Cap_ffmpeg_impl.hpp changes are not applied to opencv build

I am changed LIBAVFORMAT_INTERRUPT_OPEN_TIMEOUT_MS value. However, I do not think it is being applied after I built opencv.

Is there a way to change the interrupt callback timeout for ffmpeg in windows build?

to my best knowledge, cap_ffmpeg_impl code is used for the opencv_videoio_ffmpeg.dll, which gets compiled on an external build server,
and downloaded from there via cmake.
it is not used when building the opencv libs locally

1 Like

Does this mean that there is a pre-built opencv_ffmpeg.dll somewhere (external)? and the changes to modules/videoio/src/cap_ffmpeg_impl.hpp does not matter because it is just a copy from the external source?

Yes that’s correct, the .dll is downloaded by cmake. I found the best way to change anything inside cap_ffmpeg_impl is to link against ffmpeg libraries directly but you have to modify the cmake scripts to do this.

1 Like

Thank you. This much is clear now.