This is a sample code for streaming ip-camera image with FFmpeg.AutoGen
- Download 
ffmpeg-4.4-full_build-shared.7zof proper version (I used 4.4) from here - Extract .dll files from 
ffmpeg-4.4-full_build-shared/bin/ - Copy and paste those .dll files into 
./rtsp_test/FFmpeg/bin/x64/(in the directory, there is only one file namedffmpeg_dll_HERE.keep) - Get NuGet pacakge 'FFmpeg.Autogen' of proper version. This version must be same with ffmpeg version you downloaded in the first step.
 - uncheck Prefer 32-bit at your project property!
 
2021.06.09
- Get 32-bit shared build of proper version (ex. 
ffmpeg-4.3.1-win32-shared.zip) - Extract .dll files and copy&paste those .dll into 
./rtsp_test/FFmpeg/bin/x64/(in the directory, there is only one file namedffmpeg_dll_HERE.keep) - Get Nuget package 'FFmpeg.AutoGen' of proper version. This viersion must be same with ffmpeg version you downloaded int the first step. (ex. ver.4.3.1)
 - check Prefer 32-bit at your project property! (For Any CPU)
 
2021.06.07
I'm developing this test project to stream real-time image(video) with ffmpeg.
Opening streaming device functions had required about 6~8seconds (too slow!).
I found a nice tip to open device quicly.
I refered tCancel changeshis.
There are several tips to reduce delay during avformat_find_stream_info(_pFormatContext, null).
I only tried the first one, but the effect was great!