% dtas-splitfx(1) dtas user manual

# NAME

dtas-splitfx - split audio and apply effects to all tracks

# SYNOPSIS

dtas-splitfx SPLITFX_FILE.yml [OPTIONS] [TARGETS] [ARGS...]

# DESCRIPTION

dtas-splitfx reads as YAML file and can apply effects (including
resampling/dither), split, tag, and encode files in parallel.
dtas-splitfx is intended for splitting recordings from vinyl and live
concerts into separate files.  dtas-splitfx is inspired by cuesheets for
CD audio and the make(1) build tool.

dtas-splitfx primarily uses sox(1), but it is possible to define targets
to use ecasound(1), too.

# OPTIONS

-j, \--jobs [JOBS]
:    Number of jobs to run in parallel.  If no number is specified, all
     jobs are run in parallel.

-n, \--dry-run
:    Print, but do not run the commands to be executed

-s, \--quiet, \--silent
:    Silent operation, commands are not printed as executed

-D, \--no-dither
:    Disable automatic setting of the DITHERFX env.  This also passes
    the option to sox(1) via SOX_OPTS.

-O, \--outdir OUTDIR
:    Set output directory instead of current directory.
    User-created targets must allow a placeholder for the
    (by default, an empty string) $OUTDIR environment variable
    in the output command.

-C, \--compression FACTOR
:    Set the compression factor passed to sox(1).  See soxformat(7)
    for more information on how it works across different formats.

-r, \--rate RATE
:    Override the output sample rate in the specified TARGET

-b, \--bits BITS
:    Override the output bit depth in the specified TARGET

-t, \--trim POSITION
:    Passes a POSITION argument to the sox "trim" effect to allow
     limiting output to only process a portion of the original.
     This bypasses the "tracks" section and of the YAML file and
     outputs the result as a single file with the TRACKNUMBER
     of "000".  For ease-of-typing, commas in this command-line
     argument are automatically expanded to spaces when passed to sox.

-p, \--sox-pipe
:    Used in place of an output target to specify outputting audio data in
     the native "sox" format to another sox(1) or play(1) command.  This
     moves printing of output to stderr and disables parallel job invocation.

# FILE FORMAT

* infile - string, the pathname of the original audio file
* env - ordered hash of environment variables to set for all commands
    env: !omap
      FX: gain 3 stats
* comments - hash of common tags for all audio (e.g. ARTIST, ALBUM, YEAR)
    comments:
      ARTIST: John Smith
      ALBUM: Hello World
      YEAR: 2013
* track_start - integer, number to start the track count at (default: 1)
* cdda_align - boolean, enforce sector alignment for audio CDs (default: false)
* track_zpad - boolean or integer.  Zero-pad the TRACKNUMBER in metadata and
  filenames.  If an integer, this creates a fixed padding even if the
  padding is not necessary.  If true, this only pads as needed for the
  highest-numbered track (default: true)
* tracks - array, see "TRACKS" section
* targets - hash, see "TARGETS" section
* command - used only by dtas-player(1)

# TRACKS

Tracks may be defined by a start time, with the stop time defined
automatically by the start of the next track, stop time, or a skip
segment.

* t TIME TITLE [fade_in/fade_out=FADE_ARGS] - the start of a new track
  at TIME with TITLE.  An optional fade_in and fade_out may be specified
  for the first/last tracks.
* skip TIME - skip a segment starting at TIME.  "skip" segments are
  useful for skipping long gaps between tracks (such as flipping vinyl
  or intermission at concerts)
* stop TIME - stop the last track  This should be the last directive in
  the "tracks" array.

An example of the tracks array for a 4 track EP follows:

    tracks:
      - t  0:21    "This is the first track of an EP" fade_in='t 1'
      - t  7:11.6  "Second track of side A of an EP"
      - skip 9:18  # this is where I flip the record, comments are allowed
      - t  9:41    "3rd track of an EP"
      - t 13:36.5  "Final track of the EP" fade_out='t 1'
      - stop 18:11

# FADES

dtas-splitfx automatically sets up fade-in/fade-out effects for sox(1)
based on track times.  These are to be used in "t" (track) directives in
the "tracks" array:

* fade_in="[TYPE] LENGTH"
* fade_out="[TYPE] LENGTH"

TYPE is optional, but LENGTH is required.  See sox(1) for a description
of the fade type.

# ENVIRONMENT

dtas-splitfx sets several default environment variables for commands to
use in targets:

* INFILE - this matches the "infile" directive in the YAML file
* INDIR - the directory INFILE belongs to, without trailing slash
* INBASE - the basename of INFILE
* TBEG - the integer sample offset where the sox(1) trim effect starts
* TLEN - the integer sample count representing the length of the trim
* TRIMFX - essential, this supplys the necessary sox(1) trim effect to
  each track. In other words, this is: "trim ${TBEG}s ${TLEN}s"
* COMMENTS - expands to --comment-file=PATH for sox(1)
* OUTDIR - placeholder for --outdir, defaults to an empty string
* SUFFIX - the suffix of the output format without "." (e.g. "flac", "ogg")
* TRACKNUMBER - the track number, useful for comments and filenames
* RATEFX - rate effect and arguments for sox(1) resampling
* DITHERFX - dither effect and arguments for sox(1) dithering
* FX - any user-specified sox effects which encompases the entire file.
  (e.g. "highpass 35 gain 3 stats")

# TARGETS

The default targets will split audio and avoid applying any effects.
They are named after common audio formats supported by sox(1):

* flac
* ogg
* mp3
* sox

If not specified, "flac" is the default target.

Additional targets supported by default.

* flac-cdda - this encodes the audio to "flac" format while being
  easily decompressible to a format suitable for being burned to audio CD.

* opusenc - encodes to 16-bit, 48000 Hz Opus format using opusenc(1).
  This uses sox(1) to dither/resample/apply effects as necessary.
  This target exists as sox (as of v14.4.1) does not currently have
  native opus encoding support.

Custom targets may easily be defined to apply effects and gain.  For
example, the following "flac24" target raises the volume of the left
channel by 9.5dB and the right one by 8.5dB to compensate for channel
imbalance in a live concert recording from the audience:

    targets:
      flac24:
        command: sox -M
          "|sox $INFILE -c1 -p $TRIMFX remix 1v1 gain 9.5"
          "|sox $INFILE -c1 -p $TRIMFX remix 2v1 gain 8.5"
          $COMMENTS $OUTFMT
          ${OUTDIR}bandYYYY-MM-DD.FOO.t0"$TRACKNUMBER.$SUFFIX"
          $RATEFX $DITHERFX stats
        format:
          type: flac
          bits: 24
          rate: 48000

For reference, the "opusenc" default target is implemented as follows:

    targets:
      opusenc:
        command: sox "$INFILE" $COMMENTS $OUTFMT -
           $TRIMFX $RATEFX $DITHERFX | opusenc --music
           --raw-bits $BITS_PER_SAMPLE
           $OPUSENC_BITRATE --raw-rate $RATE --raw-chan $CHANNELS
           --raw-endianness $ENDIAN_OPUSENC
           $OPUSENC_COMMENTS - $OUTDIR$TRACKNUMBER.opus
        format:
          bits: 16
          rate: 48000
          type: s16
          channels: 2

# COPYRIGHT

Copyright 2013-2015 all contributors <dtas-all@nongnu.org>.\
License: GPLv3 or later <http://www.gnu.org/licenses/gpl-3.0.txt>

# SEE ALSO

sox(1), ecasound(1), flac(1), opusenc(1), dtas-player(1)