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Diffstat (limited to 'src/3rdparty/libwebp/README')
| -rw-r--r-- | src/3rdparty/libwebp/README | 51 |
1 files changed, 45 insertions, 6 deletions
diff --git a/src/3rdparty/libwebp/README b/src/3rdparty/libwebp/README index 4c15c4a..60da8a2 100644 --- a/src/3rdparty/libwebp/README +++ b/src/3rdparty/libwebp/README @@ -4,7 +4,7 @@ \__\__/\____/\_____/__/ ____ ___ / _/ / \ \ / _ \/ _/ / \_/ / / \ \ __/ \__ - \____/____/\_____/_____/____/v0.6.0 + \____/____/\_____/_____/____/v1.0.3 Description: ============ @@ -113,8 +113,8 @@ make install CMake: ------ -The support for CMake is minimal: it only helps you compile libwebp, cwebp and -dwebp. +With CMake, you can compile libwebp, cwebp, dwebp, gif2web, img2webp, webpinfo +and the JS bindings. Prerequisites: A compiler (e.g., gcc with autotools) and CMake. @@ -123,18 +123,27 @@ minimal build: $ sudo apt-get install build-essential cmake When building from git sources, you will need to run cmake to generate the -configure script. +makefiles. mkdir build && cd build && cmake ../ make make install -If you also want cwebp or dwebp, you will need to enable them through CMake: +If you also want any of the executables, you will need to enable them through +CMake, e.g.: cmake -DWEBP_BUILD_CWEBP=ON -DWEBP_BUILD_DWEBP=ON ../ or through your favorite interface (like ccmake or cmake-qt-gui). +Use option -DWEBP_UNICODE=ON for Unicode support on Windows (with chcp 65001). + +Finally, once installed, you can also use WebP in your CMake project by doing: + +find_package(WebP) + +which will define the CMake variables WebP_INCLUDE_DIRS and WebP_LIBRARIES. + Gradle: ------- The support for Gradle is minimal: it only helps you compile libwebp, cwebp and @@ -360,6 +369,23 @@ Use following options to convert into alternate image formats: -quiet ....... quiet mode, don't print anything -noasm ....... disable all assembly optimizations +WebP file analysis tool: +======================== + +'webpinfo' can be used to print out the chunk level structure and bitstream +header information of WebP files. It can also check if the files are of valid +WebP format. + +Usage: webpinfo [options] in_files +Note: there could be multiple input files; + options must come before input files. +Options: + -version ........... Print version number and exit. + -quiet ............. Do not show chunk parsing information. + -diag .............. Show parsing error diagnosis. + -summary ........... Show chunk stats summary. + -bitstream_info .... Parse bitstream header. + Visualization tool: =================== @@ -378,12 +404,14 @@ Options are: -nofilter .... disable in-loop filtering -dither <int> dithering strength (0..100), default=50 -noalphadither disable alpha plane dithering + -usebgcolor .. display background color -mt .......... use multi-threading -info ........ print info -h ........... this help message Keyboard shortcuts: 'c' ................ toggle use of color profile + 'b' ................ toggle background color display 'i' ................ overlay file information 'd' ................ disable blending & disposal (debug) 'q' / 'Q' / ESC .... quit @@ -434,6 +462,7 @@ File-level options (only used at the start of compression): -mixed ............... use mixed lossy/lossless automatic mode -v ................... verbose mode -h ................... this help + -version ............. print version number and exit Per-frame options (only used for subsequent images input): -d <int> ............. frame duration in ms (default: 100) @@ -445,6 +474,9 @@ Per-frame options (only used for subsequent images input): example: img2webp -loop 2 in0.png -lossy in1.jpg -d 80 in2.tiff -o out.webp +Note: if a single file name is passed as the argument, the arguments will be +tokenized from this file. The file name must not start with the character '-'. + Animated GIF conversion: ======================== Animated GIF files can be converted to WebP files with animation using the @@ -470,6 +502,8 @@ Options: -metadata <string> ..... comma separated list of metadata to copy from the input to the output if present Valid values: all, none, icc, xmp (default) + -loop_compatibility .... use compatibility mode for Chrome + version prior to M62 (inclusive) -mt .................... use multi-threading if available -version ............... print version number and exit @@ -498,6 +532,11 @@ Options: -min_psnr <float> ... minimum per-frame PSNR -raw_comparison ..... if this flag is not used, RGB is premultiplied before comparison + -max_diff <int> ..... maximum allowed difference per channel + between corresponding pixels in subsequent + frames + -h .................. this help + -version ............ print version number and exit Building: --------- @@ -558,7 +597,7 @@ The encoding flow looks like: // Setup a config, starting form a preset and tuning some additional // parameters WebPConfig config; - if (!WebPConfigPreset(&config, WEBP_PRESET_PHOTO, quality_factor)) + if (!WebPConfigPreset(&config, WEBP_PRESET_PHOTO, quality_factor)) { return 0; // version error } // ... additional tuning |