Thank you for describing the issue well, this doesn't look like to be a known issue. Most of our known issues are captured in the release notes. It's hard to tell what might be causing this issue, to debug can you send us a reproducer with the input and the details of your system to try at our end?
Please find attached 7z file that contains sample application to reproduce this issue. It includes readme.txt, source code and pre-built application. Also, I have included input file and screen shot of artifacts frame.
You can use broadwell machine i5-5300U, with window 8.1 OS, to reproduce this issue. Already I have provided details of intel driver versions.
We could not reproduce this issue with provide reproducer app (simpleTranscode) on latest graphics driver (4300). Can you please update to latest graphics drivers from https://downloadcenter.intel.com/ and test again. Let me know if artifacts are still visible with latest driver?
I have updated to latest drivers (4300) and tested it, issue is still present. In fact, there is no change in output. Can you upload or share the output of reproducer app? I am just wondering how could it possibly give two different outputs with same drivers version.
Please find below output from the repro app attached. Its interesting that with latest driver (4300) issue is still visible. Can you share log from system analyzer tool (mediaSDK/tools/system_analyzer)? Latest mediaSDK is available here: https://software.intel.com/en-us/media-sdk. Also, can you confirm, if your machine includes any discrete graphics?