For an application (Win7/ mingw) that analyses movie files I divide the reading and processing to the cores.
When trying to jump to the beginning of the parts with> VideoCapture::set> (CAP_PROP_POS_FRAMES, frameNumber);
and then
> capt >> frame;
I do not get frame with number frameNumber but some frames *before*
(the exact value depends on the movie format).
Also the first two calls of
> capt >> frame;
return the same frame.
But
> VideoCapture::set> (CAP_PROP_POS_FRAMES, frameNumber);
and then
> ret = VideoCapture::get> (CAP_PROP_POS_FRAMES);
lets frameNumber == ret
There are many threads about this issue already.
Some say that in newer versions of opencv that "bug" is gone.
Other say that it's about the keyframes in the video stream
that would make ffmpeg seek to the first keyframe AFTER the
desired position.
Has somebody up-to-date information what happens here
and how to do (this quite common task) please?
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VideoCapture::set (CAP_PROP_POS_FRAMES, frameNumber) not exact in opencv 3.2 with ffmpeg?
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How to encode video using FFMPEG in VideoWriter in Java?
I downloaded the ffmpeg and h264 dlls and added them to the java class path, but everytime I call videowriter.open on 'h264', it returns false and I don't know why.
I looked up the previous answers on this site but the answers were not satisfying.
Thanks so much!
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Build OpenCV with FFMpeg for iOS
Hi, is there a way to build OpenCV with FFMpeg for iOS? I need a way to process rtsp stream on iPhone with OpenCV. I found https://sourceforge.net/projects/ffmpeg-ios/, but how to build OpenCV with those libs? There is next line in CMakeLists.txt in the root of OpenCV repo
`OCV_OPTION(WITH_FFMPEG "Include FFMPEG support" ON IF (NOT ANDROID AND NOT IOS AND NOT WINRT) )`
Please suggest, thx
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Check, is FFmpeg or GStreamer available
What's the easiest way to check in OpenCV code, is FFmpeg or GStreamer (or both) available.
I've understood that in VideoCapture class FFmpeg requires filename or device ID, but GStreamer a pipeline, so same code doesn't work in both.
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