Hi there,

I've just downloaded the PlusV Mp3 Codec (www.plusv.org), and I'm unfortunately not in the position to evaluate its suitability, due to the speakers I'm using being completely awful.

However -- I was wondering what other peoples initial opinions to this codec were. I'm under the assumption that it does SBR (spectral band replication) like Mp3pro (or similar).

It'd be very interesting to hear any views!

Thanks

Ruairi

OK -- further to my initial post here are my first findings.

-- The WinAMP plugin is just about minimal functionality - it supports playback and seeking only. I see no sign of tagging.

-- The encoder seems to be devoid of documentation, and running PlusV.exe with files specified seems to fill the screen with garbage. Does anyone know the location of some commandline arguments, what works/what doesnt. After all, if it is merged with Lame (or "wrapped" in this sense)-- what happens with alt presets ? (I know its a bit offtopic but hey)

-- The LamePV encoder doesnt correctly support the -b argument, as I tried to create a ~48kbits stream... which averaged a lot higher unfortunately.

-- The SBR seems to take a very small amount of bitrate, how effective is this?

if it is merged into Lame, i think it'll only be used for very low bitrates. Maybe the --alt-presets bitrate < 64 kbps change. but we'll see

Given that I had (and have) no idea of what I'm doing I discovered a frontend in one of their forums. Since it just uses standard abr without any tweaking and bitrate is limited the resulting (mp3) file sounds like crap (not only because of the low cutoff which is intended but due to normal artifacts). The mp3 file with added PlusV still sounds like crap just with more highs.

So I can't really make an estimate about how good PlusV actually sounds. It might sound alot better if the underlying mp3 file was any good. Unfortunately I have not found any documentation about the applications' usage. I have yet to figure out how to do it manually.

The input plugin is buggy too, with direct sound output it's a blubbering tremolo. Waveout seems to work. I did this testing late at night when I should have been in bed 3 hours ago, keep that in mind

I have to figure out what each of the three programs do. When you type plusV -h it gives you [...] Try option "-h" for details. :ponder:

Which seems unlikely at the moment, Gabriel Bouvigne has commented on PlusV forums:

QUOTE

So license issue isn't still clear enough. :confused:

Personally i'm bit of disappointed, they just have dumped the code and software to public without any decent documentation or support. This implies that PlusV is not meant for public use, instead it's for developers to get their hands on it and to have resource for PlusV and SBR development.

If there are coders which are interested in audio compression technology, would you please take a look on the source and PlusV specifications. I and many other people would like to know what are possibilities of PlusV and is the it worth of developing further?

I talked to a few vorbis developers in #vorbis and they seem kind of indifferent to plus-v. I was thinking if plus-v is all that it is hyped up to be, it might go really well combined with ogg vorbis. *shrug*

See my earlier licensing question. The vorbis core libraries are BSD licensed. BSD is one of the few licenses that can interact with GPL on a limited level, but the combination with the patent issue still looks very blurry to me. Moreover, GPL is more restrictive than BSD, so that would make Oggs code less free. Not gonna happen I think.

Moreover, when I tested their first release a while back I was all but impressed by the current state of the technology.

_If_ I had time (which I don't) I'd like to give it a test with very low bitrate oggs.

--
GCP