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Selection of projects using MediaSPIP
2 mai 2011, parThe examples below are representative elements of MediaSPIP specific uses for specific projects.
MediaSPIP farm @ Infini
The non profit organizationInfini develops hospitality activities, internet access point, training, realizing innovative projects in the field of information and communication technologies and Communication, and hosting of websites. It plays a unique and prominent role in the Brest (France) area, at the national level, among the half-dozen such association. Its members (...)
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fate : add a test for HDR Vivid metadata in HEVC
3 mars 2022, par Limin Wang -
Ghost image issues with ffmpeg -filter_complex displace
5 juillet 2022, par raul.vilaI've (almost) been able to apply a displacement based on 2 animated gaussian noise videos, but I'm having issues with a ghost image. A picture is worth a thousand words.


Here you have a script to replicate the issue :


ffmpeg -y -t 2 -f lavfi -i color=c=blue:s=160x120 -c:v libx264 -tune stillimage -pix_fmt rgb24 00_empty.mp4
ffmpeg -y -i 00_empty.mp4 -vf "drawtext=text=string1:y=h/2:x=w-t*w/2:fontcolor=white:fontsize=60" 01_text.mp4
ffmpeg -y -t 2 -f lavfi -i color=c=gray:s=160x120 -c:v libx264 -tune stillimage -pix_fmt rgb24 02_gray.mp4
ffmpeg -y -i 01_text.mp4 -i 02_gray.mp4 -i 02_gray.mp4 -filter_complex "[0][1][2]displace=edge=mirror" 03_displaced_text.mp4


It creates a test video with a scrolling text and a gray dummy video. Then it applies a displacement based on the gray video. If I understand correctly, because the gray video is 100% gray, it should leave the video unchanged (or maybe displace everything by a fixed ammount of pixels), but it creates a "shadow". I tried with 3 different pixel formats (yuv420p, yuv444p, rgb24) because I found this question on stackoverflow talking about that :


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- Why are Cb and Cr planes displaced differently from lum by the displace complex filter in ffmpeg ?




ffmpeg version 5.0.1-full_build-www.gyan.dev


Any idea will be welcome.

Thanks !

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avfilter/vf_showinfo : fix HDR vivid info
17 mars 2023, par Zhao Zhili
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