external/libpng: optimization

[enh-google]

there's arm/intel-specific .c source that uses neon or sse intrinsics; we'll want similar for risc-v.

[dragostis]

I'm currently taking a look at this one.

[unicornx]

one question: upstream of https://android.googlesource.com/platform/external/libpng/ is from chromium(https://chromium.googlesource.com/chromium/src/third_party/libpng/) or form it's official repo, which I think is https://github.com/glennrp/libpng?

[unicornx]

I'm currently taking a look at this one.

@dragostis how is it going at your end? I'm also interested on this porting for riscv.

[enh-google]

one question: upstream of https://android.googlesource.com/platform/external/libpng/ is from chromium(https://chromium.googlesource.com/chromium/src/third_party/libpng/) or form it's official repo, which I think is https://github.com/glennrp/libpng?

for most projects in external/ you should be able to look at the METADATA file to answer this question. in this case, it's https://android.googlesource.com/platform/external/libpng/+/refs/heads/master/METADATA which says github.

(it looks like chromium only has a couple of small changes on top of "true" upstream anyway? https://chromium.googlesource.com/chromium/src/third_party/libpng/+/refs/heads/main/patches/)

[dragostis]

@unicornx, I have a PR ready. It's currently sitting on SourceForge because I was under the impression that GitHub was just a mirror since many of the latest PRs have no comment on them.

I tried contacting the maintainer a couple of times and also the impl group without much success until now.

[mschlaegl]

Hi,
I wanted to inform you that we have also implemented a libpng for RVV and evaluated the performance of different implementation candidates with our RVVRadar tool on an Allwinner D1 (RVV 0.7). Details can be found here:: https://github.com/mschlaegl/libpng_rvv-doc

There are also two older pull requests:
pnggroup/libpng#405
libpng/libpng#3
The original maintainer Glenn Randers-Patterson sadly passed away in 2018. For some time it looked like glennrp/libpng would no longer be actively maintained and the work would be moved to libpng/libpng. However, now it seems glennrp/libpng is active again.

[enh-google]

anyone familiar enough with upstream to know if/when they plan on releasing v1.6.40? (we prefer to stick to published releases, but if that's not likely any time soon we can try to switch to a SHA instead...)

[dragostis]

@enh-google it was already released.

[enh-google]

ah, that's unfortunate...

* f135775a Release libpng version 1.6.40
* afc6c595 Fix a build regression on Solaris
* e6c5bf46 Ensure that only one eXIf chunk is written in the entire datastream
* 8be5c147 Don't report a valid tRNS chunk if it was canceled
* f7abe3c4 Avoid a memory leak when allocation of a pCAL buffer fails
* 82097c21 Fix a doc typo in pnglibconf.dfa
* e519af8b cmake: Allow overwriting the debug postfix of library filenames
* efc96c9d cmake: Redo the fix for Clang support on Windows
* aab24fa1 Clean up CMakeLists.txt
* efa9c2e9 cmake: Rename the custom targets to have the png_ prefix
* c22ef3b2 Revert "cmake: Fix the Clang support on Windows"
* 66fede80 ci: Update the CI scripts
* 59fa76e1 ci: Add CMake+Ninja+Clang to the AppVeyor CI matrix
* 70fda183 cmake: Fix the Clang support on Windows
* aeb26da4 cmake: Use CMAKE_SHARED_LIBRARY_C_FLAGS in version script checks
* cd0ea2a7 Fix for universal binaries on macOS
* 9923515f Update the copyright year
* 61bfdb0c Update the configuration for Travis CI and AppVeyor CI
* 9db8cff6 ci: Fix verification under Cygwin Bash + CMake + Visual Studio; update
* b445aade ci: Rename the ci_* scripts
* 3c152a8e Fix typos
* 5a0b7e9c manuals: Remove references to libpngpf(3); update links
* b126f807 Reorganize and update the README file; add Markdown formatting
* 3c761b51 Bump version to 1.6.40.git

i'll take that update anyway (https://android-review.googlesource.com/c/platform/external/libpng/+/2636112/), but no riscv stuff in there :-(

[unicornx]

I am wondering which one of the below list would be the upstream for aosp:

• https://github.com/libpng/libpng
• https://github.com/pnggroup/libpng
• https://github.com/glennrp/libpng: info from mschlaegl that "For some time it looked like glennrp/libpng would no longer be actively maintained and the work would be moved to libpng/libpng. However, now it seems glennrp/libpng is active again.“

[enh-google]

I am wondering which one of the below list would be the upstream for aosp...

see #37 (comment) where i already answered this question (both for libpng specifically, but also for all projects in external/).

[unicornx]

I am wondering which one of the below list would be the upstream for aosp...

see #37 (comment) where i already answered this question (both for libpng specifically, but also for all projects in external/).

Yes, I had already read your comment before. I asked again due to I am wondering if the upstream of libpng (which is mentioned in the METADATA as "https://github.com/glennrp/libpng.git") will be changed. From the input from mschlaegl, it looks something is changing......

[enh-google]

no, nothing is changing. (remember anyone can comment here!)