commit d5a16911bb0da6b03daee6e9dd896429c7f8e8a1
author Matt Sarett <msarett@google.com> Tue May 16 17:06:52 2017 -0400
committer Skia Commit-Bot <skia-commit-bot@chromium.org> Wed May 17 02:24:29 2017 +0000
tree 1aae55437f046079641a7519e5702af01d311518
parent 1cdbdda91748d5a3fece595e07de5efb662aaaad

Add support for webp lossless compression

Bug: 713862
Change-Id: I8dcc6506338f3c54fb14a78620e7daaadadfedde
Reviewed-on: https://skia-review.googlesource.com/17073
Reviewed-by: Mike Reed <reed@google.com>
Reviewed-by: Leon Scroggins <scroggo@google.com>
Commit-Queue: Matt Sarett <msarett@google.com>

src/images/SkImageEncoder.cpp

diff --git a/src/images/SkImageEncoder.cpp b/src/images/SkImageEncoder.cpp
index 30493cf..d79741d 100644
--- a/src/images/SkImageEncoder.cpp
+++ b/src/images/SkImageEncoder.cpp
@@ -49,6 +49,7 @@
             }
             case SkEncodedImageFormat::kWEBP: {
                 SkWebpEncoder::Options opts;
+                opts.fCompression = SkWebpEncoder::Compression::kLossy;
                 opts.fQuality = quality;
                 opts.fUnpremulBehavior = SkTransferFunctionBehavior::kIgnore;
                 return SkWebpEncoder::Encode(dst, src, opts);

src/images/SkWebpEncoder.cpp

diff --git a/src/images/SkWebpEncoder.cpp b/src/images/SkWebpEncoder.cpp
index 5c26111..b6c6212 100644
--- a/src/images/SkWebpEncoder.cpp
+++ b/src/images/SkWebpEncoder.cpp
@@ -124,8 +124,7 @@
   return stream->write(data, data_size) ? 1 : 0;
 }
 
-static bool do_encode(SkWStream* stream, const SkPixmap& pixmap, const SkWebpEncoder::Options& opts)
-{
+bool SkWebpEncoder::Encode(SkWStream* stream, const SkPixmap& pixmap, const Options& opts) {
     if (!SkPixmapIsValid(pixmap, opts.fUnpremulBehavior)) {
         return false;
     }
@@ -168,6 +167,16 @@
         return false;
     }
 
+    // The choice of |webp_config.method| currently just match Chrome's defaults.  We
+    // could potentially expose this to the client.
+    if (Compression::kLossy == opts.fCompression) {
+        webp_config.lossless = 0;
+        webp_config.method = 3;
+    } else {
+        webp_config.lossless = 1;
+        webp_config.method = 0;
+    }
+
     WebPPicture pic;
     WebPPictureInit(&pic);
     SkAutoTCallVProc<WebPPicture, WebPPictureFree> autoPic(&pic);
@@ -236,8 +245,4 @@
     return true;
 }
 
-bool SkWebpEncoder::Encode(SkWStream* dst, const SkPixmap& src, const Options& opts) {
-    return do_encode(dst, src, opts);
-}
-
 #endif