CDRDAO

Section: User Commands (1)
Updated: May 22, 1998
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NAME

cdrdao - writes audio CD-Rs in disc-at-once mode

SYNOPSIS

DESCRIPTION

cdrdao creates audio CD-Rs in disk-at-once (DAO) mode driven by a description file called toc-file. In DAO mode it is possible to create non standard track pre-gaps that have other lengths than 2 seconds and contain nonzero audio data. This is for example useful to divide live recordings into tracks where 2 second gaps would be kind of irritating. This tool can only produce audio CDs, it is not possible to create data tracks.

COMMANDS

The first argument must be one of the following commands:
show-toc: Print out a summary about what will be written to the CD-R.
read-toc: Analyze each track of the inserted audio CD and create a toc-file that can be used to make a more or less exact copy of the CD. This command is not completely implemented, yet. Index marks will not be detected. There is a driver for Plextor CD-ROM readers that is able to detect pre-gaps. This command does not read out the audio data itself, use specialized programs like cdda2wav(1) for this purpose.
show-data: Print out all samples that would be written to the CD-R. Each line contains the sample number (starting at 0) and the decimal sample value for the left and right channel. Useful to check if the byte order of audio files is correct.
read-test: Checks if all data can be read from the audio files that are defined in the toc-file. This will also check the communication with the slave process that is responsible for writing the audio data to the CD-recorder. Mainly used for testing.
simulate: Like write but laser stays cold.
write: Write the CD-R according to the specifications in the toc-file.

OPTIONS

--device device: Set the generic SCSI device of the CD-recorder, default is /dev/cdrecorder which should be a link the actual device.
--driver driver-id: Force usage of specified driver instead of the automatically determined driver. Available driver IDs:
cdd2600: Philips CDD2600 writer
plextor: Plextor CD-ROM readers, writing is not supported
--speed value: Set the writing speed to value. Default is the highest possible speed.
--eject: Eject the CD-R after writing or write simulation.
--swap: Swap the byte order of all samples that are send to the CD-recorder.

TOC FILES

The toc-file describes what audio data is written to the CD-R and allows control over track/index positions, pre-gaps and sub-channel information. It is a simple text file, use your favorite text editor to create it. A toc-file contains an optional header and a sequence of track specifications. Comments starting with '//' reaching until end of line can be placed anywhere.

Header

CATALOG ddddddddddddd: Specifies the optional catalog number of the CD. The string must contain exactly 13 digits.

Track Specification

TRACK AUDIO: Starts a new track, the track number is incremented by 1. The length of a track must be at least 4 seconds. If the audio data length is not a multiple of the block length (588 samples) it will be padded with zeros.

The following flags may follow the track start statement. They are used to set sub-channel information for the current track. Each flag is optional. If not given the following defaults are used: copy permitted, no pre emphasis, two channel audio, no ISRC code.

[ NO ] COPY: Sets or clears the copy permitted flag.
[ NO ] PRE_EMPHASIS: Sets or clears the pre emphasis flag.
TWO_CHANNEL_AUDIO: Indicates that track contains two channel audio data.
FOUR_CHANNEL_AUDIO: Indicates that track contains four channel audio data.
ISRC CCOOOYYSSSSS: Sets ISRC code of track.
C: country code (upper case letters or digits)
O: owner code (upper case letters or digits)
Y: year (digits)
S: serial number (digits)

At least one of the following statements must appear to specify the audio data for the actual track. Lengths and start positions may be expressed in samples (1/44100 seconds) or in MSF format 'MM:SS:FF' specifying minutes, seconds and frames (0 <= 'FF' < 75) . A frame contains 588 samples (1/75 second) which is the block size of an audio CD. If more than one statement is used the track will be composed by concatenating the audio data in the specified order.

SILENCE <length>: Adds zero audio data of specified length to actual track. Useful to create silent pre-gaps.
FILE <filename> <start> [ <length> ]: Adds the audio data of specified file to actual track. It is possible to select a portion of an audio file with <start> and <length> which allows non destructive cutting. The first sample of an audio file is addressed with <start> = 0. If <length> is omitted or set to 0 all audio data from <start> until the end of file is used. Audio files may have raw or WAVE format with 16 bits per sample, 44.1 kHz sampling rate, stereo. Raw files must have the layout 'MSBLeft LSBLeft MSBRight LSBRight ...' (big endian byte order). WAVE files are expected to have little endian byte order. The option --swap reverses the expected byte order for all raw and WAVE files. Only filenames with a ".wav" ending are treated as WAVE files, all other names are assumed to be raw audio files. Use tools like sox(1) to convert other file formats to supported formats. If you are unsure abort the byte order of your audio files try the command 'show-data'. If the byte order is correct you will see a sequence of increasing or decreasing numbers for both channels. Otherwise numbers are jumping between very high and low values - high volume static.
START [ MM:SS:FF ]: Defines the length of the pre-gap (position where index switches from 0 to 1). If the MSF value is omitted or set to '00:00:00' the current track length is used. If the current track length is not a multiple of the block length the pre-gap length will be rounded up to next block boundary. If no START statement is given the track will not have a pre-gap.
PREGAP MM:SS:FF: This is an alternate way to specify a pre-gap with zero audio data. It may appear before the first SILENCE or FILE statement. Either PREGAP or START can be used within a track specification. It is equivalent to the sequence:

SILENCE MM:SS:FF

START

The end of a track specification may contain zero or more index increment statements:

INDEX MM:SS:FF: Increments the index number at given position within the track. The first statement will increment from 1 to 2. The position is relative to the real track start, not counting an existing pre-gap.

Examples

Simple track without pre-gap with all audio data from WAVE file "data.wav":

TRACK AUDIO
FILE "data.wav" 0

Standard track with two second pre-gap and ISRC code:

TRACK AUDIO
ISRC "DEXXX9800001"
PREGAP 0:2:0
FILE "data.wav" 0

Track with 10 second pre-gap containing audio data from raw file "data.cdr":

TRACK AUDIO
FILE "data.cdr" 0 
START 0:10:0

Composed track with data from different files. Pre-gap data and length is taken from "pregapdata.wav". The first minute of "track.cdr" is omitted and two seconds silence are inserted at '2:0:0'. Index will be incremented after 2 and 4 minutes past track start:

TRACK AUDIO
FILE "pregapdata.wav" 0 
START
FILE "track.cdr" 1:0:0 1:0:0
SILENCE 0:2:0
FILE "track.cdr" 2:0:0
INDEX 2:0:0
INDEX 4:0:0

BUGS

Error conditions are not handled very gracefully. If the program is terminated during the write/simulation process used IPC resources will not be released. Use ipcs(8) and ipcrm(8) to delete them.

AUTHOR

Andreas Mueller mueller@daneb.ping.de

BUGS

AUTHOR

SEE ALSO

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