On Thu, Oct 01, 2020 at 11:40:57PM +0200, Michael Koch wrote: > Am 01.10.2020 um 22:11 schrieb Paul B Mahol: > > On Tue, Sep 29, 2020 at 10:54:54PM +0200, Michael Koch wrote: > > > Hello all, > > > > > > I've programmed a C# workaround for stabilization of 360° videos. The > > > procedure is as follows: > > > > > > 1. FFmpeg: From each frame of the equirectangular input video, extract two > > > small images which are 90° apart in the input video. I call them A and B > > > images. > > > > > > 2. C# code: Analyze the x and y image shift from subsequent A and B > > > images. > > > Calculate how the equirectangular frames must be rotated (yaw, pitch, > > > roll) > > > to compensate the image shifts. This part wasn't easy. Two rotation > > > matrices > > > and one matrix multiplication are required. Write the results to a *.cmd > > > file. > > > > > > 3. FFmpeg: Read the *.cmd file and apply the rotations with the v360 > > > filter. > > > The output video is stabilized. > > > > > > For details and source code please have a look at chapter 2.78 in my book: > > > http://www.astro-electronic.de/FFmpeg_Book.pdf > > > > > > If anyone wants to implement this in FFmpeg, please feel free to do it. > > Better upload DNG files that do not decode with FFmpeg. > > In this message > http://ffmpeg.org/pipermail/ffmpeg-user/2020-August/049681.html > you find a link to many DNG images which FFmpeg can't decode correctly. > There is no error message, but the result is much too dark with low > saturation.
Use correct player like mpv, which does not ignore color_trc. > > I did convert a RAW image from a Canon 6D to DNG with Adobe DNG Converter > V12.4. FFmpeg is unable to decode this DNG image. See this message for > details: > http://ffmpeg.org/pipermail/ffmpeg-user/2020-August/049738.html > You can download the DNG image here (I will delete it from my webspace in a > few days): > www.astro-electronic.de/IMG_3459.dng > > I did also try a RAW image from a Canon 5D-MK4 with the same negative > result. > > A friend gave me a DNG image that was written by his Pentax K5 camera. Same > negative result. > > Summary: I did try DNG images from 4 different sources and in 4 of 4 cases In my testcases, 30 out of 30 DNGs decoded just fine. > FFmpeg failed. > > Michael > > > _______________________________________________ > ffmpeg-user mailing list > ffmpeg-user@ffmpeg.org > https://ffmpeg.org/mailman/listinfo/ffmpeg-user > > To unsubscribe, visit link above, or email > ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe". _______________________________________________ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".