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Dial-up bitrate listening test

Hello.

I'd like to start discussing a listening test at 48kbps.

The official reason for that bitrate is to test formats working on dial-up streaming bitrates. But my particular reason is that I would like if everyone is able to participate in my last test.

The test is scheduled to start on June 30th.

The formats I'm considering are:
- Ahead HE AAC+PS (if it's released until then. If not, I'll use HE AAC only)
- Vorbis aoTuV
- MP3pro
- WMA
- Real Audio
- QDesign
- High anchor?

I don't see much point featuring a bottom anchor, considering the bitrate is already very low.

The samples will probably be pretty much the same as the 128kbps test. I'm open to suggestions to replace samples, though.

To avoid missing the test once it starts, I suggest that interested people subscribe to the listening test newsletter.

Thank-you for your comments and feedback.

Best regards;

Roberto.

Dial-up bitrate listening test

Reply #1
48 kbps doesn't work with dial-up eventhough it should be theoretically possible. If you want to test dial-up bitrate you should use 32 kbps.

BLADE or l3enc 128 mp3 as high anchor!

Dial-up bitrate listening test

Reply #2
Quote
48 kbps doesn't work with dial-up eventhough it should be theoretically possible. If you want to test dial-up bitrate you should use 32 kbps.

Hrm... I remember listening to 48kbps Real Audio when I was on 56kbps dial-up. It was being broadcasted from my ISP, though.

Quote
BLADE or l3enc 128 mp3 as high anchor!


Do people still use them, even?

Dial-up bitrate listening test

Reply #3
Quote
Quote
48 kbps doesn't work with dial-up eventhough it should be theoretically possible. If you want to test dial-up bitrate you should use 32 kbps.

Hrm... I remember listening to 48kbps Real Audio when I was on 56kbps dial-up. It was being broadcasted from my ISP, though.

I never get over 32 kbps.

Dial-up bitrate listening test

Reply #4
I'm on dial-up and I regularly can stream ~42kbps videos. Yes, it's not that normal bitrate, but that's what Realplayer reports.

Dial-up bitrate listening test

Reply #5
Roberto,

Please please make it ~32kbps... I've just had no luck going above that on a UK connection - I've never seen anything stream higher than that on a dial up successfully...

Ruairi
rc55.com - nothing going on

Dial-up bitrate listening test

Reply #6
Quote
Please please make it ~32kbps... I've just had no luck going above that on a UK connection - I've never seen anything stream higher than that on a dial up successfully...

Jeez. But then the samples will sound so bad...

Well, if people prefer 32kbps, I'll oblige. Please post your opinion on this matter.

Dial-up bitrate listening test

Reply #7
Please use 32k.  That's the higest rate I've been able to get reliable and consistent streaming to work with dial-up.  Dial-up speeds can reach or exceed 48kbps, but maintaining it for any length of time is very unlikely.

Dial-up bitrate listening test

Reply #8
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Jeez. But then the samples will sound so bad...

lol!  It's a far cry from near-transparent, eh?

If you're going to use 32 kbps, how about using the 7 kHz and 3.5 kHz lowpass anchors that MUSHRA uses?  They also use a different rating scale (which I believe abchr-java can accomodate).  That way, you could get results which might be comparable to what they got when they tested 32 kbps codecs.

80-100  excellent
60-80  good
40-60  fair
20-40  poor
0-20  bad

ff123

Dial-up bitrate listening test

Reply #9
Another vote for 32k. Even though I no longer use Dial up (thanks god!) I would bet it's still crap = no more than 32k

Dial-up bitrate listening test

Reply #10
At 48 kbps ATRAC3plus could be considered, too.  But it  will probably never be chosen for dial-up broadcasting.
At 32 kbps, mono broadcasting ist very popular, at least with mp3 and ogg vorbis. Therefore, MP3 @ 32 kbps mono may be interesting.

Dial-up bitrate listening test

Reply #11
Quote
If you're going to use 32 kbps, how about using the 7 kHz and 3.5 kHz lowpass anchors that MUSHRA uses?  They also use a different rating scale (which I believe abchr-java can accomodate).  That way, you could get results which might be comparable to what they got when they tested 32 kbps codecs.

80-100  excellent
60-80  good
40-60  fair
20-40  poor
0-20  bad

ff123

Interesting.

That's indeed a good idea. I think ABC/HR java can only customize the ranking labels (Imperceptible, Annoying, etc.), you can't change the scale values (it always goes from 1 to 5).

So, the codec list can now be:

- Ahead HE AAC+PS (if it's released until then. If not, I'll use HE AAC only)
- Vorbis aoTuV
- MP3pro
- WMA
- Real Audio
- QDesign
- 7kHz lowpass for high anchor
- 3.5kHz lowpass for bottom anchor


(BTW, if you guys are wondering what test ff123 is talking about, it's here)

Dial-up bitrate listening test

Reply #12
Maybe I have a "tin ear",  but I'm listening to a 32k bitrate, 22KHz stereo MP3 stream, and find it quite acceptable - not sure which encoder it's using though - and it's "old time" radio, so it may start out lacking the high frequencies that tax low bitrate MP3.

On to bitrate (for Dialup)
44-49k are typical, I count 45k as "average" and 48-49 as "excellent".
38k has been observed on poor modems, or under bad conditions.
If it falls back, it's as likely to hit 31.2k as 33.6 - so even 32k is pushing the limit for "guaranteed dialup streamable".
28k modems have been observed to fall back to 26k under not uncommon conditions.

The really tough target, for guaranteed dialup streamable, would have to be 24k, though 32k is a fair choice if you hope for a 56k connect, and get a GOOD V34 - for a 56k connect, 40k would be more achievable than 48k.

I'd like to see bog-standard MP3 put through it's paces, as if you're listening to low bitrate internet radio now, it's probably going to be MP3 - so how bad IS it, do the alternatives justify the cost or effort in obtaining and installing, and tolerating the bad habits of REAL and MS.

If MP3 at low bitrate is as bad as we expect it to be, it should take the "bottom anchor" position, and be ABX'ed 100% - but at low bitrates, we can expect ALL codecs to do considerable damage.

Dial-up bitrate listening test

Reply #13
Hmm, Qdesign is included in Quicktime, but is it used by any Internet broadcaster?

Just one idea:
Include a speech sample in the test. At least I presume that the purpose of this test is to test Internet radio compression.

Dial-up bitrate listening test

Reply #14
Quote
Hmm, Qdesign is included in Quicktime, but is it used by any Internet broadcaster?

Several of the trailers at quicktime.com are/were encoded with QDesign.

Quote
Just one idea:
Include a speech sample in the test. At least I presume that the purpose of this test is to test Internet radio compression.


Yes, I will probably replace one of the problem samples with a speech sample.

Suggestions of sample?

Dial-up bitrate listening test

Reply #15
I got H.G. Wells; War of the Worlds audiobook by Jeff Wayne, and "Star Wars - The original radio drama" if you're interested... Need to rip the CDs first tho

Dial-up bitrate listening test

Reply #16
Quote
Yes, I will probably replace one of the problem samples with a speech sample.

Suggestions of sample?

I don't really have suggestions for a sample, but do you think that only one speech sample is representative of streaming at this bitrate?  The MUSHRA comparison had 4 speech samples out of 9 total.

ff123

Dial-up bitrate listening test

Reply #17
I think this is one of the tests almost everyone can get involved with - 56k rates are so much easier to determine the quality of.

Ruairi
rc55.com - nothing going on

Dial-up bitrate listening test

Reply #18
Quote
I got H.G. Wells; War of the Worlds audiobook by Jeff Wayne, and "Star Wars - The original radio drama" if you're interested... Need to rip the CDs first tho

Yes, I'm interested. Thank-you very much.

Quote
I don't really have suggestions for a sample, but do you think that only one speech sample is representative of streaming at this bitrate? The MUSHRA comparison had 4 speech samples out of 9 total.


Interesting.

Well, I'm open for suggestions. We can ditch some of the musical styles and reduce the amount of classical samples to fit more speech samples.

I believe it would indeed be interesting to have one male monologue, a female monologue, a dialog...

I don't plan to feature more than 18 samples.

Dial-up bitrate listening test

Reply #19
Is speex not useful at this bitrate,or simply not tuned for music?

Dial-up bitrate listening test

Reply #20
I can provide a cappella sample(Suzanne Vega - Tom's Diner) which might be used in place of speech sample.

Uploaded here.

BTW, I'd like to see ATRAC3plus 48kbps in the test.

Dial-up bitrate listening test

Reply #21
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Is speex not useful at this bitrate,or simply not tuned for music?

Dunno the case with speex, but most voice coders fail VERY badly on music and complex sound effects.

I think Speex belongs to a test dedicated to vocodecs. I already started discussing such test with jmvalin, hopefully he'll have time to conduce it (or someone else might become interested).

Quote
I can provide a cappella sample(Suzanne Vega - Tom's Diner) which might be used in place of speech sample.


http://pessoal.onda.com.br/rjamorim/hh.jpg 

Dial-up bitrate listening test

Reply #22
32kbps sounds very decent for mono old time radio shows; I have several GBs of such shows in MP3 format. After my recent experiments for my own website OTR stuff I think that AAC (using the Compaact! encoder, no idea how Nero does in that range) sounds far better using the VBR encoder on the quality 1 or 2 setting.
Encoding a 1953 episode of the syndicated series 'The Third Man' (AKA The Lives of Harry Lime and Harry Lime Adventures) using those settings with a length of 20:23 gave me a file 8.45 MB in size. edit: forgot to mention that the average bitrate is 50-60kbps but easily hits 40 or less on a slightly lower setting. Original source was a tape.
That was the smallest I could go with my high personal standards after listening to enough 30 minute circa 6.5 meg MP3 files that sound decent but could be better.

Dial-up bitrate listening test

Reply #23
Quote
I believe it would indeed be interesting to have one male monologue, a female monologue

For this we can test the EBU SQAM disc tracks, there are female and male speech samples: http://www.tnt.uni-hannover.de/project/mpeg/audio/sqam/
WavPack 4.3 -mfx5
LAME 3.97 -V5 --vbr-new --athaa-sensitivity 1

Dial-up bitrate listening test

Reply #24
A 32kbps audio stream is usually the most you can extract from a 56k modem, sometimes higher but what usually happens then is jittery playback with regular rebuffering.

AFAIK, even though the modem has a higher bandwidth than 32kbps and the protocol is usually UDP there is still some overhead bandwidth which knocks several kbps onto the stream. (Correct me if I'm wrong)

 
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