abook-speed

#!/bin/bash

# https://www.gnu.org/software/bash/manual/html_node/The-Set-Builtin.html
set -o errexit
set -o functrace
set -o nounset

if [ "$#" -lt 1 ]; then
  echo "Usage: abook-speed SOURCE [SPEED_MULTIPLIER] [VOLUME_BOOST_DECIBELS]"
  echo
  echo "  SPEED_MULTIPLIER: 1.4 by default"
  exit
fi

function parse_extension { FILE_NAME_WITH_EXT="$1"
  echo "$FILE_NAME_WITH_EXT" | rev | cut -f 1 -d '.' | rev
}

# TODO replace with basename filename ext?
function parse_file_name_no_ext { FILE_NAME_WITH_EXT="$1"
  EXTENSION=$(parse_extension "$FILE_NAME_WITH_EXT")
  #echo "DEBUG: parse_file_name_no_ext: EXTENSION: $EXTENSION"
  echo "$FILE_NAME_WITH_EXT" | sed -e s/\.${EXTENSION}$//g
}

function mediainfo_duration { FILE_PATH="$1"
  DURATION=$(mediainfo "$FILE_PATH" | grep Duration | head -n 1 | sed -n -e 's/^Duration[ ]*:[ ]*//p')
  echo "$DURATION"
}

set +o nounset
SOURCE_PATH="$1"
SPEED_MULTIPLIER="$2"
VOLUME_BOOST_DECIBELS="$3"

VOLUME_BOOST_COMMAND_PART=
VOLUME_BOOST_FILE_NAME_PART=

set -o nounset

if [ -z "$SPEED_MULTIPLIER" ]; then
  SPEED_MULTIPLIER=1.25
fi

if [ -n "$VOLUME_BOOST_DECIBELS" ]; then
  VOLUME_BOOST_COMMAND_PART="norm ${VOLUME_BOOST_DECIBELS}"
  VOLUME_BOOST_FILE_NAME_PART="__vol${VOLUME_BOOST_DECIBELS}"
fi


SOURCE_DURATION=$(mediainfo_duration "$SOURCE_PATH")

echo "Source Duration: $SOURCE_DURATION"
echo

SOURCE_DIR=$(dirname "$SOURCE_PATH")
SOURCE_FILENAME=$(basename "$SOURCE_PATH")
SOURCE_EXT=$(parse_extension "$SOURCE_FILENAME")
SOURCE_NAME_NO_EXT=$(parse_file_name_no_ext "$SOURCE_FILENAME")
DEST_DIR="$SOURCE_DIR/speed"
DEST_PATH="${DEST_DIR}/${SOURCE_NAME_NO_EXT}__${SPEED_MULTIPLIER}x${VOLUME_BOOST_FILE_NAME_PART}.${SOURCE_EXT}"

mkdir -p "$DEST_DIR"


(
  set -x;
  # https://madskjeldgaard.dk/posts/sox-tutorial-batch-processing/#normalize
  # norm effect which only takes one parameter which is the sound level to normalize to. A reasonable normalization level is -0.1 dB so let us use that in our conversion process.
  /usr/bin/time -f "Conversion process time:\t%E" sox "$SOURCE_PATH" "$DEST_PATH" tempo "$SPEED_MULTIPLIER" $VOLUME_BOOST_COMMAND_PART
)

DEST_DURATION=$(mediainfo_duration "$DEST_PATH")
echo
echo "Dest Duration: $DEST_DURATION"