tools/resources/optimize-png-files.sh

   1 #!/bin/bash -i
   2 # Copyright 2013 The Chromium Authors. All rights reserved.
   3 # Use of this source code is governed by a BSD-style license that can be
   4 # found in the LICENSE file.
   5
   6 # The optimization code is based on pngslim (http://goo.gl/a0XHg)
   7 # and executes a similar pipleline to optimize the png file size.
   8 # The steps that require pngoptimizercl/pngrewrite/deflopt are omitted,
   9 # but this runs all other processes, including:
  10 # 1) various color-dependent optimizations using optipng.
  11 # 2) optimize the number of huffman blocks.
  12 # 3) randomize the huffman table.
  13 # 4) Further optimize using optipng and advdef (zlib stream).
  14 # Due to the step 3), each run may produce slightly different results.
  15 #
  16 # Note(oshima): In my experiment, advdef didn't reduce much. I'm keeping it
  17 # for now as it does not take much time to run.
  18
  19 readonly ALL_DIRS="
  20 ash/resources
  21 chrome/android/java/res
  22 chrome/app/theme
  23 chrome/browser/resources
  24 chrome/renderer/resources
  25 content/public/android/java/res
  26 content/renderer/resources
  27 content/shell/resources
  28 remoting/resources
  29 ui/resources
  30 ui/webui/resources/images
  31 webkit/glue/resources
  32 win8/metro_driver/resources
  33 "
  34
  35 # Files larger than this file size (in bytes) will
  36 # use the optimization parameters tailored for large files.
  37 LARGE_FILE_THRESHOLD=3000
  38
  39 # Constants used for optimization
  40 readonly DEFAULT_MIN_BLOCK_SIZE=128
  41 readonly DEFAULT_LIMIT_BLOCKS=256
  42 readonly DEFAULT_RANDOM_TRIALS=100
  43 # Taken from the recommendation in the pngslim's readme.txt.
  44 readonly LARGE_MIN_BLOCK_SIZE=1
  45 readonly LARGE_LIMIT_BLOCKS=2
  46 readonly LARGE_RANDOM_TRIALS=1
  47
  48 # Global variables for stats
  49 TOTAL_OLD_BYTES=0
  50 TOTAL_NEW_BYTES=0
  51 TOTAL_FILE=0
  52 CORRUPTED_FILE=0
  53 PROCESSED_FILE=0
  54
  55 declare -a THROBBER_STR=('-' '\\' '|' '/')
  56 THROBBER_COUNT=0
  57
  58 VERBOSE=false
  59
  60 # Echo only if verbose option is set.
  61 function info {
  62   if $VERBOSE ; then
  63     echo $@
  64   fi
  65 }
  66
  67 # Show throbber character at current cursor position.
  68 function throbber {
  69   info -ne "${THROBBER_STR[$THROBBER_COUNT]}\b"
  70   let THROBBER_COUNT=$THROBBER_COUNT+1
  71   let THROBBER_COUNT=$THROBBER_COUNT%4
  72 }
  73
  74 # Usage: pngout_loop <file> <png_out_options> ...
  75 # Optimize the png file using pngout with the given options
  76 # using various block split thresholds and filter types.
  77 function pngout_loop {
  78   local file=$1
  79   shift
  80   local opts=$*
  81   if [ $OPTIMIZE_LEVEL == 1 ]; then
  82     for j in $(eval echo {0..5}); do
  83       throbber
  84       pngout -q -k1 -s1 -f$j $opts $file
  85     done
  86   else
  87     for i in 0 128 256 512; do
  88       for j in $(eval echo {0..5}); do
  89         throbber
  90         pngout -q -k1 -s1 -b$i -f$j $opts $file
  91       done
  92     done
  93   fi
  94 }
  95
  96 # Usage: get_color_depth_list
  97 # Returns the list of color depth options for current optimization level.
  98 function get_color_depth_list {
  99   if [ $OPTIMIZE_LEVEL == 1 ]; then
 100     echo "-d0"
 101   else
 102     echo "-d1 -d2 -d4 -d8"
 103   fi
 104 }
 105
 106 # Usage: process_grayscale <file>
 107 # Optimize grayscale images for all color bit depths.
 108 #
 109 # TODO(oshima): Experiment with -d0 w/o -c0.
 110 function process_grayscale {
 111   info -ne "\b\b\b\b\b\b\b\bgray...."
 112   for opt in $(get_color_depth_list); do
 113     pngout_loop $file -c0 $opt
 114   done
 115 }
 116
 117 # Usage: process_grayscale_alpha <file>
 118 # Optimize grayscale images with alpha for all color bit depths.
 119 function process_grayscale_alpha {
 120   info -ne "\b\b\b\b\b\b\b\bgray-a.."
 121   pngout_loop $file -c4
 122   for opt in $(get_color_depth_list); do
 123     pngout_loop $file -c3 $opt
 124   done
 125 }
 126
 127 # Usage: process_rgb <file>
 128 # Optimize rgb images with or without alpha for all color bit depths.
 129 function process_rgb {
 130   info -ne "\b\b\b\b\b\b\b\brgb....."
 131   for opt in $(get_color_depth_list); do
 132     pngout_loop $file -c3 $opt
 133   done
 134   pngout_loop $file -c2
 135   pngout_loop $file -c6
 136 }
 137
 138 # Usage: huffman_blocks <file>
 139 # Optimize the huffman blocks.
 140 function huffman_blocks {
 141   info -ne "\b\b\b\b\b\b\b\bhuffman."
 142   local file=$1
 143   local size=$(stat -c%s $file)
 144   local min_block_size=$DEFAULT_MIN_BLOCK_SIZE
 145   local limit_blocks=$DEFAULT_LIMIT_BLOCKS
 146
 147   if [ $size -gt $LARGE_FILE_THRESHOLD ]; then
 148     min_block_size=$LARGE_MIN_BLOCK_SIZE
 149     limit_blocks=$LARGE_LIMIT_BLOCKS
 150   fi
 151   let max_blocks=$size/$min_block_size
 152   if [ $max_blocks -gt $limit_blocks ]; then
 153     max_blocks=$limit_blocks
 154   fi
 155
 156   for i in $(eval echo {2..$max_blocks}); do
 157     throbber
 158     pngout -q -k1 -ks -s1 -n$i $file
 159   done
 160 }
 161
 162 # Usage: random_huffman_table_trial <file>
 163 # Try compressing by randomizing the initial huffman table.
 164 #
 165 # TODO(oshima): Try adjusting different parameters for large files to
 166 # reduce runtime.
 167 function random_huffman_table_trial {
 168   info -ne "\b\b\b\b\b\b\b\brandom.."
 169   local file=$1
 170   local old_size=$(stat -c%s $file)
 171   local trials_count=$DEFAULT_RANDOM_TRIALS
 172
 173   if [ $old_size -gt $LARGE_FILE_THRESHOLD ]; then
 174     trials_count=$LARGE_RANDOM_TRIALS
 175   fi
 176   for i in $(eval echo {1..$trials_count}); do
 177     throbber
 178     pngout -q -k1 -ks -s0 -r $file
 179   done
 180   local new_size=$(stat -c%s $file)
 181   if [ $new_size -lt $old_size ]; then
 182     random_huffman_table_trial $file
 183   fi
 184 }
 185
 186 # Usage: final_comprssion <file>
 187 # Further compress using optipng and advdef.
 188 # TODO(oshima): Experiment with 256.
 189 function final_compression {
 190   info -ne "\b\b\b\b\b\b\b\bfinal..."
 191   local file=$1
 192   if [ $OPTIMIZE_LEVEL == 2 ]; then
 193     for i in 32k 16k 8k 4k 2k 1k 512; do
 194       throbber
 195       optipng -q -nb -nc -zw$i -zc1-9 -zm1-9 -zs0-3 -f0-5 $file
 196     done
 197   fi
 198   for i in $(eval echo {1..4}); do
 199     throbber
 200     advdef -q -z -$i $file
 201   done
 202
 203   # Clear the current line.
 204   if $VERBOSE ; then
 205     printf "\033[0G\033[K"
 206   fi
 207 }
 208
 209 # Usage: get_color_type <file>
 210 # Returns the color type name of the png file. Here is the list of names
 211 # for each color type codes.
 212 # 0: grayscale
 213 # 2: RGB
 214 # 3: colormap
 215 # 4: gray+alpha
 216 # 6: RGBA
 217 # See http://en.wikipedia.org/wiki/Portable_Network_Graphics#Color_depth
 218 # for details about the color type code.
 219 function get_color_type {
 220   local file=$1
 221   echo $(file $file | awk -F, '{print $3}' | awk '{print $2}')
 222 }
 223
 224 # Usage: optimize_size <file>
 225 # Performs png file optimization.
 226 function optimize_size {
 227   # Print filename, trimmed to ensure it + status don't take more than 1 line
 228   local filename_length=${#file}
 229   local -i allowed_length=$COLUMNS-11
 230   local -i trimmed_length=$filename_length-$COLUMNS+14
 231   if [ "$filename_length" -lt "$allowed_length" ]; then
 232     info -n "$file|........"
 233   else
 234     info -n "...${file:$trimmed_length}|........"
 235   fi
 236
 237   local file=$1
 238
 239   advdef -q -z -4 $file
 240
 241   pngout -q -s4 -c0 -force $file $file.tmp.png
 242   if [ -f $file.tmp.png ]; then
 243     rm $file.tmp.png
 244     process_grayscale $file
 245     process_grayscale_alpha $file
 246   else
 247     pngout -q -s4 -c4 -force $file $file.tmp.png
 248     if [ -f $file.tmp.png ]; then
 249       rm $file.tmp.png
 250       process_grayscale_alpha $file
 251     else
 252       process_rgb $file
 253     fi
 254   fi
 255
 256   info -ne "\b\b\b\b\b\b\b\bfilter.."
 257   local old_color_type=$(get_color_type $file)
 258   optipng -q -zc9 -zm8 -zs0-3 -f0-5 $file -out $file.tmp.png
 259   local new_color_type=$(get_color_type $file.tmp.png)
 260   # optipng may corrupt a png file when reducing the color type
 261   # to grayscale/grayscale+alpha. Just skip such cases until
 262   # the bug is fixed. See crbug.com/174505, crbug.com/174084.
 263   # The issue is reported in
 264   # https://sourceforge.net/tracker/?func=detail&aid=3603630&group_id=151404&atid=780913
 265   if [[ $old_color_type == "RGBA" && $new_color_type == gray* ]] ; then
 266     rm $file.tmp.png
 267   else
 268     mv $file.tmp.png $file
 269   fi
 270   pngout -q -k1 -s1 $file
 271
 272   huffman_blocks $file
 273
 274   # TODO(oshima): Experiment with strategy 1.
 275   info -ne "\b\b\b\b\b\b\b\bstrategy"
 276   if [ $OPTIMIZE_LEVEL == 2 ]; then
 277     for i in 3 2 0; do
 278       pngout -q -k1 -ks -s$i $file
 279     done
 280   else
 281     pngout -q -k1 -ks -s1 $file
 282   fi
 283
 284   if [ $OPTIMIZE_LEVEL == 2 ]; then
 285     random_huffman_table_trial $file
 286   fi
 287
 288   final_compression $file
 289 }
 290
 291 # Usage: process_file <file>
 292 function process_file {
 293   local file=$1
 294   local name=$(basename $file)
 295   # -rem alla removes all ancillary chunks except for tRNS
 296   pngcrush -d $TMP_DIR -brute -reduce -rem alla $file > /dev/null 2>&1
 297
 298   if [ -f $TMP_DIR/$name -a $OPTIMIZE_LEVEL != 0 ]; then
 299     optimize_size $TMP_DIR/$name
 300   fi
 301 }
 302
 303 # Usage: optimize_file <file>
 304 function optimize_file {
 305   local file=$1
 306   if $using_cygwin ; then
 307     file=$(cygpath -w $file)
 308   fi
 309
 310   local name=$(basename $file)
 311   local old=$(stat -c%s $file)
 312   local tmp_file=$TMP_DIR/$name
 313   let TOTAL_FILE+=1
 314
 315   process_file $file
 316
 317   if [ ! -e $tmp_file ] ; then
 318     let CORRUPTED_FILE+=1
 319     echo "$file may be corrupted; skipping\n"
 320     return
 321   fi
 322
 323   local new=$(stat -c%s $tmp_file)
 324   let diff=$old-$new
 325   let percent=$diff*100
 326   let percent=$percent/$old
 327
 328   if [ $new -lt $old ]; then
 329     info "$file: $old => $new ($diff bytes: $percent%)"
 330     cp "$tmp_file" "$file"
 331     let TOTAL_OLD_BYTES+=$old
 332     let TOTAL_NEW_BYTES+=$new
 333     let PROCESSED_FILE+=1
 334   else
 335     if [ $OPTIMIZE_LEVEL == 0 ]; then
 336       info "$file: Skipped"
 337     else
 338       info "$file: Unable to reduce size"
 339     fi
 340     rm $tmp_file
 341   fi
 342 }
 343
 344 function optimize_dir {
 345   local dir=$1
 346   if $using_cygwin ; then
 347     dir=$(cygpath -w $dir)
 348   fi
 349
 350   for f in $(find $dir -name "*.png"); do
 351     optimize_file $f
 352   done
 353 }
 354
 355 function install_if_not_installed {
 356   local program=$1
 357   local package=$2
 358   which $program > /dev/null 2>&1
 359   if [ "$?" != "0" ]; then
 360     if $using_cygwin ; then
 361       echo "Couldn't find $program. " \
 362            "Please run cygwin's setup.exe and install the $package package."
 363       exit 1
 364     else
 365       read -p "Couldn't find $program. Do you want to install? (y/n)"
 366       [ "$REPLY" == "y" ] && sudo apt-get install $package
 367       [ "$REPLY" == "y" ] || exit
 368     fi
 369   fi
 370 }
 371
 372 function fail_if_not_installed {
 373   local program=$1
 374   local url=$2
 375   which $program > /dev/null 2>&1
 376   if [ $? != 0 ]; then
 377     echo "Couldn't find $program. Please download and install it from $url ."
 378     exit 1
 379   fi
 380 }
 381
 382 function show_help {
 383   local program=$(basename $0)
 384   echo \
 385 "Usage: $program [options] <dir> ...
 386
 387 $program is a utility to reduce the size of png files by removing
 388 unnecessary chunks and compressing the image.
 389
 390 Options:
 391   -o<optimize_level>  Specify optimization level: (default is 1)
 392       0  Just run pngcrush. It removes unnecessary chunks and perform basic
 393          optimization on the encoded data.
 394       1  Optimize png files using pngout/optipng and advdef. This can further
 395          reduce addtional 5~30%. This is the default level.
 396       2  Aggressively optimize the size of png files. This may produce
 397          addtional 1%~5% reduction.  Warning: this is *VERY*
 398          slow and can take hours to process all files.
 399   -r<revision> If this is specified, the script processes only png files
 400                changed since this revision. The <dir> options will be used
 401                to narrow down the files under specific directories.
 402   -v  Shows optimization process for each file.
 403   -h  Print this help text."
 404   exit 1
 405 }
 406
 407 if [ ! -e ../.gclient ]; then
 408   echo "$0 must be run in src directory"
 409   exit 1
 410 fi
 411
 412 if [ "$(expr substr $(uname -s) 1 6)" == "CYGWIN" ]; then
 413   using_cygwin=true
 414 else
 415   using_cygwin=false
 416 fi
 417
 418 # The -i in the shebang line should result in $COLUMNS being set on newer
 419 # versions of bash.  If it's not set yet, attempt to set it.
 420 if [ -z $COLUMNS ]; then
 421   which tput > /dev/null 2>&1
 422   if [ "$?" == "0" ]; then
 423     COLUMNS=$(tput cols)
 424   else
 425     # No tput either... give up and just guess 80 columns.
 426     COLUMNS=80
 427   fi
 428   export COLUMNS
 429 fi
 430
 431 OPTIMIZE_LEVEL=1
 432 # Parse options
 433 while getopts o:r:h:v opts
 434 do
 435   case $opts in
 436     r)
 437       COMMIT=$(git svn find-rev r$OPTARG | tail -1) || exit
 438       if [ -z "$COMMIT" ] ; then
 439         echo "Revision $OPTARG not found"
 440         show_help
 441       fi
 442       ;;
 443     o)
 444       if [[ "$OPTARG" != 0 && "$OPTARG" != 1 && "$OPTARG" != 2 ]] ; then
 445         show_help
 446       fi
 447       OPTIMIZE_LEVEL=$OPTARG
 448       ;;
 449     v)
 450       VERBOSE=true
 451       ;;
 452     [h?])
 453       show_help;;
 454   esac
 455 done
 456
 457 # Remove options from argument list.
 458 shift $(($OPTIND -1))
 459
 460 # Make sure we have all necessary commands installed.
 461 install_if_not_installed pngcrush pngcrush
 462 if [ $OPTIMIZE_LEVEL -ge 1 ]; then
 463   install_if_not_installed optipng optipng
 464
 465   if $using_cygwin ; then
 466     fail_if_not_installed advdef "http://advancemame.sourceforge.net/comp-readme.html"
 467   else
 468     install_if_not_installed advdef advancecomp
 469   fi
 470
 471   if $using_cygwin ; then
 472     pngout_url="http://www.advsys.net/ken/utils.htm"
 473   else
 474     pngout_url="http://www.jonof.id.au/kenutils"
 475   fi
 476   fail_if_not_installed pngout $pngout_url
 477 fi
 478
 479 # Create tmp directory for crushed png file.
 480 TMP_DIR=$(mktemp -d)
 481 if $using_cygwin ; then
 482   TMP_DIR=$(cygpath -w $TMP_DIR)
 483 fi
 484
 485 # Make sure we cleanup temp dir
 486 #trap "rm -rf $TMP_DIR" EXIT
 487
 488 # If no directories are specified, optimize all directories.
 489 DIRS=$@
 490 set ${DIRS:=$ALL_DIRS}
 491
 492 info "Optimize level=$OPTIMIZE_LEVEL"
 493
 494 if [ -n "$COMMIT" ] ; then
 495  ALL_FILES=$(git diff --name-only $COMMIT HEAD $DIRS | grep "png$")
 496  ALL_FILES_LIST=( $ALL_FILES )
 497  echo "Processing ${#ALL_FILES_LIST[*]} files"
 498  for f in $ALL_FILES; do
 499    if [ -f $f ] ; then
 500      optimize_file $f
 501    else
 502      echo "Skipping deleted file: $f";
 503    fi
 504  done
 505 else
 506   for d in $DIRS; do
 507     if [ -d $d ] ; then
 508       info "Optimizing png files in $d"
 509       optimize_dir $d
 510       info ""
 511     elif [ -f $d ] ; then
 512       optimize_file $d
 513     else
 514       echo "Not a file or directory: $d";
 515     fi
 516   done
 517 fi
 518
 519 # Print the results.
 520 echo "Optimized $PROCESSED_FILE/$TOTAL_FILE files in" \
 521      "$(date -d "0 + $SECONDS sec" +%Ts)"
 522 if [ $PROCESSED_FILE != 0 ]; then
 523   let diff=$TOTAL_OLD_BYTES-$TOTAL_NEW_BYTES
 524   let percent=$diff*100/$TOTAL_OLD_BYTES
 525   echo "Result: $TOTAL_OLD_BYTES => $TOTAL_NEW_BYTES bytes" \
 526        "($diff bytes: $percent%)"
 527 fi
 528 if [ $CORRUPTED_FILE != 0 ]; then
 529   echo "Warning: corrupted files found: $CORRUPTED_FILE"
 530   echo "Please contact the author of the CL that landed corrupted png files"
 531 fi