DAC How To


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. . . . . . MP3 How-To . . . . . .


DAC MP3 "Mini How-To" V4.0.1
Revision [30/08/1996 EDT 00:00]
(Non-internal/First public release)
by ShereKhan/MegaByte/MindRape of DAC


This Mini HowTo started out as an internal document for DAC members, to
standardize how DAC music releases are ripped, encoded, and packaged.
Since then, MPEG Layer III Audio (heretofore called "MP3") has grown in
popularity rapidly. However, quality has not improved similarly and many
of the new encodings I've encountered sound like crap. Most people who
have approached DAC (and I'm sure this is even more the case for the
online community in general) just do not have the experience in recording
digital audio, nor the familiarity with encoding MP3 needed to produce
the near-perfect quality we expect in all DAC releases. Hopefully this
guide will help you achieve the purest possible encodes from your CDs as
well.

Before going further, you need to get latest MP3 encoder, L3ENC v2.60 for
DOS (Linux/SunOS/NeXT versions are also available if you prefer), one or
more of the CD-ripping utilities mentioned in this guide (CDDA, DIDO, DAC,
CD-Grab Pro), and a good WAV-editing program such as CoolEdit95, Sound
Forge/32, or GoldWave. DAC members also need the current release NFO and
DIZ files. Please read through this ENTIRE HowTo, before running to one
of us for help!

Many of these tools can be found at MindRape's DAMAGED CYBERNETICS page at:

http://www.futureone.com/~damaged

Good Luck!


1. Resources for DAC members

1.1 /DAC-PAK on the #DAC bot(s)

All the ripping/encoding utilities, plus the current NFO and DIZ
for packaging into releases (as well as this How-To) are available
from the channel bot. Always make sure you are using the LATEST
versions of the NFO/DIZ before finalizing any release!

1.2 DAC WWW Page (ask members for address)

fRSTGUMP has put up a quick WWW page for DAC, with the latest NFO,
DIZ, and a table of DAC releases (not always 100% current, but the
closest thing). The server is secured with htaccess (DAC internal
use ONLY); if you have access to the channel bot, you should be
able to use the same login and passwd for the WWW page.


2. Ripping a song from CD (direct digital copy)

2.1 Mitsumi CD-ROM drives

Before pulling out your hair trying to rip with a Mitsumi CD-ROM,
I should tell you that most (all?) Mitsumi CD-ROM drives cannot
read "raw" CDDA data (Read_Long) and therefore cannot be used to
aquire CD-audio by direct digital copy with ANY program; this
includes CDDA/DIDO/DAC/etc. Mitsumi FX001D/FX001DE (2X) and the
newer FX400* (4X) drives are known to have this "defect"; the
manufacturer has purposely not included Read_Long in their drive
logic or drivers to prevent copyright infringement (lesson: don't
buy Mitsumi from now on.)

2.2 CDDA Version 1.4 build 12c [DOS]

CDDA is a DOS-based, command line CD ripping tool which allows
you to copy CD redbook audio DIRECT to WAV without recording or
sampling of any kind ... This type of "copying" gives the cleanest
possible results and is MUCH preferred over trying to record the
playback from the CD with CoolEdit or GoldWave. Direct copying, or
"ripping" as we like to call it, gives you the maximum dynamic
range from the songs, and thus NO clipping (which is a real problem
with the "record" technique), since with CDDA you are copying the
original signal strengths too with every signal peak. Think of it
as "Automatic Level Detection" for your CDROM drive. Also ripping
does not have problems with "skipping" due to buffer over/underrun
you often encounter when record CD playback using SoundRecorder,
CoolEdit, etc.

MegaByte has done a quick comparison test of CDDA and DIDO4 and
lists a few pros and cons for CDDA:

PROS: De-jittering technique MAY improve sound quality (unknown)

CONS: Must use /o switch to override CD copy protection.
DOS based; may not work under windows on some systems.
Does not work on some systems.

If you are using Win95, you will need to first make sure you are
using the DOS or 16-bit (Real Mode) Win3.x drivers for your CD-ROM
drive, as the Win95 built-in drivers are NOT compatible with CDDA
or any of the other direct copy utilities! Also make sure to read
the manual with CDDA and use the included tester programs to see
if your CDROM drive is capable of "long reads" (if not, you can't
do a direct rip). These test utilities (for DOS) are useful even
if you decide to use another ripper than CDDA.

A sample command line to rip a track off an *IDE* CD-Rom drive with
CD-DA might be: "CDDA /t [track] /m /f [filewav.wav] /w /o" PLEASE
read the CDDA manual to see what switches you need to use ... ATAPI,
SCSI, IDE all need different command line options! Additional info
from MegaByte's comparison tests on CDDA's dejitter feature:

[From CDDA.DOC:]
> "Many CDs have been mastered from digital sources. In this
> case the source may have been synthesized digitally which gives
> absolutely perfect sounds which are very repetitive and exactly
> the same. When this happens, it may possibly confuse the jitter
> correction routines. There is not a lot I can do about it at
> the moment, and there is less that any of the other programs
> like mine can do."

In one particular CD, which had repeating sound patterns, CDDA
had a dejitter error. In another CD, which had more "analog"
music, the error wasn't preesent. This may or may not be a
result of the problem expressed in the above quote.

2.3 DIDO 4.0 [Windows]

DIDO4 is a Windows-based CD ripping tool with a GUI. Like CDDA, it
copies the RedBook audio data directly from the CD to WAV. I have
not personally tested it but from MegaByte's comparison testing,
DIDO4 sounds very good. As with the other ripping utilities, you
need to use the *DOS* or older 16-bit "real mode" Win3.1 CDROM
drivers if you're under Win95. Some pros/cons from MegaByte:

PROS: GUI, easy to use, easy track view/recording time selector.

CONS: Has errors on some systems in accessing CD-ROM drives.
(see the workaround below)
Sometimes produces synchronization errors.
(can be worked around by changing end time a little)

MegaByte's workaround for the DIDO4 errors:

DIDO4 seems to have some difficulties reading CD's under Windows.
On [my] computer it stalls at 0 sectors on the read. To work
around this problem, eject the CD and reinsert it at the Save
File dialog box. Remember to hold the shift key under Windows 95
to prevent Autoplay. Also, disabling Flexi-CD can solve some
problems. If the CD is ejected, reinserted, and then "ok" in the
save dialog box is clicked, recording works... as long as no
autoplay program has opened.

2.4 DAC 2.2 [DOS]

People who have not been able to use CDDA has reported success
with DAC in some cases. DAC has a nicer menu interface and is
fairly easy to use. However, we do not have a registered version
of DAC, which means you cannot do partial rips (to test sound
quality, as you can with DIDO4 or CDDA) ... only the full track.
Also at least one of the optimization switches is missing in the
shareware version of DAC.

Here is a quick start to using DAC to rip CD tracks:

Load up DAC 2.2
Select the track to copy
Go to Action
Select copy
Pretty easy eh?

Of course, read the docs for DAC to see if you need to enable any
special options. As with CDDA and DIDO, you'll have to use the DOS
or old 16-bit "real mode" Win3.x CD-ROM drivers under Win95, NOT
the built-in Win95 miniport drivers! (Win95 CDROM drivers usually
don't support CDDA/"raw" mode).

2.5 CD-Grab Pro V3.21 [DOS]

This is similar to CDDA, just a bit older. Haven't used this yet,
anyone want to review it and let me know if it's good? I know that
this ripper DOES have dejitter functions.

2.6 General problems ripping in Win95

Some Win95 users may encounter problems when starting a copy with
CDDA, even if they have the correct DOS/real-mode drivers installed
and their drive DOES support Read_Long ... this can often be fixed
by starting up CD Player (in Win95) and putting the CD-ROM into
pause mode; while the player is still paused, open a DOS window
(if you're using a DOS-based ripper) and start copying the audio
with CDDA/DIDO/etc.

2.7 Using a CD-R (burner)

If you are lucky enough to have use of a CD-R burner, you can use
EZ-CD Pro (for Win3/Win95) or one of the various programs bundled
with the burner to direct COPY audio tracks from any CD. Typically
the read mechanism in CD-R drives are higher quality than regular
CD-ROMs and the drivers/software are made with copying in mind.


3. Sampling (recording output from CD player)

Although this method of aquiring a CD track as WAV isn't recommended,
many people either have incompatible hardware (Mitsumi or other CDROM
incapable of Read_Long) or software (try booting to DOS mode if you use
Win95, though!) and thus have no other choice than to sample the audio.
Unfortunately, many people who CAN (and should) use direct digital copy
are still sampling their CDs, either out of ignorance or laziness. This
accounts for MANY of the shittier sounding MP3 encodes out there.

You'll need good WAV-editing tools if you want to do a good sampling
job; the "standard" recorder/editor programs bundled with Sound Blaster
or PAS16, etc. usually aren't flexible enough and lack the buffering
features required to make a skip-free recording. Instead, you should
use a high-quality package such as SoundForge32, CoolEdit95, or Gold
Wave to do your sampling and post-processing (read on). A section on
using these programs will be in a future version of this How-To ...


4. Examining the WAV prior to compression

This is perhaps the MOST IMPORTANT STEP quality-wise in the process!
It is critical that you load the WAV you're ripped with CDDA/DIDO4/etc
into CoolEdit95 or SoundForge32 (or similar wave editors) and examine
it for defects, clipping, too quiet, etc. Visually you can see defects
that might not be noticible to the ear until AFTER compression (then
it's much more annoying to fix!) Here are some common problems you might
find in your freshly ripped (or if you cannot rip, recorded *bleh*) WAV:

4.1 Clipping

If you hear a tiny "pops" during playback of your WAV, and/or see
a lot of sound peaks that look cut off (pops and cut-off waveforms
should coincide) you've clipped the audio. This shouldn't happen
with direct ripping, but with recording it happens often. You'll
have to do it over if you have any noticible clips. Remember that
different parts of the same song may have very different volume
levels, so it isn't sufficient to just listen to one part of the
WAV when determining the correct recording level (if you sampled).

4.2 Too quiet

The other common problem is the entire wave is too quiet. When you
view a properly ripped/recorded WAV in SoundForge or CoolEdit, etc,
the loudest parts of the song should have peaks that ALMOST reach
the top/bottom edges of the waveform display; if even the loudest
peaks never get close to the limits, then you'll either have to set
the recording level a bit higher (if you're recording), or use the
"Normalize" feature of CoolEdit/SoundForge (do this ONLY if you did
a direct digital copy and know that no noise was introduced, other
wise the flaws will be amplified) Again, IF you did a direct rip,
and the resulting WAV is still very quiet, the Normalize (sort of
a smart amplify) function to maximize the dynamic range for the
entire file. Now you should see the loudest peaks in the song JUST
touch the top/bottom margins, without blowing out the passages in
the song that are supposed to be quiet.

4.3 Rough ends

After you're satisfied with the quality of your WAV rip, use your
wave editor to create "smooth ends" for the song. In CoolEdit95,
Select Entire Wave, use the "Envelope" function and choose "Smooth
Ends". If you cut the beginning or end of the song accidentally (or
on purpose) you might have to use the "fade-in" and or "fade-out"
tools to make a nice intro/ending. Finally, save to Microsoft PCM
(.WAV) at 44100Hz/16-bit/stereo.


5. Compressing from WAV to MPEG Layer III Audio (MP3)

5.1 L3ENC 2.60 Registered [DOS] - ftp.fhg.de /pub/layer3/

This is the encoder for DOS. Make SURE you register the encoder,
otherwise many of the command-line options will be locked out,
ones DAC members will need to use for their releases! (Registration
codes are below:

> From: Psychotron <mikead@slip.net>
> X-Sender: ShereKhan <ursus@alpha.c2.org>
> Newsgroups: alt.binaries.sounds.music,alt.binaries.sounds.utilities
> Subject: THE "FIRST" REG CODES 4 WINPLAY3 AND L3ENC This iz kewl!!!
> Date: Tue, 06 Aug 1996 23:28:13 -0700
>
> You may like to know that these are the very first reg
> codes for both "l3enc" and "WinPlay3", They will not make
> the programs run any better then from any other code but
> if you look at the serial number on your program after
> you reg your software with these number it will say 0001.
> kina kewl isn't it. Get it while you can
>
> L3ENC = 909GCB0A091E-9
> WINPLAY3 = 100011-301000-5000

NOTE: Here is another reg code for WinPlay3 v1.40
(from WinPlay3 v1.30, when it was freeware):

UserName=ISO FreeWare
RegistrationCode=222221-025226-0002

Here is a sample commandline for compressing a WAV (infile.wav) to
MP3 (outfile.mp3) REMEMBER YOU MUST REGISTER THE ENCODER FIRST!:

l3enc [infile.wav] [outfile.mp3] -br 128000 -crc

The -br 128000 tells L3ENC to produce a MP3 that will playback at
at 128000 bit/s ... this is the optimum compromise setting to get
the maximum compression ratio for CD-quality music while still
producing a MP3 that has virtually all the clarity of the original
song and a very respectable dynamic range (16khz rolloff at -br
128000) Compare this to the original CD-audio specification, which
rolls off at 22khz; humans can only hear up to about 20khz besides,
and virtually no natural sources, and very few artificially created
sounds you might find on a CD ever approach 20khz.

The default for the shareware L3ENC (pre-2.60) USED to be -br
128000 but for 2.60 and newer, it has been changed to -br 112000.
We at DAC feel a 112k bitrate sacrifices too much dynamic range
for a minimal gain in compression ratio, and therefore recommend
that -br 128000 be used for all encodes from CD sources.

An average 3-4 minute song will need about 10,000 frames to encode;
if you're smart, you'll encode only about 1,000 frames or so the
first time around (press CTRL+C to stop the encoder) to see if the
MP3 sounds good (no popping or dropouts, not too quiet) When you
seem to have a good test encode then delete the partial MP3 and
make the full-length MP3. L3ENC v2.60 has a nice progress indicator
which tells you what % of the encoding is completed.

If you have a fast computer (>P100) then you can try using the
"High Quality" switch in L3ENC (-hq). This will make the encoder
do extra quality checking so no errors are produced in the final
MP3 file. WARNING: this may take up to 3x as long (according to
RainMkr). Basically, -hq possibly may give you slightly higher
quality MP3, but at greatly reduced encoding speed. Try it for
yourself.

You better have a fast CPU, like P133 -> PP200, if you're going to
do a lot of encoding. ESPECIALLY if you want to use the -hq switch.
Otherwise do the encoding at night while you are sleeping, watching
tele, or whatnot. Encoding a 5 minute song on a i586-133 takes
approximately 15-20 minutes, while on a i486-80 it takes almost
1 hour. L3ENC is a 32-bit DOS executable, but it will run under
Win95/NT DOS boxes just fine. In fact. many people have run 4 DOS
sessions parallel, encoding 4 songs at once without problems.

5.2 Linux version of L3ENC V2.60

Some people report that the unix L3ENCoder is faster than the DOS
version, although I haven't tested it myself. Should work exactly
the same as DOS version. There is no Linux realtime player like
WinPlay3, unfortunately. Also since I don't know which tools you'd
use to rip the cd audio to WAV, I'm not sure it would be practical
to encode MP3 with Linux unless you also had DOS bootable on the
same machine (FTPing 40-50MB isn't fun, even on a T1).


6. Testing the completed MPEG3 file

6.1 Listening test

After you've finished compressing the MP3 you'll want to check it
over thoroughly of course ... Listen to it with WinPlay3 V1.40
REGISTERED (unregged V1.40 has a 20-second time limit for playback)
The reg code for WinPlay3 V1.40 is listed above. Make sure you have
at least a P90 to be able to playback at full 44100Hz/16-bit/stereo
output. You should not hear ANY nasty clicks, pops, or other defect
that aren't heard on the CD; these might mean doing the rip/encode
again. Also, if the song is VERY quiet, you might have set the
record level too low, or forgot to Normalize the WAV before
compressing (if you ripped). Lesson: be careful when you're making
the source WAV; most problems aren't from the L3ENC, so save time
by making sure the input WAV is pristine before encoding!


7. Packaging for DAC release

Non-DAC members can probably skip this section, which simply outlines
our procedure for putting together a release, starting from the freshly
encoded MP3 song.

7.1 Generate a MD5 checksum

After you've finished encoding your song(s) with L3ENC, use the
utility MD5SUM to calculate a MD5 checksum for the file. This is
for the release list maintainer to archive, as it allows you to
see if a file is the same as the checksum you originally generated
(test for dupes, other groups ripping off DAC releases, etc). The
way to use MD5SUM is as follows:

md5sum -bv file.mp3

This will print the MD5 sum for file.mp3 to the screen; put it into
the appropriate place in the DAC.NFO file (which you will e-mail to
dac@jt.org as well as package into the release ZIP ... read on)

If you have a whole list of files, you can generate a set of their
MD5 checksums by piping the output to a text file:

md5sum -bv *.mp3>md5sum.txt

After the output file is generated (md5sum.txt) you can later check
any of the MP3 files against their checksums in the md5sum.txt
(tells you if the files are identical). This is accomplished by
executing:

md5sum -cv md5sum.txt

NOTE: md5sum.exe will expect the files to check to be in the same
locations as were defined in the input list (md5sum.txt), so if you
later move the MP3s you should edit the paths in the MD5SUM.TXT to
reflect that.

7.2 Filling out the NFO/DIZ

This part is probably the easiest, just fill in all the appropriate
checkboxes and blanks in the DAC.NFO and DAC.DIZ. Remember to
rename DAC.DIZ to File_ID.DIZ before you zip up the package! Always
use the most current NFO and DIZ from ShereKhan or the channel bot.

7.3 Email NFO to fRSTGUMP

Don't forget to Email your completed NFO to fRSTGUMP so he can keep
an accurate list of our releases ... This is particularly important
to avoid duping already encoded songs by CDA or other groups.In the
near future this step may be replaced with a WWW forms inteface ...

7.4 Releasing the package

Each release should include a filled-out DIZ, NFO (always use the
latest available) and the actual MP3 song. Make sure the ZIP file
is named DAC-????.zip and FTP the completed package to the archive
site and/or any mirror sites DAC is feeding at the time. Also make
sure you DCC a copy of the ZIP to whomever is managing the current
offer bot(s).


--
DAC MP3 "Mini How-To" V4.0.1
Revision [30/08/96 EDT 00:00]
by ShereKhan, et al of DAC