[aapt2] Add a compression control option to 'compile'
aapt2 recompresses all PNGs it compiles, and by default it
uses the best (and slowest) zlib compression level, 9.
This change adds a command line option --png-compression-level
to control that, so it's possible to set it to something faster
e.g. 6 which is usually 5x faster and around 101% of the size
of level 9 PNGs
Test: manual, compile Framework
Flag: EXEMPT tool
Change-Id: Ibe5f47b82e1c13be0a4ffff0e07e675871abc956
diff --git a/libs/androidfw/PngCrunch.cpp b/libs/androidfw/PngCrunch.cpp
index cf3c0ee..e945405 100644
--- a/libs/androidfw/PngCrunch.cpp
+++ b/libs/androidfw/PngCrunch.cpp
@@ -506,8 +506,7 @@
// Set up the write functions which write to our custom data sources.
png_set_write_fn(write_ptr, (png_voidp)out, WriteDataToStream, nullptr);
- // We want small files and can take the performance hit to achieve this goal.
- png_set_compression_level(write_ptr, Z_BEST_COMPRESSION);
+ png_set_compression_level(write_ptr, options.compression_level);
// Begin analysis of the image data.
// Scan the entire image and determine if: