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 component/resources
  26 content/public/android/java/res
  27 content/app/resources
  28 content/renderer/resources
  29 content/shell/resources
  30 remoting/resources
  31 ui/android/java/res
  32 ui/resources
  33 ui/chromeos/resources
  34 ui/webui/resources/images
  35 win8/metro_driver/resources
  36 "
  37
  38 # Files larger than this file size (in bytes) will
  39 # use the optimization parameters tailored for large files.
  40 LARGE_FILE_THRESHOLD=3000
  41
  42 # Constants used for optimization
  43 readonly DEFAULT_MIN_BLOCK_SIZE=128
  44 readonly DEFAULT_LIMIT_BLOCKS=256
  45 readonly DEFAULT_RANDOM_TRIALS=100
  46 # Taken from the recommendation in the pngslim's readme.txt.
  47 readonly LARGE_MIN_BLOCK_SIZE=1
  48 readonly LARGE_LIMIT_BLOCKS=2
  49 readonly LARGE_RANDOM_TRIALS=1
  50
  51 # Global variables for stats
  52 TOTAL_OLD_BYTES=0
  53 TOTAL_NEW_BYTES=0
  54 TOTAL_FILE=0
  55 CORRUPTED_FILE=0
  56 PROCESSED_FILE=0
  57
  58 declare -a THROBBER_STR=('-' '\\' '|' '/')
  59 THROBBER_COUNT=0
  60
  61 VERBOSE=false
  62
  63 # Echo only if verbose option is set.
  64 function info {
  65   if $VERBOSE ; then
  66     echo $@
  67   fi
  68 }
  69
  70 # Show throbber character at current cursor position.
  71 function throbber {
  72   info -ne "${THROBBER_STR[$THROBBER_COUNT]}\b"
  73   let THROBBER_COUNT=$THROBBER_COUNT+1
  74   let THROBBER_COUNT=$THROBBER_COUNT%4
  75 }
  76
  77 # Usage: pngout_loop <file> <png_out_options> ...
  78 # Optimize the png file using pngout with the given options
  79 # using various block split thresholds and filter types.
  80 function pngout_loop {
  81   local file=$1
  82   shift
  83   local opts=$*
  84   if [ $OPTIMIZE_LEVEL == 1 ]; then
  85     for j in $(eval echo {0..5}); do
  86       throbber
  87       pngout -q -k1 -s1 -f$j $opts $file
  88     done
  89   else
  90     for i in 0 128 256 512; do
  91       for j in $(eval echo {0..5}); do
  92         throbber
  93         pngout -q -k1 -s1 -b$i -f$j $opts $file
  94       done
  95     done
  96   fi
  97 }
  98
  99 # Usage: get_color_depth_list
 100 # Returns the list of color depth options for current optimization level.
 101 function get_color_depth_list {
 102   if [ $OPTIMIZE_LEVEL == 1 ]; then
 103     echo "-d0"
 104   else
 105     echo "-d1 -d2 -d4 -d8"
 106   fi
 107 }
 108
 109 # Usage: process_grayscale <file>
 110 # Optimize grayscale images for all color bit depths.
 111 #
 112 # TODO(oshima): Experiment with -d0 w/o -c0.
 113 function process_grayscale {
 114   info -ne "\b\b\b\b\b\b\b\bgray...."
 115   for opt in $(get_color_depth_list); do
 116     pngout_loop $file -c0 $opt
 117   done
 118 }
 119
 120 # Usage: process_grayscale_alpha <file>
 121 # Optimize grayscale images with alpha for all color bit depths.
 122 function process_grayscale_alpha {
 123   info -ne "\b\b\b\b\b\b\b\bgray-a.."
 124   pngout_loop $file -c4
 125   for opt in $(get_color_depth_list); do
 126     pngout_loop $file -c3 $opt
 127   done
 128 }
 129
 130 # Usage: process_rgb <file>
 131 # Optimize rgb images with or without alpha for all color bit depths.
 132 function process_rgb {
 133   info -ne "\b\b\b\b\b\b\b\brgb....."
 134   for opt in $(get_color_depth_list); do
 135     pngout_loop $file -c3 $opt
 136   done
 137   pngout_loop $file -c2
 138   pngout_loop $file -c6
 139 }
 140
 141 # Usage: huffman_blocks <file>
 142 # Optimize the huffman blocks.
 143 function huffman_blocks {
 144   info -ne "\b\b\b\b\b\b\b\bhuffman."
 145   local file=$1
 146   local size=$(stat -c%s $file)
 147   local min_block_size=$DEFAULT_MIN_BLOCK_SIZE
 148   local limit_blocks=$DEFAULT_LIMIT_BLOCKS
 149
 150   if [ $size -gt $LARGE_FILE_THRESHOLD ]; then
 151     min_block_size=$LARGE_MIN_BLOCK_SIZE
 152     limit_blocks=$LARGE_LIMIT_BLOCKS
 153   fi
 154   let max_blocks=$size/$min_block_size
 155   if [ $max_blocks -gt $limit_blocks ]; then
 156     max_blocks=$limit_blocks
 157   fi
 158
 159   for i in $(eval echo {2..$max_blocks}); do
 160     throbber
 161     pngout -q -k1 -ks -s1 -n$i $file
 162   done
 163 }
 164
 165 # Usage: random_huffman_table_trial <file>
 166 # Try compressing by randomizing the initial huffman table.
 167 #
 168 # TODO(oshima): Try adjusting different parameters for large files to
 169 # reduce runtime.
 170 function random_huffman_table_trial {
 171   info -ne "\b\b\b\b\b\b\b\brandom.."
 172   local file=$1
 173   local old_size=$(stat -c%s $file)
 174   local trials_count=$DEFAULT_RANDOM_TRIALS
 175
 176   if [ $old_size -gt $LARGE_FILE_THRESHOLD ]; then
 177     trials_count=$LARGE_RANDOM_TRIALS
 178   fi
 179   for i in $(eval echo {1..$trials_count}); do
 180     throbber
 181     pngout -q -k1 -ks -s0 -r $file
 182   done
 183   local new_size=$(stat -c%s $file)
 184   if [ $new_size -lt $old_size ]; then
 185     random_huffman_table_trial $file
 186   fi
 187 }
 188
 189 # Usage: final_comprssion <file>
 190 # Further compress using optipng and advdef.
 191 # TODO(oshima): Experiment with 256.
 192 function final_compression {
 193   info -ne "\b\b\b\b\b\b\b\bfinal..."
 194   local file=$1
 195   if [ $OPTIMIZE_LEVEL == 2 ]; then
 196     for i in 32k 16k 8k 4k 2k 1k 512; do
 197       throbber
 198       optipng -q -nb -nc -zw$i -zc1-9 -zm1-9 -zs0-3 -f0-5 $file
 199     done
 200   fi
 201   for i in $(eval echo {1..4}); do
 202     throbber
 203     advdef -q -z -$i $file
 204   done
 205
 206   # Clear the current line.
 207   if $VERBOSE ; then
 208     printf "\033[0G\033[K"
 209   fi
 210 }
 211
 212 # Usage: get_color_type <file>
 213 # Returns the color type name of the png file. Here is the list of names
 214 # for each color type codes.
 215 # 0: grayscale
 216 # 2: RGB
 217 # 3: colormap
 218 # 4: gray+alpha
 219 # 6: RGBA
 220 # See http://en.wikipedia.org/wiki/Portable_Network_Graphics#Color_depth
 221 # for details about the color type code.
 222 function get_color_type {
 223   local file=$1
 224   echo $(file $file | awk -F, '{print $3}' | awk '{print $2}')
 225 }
 226
 227 # Usage: optimize_size <file>
 228 # Performs png file optimization.
 229 function optimize_size {
 230   # Print filename, trimmed to ensure it + status don't take more than 1 line
 231   local filename_length=${#file}
 232   local -i allowed_length=$COLUMNS-11
 233   local -i trimmed_length=$filename_length-$COLUMNS+14
 234   if [ "$filename_length" -lt "$allowed_length" ]; then
 235     info -n "$file|........"
 236   else
 237     info -n "...${file:$trimmed_length}|........"
 238   fi
 239
 240   local file=$1
 241
 242   advdef -q -z -4 $file
 243
 244   pngout -q -s4 -c0 -force $file $file.tmp.png
 245   if [ -f $file.tmp.png ]; then
 246     rm $file.tmp.png
 247     process_grayscale $file
 248     process_grayscale_alpha $file
 249   else
 250     pngout -q -s4 -c4 -force $file $file.tmp.png
 251     if [ -f $file.tmp.png ]; then
 252       rm $file.tmp.png
 253       process_grayscale_alpha $file
 254     else
 255       process_rgb $file
 256     fi
 257   fi
 258
 259   info -ne "\b\b\b\b\b\b\b\bfilter.."
 260   local old_color_type=$(get_color_type $file)
 261   optipng -q -zc9 -zm8 -zs0-3 -f0-5 $file -out $file.tmp.png
 262   local new_color_type=$(get_color_type $file.tmp.png)
 263   # optipng may corrupt a png file when reducing the color type
 264   # to grayscale/grayscale+alpha. Just skip such cases until
 265   # the bug is fixed. See crbug.com/174505, crbug.com/174084.
 266   # The issue is reported in
 267   # https://sourceforge.net/tracker/?func=detail&aid=3603630&group_id=151404&atid=780913
 268   if [[ $old_color_type == "RGBA" && $new_color_type == gray* ]] ; then
 269     rm $file.tmp.png
 270   else
 271     mv $file.tmp.png $file
 272   fi
 273   pngout -q -k1 -s1 $file
 274
 275   huffman_blocks $file
 276
 277   # TODO(oshima): Experiment with strategy 1.
 278   info -ne "\b\b\b\b\b\b\b\bstrategy"
 279   if [ $OPTIMIZE_LEVEL == 2 ]; then
 280     for i in 3 2 0; do
 281       pngout -q -k1 -ks -s$i $file
 282     done
 283   else
 284     pngout -q -k1 -ks -s1 $file
 285   fi
 286
 287   if [ $OPTIMIZE_LEVEL == 2 ]; then
 288     random_huffman_table_trial $file
 289   fi
 290
 291   final_compression $file
 292 }
 293
 294 # Usage: process_file <file>
 295 function process_file {
 296   local file=$1
 297   local name=$(basename $file)
 298   # -rem alla removes all ancillary chunks except for tRNS
 299   pngcrush -d $TMP_DIR -brute -reduce -rem alla $file > /dev/null 2>&1
 300
 301   if [ -f $TMP_DIR/$name -a $OPTIMIZE_LEVEL != 0 ]; then
 302     optimize_size $TMP_DIR/$name
 303   fi
 304 }
 305
 306 # Usage: optimize_file <file>
 307 function optimize_file {
 308   local file=$1
 309   if $using_cygwin ; then
 310     file=$(cygpath -w $file)
 311   fi
 312
 313   local name=$(basename $file)
 314   local old=$(stat -c%s $file)
 315   local tmp_file=$TMP_DIR/$name
 316   let TOTAL_FILE+=1
 317
 318   process_file $file
 319
 320   if [ ! -e $tmp_file ] ; then
 321     let CORRUPTED_FILE+=1
 322     echo "$file may be corrupted; skipping\n"
 323     return
 324   fi
 325
 326   local new=$(stat -c%s $tmp_file)
 327   let diff=$old-$new
 328   let percent=$diff*100
 329   let percent=$percent/$old
 330
 331   if [ $new -lt $old ]; then
 332     info "$file: $old => $new ($diff bytes: $percent%)"
 333     cp "$tmp_file" "$file"
 334     let TOTAL_OLD_BYTES+=$old
 335     let TOTAL_NEW_BYTES+=$new
 336     let PROCESSED_FILE+=1
 337   else
 338     if [ $OPTIMIZE_LEVEL == 0 ]; then
 339       info "$file: Skipped"
 340     else
 341       info "$file: Unable to reduce size"
 342     fi
 343     rm $tmp_file
 344   fi
 345 }
 346
 347 function optimize_dir {
 348   local dir=$1
 349   if $using_cygwin ; then
 350     dir=$(cygpath -w $dir)
 351   fi
 352
 353   for f in $(find $dir -name "*.png"); do
 354     optimize_file $f
 355   done
 356 }
 357
 358 function install_if_not_installed {
 359   local program=$1
 360   local package=$2
 361   which $program > /dev/null 2>&1
 362   if [ "$?" != "0" ]; then
 363     if $using_cygwin ; then
 364       echo "Couldn't find $program. " \
 365            "Please run cygwin's setup.exe and install the $package package."
 366       exit 1
 367     else
 368       read -p "Couldn't find $program. Do you want to install? (y/n)"
 369       [ "$REPLY" == "y" ] && sudo apt-get install $package
 370       [ "$REPLY" == "y" ] || exit
 371     fi
 372   fi
 373 }
 374
 375 function fail_if_not_installed {
 376   local program=$1
 377   local url=$2
 378   which $program > /dev/null 2>&1
 379   if [ $? != 0 ]; then
 380     echo "Couldn't find $program. Please download and install it from $url ."
 381     exit 1
 382   fi
 383 }
 384
 385 # Check pngcrush version and exit if the version is in bad range.
 386 # See crbug.com/404893.
 387 function exit_if_bad_pngcrush_version {
 388   local version=$(pngcrush -v 2>&1 | awk "/pngcrush 1.7./ {print \$3}")
 389   local version_num=$(echo $version | sed "s/\.//g")
 390   if [[ (1748 -lt $version_num && $version_num -lt 1773) ]] ; then
 391     echo "Your pngcrush ($version) has a bug that exists from " \
 392          "1.7.49 to 1.7.72  (see crbug.com/404893 for details)."
 393     echo "Please upgrade pngcrush and try again"
 394     exit 1;
 395   fi
 396 }
 397
 398 function show_help {
 399   local program=$(basename $0)
 400   echo \
 401 "Usage: $program [options] <dir> ...
 402
 403 $program is a utility to reduce the size of png files by removing
 404 unnecessary chunks and compressing the image.
 405
 406 Options:
 407   -o<optimize_level>  Specify optimization level: (default is 1)
 408       0  Just run pngcrush. It removes unnecessary chunks and perform basic
 409          optimization on the encoded data.
 410       1  Optimize png files using pngout/optipng and advdef. This can further
 411          reduce addtional 5~30%. This is the default level.
 412       2  Aggressively optimize the size of png files. This may produce
 413          addtional 1%~5% reduction.  Warning: this is *VERY*
 414          slow and can take hours to process all files.
 415   -r<revision> If this is specified, the script processes only png files
 416                changed since this revision. The <dir> options will be used
 417                to narrow down the files under specific directories.
 418   -v  Shows optimization process for each file.
 419   -h  Print this help text."
 420   exit 1
 421 }
 422
 423 if [ ! -e ../.gclient ]; then
 424   echo "$0 must be run in src directory"
 425   exit 1
 426 fi
 427
 428 if [ "$(expr substr $(uname -s) 1 6)" == "CYGWIN" ]; then
 429   using_cygwin=true
 430 else
 431   using_cygwin=false
 432 fi
 433
 434 # The -i in the shebang line should result in $COLUMNS being set on newer
 435 # versions of bash.  If it's not set yet, attempt to set it.
 436 if [ -z $COLUMNS ]; then
 437   which tput > /dev/null 2>&1
 438   if [ "$?" == "0" ]; then
 439     COLUMNS=$(tput cols)
 440   else
 441     # No tput either... give up and just guess 80 columns.
 442     COLUMNS=80
 443   fi
 444   export COLUMNS
 445 fi
 446
 447 OPTIMIZE_LEVEL=1
 448 # Parse options
 449 while getopts o:r:h:v opts
 450 do
 451   case $opts in
 452     r)
 453       COMMIT=$(git svn find-rev r$OPTARG | tail -1) || exit
 454       if [ -z "$COMMIT" ] ; then
 455         echo "Revision $OPTARG not found"
 456         show_help
 457       fi
 458       ;;
 459     o)
 460       if [[ "$OPTARG" != 0 && "$OPTARG" != 1 && "$OPTARG" != 2 ]] ; then
 461         show_help
 462       fi
 463       OPTIMIZE_LEVEL=$OPTARG
 464       ;;
 465     v)
 466       VERBOSE=true
 467       ;;
 468     [h?])
 469       show_help;;
 470   esac
 471 done
 472
 473 # Remove options from argument list.
 474 shift $(($OPTIND -1))
 475
 476 # Make sure we have all necessary commands installed.
 477 install_if_not_installed pngcrush pngcrush
 478 exit_if_bad_pngcrush_version
 479
 480 if [ $OPTIMIZE_LEVEL -ge 1 ]; then
 481   install_if_not_installed optipng optipng
 482
 483   if $using_cygwin ; then
 484     fail_if_not_installed advdef "http://advancemame.sourceforge.net/comp-readme.html"
 485   else
 486     install_if_not_installed advdef advancecomp
 487   fi
 488
 489   if $using_cygwin ; then
 490     pngout_url="http://www.advsys.net/ken/utils.htm"
 491   else
 492     pngout_url="http://www.jonof.id.au/kenutils"
 493   fi
 494   fail_if_not_installed pngout $pngout_url
 495 fi
 496
 497 # Create tmp directory for crushed png file.
 498 TMP_DIR=$(mktemp -d)
 499 if $using_cygwin ; then
 500   TMP_DIR=$(cygpath -w $TMP_DIR)
 501 fi
 502
 503 # Make sure we cleanup temp dir
 504 #trap "rm -rf $TMP_DIR" EXIT
 505
 506 # If no directories are specified, optimize all directories.
 507 DIRS=$@
 508 set ${DIRS:=$ALL_DIRS}
 509
 510 info "Optimize level=$OPTIMIZE_LEVEL"
 511
 512 if [ -n "$COMMIT" ] ; then
 513  ALL_FILES=$(git diff --name-only $COMMIT HEAD $DIRS | grep "png$")
 514  ALL_FILES_LIST=( $ALL_FILES )
 515  echo "Processing ${#ALL_FILES_LIST[*]} files"
 516  for f in $ALL_FILES; do
 517    if [ -f $f ] ; then
 518      optimize_file $f
 519    else
 520      echo "Skipping deleted file: $f";
 521    fi
 522  done
 523 else
 524   for d in $DIRS; do
 525     if [ -d $d ] ; then
 526       info "Optimizing png files in $d"
 527       optimize_dir $d
 528       info ""
 529     elif [ -f $d ] ; then
 530       optimize_file $d
 531     else
 532       echo "Not a file or directory: $d";
 533     fi
 534   done
 535 fi
 536
 537 # Print the results.
 538 echo "Optimized $PROCESSED_FILE/$TOTAL_FILE files in" \
 539      "$(date -d "0 + $SECONDS sec" +%Ts)"
 540 if [ $PROCESSED_FILE != 0 ]; then
 541   let diff=$TOTAL_OLD_BYTES-$TOTAL_NEW_BYTES
 542   let percent=$diff*100/$TOTAL_OLD_BYTES
 543   echo "Result: $TOTAL_OLD_BYTES => $TOTAL_NEW_BYTES bytes" \
 544        "($diff bytes: $percent%)"
 545 fi
 546 if [ $CORRUPTED_FILE != 0 ]; then
 547   echo "Warning: corrupted files found: $CORRUPTED_FILE"
 548   echo "Please contact the author of the CL that landed corrupted png files"
 549 fi