New Lossless MP3 Format Explained

CNETNate writes "Thomson, the company that licenses the MP3 patent, has released a new lossless MP3 format called mp3HD. It utilises both lossless and lossy audio contained inside a single .mp3 file, and the files will play on all existing MP3 players. The idea is simple: lossless files on your desktop that can be transferred without conversion to iPods and MP3 players. The issue, it transpires, is that although the full lossless/lossy hybrid MP3 file is transferred to players, only the lossy element can be played back. A command line encoder can be found on Thomson's Web site."

Comments

The obvious problem

[pxc]

that you probably thought of when you read the summary ("So now I get a larger-than-FLAC sized file on my portable player so I can get 128kbps?") is acknowledged in TFA.

The problems

At face value it's remarkably convenient, like a car that doubles up as a plane. But like your aeromobile, there are problems for the average consumer. Firstly, file size. A normal 320Kbps MP3 of the same Pink Floyd song was just 14.6MB, and 320Kbps is all you'll hear if you listen to an mp3HD track on your iPod.

But the lossless audio stored in the file will be stored on your iPod nevertheless, taking up precious storage space. (Although we should point out to audiophiles that the hybrid files are smaller than the combined size of a FLAC and 320Kbps MP3, although are less efficient to encode than FLAC.)

I don't really see to whom this will be a valuable technology--audiophiles will probably have a large enough music collection that they don't see the benefit in taking up 10x as much space on their portable device, and are probably capable of reencoding when they transfer (some media players can do this automatically). Most everyone else just listens to low quality Limewire rips on their PC anyway.

Anyone here think they would really want to use this format? (genuine question)

Learn with history or make the same mistakes.

[Volanin]

I dare say that this insistence on backward compatibility is going to kill this format.

If anyone still remembers, many years ago Thomson released the mp3PRO format.
It was a low bitrate MP3 with some added spectral band data that could recreate the original
music sound quality. So in theory, you could have the same quality for half the bitrate/size.

To my decaying ears, it sounded really good at the time... if played on the supported players.
But when you played these files in any unsupported player, which happened to be all of them
except for the Thomson's Player or the Thomson's Winamp Plugin, you ended up listening to
a HORRIBLE low bitrate sound quality, since the extra mp3PRO information was ignored.

And even worse: you had no way of telling if a file being downloaded was an original mp3 file
or a new mp3PRO file, since they both used the same file extension. Maybe if they had renamed
the extension to .mp3pro or something like that, the mp3PRO format might have had some chance...

Years pass... and now they are doing the same thing again.

Instead of focusing on a lossless mp3 codec for a specific kind of market/enthusiast, they are
insisting in keeping backward compatibility with players using the same method as mp3PRO did.
And once more the files are going to have the same extension as the original ones, instead
of .mp3hd or something similar.

I hope I am wrong, but this surely spells doom to me.

Re:why?

[Anonymous Coward]

In case it isn't bleeding obvious (apparently it isn't): The key to good compression is prediction. If you can predict the signal to within a small margin of error, then you only need to encode a small error correction stream. In this case, the MP3 signal serves as the prediction and the remaining data is the correction stream. This concept requires that the prediction is stable, and since the prediction isn't an algorithm but based on actual data, that data has to be delivered with the correction stream. So this isn't so much MP3 with additional information as it's a lossless format which happens to use an MP3 stream as a component and is formatted such that MP3 players recognize just that stream.

Re:why?

[petermgreen]

The only use case can see is if you own a mp3 player with large storage that doesn't support playback of a proper lossless format.

With this you can keep and listen to the files on your mp3 player while also being able to decode them losslessly when you plug that player into a computer.

also given the filesize stats in the article it appears they aren't just bundling together a lossy and lossless format but actually making the lossless format build on the lossy format (either that or they have a lossless format that is considerablly better than flac).

Re:why?

[1u3hr]

So this isn't so much MP3 with additional information as it's a lossless format which happens to use an MP3 stream as a component and is formatted such that MP3 players recognize just that stream.

I've seen some comparisons at another site. A 41 MB wave file gives a 20 MB FLAC, and 22 MB MP3HD. So if the MP3 was indeed a skeleton of the lossless portion, it isn't very efficient. It's the same size as a normal lossless format + a separate MP3, stuffed into the same file. Actually, I doubt the MP3 has any use at all in the lossless playback, but I am ready to be corrected if anyone can cite something and not just speculate.