Dial-up bitrate listening test

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Dial-up bitrate listening test

Reply #100 – 2004-06-25 08:48:30

Uh, OH ! "My domain" listening test, finally.

1. 32 Kbps is enough for modems. Anyway i think you shouldn't focus on bandwidth only, but balancing it on listening quality too. I mean that you should consider to downsample (SSRC, obviously) files to 32 KHz for mono or 22 KHz for stereo... (i prefer mono 'cause stereo image is not so important for internet radio due to speaker's speech, and no DRM needed).

2. About samples: don't use only speech or single instrument samples.
Real world internet radios streams so mutch different styles of music that you should consider at least 9 - or more - generes (world, classical, jazz, pop, dance, electronic, progressive, extreme metal).
I can provide interesting world and extreme metal samples, if you need (check out this file, to get an idea - interesting spectrum, isn't it ?)

Dial-up bitrate listening test

Reply #101 – 2004-06-25 09:03:37

I personally have high hopes for HE-AAC+PS at 32kbps - even in stereo. Months ago when the HE-AAC encoder first came out I did some test HE-AAC 32kbps material and was very impressed, sounded especially good with synthetic music. (dance, etc.) Unfortunately I haven't been able to test it recently as Nero has begun producing very strange sounding .mp4's (sped up, weird crackling all through it, just whack sounding) on my system even after a clean virgin win2k install + nero latest version...but yes with PS I can imagine it will be quite good.

Dial-up bitrate listening test

Reply #102 – 2004-06-25 09:18:26

Quote

Low anchor: MP3 at 32kbps, 12kHz

If the mp3 enchor is Lame, I'd suggest letting it use its default sampling rate.

Example: at 32kbps, the lowpass is around 5.5kHz, but the sampling rate is 16kHz and not 12kHz. The sample rate used by Lame is determined automatically in order to avoid use of sfb21. By using a 12kHz rate, Lame would have to use the problematic sfb21.

Dial-up bitrate listening test

Reply #103 – 2004-06-25 10:00:25

Quote

Now, it only remains to be tested what sampling rates will be used with WMA and Real. Maybe I should set up a really simple and quick pre-test?

In Real the samplerates are forced by the flavor. If your input is a another samplerate it gets resampled automatically. You have only two flavors (20 and 21) with 32kbps, one with 22050 Hz and one 44100 Hz. You cannot use another samplerate.

Dial-up bitrate listening test

Reply #104 – 2004-06-25 16:14:00

Quote

If the mp3 enchor is Lame, I'd suggest letting it use its default sampling rate.

I was considering FhG, since it's believed FhG offers better quality at low bitrates.

If people prefer I use Lame, I will use it instead.

Quote

In Real the samplerates are forced by the flavor. If your input is a another samplerate it gets resampled automatically. You have only two flavors (20 and 21) with 32kbps, one with 22050 Hz and one 44100 Hz. You cannot use another samplerate.

That's interesting. I never saw these "flavors" in Real Producer. Where can I reach them?

Dial-up bitrate listening test

Reply #105 – 2004-06-25 17:19:07

I'm looking forward to this test because results would also be useful for ultra-low bitrate dvd backups, so 32kb/s does look as the common bottom for all these codecs. I use 64 bit HE-AAC for my movies and it sounds really good while still small, ill test ps whenever nero releases the new version and i could try 56, as stated in the last test.

So my hopes are also with HE-AAC+PS.

Allow me to ask something dumb but quick, theres no point on using parametric stereo on mono files right?? just to be sure

Dial-up bitrate listening test

Reply #106 – 2004-06-25 17:42:01

Quote

Quote
If the mp3 enchor is Lame, I'd suggest letting it use its default sampling rate.

I was considering FhG, since it's believed FhG offers better quality at low bitrates.

If people prefer I use Lame, I will use it instead.

Quote
In Real the samplerates are forced by the flavor. If your input is a another samplerate it gets resampled automatically. You have only two flavors (20 and 21) with 32kbps, one with 22050 Hz and one 44100 Hz. You cannot use another samplerate.

That's interesting. I never saw these "flavors" in Real Producer. Where can I reach them?

Quote

That's interesting. I never saw these "flavors" in Real Producer. Where can I reach them?

The 44.1 versions are the "High Response" versions.

I'd say that with more sources than not, the non-High Response versions sound better. But there are plenty of exceptions.

Dial-up bitrate listening test

Reply #107 – 2004-06-25 18:07:46

Quote

Allow me to ask something dumb but quick, theres no point on using parametric stereo on mono files right?? just to be sure

Seems that yes. Mono file will use SBR only...
EDIT:

Quote

So my hopes are also with HE-AAC+PS.

Still unsure after test of samples that Garf provided. Seems that it will sound better than anything else on such a bitrates, but not sufficient for DVD backup... Sometimes it poduce ugly result. The only hope is that sound in movie is much less complex than music...
BTW, about 56Kbit you mentioned, As I understand Garf posts, new HEAAC encoder will produce 56Kbit stream with a similiar quality to current 64Kbit... They claim that HEAAC is avanced a lot in their encoder... Have to wait and test for myself

Dial-up bitrate listening test

Reply #108 – 2004-06-26 17:17:09

Quote

That's interesting. I never saw these "flavors" in Real Producer. Where can I reach them?

Did you never used Helix Producer? It´s the completly free RealMedia CLI-encoder for Windows, Linux and Mac. It´s even open-source (only the application, not the codecs). Here you can use all advanced features and change special options you don´t see in the other tools, but in fact these flavors are used everywhere, they are also stored in the output file, but in the more easy to use tools you cannot see them, but each audio option in this drop-down list with the bitrates represents one flavor.
You can download Helix-Producer here: https://helix-producer.helixcommunity.org/downloads.htm
For a list of all currectly used codecs with all flavors etc.: https://producerapps.helixcommunity.org/cmd...io_Codec_Tables
Note: This list is not complete and aac flavors are not correct, I have a file called "AudienceDefaults.xls" containing all ever used codecs, but in there reordered website I cannot find it anymore, also it is not up-to-date, the aac codecs are missing.

Dial-up bitrate listening test

Reply #109 – 2004-06-27 01:47:59

Thank-you for the information, benwaggoner and S_O

Yes, I already used Helix Producer, but I prefer to work on Real Producer's GUI

Here's a little favour I would like to ask from you guys:

I uploaded 4 samples encoded to WMA 32kbps at 22.050, 32.000 and 44.100Hz. This is a little pre-test to try to find out at what sampling rate WMA sounds best.

The sample packages are here:
http://www.rarewares.org/samples/

Testing them shouldn't take more than 5 minutes. Download the package, unzip it, unflac the samples, load them on ABC/HR or ABC/HR Java (the sample with no _X at the filename is the reference), and post the results file (no need to ABX, the samples should sound plenty bad anyway ).

Thank-you very much for helping. Tomorrow I'll probably conduce another quick test with Real Audio or QDesign.

How I created those samples: I loaded the WAV files on Windows Media Encoder 9 (probably the crappiest piece of software I've ever found), saved them to 32kbps (either 44.1, 32 or 22.05kHz), decoded the WMAs with dbpoweramp, converted all samples to 44.1kHz with SSRC HP (to avoid problems related to bad sound card resamplers) and FLACd.

Best regards;

Roberto.

Dial-up bitrate listening test

Reply #110 – 2004-06-27 04:48:41

I don't know what was worse.....waiting for the samples to download on my crappy 20kbps dialup, or actually listening to them In any case, I'll post results for the others as I test them.

Overall, I must mention that I do already have a personal preference when it comes to low-bitrate audio: the duller sound of lowpassed or downsampled audio is much preferred over the ringing, lispy artifacts one finds with higher sampling rates and/or lowpasses. Thus, I didn't find the two low sampling rate clips to be terribly annoying, but close in quality to MW radio. At these ultra-low bitrates, sound quality might be a function of personal preference, since all these samples are quite bad from a quantitative perspective, but yet are qualitatively quite different. Some might prefer WMA's metallic HF artifacts to MP3's very sharp lowpass or Vorbis' collapsed stereo image; it's simply a matter of personal taste. I've listened to ballgames on AM radio for over 20 years, so that type of sound is preferred for me, and thus my ratings might be higher for dull samples than others may report.

ABC/HR for Java Version 0.4b, 26 June 2004
Testname: Female Speech @ 32kbps

1R = /Users/Angelo/Desktop/female_speech/female_speech_2.wav
2L = /Users/Angelo/Desktop/female_speech/female_speech_1.wav
3R = /Users/Angelo/Desktop/female_speech/female_speech_3.wav

---------------------------------------
General Comments: Sample 2 is horrible; tons of pre and post-echo. Speech intelligible but annoying.
---------------------------------------
1R File: /Users/Angelo/Desktop/female_speech/female_speech_2.wav
1R Rating: 1.5
1R Comment: Extremely annoying pre and post-echo. Speech is still intelligible, but unpleasant to listen to.
---------------------------------------
2L File: /Users/Angelo/Desktop/female_speech/female_speech_1.wav
2L Rating: 3.5
2L Comment: Duller than sample 2, but much more pleasant to listen to. Definitely less noticeable artifcating than aforementioned sample.
---------------------------------------
3R File: /Users/Angelo/Desktop/female_speech/female_speech_3.wav
3R Rating: 3.5
3R Comment: Not sure that I can hear a difference between this and Sample 1.....dull because of lower sampling rate, but still listenable.
---------------------------------------

Dial-up bitrate listening test

Reply #111 – 2004-06-27 05:43:44

Ok....here's the results for the Kraftwerk sample. Again, two of the samples are very close, if not the same to me in terms of sound quality, and I'm not sure if I can really hear a difference between the two (in lieu of ABX). The remaining sample is, like with the female speech sample, unbearably awful....classic WMA sound, I would say

ABC/HR for Java Version 0.4b, 26 June 2004
Testname: Kraftwerk @ 32kbps

1R = /Users/Angelo/Desktop/kraftwerk/kraftwerk_1.wav
2L = /Users/Angelo/Desktop/kraftwerk/kraftwerk_3.wav
3R = /Users/Angelo/Desktop/kraftwerk/kraftwerk_2.wav

---------------------------------------
General Comments:
---------------------------------------
1R File: /Users/Angelo/Desktop/kraftwerk/kraftwerk_1.wav
1R Rating: 3.0
1R Comment: Dull; attacks much less sharp than reference (pre-echo), but not horribly annoying.
---------------------------------------
2L File: /Users/Angelo/Desktop/kraftwerk/kraftwerk_3.wav
2L Rating: 3.2
2L Comment: Dull, but maybe a little more HF than sample 1? Very close to sample 1, not sure if there is a real difference.
---------------------------------------
3R File: /Users/Angelo/Desktop/kraftwerk/kraftwerk_2.wav
3R Rating: 1.3
3R Comment: Awful pre and post echo....artifacts before and after attacks. Worst of bunch by far.
---------------------------------------

Dial-up bitrate listening test

Reply #112 – 2004-06-27 06:55:19

Well, it looks like no more testing for tonight....ABC/HR (Java version since I'm on a *nix system) suddenly went flakey on me. Although I was able to set up two new tests earlier, the program will not open that option, or load any saved configurations (it simply does nothing when those options are clicked upon). I even unzipped a fresh copy, restarted the computer, and cleared out my Java cache, all to no avail! What's wrong here? (I'm using Darwin w/ OS X 10.3.4 and Java 1.4.2).

(My apologies for going OT).

Dial-up bitrate listening test

Reply #113 – 2004-06-27 07:09:05

[span style='font-size:8pt;line-height:100%']
ABC/HR Version 1.0, 6 May 2004
Testname: Bartok_strings2

Tester: ff123

1R = D:\junk\pretest\Bartok_strings2_3.wav
2L = D:\junk\pretest\Bartok_strings2_2.wav
3R = D:\junk\pretest\Bartok_strings2_1.wav

---------------------------------------
General Comments:
pretty much rated by lowpass
---------------------------------------
1R File: D:\junk\pretest\Bartok_strings2_3.wav
1R Rating: 1.8
1R Comment:
---------------------------------------
2L File: D:\junk\pretest\Bartok_strings2_2.wav
2L Rating: 3.4
2L Comment:
---------------------------------------
3R File: D:\junk\pretest\Bartok_strings2_1.wav
3R Rating: 2.5
3R Comment:
---------------------------------------
ABX Results:

ABC/HR Version 1.0, 6 May 2004
Testname: female_speech

Tester: ff123

1L = D:\junk\pretest\female_speech_1.wav
2R = D:\junk\pretest\female_speech_2.wav
3R = D:\junk\pretest\female_speech_3.wav

---------------------------------------
General Comments:

---------------------------------------
1L File: D:\junk\pretest\female_speech_1.wav
1L Rating: 2.5
1L Comment:
---------------------------------------
2R File: D:\junk\pretest\female_speech_2.wav
2R Rating: 2.0
2R Comment: higher frequencies more apparent, but so is additional noise pumping
---------------------------------------
3R File: D:\junk\pretest\female_speech_3.wav
3R Rating: 2.5
3R Comment:
---------------------------------------
ABX Results:

ABC/HR Version 1.0, 6 May 2004
Testname: kraftwerk

Tester: ff123

1L = D:\junk\pretest\kraftwerk_1.wav
2R = D:\junk\pretest\kraftwerk_3.wav
3L = D:\junk\pretest\kraftwerk_2.wav

---------------------------------------
General Comments:

---------------------------------------
1L File: D:\junk\pretest\kraftwerk_1.wav
1L Rating: 2.3
1L Comment:
---------------------------------------
2R File: D:\junk\pretest\kraftwerk_3.wav
2R Rating: 2.9
2R Comment: sharpest attacks
---------------------------------------
3L File: D:\junk\pretest\kraftwerk_2.wav
3L Rating: 2.9
3L Comment: best frequency response; can't choose between the attacks or the frequency response on this particular sample
---------------------------------------
ABX Results:

ABC/HR Version 1.0, 6 May 2004
Testname: waiting

Tester: ff123

1L = D:\junk\pretest\Waiting_1.wav
2R = D:\junk\pretest\Waiting_3.wav
3L = D:\junk\pretest\Waiting_2.wav

---------------------------------------
General Comments:
typical wma ringing sound in the background
---------------------------------------
1L File: D:\junk\pretest\Waiting_1.wav
1L Rating: 2.0
1L Comment:
---------------------------------------
2R File: D:\junk\pretest\Waiting_3.wav
2R Rating: 2.3
2R Comment:
---------------------------------------
3L File: D:\junk\pretest\Waiting_2.wav
3L Rating: 2.8
3L Comment: strongest ringing, but also best frequency response.
---------------------------------------
ABX Results:
[/span]

Dial-up bitrate listening test

Dial-up bitrate listening test

Reply #121 – 2004-06-29 20:06:30

Nero AAC Codec 2.9.9.95

It´s nice to have the latest AAC encoder without having to download 30MB

Is "Downnsampled SBR" already avaible in this release? I don´t think so because I cant´t select HE-AAC when choosing a bitrate of 128kb/s.

Dial-up bitrate listening test

Reply #122 – 2004-06-29 20:28:54

Hi, just a few reminders.

Dialup modems using v.90 can't send faster than 33.6kbps. v.92 allows a tiny little bit more if line conditions allow, something like 40kbps.

For .v9x to work, there needs to be a digital isdn like thingie at the other end (eg. ISP), otherwise you are stuck at v.34 (33.6kbps max bi-dir). It is not uncommon for modems to throttle down when line noise increases.

You also have to accomodate for protocol overhead (v.xx+ppp+tcp, etc). There is a little help with the use of realtime lzw compression (around 4:1 for text). On the other hand, too many people nowdays use softmodems, which tie the cpu since the whole modulation demodulation is done in software. This cause too many unexpected issues, be lucky if it works at all..

So i think 32kbps should be the maximun intended bitrate for dialup modems. Some people may get thru with a little more, but not all. In fact, sometimes establishing a 33.6kbps link can be difficult, 31.2, 28.8 and 26.4 are not uncommon connect rates.

Also, i am one of those people who favored ogg vorbis instead of speex for mostly speech based content. After many tests, my reasoning is this:

Yes, for the same bitrate, the speech codecs can make the voice sound better, BUT, add something else in the content (hand clap, second voice, instruments, street noise, etc, etc, etc), and a major artifact will come, often distorting the main voice. When using a non speech codec, it may have an overall reduced quality, but this quality tends to remain stable (ie, not suddendly adding very annoying artifacts).

With Ogg Vorbis, streaming an AM radio (live) just using -q-1 and --resample 8000 (mono) i get a very listenable landline telephone like quality, averaging around 9kbps with peaks never exceeding 12kbps. I have set up a test stream you can access here (spanish language) http://mipagina.cantv.net/artemis3/radio/

I understand this is not the fault of the speech codecs, they were just intended for other things.

This will be an interesting test, and most ppl can participate

Dial-up bitrate listening test

Reply #123 – 2004-06-30 04:29:28

Quote

Hello.

Ivan sent me the AAC encoder that will be available in next Nero release, featuring that stereo enhancement technique. I'm posting it here for peer review before the test starts:
http://pessoal.onda.com.br/rjamorim/nero_aac.zip (909Kb)

The interface is the same as before but, according to Ivan, that enhancement technique kicks in at 32kbps CBR and lower when using HE AAC. I don't know about VBR profiles using this technique.

Test should start in 24-30 hours.

Best regards;

Roberto.

umm so ps isnt going to be available at say... 56kb/s?? i thought the test with the samples showed good results between 56ps vs 64 non-ps, is it just me? Also was the quality tuned for portable preset? i want to know if its worth to reencode my portable files and if the same applies even for transparent preset...

btw, i tried to select the downmix to mono option and it crashed

thnx in advance

Dial-up bitrate listening test

Reply #124 – 2004-06-30 04:52:53

quick test:

mono file was tested and i couldnt abx, was raw he-aac tuned at this bitrate? (tape preset, in mono around 16kbps)

Dumbly, i overwrote the dlls and a sample i had before ps so i cant test the before ps encoder anymore, cbr vs cbr. anyway i encoded a stereo file in tape preset and also in cbr 32kbps and tried to compare em, conclusion: my ears are crap, thats why i dont participate ever in tests didnt notice difference, the only way i can tell difference is between diferent bitrates or resolutions lol, or maybe ps also works in tape preset now?? dunno

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