cdda2wav.1

刻录光盘的程序

.B pitchplay
as an example. This option was contributed by Raul Sobon.
.IP "Select mono or stereo recording"
.B \-m
or
.B "\-c 1"
selects mono recording (both stereo channels are mixed),
.B \-s
or
.B "\-c 2"
or
.B "\-c s"
selects stereo recording (doubles file size). Parameter s
will swap both sound channels.
.IP "Select maximum quality"
.B \-x
will set stereo, 16 bits per sample at 44.1 KHz (full CD quality).  Note
that other format options given later can change this setting.
.IP "Select sample quality"
.B "\-b 8"
specifies 8 bit (1 Byte) for each sample in each channel;
.B "\-b 12"
specifies 12 bit (2 Byte) for each sample in each channel;
.B "\-b 16"
specifies 16 bit (2 Byte) for each sample in each channel (Ensure that
your sample player or sound card is capable of playing 12-bit or 16-bit
samples). Selecting 12 or 16 bits doubles file size.  12-bit samples are
aligned to 16-bit samples, so they waste some disk space.
.IP "Select sample rate"
.BI \-r " samplerate"
selects a sample rate.
.I samplerate
can be in a range between 44100 and 900. Option
.B \-R
lists all available rates.
.IP "Select sample rate divider"
.BI \-a " divider"
selects a sample rate divider.
.I divider
can be minimally 1 and maximally 50.5 and everything between in steps of 0.5.
Option
.B \-R
lists all available rates.
.IP
To make the sound smoother at lower sampling rates,
.B cdda2wav
sums over
.I n
samples (where
.I n
is the specific dividend). So for 22050 Hertz output we have to sum over
2 samples, for 900 Hertz we have to sum over 49 samples.  This cancels
higher frequencies. Standard sector size of an audio CD (ignoring
additional information) is 2352 Bytes. In order to finish summing
for an output sample at sector boundaries the rates above have to be
choosen.  Arbitrary sampling rates in high quality would require some
interpolation scheme, which needs much more sophisticated programming.
.IP "List a table of all sampling rates"
.BI \-R
shows a list of all sample rates and their dividers. Dividers can range
from 1 to 50.5 in steps of 0.5.
.IP "Select start track and optionally end track"
.BI \-t " n+m"
selects
.B n
as the start track and optionally
.B m
as the last track of a range to be recorded.
These tracks must be from the table of contents.  This sets
the track where recording begins. Recording can advance through the
following tracks as well (limited by the optional end track or otherwise
depending on recording time). Whether one file or different files are
then created depends on the
.B \-B
option (see below).
.IP "Select start index"
.BI \-i " n"
selects the index to start recording with.  Indices other than 1 will
invoke the index scanner, which will take some time to find the correct
start position. An offset may be given additionally (see below).
.IP "Set recording time"
.B \-d " n"
sets recording time to
.I n
seconds or set recording time for whole track if
.I n
is zero. In order to specify the duration in frames (sectors) also, the
argument can have an appended 'f'. Then the numerical argument is to be
taken as frames (sectors) rather than seconds.
Please note that if track ranges are being used they define the recording
time as well thus overriding any
.BR \-d " option"
specified times.
.IP
Recording time is defined as the time the generated sample will play (at
the defined sample rate). Since it's related to the amount of generated
samples, it's not the time of the sampling process itself (which can be
less or more).  It's neither strictly coupled with the time information on
the audio CD (shown by your hifi CD player).
Differences can occur by the usage of the
.B \-o
option (see below). Notice that recording time will be shortened, unless
enough disk space exists. Recording can be aborted at anytime by
pressing the break character (signal SIGQUIT).
.IP "Record a complete audio CD in one go in different files"
.B \-B
copies each track into a seperate file. A base name can be given. File names
have an appended track number and an extension corresponding to the audio
format. To record all audio tracks of a CD, use a sufficient high duration
(i.e. -d99999).
.IP "Set start sector offset"
.BI \-o " sectors"
increments start sector of the track by
.IR sectors .
By this option you are able to skip a certain amount at the beginning of
a track so you can pick exactly the part you want. Each sector runs for 1/75
seconds, so you have very fine control. If your offset is so high that
it would not fit into the current track, a warning message is issued
and the offset is ignored.  Recording time is not reduced.  (To skip
introductory quiet passages automagically, use the
.B \-w
option see below.)
.IP "Wait for signal option"
.B \-w
Turning on this option will suppress all silent output at startup,
reducing possibly file size.
.B cdda2wav
will watch for any signal in the output signal and switches on writing
to file.
.IP "Find extrem samples"
.B \-F
Turning on this option will display the most negative and the most positive
sample value found during recording for both channels. This can be useful
for readjusting the volume. The values shown are not reset at track
boundaries, they cover the complete sampling process. They are taken from
the original samples and have the same format (i.e. they are independent
of the selected output format).
.IP "Find if input samples are in mono"
.B \-G
If this option is given, input samples for both channels will be compared. At
the end of the program the result is printed. Differences in the channels
indicate stereo, otherwise when both channels are equal it will indicate mono.
.IP "Undo the pre-emphasis in the input samples"
.B \-T
Some older audio CDs are recorded with a modified frequency response called
pre-emphasis. This is found mostly in classical recordings. The correction
can be seen in the flags of the Table Of Contents often. But there are
recordings, that show this setting only in the subchannels. If you know you
have a pre-emphasized recording and want cdda2wav to undo this, you have to
specify this option. A reverse filtering is done before the samples are
written into the audio file.
.IP "Set audio format"
.B \-O " audiotype"
can be 
.I wav
(for wav files) or
.I au
or
.I sun
(for sun PCM files) or
.I cdr
or
.I raw
(for headerless files to be used for cd writers).
All file samples are coded in linear pulse code modulation (as done
in the audio compact disc format). This holds for all audio formats.
Wav files are compatible to Wind*ws sound files, they have lsb,msb byte order
as being used on the audio cd. The default filename extension is '.wav'.
Sun type files are not like the older common logarithmically coded .au files,
but instead as mentioned above linear PCM is used. The byte order is msb,lsb
to be compatible. The default filename extension is '.au'.
The AIFF and the newer variant AIFC from the Apple/SGI world store their samples
in bigendian format (msb,lsb). In AIFC no compression is used.
Finally the easiest 'format',
the cdr aka raw format. It is done per default in msb,lsb byte order to satisfy
the order wanted by most cd writers. Since there is no header information in this
format, the sample parameters can only be identified by playing the samples
on a soundcard or similiar. The default filename extension is '.cdr' or '.raw'.
.IP "Select cdrom drive reading speed"
.B \-S " speed"
allows to switch the cdrom drive to a certain level of speed in order to
reduce read errors. The actual speed
factor can generally be given completely freely, since there are often less
settings than factors possible. Details depend very much on the cdrom drives.
An argument of 0 for example is often the default speed of the drive,
a value of 1 often selects single speed.
.IP "Enable MD5 checksums"
.B \-M " count"
enables calculation of MD-5 checksum for 'count' bytes from the beginning of a
track. This was introduced for quick comparisons of tracks.
.IP "Do linear or overlapping reading of sectors"
.B \-P " sectors"
sets the given number of sectors for initial overlap sampling for jitter
correction. Two cases are to be distinguished. For nonzero values,
some sectors are read twice to enable cdda2wav's jitter correction.
If an argument of zero is given, no overlap sampling will be used.
.B NEWS!
For nonzero overlap sectors cdda2wav dynamically adjusts the setting during
sampling (like cdparanoia does).
If no match can be found, cdda2wav retries the read with an increased overlap.
If the amount of jitter is lower than the current overlapped samples, cdda2wav
reduces the overlap setting, resulting in a higher reading speed.
The argument given has to be lower than the total number of sectors per request
(see option
.I -n
below).
Cdda2wav will check this setting and issues a error message otherwise.
The case of zero sectors is nice on low load situations or errorfree (perfect)
cdrom drives and perfect (not scratched) audio cds.
.IP "Set the transfer size"
.B \-n " sectors"
will set the transfer size to the specified sectors per request.
.IP "Set number of ring buffer elements"
.B \-l " buffers"
will allocate the specified number of ring buffer elements.
.IP "Set endianess of input samples"
.B \-C " endianess"
will override the default settings of the input format.
Endianess can be set explicitly to "little" or "big" or to the automatic
endianess detection based on voting with "guess".
.IP "Set endianess of output samples"
.B \-E " endianess"
(endianess can be "little" or "big") will override the default settings 
of the output format.
.IP "Verbose option"
.B \-v " level"
prints more information. A binary mask allows selection of different
information.
.sp
.B "0"
keeps quiet
.sp
.B "1"
displays the table of contents
.sp
.B "2"
displays a summary of recording parameters
.sp
.B "4"
invokes the index scanner and displays start positions of indices
.sp
.B "8"
retrieves and displays a media catalog number
.sp
.B "16"
retrieves and displays international standard recording codes
.sp
.B "32"
displays track start positions in absolute sector notation
.sp
To combine several requests just add the numbers and give the sum as argument.
.IP "The table of contents"
The display will show the table of contents with number of tracks and
total time (displayed in
.IR mm : ss . hh
format,
.IR mm =minutes,
.IR ss =seconds,
.IR hh "=rounded 1/100 seconds)."
The following list displays track number and track time for each entry.
The summary gives a line per track describing the type of the track.
.sp
.ce 1
.B "track preemphasis copypermitted tracktype chans"
.sp
The
.B track
column holds the track number.
.B preemphasis
shows if that track has been given a non linear frequency response.
NOTE: You can undo this effect with the
.B \-T
option.
.B "copy-permitted"
indicates if this track is allowed to copy.
.B "tracktype"
can be data or audio. On multimedia CDs (except hidden track CDs) 
both of them should be present.
.B "channels"
is defined for audio tracks only. There can be two or four channels.
.IP "No file output"
.B \-N
this debugging option switches off writing to a file.
.IP "No infofile generation"
.B \-H
this option switches off creation of an info file and a cddb file.
.IP "Generation of simple output for gui frontends"
.B \-g
this option switches on simple line formatting, which is needed to support
gui frontends (like xcd-roast).
.IP "Verbose SCSI logging"
.B \-V
this option switches on logging of SCSI commands. This will produce
a lot of output (when SCSI devices are being used),
which is needed for debugging purposes. The format
is the same as being used with the cdrecord package from J鰎g Schilling.
I will not describe it here.
.IP "Quiet option"
.B \-q
suppresses all screen output except error messages.
That reduces cpu time resources.
.IP "Just show information option"
.B \-J
does not write a file, it only prints information about the disc (depending
on the
.B \-v
option). This is just for information purposes.
.SH "HINTS ON USAGE"
Don't create samples you cannot read. First check your sample player
software and sound card hardware. I experienced problems with very low
sample rates (stereo <= 1575 Hz, mono <= 3675 Hz) when trying to play
them with standard WAV players for sound blaster (maybe they are not
legal in
.B WAV
format). Most CD-Writers insist on audio samples in a bigendian format.
Now cdda2wav supports the 
.B \-E " endianess"
option to control the endianess of the written samples.
.PP
If your hardware is fast enough to run cdda2wav
uninterrupted and your CD drive is one of the 'perfect' ones, you will
gain speed when switching all overlap sampling off with
the
.B \-P " 0"
option. Further fine tuning can be done with the
.B \-n " sectors"
option. You can specify how much sectors should be requested in one go.
.PP
Cdda2wav supports
.B pipes
now. Use a filename of
.B \-
to let cdda2wav output its samples to standard output.
.PP
Conversion to other sound formats can be done using the
.B sox
program package (although the use of
.B sox -x
to change the byte order of samples should be no more necessary; see option
.B \-E
to change the output byteorder).
.PP
If you really want to sample more than one track into
different files in one run, this is currently possible with the
.B \-B
option. When recording time exceeds the track limit a new file will
be opened for the next track.
.SH WARNING
.B IMPORTANT:
it is prohibited to sell copies of copyrighted material by noncopyright
holders. This program may not be used to circumvent copyrights.
The user acknowledges this constraint when using the software.
.SH BUGS
Performance may not be optimal on slower systems.
.sp
The index scanner may give timeouts.
.sp
The resampling (rate conversion code) uses polynomial interpolation, which
is not optimal.
.sp
Cdda2wav should use threads.
.sp
When using jitter correction with ATAPI cdrom drives, track endings
are not handled correctly.
.SH ACKNOWLEDGEMENTS
Thanks goto Project MODE (http://www.mode.net/) and Fraunhofer Institut f黵
integrierte Schaltungen (FhG-IIS) (http://www.iis.fhg.de/) for financial
support.
Plextor Europe and Ricoh Japan provided cdrom disk drives and cd burners
which helped a lot to develop this software.
Rammi has helped a lot with the debugging and showed a lot of stamina when
hearing 100 times the first 16 seconds of the first track of the Krupps CD.
Paranoia patches contributed by Monty [e-mail].
.SH AUTHOR
Heiko Eissfeldt [e-mail]
.SH DATE
25 Mar 1999