not in an MPEG 4 container format and the standard MP4 file extension when used in an MPEG 4 container file.

Here is the quote of his reply to me:
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Hello,

I can't remember having posted a message at hydrogenaudio recently - but
the file extension will presumably be ALS, or MP4 if it's multiplexed
with the MPEG-4 file format.
I think there won't be any syntax or other significant changes to the
codec after the October MPEG meeting, but we have to go through the
standardisation stages (PDAM, FPDAM,...), which may take a while...

Tilman Liebchen


Also why don't both dbPowerAmp and Foobar2000 support the current LPAC format? If this LPAC (current frozen version) is going to be the MPEG 4 ALS standard, and the author (Mr. Liebchen) on his web page says he will provide a tool to convert LPAC to ALS when the standard is finalized, why shouldn't the audio apps start to support LPAC now? Then we can convert from LPAC to ALS once the standard is finalized. According to the author's web site no recoding will be necessary to convert from LPAC --> ALS.

LPAC development freeze at its current state

Reply #18
foo_lpac
"To understand me, you'll have to swallow a world." Or maybe your words.

LPAC development freeze at its current state

Reply #19
Thanks for the link. Was unaware that foobar could support lpac. Didn't see any mention of lpac on the foobar2000.org site as being a supported format. Does dbPowerAMP have such a lpac converter plug-in available?

LPAC development freeze at its current state

Reply #20
I tested LPAC when the first post of it becoming the MPEG-4 Lossless Standard and I'd have to say that I'm a bit disappointed. I don't see much size difference compared to FLAC, but the encoding time was a bit longer. It takes forever to skip through a song because the indexing support is pretty crappy.

I think I'll stick with FLAC for my archiving to DVD-R. Maybe once the final release is complete and working well, I'll change over. By that time, DVD-Rs will be cheap enough (because of Dual Layer discs knocking the prices down) that I wouldn't mind transcoding my existing FLAC collection to fewer DVD-Rs. That is, if they manage to make the size difference noticably smaller.

LPAC development freeze at its current state

Reply #21
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If this LPAC (current frozen version) is going to be the MPEG 4 ALS standard,

That is not what it says:

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An improved version of the LPAC algorithm was recently chosen as reference model for "MPEG-4 Audio Lossless Coding (ALS)", so I decided to freeze the development of LPAC at its current state

LPAC development freeze at its current state

Reply #22
I guess I'll wait to use it too, until the standard comes out for MPEG 4 ALS.

It will be nice having a lossless international standard though so you know your files will playback and can be decoded for years to come...

LPAC development freeze at its current state

Reply #23
Thanks Garf, I missed that. Yes I'll wait then and not use lpac in its current form.

LPAC development freeze at its current state

Reply #24
any news about "MPEG-4 Audio Lossless Coding" aka "MPEG-4 ALS"?
.halverhahn

 
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