#!/bin/bash
# volume
#
# Copyright 2007, Michael T. Dean (mtdean at thirdcontact dt com)
#
# This program is free software; you can redistribute it and/or modify it under
# the terms of the GNU General Public License as published by the Free Software
# Foundation; either version 2 of the License, or (at your option) any later
# version.
#
# This program is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
# FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
# details.
#
# You should have received a copy of the GNU General Public License along with
# this program; if not, write to the Free Software Foundation, Inc., 51
# Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
#
# Description:
#   This script can be used to adjust the volume of any control provided by your
#   sound card and can optionally display a message using either xosd or
#   mythtvosd.  The script is useful to MythTV users whose sound cards require
#   changing some volume control other than PCM or Master (the only two choices
#   MythTV supports) or who wish to modify multiple controls; or to anyone
#   wishing to add a low-dependency volume control with OSD to any system using,
#   for example, multimedia keys (i.e. XF86AudioRaiseVolume,
#   XF86AudioLowerVolume, XF86AudioMute) or LIRC.
#
# Version: 0.2
#
# Revision History:
#   0.2 (20070310): complete rewrite; added support for xosd; added volume
#                   control override; added mute toggle; changed script to use
#                   control limits (rather than percents--which pose rounding
#                   problems); each control is modified relative to current
#                   value (instead of setting all to the same value); removed
#                   usage of linefeed IFS; added error checking and defaults
#                   for robustness; put some code in functions
#   0.1 (20060123): initial version
#
# Quickstart:
#   Verify your amixer reports sane values as described in the first paragraph
#   of "Usage" below.  Then, run the script as shown below:
#     ./volume up PCM
#     ./volume down PCM
#     ./volume mute PCM
#     ./volume unmute PCM
#     ./volume toggle PCM
#
# Usage:
#   volume {up|down|mute|unmute|toggle} [control1 [control2 [...]]]
#
#   First, verify that amixer reports sane values for the control limits and
#   current volume.  Control limits must be specified in the format "  Limits:
#   Playback 0 - 31" in any line of output.  Current volume must be specified
#   in the format "<anything>: Playback 28 [90%]" in any line of output.
#   Please test that your version of amixer does this for each control you've
#   specified in VOLUME_CONTROLS or you may blow out your speakers.
#
#   Then, modify the default values specified below to allow usage of the
#   script in most cases without listing control names in the command line
#   (i.e. ./volume {up|down|mute|unmute|toggle}).
#
#   To use with multimedia keys or other keyboard controls, map the appropriate
#   commands to the desired keys in your window manager's or some other key
#   handler's keybindings.
#
#   To use with LIRC, you must run irexec (i.e. add the lines, "killall irexec"
#   and "irexec -d" (no quotes)--and in the order given)--to your X start
#   script (i.e. ~/.xinitrc).  Then, add the following lines to your LIRC
#   configuration (i.e. ~/.lircrc) and adjust button names and config path as
#   appropriate:
#
#     begin
#       prog = irexec
#       button = volume-up
#       config = /path/to/volume up &
#       repeat = 2
#     end
#     begin
#       prog = irexec
#       button = volume-down
#       config = /path/to/volume down &
#       repeat = 2
#     end
#     begin
#       prog = irexec
#       button = mute
#       config = /path/to/volume mute &
#       config = /path/to/volume unmute &
#       repeat = 0
#     end
#

# Modify the following default values as appropriate for your system.

# Set the VOLUME_CONTROLS to the array of volume controls you want the script
# to adjust.  Place spaces (no commas) between elements of the array.  Use
# single quotes around elements with spaces, and optionally on elements without
# spaces).
# The list of volume controls may be overriden by specifying the names of
# controls to modify at the end of the command-line.  When overriding the
# volume controls, each control will be adjusted by only 1 unit.  See, also,
# MIXER_ADJ_AMOUNT, below.
#VOLUME_CONTROLS=('PCM' 'Surround' 'Center' 'LFE' 'Analog Front')
#VOLUME_CONTROLS=('PCM')
VOLUME_CONTROLS=('Master')

# Set the MIXER_ADJ_AMOUNT to the array of the desired number of units by which
# you want to adjust the volume of each control specified in VOLUME_CONTROLS.
# You should specify the same number of adjustments as you specified controls
# in VOLUME_CONTROLS.
# The units used are specific to the sound card control.  The range of
# available values is reported by "amixer sget <control>" on the line that
# starts with "  Limits:" and may differ for the controls you've specified.
# By choosing appropriate values, you can ensure all controls change by the
# same relative volume.
# If not specified, all controls will be adjusted by 1 unit.
#MIXER_ADJ_AMOUNT=(1 1 1 1 1)
#MIXER_ADJ_AMOUNT=(1)

# Set the OSD_VOLUME_CONTROL to the name of the ALSA control whose volume
# should be reported when using the OSD.
# This control must be included in VOLUME_CONTROLS above or the volume will
# always be set to the same value;
# If not specified, the first value in VOLUME_CONTROLS will be used.
#OSD_VOLUME_CONTROL='Center'
#OSD_VOLUME_CONTROL='PCM'
#OSD_VOLUME_CONTROL='Master'

# Display the current volume using the specified OSD application (Currently,
# only 'xosd' and 'mythtvosd' are supported).  Use '' or comment out if you do
# not want to display the volume
# Note that if using mythtvosd, the volume message will only be displayed when
# using Myth's internal player to play back videos.  When using xosd, the
# volume message will be displayed whether playing back videos or in the
# frontend menus (or anywhere else in X).
USE_OSD='xosd'
#USE_OSD='mythtvosd'
#USE_OSD=''

# OSD application executables.
# Provide the full path to the executable if it is not in your PATH.
XOSD='osd_cat'
MYTHTVOSD='mythtvosd'

# Arguments to pass to xosd (do not specify -b, -P, and -T).
# This is the location at which to specify font, position, alignment, offset,
# delay, lines, shadow, and color
XOSD_ARGS='-f -adobe-helvetica-bold-r-normal-*-*-240-100-100-p-*-iso8859-1 -p bottom -A center -o 80 -d 1 -l 1 -s 2 -c Green'

# xosd barmode to use--either percentage or slider
XOSD_BARMODE=percentage
#XOSD_BARMODE=slider

# Set the BROADCAST_ADDRESS to the address of the frontend on which you want to
# display the volume OSD when using mythtvosd.
# Using 127.0.0.1 will generally work.
BROADCAST_ADDRESS='127.0.0.1'

# No changes should be required below this line.

ACTION=$1
shift

if [ $# -gt 0 ]; then
  unset VOLUME_CONTROLS MIXER_ADJ_AMOUNT OSD_VOLUME_CONTROL
  for INDEX in `seq 0 $(($# - 1))`; do
    VOLUME_CONTROLS[${INDEX}]="$1"
    shift
  done
fi

if [ "x${OSD_VOLUME_CONTROL}" = "x" ]; then
  OSD_VOLUME_CONTROL=${VOLUME_CONTROLS[0]}
fi

NUM_CONTROLS=$((${#VOLUME_CONTROLS[*]} - 1))

set_volume() {
    for INDEX in `seq 0 ${NUM_CONTROLS}`; do
      unset CONTROL RANGE VOLUME ADJUST_AMOUNT
      CONTROL=${VOLUME_CONTROLS[$INDEX]}

      if [ "x${CONTROL}" = "x" ]; then
        continue
      fi

      # Relies on amixer reporting limits in the format
      # "  Limits: Playback 0 - 31" in any line of output.  Please test that
      # your version of amixer does this for each control you've specified in
      # VOLUME_CONTROLS or you may blow out your speakers.
      RANGE=(`amixer sget "${CONTROL}" | awk '/Limits/ {split($0,a); print a[3] " " a[5]; exit }'`)

      if [ "x${RANGE[0]}" = "x" -o "x${RANGE[1]}" = "x" ]; then
        # Couldn't get the range.  Skip this control
        continue
      fi

      # Relies on amixer reporting volume in the format
      # "<anything>: Playback 28 [90%]" in any line of output.  Please test
      # that your version of amixer does this for each control you've specified
      # in VOLUME_CONTROLS or you may blow out your speakers.
      VOLUME=`amixer sget "${CONTROL}" | awk '/[%]/ {split($0,a,":"); split(a[2],a); print a[2]; exit}'`

      if [ "x${VOLUME}" = "x" ]; then
        # Couldn't get the volume.  Skip this control
        continue
      fi

      ADJUST_AMOUNT=${MIXER_ADJ_AMOUNT[$INDEX]}
      if [ "x${ADJUST_AMOUNT}" = "x" ]; then
        ADJUST_AMOUNT=1
      fi
      if [ "x$1" != "xup" ]; then
        ADJUST_AMOUNT=-${ADJUST_AMOUNT}
      fi
      NEW_VOLUME="$((${VOLUME} + ${ADJUST_AMOUNT}))"
      if [ ${NEW_VOLUME} -lt ${RANGE[0]} ]; then
        NEW_VOLUME=${RANGE[0]}
      elif [ ${NEW_VOLUME} -gt ${RANGE[1]} ]; then
        NEW_VOLUME=${RANGE[1]}
      fi
      amixer -q set ${CONTROL} ${NEW_VOLUME} &
    done
}

simple_message() {
  MESSAGE=$1
  if [ "x${MESSAGE}" = "x" ]; then
    return
  fi
  if [ "x${USE_OSD}" = "xxosd" ]; then
    if [ "x${XOSD}" != "x" -a "x${DISPLAY}" != "x" ]; then
      # Kill any running xosd processes (to clear the previous message)
      killall -q ${XOSD} > /dev/null 2>&1
      echo ${MESSAGE} | ${XOSD} ${XOSD_ARGS} > /dev/null 2>&1 &
    fi
  elif [ "x${USE_OSD}" = "xmythtvosd" ]; then
    if [ "x${MYTHTVOSD}" != "x" ]; then
      ${MYTHTVOSD} --bcastaddr="${BROADCAST_ADDRESS}" \
                   --template='alert' \
                   --alert_text="${MESSAGE}" > /dev/null 2>&1 &
    fi
  fi
}

show_percent() {
  if [ "x${USE_OSD}" = "xxosd" ]; then
    # Relies on amixer reporting volume in the format "[90%]" in any line of
    # output.
    NEW_VOLUME_PCT=`amixer sget "${OSD_VOLUME_CONTROL}" | awk '/[%]/ {split($0,a,"["); split(a[2],a,"%"); print a[1]; exit}'`
    if [ "x${NEW_VOLUME_PCT}" = "x" ]; then
      # Couldn't get the volume.  Do not display the OSD.
      return
    fi
    if [ "x${XOSD}" != "x" -a "x${DISPLAY}" != "x" ]; then
      # Kill any running xosd processes (to clear the previous message)
      killall -q ${XOSD} > /dev/null 2>&1
      ${XOSD} -b ${XOSD_BARMODE} -P ${NEW_VOLUME_PCT} \
              -T "${OSD_VOLUME_CONTROL} Volume: ${NEW_VOLUME_PCT}%" ${XOSD_ARGS} > /dev/null 2>&1 &
    fi
  elif [ "x${USE_OSD}" = "xmythtvosd" ]; then
    if [ "x${MYTHTVOSD}" != "x" ]; then
      ${MYTHTVOSD} --bcastaddr="${BROADCAST_ADDRESS}" \
                   --template='alert' \
                   --alert_text="${OSD_VOLUME_CONTROL} Volume: ${NEW_VOLUME_PCT}%" \
                     > /dev/null 2>&1 &
    fi
  fi
}

case "${ACTION}" in
  up|down)
    set_volume "${ACTION}"
    show_percent
    ;;
  mute|unmute)
    for INDEX in `seq 0 ${NUM_CONTROLS}`; do
      unset CONTROL
      CONTROL=${VOLUME_CONTROLS[$INDEX]}
      amixer -q set ${CONTROL} ${ACTION} &
    done
    MESSAGE=`echo "${ACTION}" | tr  [:lower:] [:upper:]` > /dev/null 2>&1
    simple_message ${MESSAGE}
    ;;
  toggle)
    for INDEX in `seq 0 ${NUM_CONTROLS}`; do
      unset CONTROL CURRENT_STATE
      CONTROL=${VOLUME_CONTROLS[$INDEX]}
      # Relies on amixer reporting mute state in the format
      # "<anything>[90%] [7.50dB] [on]" in any line of output.  Please test
      # that your version of amixer does this for each control you've specified
      # in VOLUME_CONTROLS.
      CURRENT_STATE=`amixer sget "${CONTROL}" | awk '/[%]/ {split($0,a,"["); split(a[4],a,"]"); print a[1]; exit}'`
      if [ "x${CURRENT_STATE}" = "x" ]; then
        # Couldn't get the mute state.  Skip this control.
        continue
      fi
      if [ "x${CURRENT_STATE}" = "xoff" ]; then
        MUTE=unmute
      else
        MUTE=mute
      fi
      amixer -q set ${CONTROL} ${MUTE} &
    done
    # Assume the mute state of all controls is the same as that of the
    # last successfully set control.  Using toggle with multiple controls
    # in different states doesn't make much sense.
    MESSAGE=`echo "${MUTE}" | tr  [:lower:] [:upper:]` > /dev/null 2>&1
    simple_message ${MESSAGE}
    ;;
  *)
    echo "Usage: $0 {up|down|mute|unmute|toggle} [control1 [control2 [...]]]"
    exit 1
    ;;
esac