Hello everybody,

I have two questions about Ogg;

1. How "big" has Ogg been compared to MP3?
(Probably hard to answer, but I hope to get some feedback here)

2. Can MP3's be converted to Ogg without loosing any quality, or is the best alternative to re-encode the files?

Thanks in advance,
Mikael Stalvik

Not sure what you mean by "big" exactly. You'll have to be more specific.



Theoretically? Maybe. Practically? Probably not. It's never optimal to convert between two lossy formats -- ever. If you have a choice, you should always re-encode from the original source.

If you mean 'big' as in use and supported hardware and software, well at the moment it isnt as widely used as MP3,probably never will be,but its use is rapidly increasing as more people get to hear of it and manufacturers start offering support for it.

If you mean file size it will yield better quality sound at a similar or somewhat lower filesize.

To respond to the second question.

I have just completed re-writing the oggvorbis interface within lame which as of a little later today will be available at rjamorim's site under the name 'xcLAME'.

This provides full wave/mp3/ogg encoding/decoding/re-encoding/transcoding in all combinations. As to how good the mp3 transcoded to ogg is? Well, if the original mp3 file is of 'good' quality, the ogg file will be reasonable. BUT, do remember there is no point in trying to increase the quality, ie going to a higher bitrate, it just won't produce the results you hoped for.

john33

John33,

Duuuude! That r0x. If I were you I'd get JohnV or someone to push it to the news queue!

Ruairi

Thanks everybody for the answers.

What I originally ment with "Big" was how supported (both hardware and software) it has become, as well as how "popular" it seems to be by the users.

I was curious to know if ppl "converts" from MP3 to Ogg (although it might be difficult to know) etc.

I personally likes Ogg a lot (esp. the tagging system/song quality), and think of converting my MP3 (parts of) collection to Ogg.

I also plan to write some applications for catalogizing, if it's of any interest (therefore my questions ).

Regards,
Mikael

Ogg Vorbis is set to grow in popularity a lot more, thanks to its repeated exposure on sites such as Slashdot, and now even more so because the input plugin is now included as default with every WinAMP installation. Currently I'm finding that searching for Ogg's through p2p systems bears little... though perhaps in time it could get a lot better. Ogg Vorbis is supported very well under Linux (most media players support it), and Windows is gaining ground (a DirectShow/Windows Media Player filter is in progress).

As far as hardware players go, a few players do support it, however the main problem with supporting Ogg Vorbis for most player manufacturers is that a fixed point decoder (i.e. a playback program which does not require a floating point unit) is not available for free, and a lot of the flash enabled portable players require this. That said, its worth looking though the Xiph.org mailing lists and seeing if anything does.

Converting from Mp3 -> Ogg is generally a bad idea because both codec's are lossy, and combining two methods would more than likely create further loss of audio fidelity. It may be a practise done, but I'd be far happier keeping the mp3's.

I personally use EAC and MPC to archive music, because of the fast encoding speeds and excellent performance of the standard encoding profile. It is a closed architecture as far as the encoder goes but the decoder source is available and often updated. I will move to Ogg when the encoder reaches 1.0 and the bitrates improve upon MPC.

Ruairi

The hardware and software support of Vorbis is still pretty minimal compared to mp3.

About this xcLame.. haven't tried it yet, but it should give BIG warnings that transcoding loses quality.

Someone called Nicolas Pitre has independently developped a fixed point decoder (from the reference floating point decoder), and he's considering offering it for free under GPL.

See the OGG DEV list archive for the message and its follow-ups at
<http://www.xiph.org/archives/vorbis-dev/200205/0003.html>.

That seems well worth keeping an eye on - however selling a fixed point decoder is one of the revenue streams for Xiph.org - it'll be interesting to see how this unfolds.

Ruairi

Reading the rest of the messages, it looks like he'll be using the GPL, so his decoder and Tremor (the closed integer implementation) pair together nicely.

In my opinion never transcode from one format to another. The original PCM sample input is always the "best source" it's useless to do transcoding never the less, because in theory you are already getting a quantized (reconstructed) version of the spectrum in which physcoacoustic masking has already been performed. If you have any type of music in two seperate audio compression formats it's best to keep them that way. Re-encoding won't help much either, but rather as what was stated above will sound much worse subjectivly.

Just thought some of you might want to know: Nicolas has made available his integer decoder on ftp.

See the original message at <http://www.xiph.org/archives/vorbis-dev/200205/0038.html>.

a 10 second beep from the internal speaker whenever transcoding is chosen sounds about right


And big flashing pink letters too...