Dial-Up Audio Public Listening Test Opened

CaptainCheese writes "Hydrogenaudio.org's Roberto Amorim just announced the opening of their 32kps multi-format listening test, intended to test the current 'dial-up' quality codecs. From the Announcement: "The formats featured are Nero Digital Audio (HE-AAC+PS), Ogg Vorbis, WMA9 Std., MP3pro, Real Audio and QDesign Music Codec. Lame MP3 is being used as low anchor, and a lowpass at 7kHz is being used as high anchor." These codec tests are unusual in that they adhere to ITU-R BS.1116-1. The test is open until July 11th and all are invited to participate. There's more info in the original test discussion, which indicates the originator is interested in 'testing formats working on dial-up streaming bitrates' - the test page notes: 'The real arena where codecs are competing, and most development is going, is at low bitrates.'"

Results may be flawed

[Atario]

...since I'm liable to vote for whichever one sounds most like the Centurions from Battlestar Galactica, or the voice communications from THX-1138. Not best quality, not most understandable, just coolest.

What's the point?

[TommydCat]

I personally don't get the goal of a test like this. Listening at that low quality doesn't have as much commercial, and quite frankly, personal appeal as it did back in the 90's.

I've seen the double-blind tests done at 128kbps and again fail to see the point.

What I really want to see is a rating of codecs that are able to achieve DBT-proven audible transparency and see them rated in terms of storage space (thus allowing the VBR schemes to finally compete).

Of course FLAC would come in last (considering WAV is the 'source'), but can my high quality VBR LAME MP3 pass for the original and take less space than MPC?

Re:Get the news out to portable music player

[glassjaw rocks]

I really think that the mp3 format is going to be around for quite a while, mainly just because of how widely-used it is. Even though I know the wma format is superior to mp3, I still encode all of my cds to mp3, more or less out of habit.

Why bother?

[TexasDex]

I really have no use for low-bitrate music. I have a nice 1.5Mbit connection. Really, there's no point in listening to a low bitrate music stream because no matter how good the codecs are, 32kb/s music just doesn't cut it.

BUT...
Although it wouldn't help for internet music, better low-bitrate codecs could make internet talk radio more feasible. It lets companies save bandwidth on the server side and still maintain quality that at worst is a bit better than the phone connections of people calling in (VoIP notwithstanding).

hm... the days of dialup

[vmircea]

I remember back when I had dialup, it totally sucked, it took me absolutely forever to download ANYTHING, I would read a magazine while I used the computer because it would take so long for pages to load... when I got broadband at home it was a very happy day... but lots of people I know still don't have broadband in their area, which is why I think it is nice for people to do things like this, but also I think you could use this for voice over ip... just my two cents

Still too bandwidth intensive to be useful?

[Wild Bill TX]

No matter how optimized it is, won't it will still use too much bandwidth for dial-up users who actually want to do something else with their connection? All of the streams I ever tried to listen to, including the 8kbps ones, gladly used all of my available bandwidth. I don't know about anybody else, but I'm not interested in only getting a fraction of my 2 KB/sec max for browsing, using chats, or other tasks.

More interested in 32kbps speech

[Dr. Spork]

I am in the process of starting a project [syr.edu] which needs accurate speech encoding at 32kbps. For now we're going with LAME at --alt-preset -b 32 -a --resample 22 --lowpass 6 -Z based on informal tests we did (ideas also came from here [hydrogenaudio.org]), but I'd love to see something more formal.

Notice all the different non-standard switches I had to use, which together help noticably. That's the sort of stuff you need to do to LAME before it produces acceptable results at very low bitrates. It is optimized only for 44.1KHz, so we should keep that in mind when we see the results. Notice now that none of these switches are being used for this test, so I'm almost certain that LAME will come out looking much worse than it is.

I would love for there to be a LAME-based encoder that is optimized for speech, low bitrates and sample rates. If it is made, I am prepared to re-encode all the readings that are (and are about to be) posted on my site.

one use: books!

[timothy]

A lot of people are complaining here that low-bitrate recording is useless / stupid / so 1988 etc. Fine for them :) I'm glad that people are fanatic about sound quality and that storage prices make it reasonable for many people to use nothing but lossless codecs etc., and to care about the difference between 192kbps and 256kbps MP3s. Lossless is certainly a good storage answer for the long term, as the file can be inflated and re-squashed with the latest n' greatest lossy codecs as appropriate.

However, there are reasons and times where the lossy stuff, even hugely lossy stuff like this listening test focuses on, makes a lot of sense and has no big downside. For me, squashing audiobooks is this way. I can fit about 30 hours of book into one CD-R size chunk of hard drive as a series of (extremely listenable) quality zero mono ogg vorbis files. Beats carrying 30 CDs around.

timothy

Re:Results may be flawed

[zoeblade]

...wouldn't an automated test that just compared the output of a compressed audio track to the original be more accurate? Or is there more truth than I think to certain frequencies being worthless and inaudible by human ears?

The whole idea behind lossy audio codecs is that the human brain and ear aren't that good at what they do :) As was pointed out [vorbis.com] on the Ogg Vorbis mailing list a looong time ago, technical tests like you're proposing would only tell you what computers would find more pleasant to listen to, not what humans would. So yeah, there's more to certain frequencies being inaudible to human ears :)