On Fri, Oct 02, 2020 at 07:59:12PM +0200, Michael Koch wrote: > Am 02.10.2020 um 10:10 schrieb Paul B Mahol: > > 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. > > A player? The output is a jpg image and it's too dark.
Yes, player, ffmpeg is not correct in conversion. Because swscale is old and ignores color_trc metadata that is required for correct display. Use zscale instead for converting pixel formats. > > ffmpeg -i input.dng output.jpg > > > > > 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. > > Did any of your 30 DNGs come from Adobe DNG converter V12.4, or from a > Pentax K5 camera? No, as that converter tends to create invalid DNG files. But thanks for uploading only one DNG file, I added support for it. > > 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".