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Topic: Transcode Test is now OPEN! (Read 17956 times) previous topic - next topic
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Transcode Test is now OPEN!

The rumored test is finally here!! http://twolf1300.net/transcode/

With the rise in popularity of hardware mp3 players, mp3 has become the standard by which people store their CDs onto their computers. Unfortunately, the convenience of hardware players has discouraged the adoptment of other potentially better codecs, such as Ogg Vorbis or Musepack. Those who have a hardware mp3 player must choose between storing their music with either lossless codecs or in mp3. A third choice is to transcode from the other codecs. This is considered blasphemy in audiophile circles. The objective of this test is to help determine whether that notion is valid.

For those who were not aware of the discussion preceding this test, please read up http://www.hydrogenaudio.org/forums/index....topic=11734&hl=.

Thanks,
-Steve

Transcode Test is now OPEN!

Reply #1 –
sounds interesting
(though I'm probbably one of the ppl where point 1. comes true...  )
Nothing but a Heartache - Since I found my Baby ;)

Transcode Test is now OPEN!

Reply #3 –
Sheesh...it's about time!      (JUST KIDDING!)

I think with the release of several new portables that actually play something other than MP3, that transcoding is becoming more relevant.  I've noticed more interest/questions about it in the past few weeks especially (the PC release of iTunes was a significant factor as well).  Many people in the world have MP3 collections, and may want to transcode to another format or to a lower bitrate for their portable.

Thanks for the effort you put into this, Steve.  I'll do my best to participate before the close date.

Transcode Test is now OPEN!

Reply #4 –
The following offsets should be appended to each config file:

Offset2 = 25
Offset4 = 125

These offsets are rather large, so they have the potential to cause ABX to have false positive results.

wavgain did a good job of leveling the volume.

ff123

Transcode Test is now OPEN!

Reply #5 –
Well I hope transcoding from  Lame--alt-preset standard does well cause that's what I transcode from for my portable player.

Transcode Test is now OPEN!

Reply #6 –
The instructions say, in part:

"Do not worry if you can't tell the difference between the files, but please attempt to distinguish between the two files using the ABX portion of the ABC/HR program.  ALL RESULTS THAT DON'T HAVE EVIDENCE OF AN ABX ATTEMPT WILL BE THROWN OUT."

There are 5 files plus a reference.  We are supposed to ABX each of the 5 files against the reference, correct?  How many ABX trials are we supposed to perform at minimum?  I presume we are also supposed to rate the 5 files against each other in the ABC/HR portion?

ff123

Transcode Test is now OPEN!

Reply #7 –
Two questions:

1. How do I use the offsets referred to by ff123? Do I just add these to each config file.

2. Is it absolutely necessary to ABX each one? I'm one of the guilty ones who doesn't bother ABXing in a ABC/HR type test if it is incredibly obvious, which it has been with most of the tests done here recently... I've got it right every time during the last lot of tests.

Mind you it might not be the case this time around...

Transcode Test is now OPEN!

Reply #8 –
54 tests that's a bit much for me, I'll just say I found very small differences in a couple and couldn't tell the difference on the rest of the ones I listened to.

Transcode Test is now OPEN!

Reply #9 –
Quote
1. How do I use the offsets referred to by ff123? Do I just add these to each config file.

2. Is it absolutely necessary to ABX each one? I'm one of the guilty ones who doesn't bother ABXing in a ABC/HR type test if it is incredibly obvious, which it has been with most of the tests done here recently... I've got it right every time during the last lot of tests.

The start file has been updated already at my site.  Hopefully Rjamorim will update his site soon.  I don't know HOW ff123 managed to find the offsets, but I appreciate it.

As for ABX'ing, I think that a good minimum value is 8.  There is at least 1 obvious crap file (I'm not saying which and I'd rather no one else did either).  8 trials for that one will take you all of 2 minutes tops.  Since I know which one the crap sample is, I'll be forgiving/understanding if there isn't an ABX score associated with that file.

The rest are sufficiently difficult enough that you'll probably need 8 trials.  Without that information, you could be just guessing (which is perfectly alright and there's no shame in this), but it won't be shown in the results. Like I said, the ABX attempts are more important than the actual score that you guys give.  This isn't a "How bad is the difference test?" but more of a "Is there an audible difference?"

Transcode Test is now OPEN!

Reply #10 –
Quote
54 tests that's a bit much for me, I'll just say I found very small differences in a couple and couldn't tell the difference on the rest of the ones I listened to.

I didn't emphasize this enough in the start file, but I'm perfectly aware that 54 tests is a friggin' s***load.

But I'd rather you do (and send the results) to just ONE sample than none.  One sample amounts to 6 tests, which will probably take about 30-60 minutes to do.  And I can push back the test date to accomodate anyone who's working on it (assuming enough people ARE in fact working on it).

Transcode Test is now OPEN!

Reply #11 –
Very good work. I'll start testing some samples later tonight and try to finish as many as possible.
"To understand me, you'll have to swallow a world." Or maybe your words.

Transcode Test is now OPEN!

Reply #12 –
Quote
Hopefully Rjamorim will update his site soon.

I updated it half an hour ago.

Transcode Test is now OPEN!

Reply #13 –
Quote
The start file has been updated already at my site.  Hopefully Rjamorim will update his site soon.  I don't know HOW ff123 managed to find the offsets, but I appreciate it.

I used CoolEdit to inspect the length of the silence at the beginning of each file.  However, one should also be able to use Schnofler's automatic offset finder to get the offset values.

ff123

Edit:  I tried using Schnofler's offset finder (located in his abchr-java app in the "Setup Test" menu), and it came up with the exact same offsets.

Transcode Test is now OPEN!

Reply #14 –
Quote
I tried using Schnofler's offset finder (located in his abchr-java app in the "Setup Test" menu), and it came up with the exact same offsets.

When I checked with the Java ABC/HR program that I had, there was no offset calculator.  But I just downloaded it again, tried it and there it was; and it worked.

The older one was included in the start file. I've updated the start file to include the newer version of Java ABC/HR and I've corrected some of the bash scripts I wrote (I can't believe I let those go by for this long).

The old start.zip file can be found at http://twolf1300.net/transcode/startOld.zip if you want to check out the older version of Java ABC/HR.

Transcode Test is now OPEN!

Reply #15 –
Just updated the start.zip package at my server again.

Transcode Test is now OPEN!

Reply #16 –
I downloaded the whole transcode test and zipped everything into one 35 MB archive. This file is now available through EDonkey / EMule / ... - perhaps it helps saving some bandwidth for RareWares:

ed2k://|file|Transcode.Test.zip|36309672|448B2EC30BB393B490DFAFC53DCF5277|/

Regards, fileman.

Edit: removed URL tag - ED2K-links aren't supported by the board software.

Transcode Test is now OPEN!

Reply #17 –
Should this thread be in Listening Tests area (also)?

Transcode Test is now OPEN!

Reply #18 –
why don't we use BitTorrent? It could very well save a lot of bandwith to dibron ... for fb2k also ... rarewares, etc ...

PS: BT is way faster than emule/edonkey ... i never get more than 10kb and 30 with BT ...

Transcode Test is now OPEN!

Reply #19 –
Feel free to use my BitTorrent Tracker:

Code: [Select]
http://emo-irc.mine.nu:81/announce
"To understand me, you'll have to swallow a world." Or maybe your words.

Transcode Test is now OPEN!

Reply #20 –
Haha.. with 3 people sharing the file in either eMule or BitTorrent, the speed will just depend on their bandwith.. assuming those with eMule powershare the file..
< w o g o n e . c o m / l o l >

Transcode Test is now OPEN!

Reply #21 –
wouldn't be better to test transcoding from LAME MP3 Encoder 3.90.3 --alt-preset xtreme instead (or also) from LAME MP3 Encoder 3.90.3 --alt-preset standard ?

Transcode Test is now OPEN!

Reply #22 –
Quote
wouldn't be better to test transcoding from LAME MP3 Encoder 3.90.3 --alt-preset xtreme instead (or also) from LAME MP3 Encoder 3.90.3 --alt-preset standard ?


These issues were discussed before in another thread. It probably isn't useful bringing them up here after the test is underway.

I think the various options were chosen based on typical use here at HA, and the general impression one gets is that --alt-preset standard is used more often here for lossy storage than xtreme, but I could be wrong.

Also, in my own transcoding experience, a sample that transcodes poorly from standard will also have problems from xtreme and insane, but hey you never know. My own testing was only on a limited number of samples.

Transcode Test is now OPEN!

Reply #23 –
Quote
I think the various options were chosen based on typical use here at HA, and the general impression one gets is that --alt-preset standard is used more often here for lossy storage than xtreme, but I could be wrong.

I did choose the settings based on typical usage at HA.  The only exception being MPC --insane, which I don't think is as popular as --standard.  That particular setting was chosen only to see whether increased bitrates will ensure a transparent transcode.

As such, I didn't think that an mp3 -> mp3 transcode was a terribly good idea, but the results will be interesting, especially in comparison with the others.  Most can't ABX Lame standard anyways, except with problem samples. Even then, problem samples don't always get better with xtreme.

Transcode Test is now OPEN!

Reply #24 –
I believe your batch files have a small problem with the last line, they don't wavegain anything (at least in my system)   

two last lines from Sample01.bat:

Code: [Select]
madplay -d -o..\Sample01\Autobahn_6.wav ..\Sample01\Autobahn_6.mp3
wavegain -r -y *.wav


I think it should be

Code: [Select]
madplay -d -o..\Sample01\Autobahn_6.wav ..\Sample01\Autobahn_6.mp3
wavegain -r -y ..\Sample01\*.wav



Cheers, Joey.

[Edit: running WinXP]