#!/bin/bash
# Copyright 2013 The Chromium Authors
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
# The optimization code is based on pngslim (http://goo.gl/a0XHg)
# and executes a similar pipleline to optimize the png file size.
# The steps that require pngoptimizercl/pngrewrite/deflopt are omitted,
# but this runs all other processes, including:
# 1) various color-dependent optimizations using optipng.
# 2) optimize the number of huffman blocks.
# 3) randomize the huffman table.
# 4) Further optimize using optipng and advdef (zlib stream).
# Due to the step 3), each run may produce slightly different results.
#
# Note(oshima): In my experiment, advdef didn't reduce much. I'm keeping it
# for now as it does not take much time to run.
readonly ALL_DIRS="
ash/resources
chrome/android/java/res
chrome/app/theme
chrome/browser/resources
chrome/renderer/resources
content/public/android/java/res
content/shell/resources
remoting/resources
ui/android/java/res
ui/resources
ui/chromeos/resources
ui/webui/resources/images
"
# Files larger than this file size (in bytes) will
# use the optimization parameters tailored for large files.
LARGE_FILE_THRESHOLD=3000
# Constants used for optimization
readonly DEFAULT_MIN_BLOCK_SIZE=128
readonly DEFAULT_LIMIT_BLOCKS=256
readonly DEFAULT_RANDOM_TRIALS=100
# Taken from the recommendation in the pngslim's readme.txt.
readonly LARGE_MIN_BLOCK_SIZE=1
readonly LARGE_LIMIT_BLOCKS=2
readonly LARGE_RANDOM_TRIALS=1
# Global variables for stats
TOTAL_OLD_BYTES=0
TOTAL_NEW_BYTES=0
TOTAL_FILE=0
CORRUPTED_FILE=0
PROCESSED_FILE=0
declare -a THROBBER_STR=('-' '\\' '|' '/')
THROBBER_COUNT=0
VERBOSE=false
# Echo only if verbose option is set.
function info {
if $VERBOSE ; then
echo $@
fi
}
# Show throbber character at current cursor position.
function throbber {
info -ne "${THROBBER_STR[$THROBBER_COUNT]}\b"
let THROBBER_COUNT=$THROBBER_COUNT+1
let THROBBER_COUNT=$THROBBER_COUNT%4
}
# Usage: pngout_loop <file> <png_out_options> ...
# Optimize the png file using pngout with the given options
# using various block split thresholds and filter types.
function pngout_loop {
local file=$1
shift
local opts=$*
if [ $OPTIMIZE_LEVEL == 1 ]; then
for j in $(eval echo {0..5}); do
throbber
pngout -q -k1 -s1 -f$j $opts $file
done
else
for i in 0 128 256 512; do
for j in $(eval echo {0..5}); do
throbber
pngout -q -k1 -s1 -b$i -f$j $opts $file
done
done
fi
}
# Usage: get_color_depth_list
# Returns the list of color depth options for current optimization level.
function get_color_depth_list {
if [ $OPTIMIZE_LEVEL == 1 ]; then
echo "-d0"
else
echo "-d1 -d2 -d4 -d8"
fi
}
# Usage: process_grayscale <file>
# Optimize grayscale images for all color bit depths.
#
# TODO(oshima): Experiment with -d0 w/o -c0.
function process_grayscale {
info -ne "\b\b\b\b\b\b\b\bgray...."
for opt in $(get_color_depth_list); do
pngout_loop $file -c0 $opt
done
}
# Usage: process_grayscale_alpha <file>
# Optimize grayscale images with alpha for all color bit depths.
function process_grayscale_alpha {
info -ne "\b\b\b\b\b\b\b\bgray-a.."
pngout_loop $file -c4
for opt in $(get_color_depth_list); do
pngout_loop $file -c3 $opt
done
}
# Usage: process_rgb <file>
# Optimize rgb images with or without alpha for all color bit depths.
function process_rgb {
info -ne "\b\b\b\b\b\b\b\brgb....."
for opt in $(get_color_depth_list); do
pngout_loop $file -c3 $opt
done
pngout_loop $file -c2
pngout_loop $file -c6
}
# Usage: huffman_blocks <file>
# Optimize the huffman blocks.
function huffman_blocks {
info -ne "\b\b\b\b\b\b\b\bhuffman."
local file=$1
local size=$(stat -c%s $file)
local min_block_size=$DEFAULT_MIN_BLOCK_SIZE
local limit_blocks=$DEFAULT_LIMIT_BLOCKS
if [ $size -gt $LARGE_FILE_THRESHOLD ]; then
min_block_size=$LARGE_MIN_BLOCK_SIZE
limit_blocks=$LARGE_LIMIT_BLOCKS
fi
let max_blocks=$size/$min_block_size
if [ $max_blocks -gt $limit_blocks ]; then
max_blocks=$limit_blocks
fi
for i in $(eval echo {2..$max_blocks}); do
throbber
pngout -q -k1 -ks -s1 -n$i $file
done
}
# Usage: random_huffman_table_trial <file>
# Try compressing by randomizing the initial huffman table.
#
# TODO(oshima): Try adjusting different parameters for large files to
# reduce runtime.
function random_huffman_table_trial {
info -ne "\b\b\b\b\b\b\b\brandom.."
local file=$1
local old_size=$(stat -c%s $file)
local trials_count=$DEFAULT_RANDOM_TRIALS
if [ $old_size -gt $LARGE_FILE_THRESHOLD ]; then
trials_count=$LARGE_RANDOM_TRIALS
fi
for i in $(eval echo {1..$trials_count}); do
throbber
pngout -q -k1 -ks -s0 -r $file
done
local new_size=$(stat -c%s $file)
if [ $new_size -lt $old_size ]; then
random_huffman_table_trial $file
fi
}
# Usage: final_comprssion <file>
# Further compress using optipng and advdef.
# TODO(oshima): Experiment with 256.
function final_compression {
info -ne "\b\b\b\b\b\b\b\bfinal..."
local file=$1
if [ $OPTIMIZE_LEVEL == 2 ]; then
for i in 32k 16k 8k 4k 2k 1k 512; do
throbber
optipng -q -nb -nc -zw$i -zc1-9 -zm1-9 -zs0-3 -f0-5 $file
done
fi
for i in $(eval echo {1..4}); do
throbber
advdef -q -z -$i $file
done
# Clear the current line.
if $VERBOSE ; then
printf "\033[0G\033[K"
fi
}
# Usage: get_color_type <file>
# Returns the color type name of the png file. Here is the list of names
# for each color type codes.
# 0: grayscale
# 2: RGB
# 3: colormap
# 4: gray+alpha
# 6: RGBA
# See http://en.wikipedia.org/wiki/Portable_Network_Graphics#Color_depth
# for details about the color type code.
function get_color_type {
local file=$1
echo $(file $file | awk -F, '{print $3}' | awk '{print $2}')
}
# Usage: optimize_size <file>
# Performs png file optimization.
function optimize_size {
# Print filename, trimmed to ensure it + status don't take more than 1 line
local filename_length=${#file}
local -i allowed_length=$COLUMNS-11
local -i trimmed_length=$filename_length-$COLUMNS+14
if [ "$filename_length" -lt "$allowed_length" ]; then
info -n "$file|........"
else
info -n "...${file:$trimmed_length}|........"
fi
local file=$1
advdef -q -z -4 $file
pngout -q -s4 -c0 -force $file $file.tmp.png
if [ -f $file.tmp.png ]; then
rm $file.tmp.png
process_grayscale $file
process_grayscale_alpha $file
else
pngout -q -s4 -c4 -force $file $file.tmp.png
if [ -f $file.tmp.png ]; then
rm $file.tmp.png
process_grayscale_alpha $file
else
process_rgb $file
fi
fi
info -ne "\b\b\b\b\b\b\b\bfilter.."
local old_color_type=$(get_color_type $file)
optipng -q -zc9 -zm8 -zs0-3 -f0-5 -out $file.tmp.png $file
local new_color_type=$(get_color_type $file.tmp.png)
# optipng may corrupt a png file when reducing the color type
# to grayscale/grayscale+alpha. Just skip such cases until
# the bug is fixed. See crbug.com/174505, crbug.com/174084.
# The issue is reported in
# https://sourceforge.net/tracker/?func=detail&aid=3603630&group_id=151404&atid=780913
if [[ $old_color_type == "RGBA" && $new_color_type == gray* ]] ; then
rm $file.tmp.png
else
mv $file.tmp.png $file
fi
pngout -q -k1 -s1 $file
huffman_blocks $file
# TODO(oshima): Experiment with strategy 1.
info -ne "\b\b\b\b\b\b\b\bstrategy"
if [ $OPTIMIZE_LEVEL == 2 ]; then
for i in 3 2 0; do
pngout -q -k1 -ks -s$i $file
done
else
pngout -q -k1 -ks -s1 $file
fi
if [ $OPTIMIZE_LEVEL == 2 ]; then
random_huffman_table_trial $file
fi
final_compression $file
}
# Usage: process_file <file>
function process_file {
local file=$1
local name=$(basename $file)
# -rem alla removes all ancillary chunks except for tRNS
pngcrush -d $TMP_DIR -brute -reduce -rem alla $file > /dev/null 2>&1
if [ -f $TMP_DIR/$name -a $OPTIMIZE_LEVEL != 0 ]; then
optimize_size $TMP_DIR/$name
fi
}
# Usage: optimize_file <file>
function optimize_file {
local file=$1
if $using_cygwin ; then
file=$(cygpath -w $file)
fi
local name=$(basename $file)
local old=$(stat -c%s $file)
local tmp_file=$TMP_DIR/$name
let TOTAL_FILE+=1
process_file $file
if [ ! -e $tmp_file ] ; then
let CORRUPTED_FILE+=1
echo "$file may be corrupted; skipping\n"
return
fi
local new=$(stat -c%s $tmp_file)
let diff=$old-$new
let percent=$diff*100
let percent=$percent/$old
if [ $new -lt $old ]; then
info "$file: $old => $new ($diff bytes: $percent%)"
cp "$tmp_file" "$file"
let TOTAL_OLD_BYTES+=$old
let TOTAL_NEW_BYTES+=$new
let PROCESSED_FILE+=1
else
if [ $OPTIMIZE_LEVEL == 0 ]; then
info "$file: Skipped"
else
info "$file: Unable to reduce size"
fi
rm $tmp_file
fi
}
function optimize_dir {
local dir=$1
if $using_cygwin ; then
dir=$(cygpath -w $dir)
fi
for f in $(find $dir -name "*.png"); do
optimize_file $f
done
}
function install_if_not_installed {
local program=$1
local package=$2
which $program > /dev/null 2>&1
if [ "$?" != "0" ]; then
if $using_cygwin ; then
echo "Couldn't find $program. " \
"Please run cygwin's setup.exe and install the $package package."
exit 1
else
read -p "Couldn't find $program. Do you want to install? (y/n)"
[ "$REPLY" == "y" ] && sudo apt-get install $package
[ "$REPLY" == "y" ] || exit
fi
fi
}
function fail_if_not_installed {
local program=$1
local url=$2
which $program > /dev/null 2>&1
if [ $? != 0 ]; then
echo "Couldn't find $program. Please download and install it from $url ."
exit 1
fi
}
# Check pngcrush version and exit if the version is in bad range.
# See crbug.com/404893.
function exit_if_bad_pngcrush_version {
local version=$(pngcrush -v 2>&1 | awk "/pngcrush 1.7./ {print \$3}")
local version_num=$(echo $version | sed "s/\.//g")
if [[ (1748 -lt $version_num && $version_num -lt 1773) ]] ; then
echo "Your pngcrush ($version) has a bug that exists from " \
"1.7.49 to 1.7.72 (see crbug.com/404893 for details)."
echo "Please upgrade pngcrush and try again"
exit 1;
fi
}
function show_help {
local program=$(basename $0)
echo \
"Usage: $program [options] <dir> ...
$program is a utility to reduce the size of png files by removing
unnecessary chunks and compressing the image.
Options:
-o<optimize_level> Specify optimization level: (default is 1)
0 Just run pngcrush. It removes unnecessary chunks and perform basic
optimization on the encoded data.
1 Optimize png files using pngout/optipng and advdef. This can further
reduce addtional 5~30%. This is the default level.
2 Aggressively optimize the size of png files. This may produce
addtional 1%~5% reduction. Warning: this is *VERY*
slow and can take hours to process all files.
-c<commit> Same as -r but referencing a git commit. Only files changed
between this commit and HEAD will be processed.
-v Shows optimization process for each file.
-h Print this help text."
exit 1
}
if [ "$(expr substr $(uname -s) 1 6)" == "CYGWIN" ]; then
using_cygwin=true
else
using_cygwin=false
fi
# The -i in the shebang line should result in $COLUMNS being set on newer
# versions of bash. If it's not set yet, attempt to set it.
if [ -z $COLUMNS ]; then
which tput > /dev/null 2>&1
if [ "$?" == "0" ]; then
COLUMNS=$(tput cols)
else
# No tput either... give up and just guess 80 columns.
COLUMNS=80
fi
export COLUMNS
fi
OPTIMIZE_LEVEL=1
# Parse options
while getopts o:c:h:v opts
do
case $opts in
c)
COMMIT=$OPTARG
;;
o)
if [[ "$OPTARG" != 0 && "$OPTARG" != 1 && "$OPTARG" != 2 ]] ; then
show_help
fi
OPTIMIZE_LEVEL=$OPTARG
;;
v)
VERBOSE=true
;;
[h?])
show_help;;
esac
done
# Remove options from argument list.
shift $(($OPTIND -1))
# Make sure we have all necessary commands installed.
install_if_not_installed pngcrush pngcrush
exit_if_bad_pngcrush_version
if [ $OPTIMIZE_LEVEL -ge 1 ]; then
install_if_not_installed optipng optipng
if $using_cygwin ; then
fail_if_not_installed advdef "http://advancemame.sourceforge.net/comp-readme.html"
else
install_if_not_installed advdef advancecomp
fi
if $using_cygwin ; then
pngout_url="http://www.advsys.net/ken/utils.htm"
else
pngout_url="http://www.jonof.id.au/kenutils"
fi
fail_if_not_installed pngout $pngout_url
fi
# Create tmp directory for crushed png file.
TMP_DIR=$(mktemp -d)
if $using_cygwin ; then
TMP_DIR=$(cygpath -w $TMP_DIR)
fi
# Make sure we cleanup temp dir
#trap "rm -rf $TMP_DIR" EXIT
# If no directories are specified, optimize all directories.
DIRS=$@
set ${DIRS:=$ALL_DIRS}
info "Optimize level=$OPTIMIZE_LEVEL"
if [ -n "$COMMIT" ] ; then
# To keep git logic below sane, require it be run from the top dir.
if [ ! -e ../.gclient ]; then
echo "$0 must be run in src directory"
exit 1
fi
ALL_FILES=$(git diff --name-only $COMMIT HEAD $DIRS | grep "png$")
ALL_FILES_LIST=( $ALL_FILES )
echo "Processing ${#ALL_FILES_LIST[*]} files"
for f in $ALL_FILES; do
if [ -f $f ] ; then
optimize_file $f
else
echo "Skipping deleted file: $f";
fi
done
else
for d in $DIRS; do
if [ -d $d ] ; then
info "Optimizing png files in $d"
optimize_dir $d
info ""
elif [ -f $d ] ; then
optimize_file $d
else
echo "Not a file or directory: $d";
fi
done
fi
# Print the results.
echo "Optimized $PROCESSED_FILE/$TOTAL_FILE files in" \
"$(date -d "0 + $SECONDS sec" +%Ts)"
if [ $PROCESSED_FILE != 0 ]; then
let diff=$TOTAL_OLD_BYTES-$TOTAL_NEW_BYTES
let percent=$diff*100/$TOTAL_OLD_BYTES
echo "Result: $TOTAL_OLD_BYTES => $TOTAL_NEW_BYTES bytes" \
"($diff bytes: $percent%)"
fi
if [ $CORRUPTED_FILE != 0 ]; then
echo "Warning: corrupted files found: $CORRUPTED_FILE"
echo "Please contact the author of the CL that landed corrupted png files"
fi
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