Question: am trying to focus the scroll based on the selected add class,when clicking on the previous and next button the scroll need to focus it. how can i make it possible please check my fiddle 
<https://jsfiddle.net/kannankds/bcszkqLu/>

```
<ul class="kds">
<li>tile dtls1</li>
<li>tile dtls2</li>
<li>tile dtls3</li>
</ul>
<input type="button" value="previous" class="previous">
<input type="button" value="next" class="next">

```

Answer: 
It appears that this commit fixes the issue, while still keeping NEON support for iOS devices:

<https://github.com/opencv/opencv/commit/262a52f3063c50fbb1236e2cba2bd3c68f9979bb>

Essentially, the clause that appends `-DENABLE_NEON=ON` to the `cmake` line was only applying to architectures beginning with `"armv"` (note the "v"); the above commit changes `opencv/platforms/ios/build_framework.py` to allow the cmake command to work with `"arm64"` as well.

Before:

```
    if arch.startswith("armv"):
        cmakecmd.append("-DENABLE_NEON=ON")

```

After:

```
    if arch.startswith("armv") or arch.startswith("arm64"):
        cmakecmd.append("-DENABLE_NEON=ON")

```

---

Diagnostic process, since it might be useful:

Found this by starting a `script build.log` before invoking `python ../opencv/platforms/ios/build_framework.py ios` and digging through output; `arm_init.c` was not built for `arm64` (which is where `png_init_filter_functions_neon` was defined) but was for `armv7` and `armv7s`. From there, looking through `3rdparty/libpng/CMakeLists.txt` pointed at `ENABLE_NEON` not being set.
I faced the same problem as @shahzaib described. In simulator it works but in iPhone its not working and showing the same error.

Previously I manually added OpenCV 3.1 in my iOS project. Later I changed it and install the OpenCV library via cocoapod <https://cocoapods.org/pods/OpenCV>

And in cocoapod there is 3.1.0.1 version which fixed the issue.

```
  pod 'OpenCV', '~> 3.1.0.1'

```