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Autres articles (112)
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Personnaliser en ajoutant son logo, sa bannière ou son image de fond
5 septembre 2013, parCertains thèmes prennent en compte trois éléments de personnalisation : l’ajout d’un logo ; l’ajout d’une bannière l’ajout d’une image de fond ;
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Websites made with MediaSPIP
2 mai 2011, parThis page lists some websites based on MediaSPIP.
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Creating farms of unique websites
13 avril 2011, parMediaSPIP platforms can be installed as a farm, with a single "core" hosted on a dedicated server and used by multiple websites.
This allows (among other things) : implementation costs to be shared between several different projects / individuals rapid deployment of multiple unique sites creation of groups of like-minded sites, making it possible to browse media in a more controlled and selective environment than the major "open" (...)
Sur d’autres sites (14628)
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encode YUV420 frame to VP9
21 novembre 2018, par User800222As title,
I’m pulling frames from a IP camera. I converted the input raw data to YUV420 format, and would like to encode YUV420 to VP9, and save frames as .webm format. Would I be able to do that ? Or should I input a BGR444 format for encoding ?
BTW, to set up the parameters for encoding vp9. Is the
av_dict_set()
the right function for setting parameters ?Ex : (http://wiki.webmproject.org/ffmpeg/vp9-encoding-guide)
av_dict_set(&opt, "crf" , "23", 0);
av_dict_set(&opt, "speed" , "4" , 0);
av_dict_set(&opt, "threads", "8" , 0);
av_dict_set(&opt, "pass" , "1" , 0);
av_dict_set(&opt, "b:v", "1400k", 0);Edit : The wiki uses 2 pass for setting parameters, would I be able to do in with 1 pass ?
Edit2 : Blow code seems to be working, wonder how can I bring the size of the videos (vp9) down ? Currently, I have similar size as using h264 encoder.
av_dict_set(&opt, "crf" , "45", 0);
av_dict_set(&opt, "speed" , "8" , 0);
av_dict_set(&opt, "quality", "realtime", 0);
av_dict_set(&opt, "threads", "8" , 0);
av_dict_set(&opt, "tile-columns", "3", 0);
av_dict_set(&opt, "frame-parallel", "1", 0);
av_dict_set(&opt, "row-mt", "1", 0);Update1 :
YUV420P can be encoded as VP9 ! -
Create a looped video with countdown
13 décembre 2016, par Enrico DeleoSomething maybe challenging here :
I want to stream (via rtmp) a video with a fixed image and a countdown applied on it. I know I can create a slideshow with even audio background with ffmtp (http://trac.ffmpeg.org/wiki/Create%20a%20video%20slideshow%20from%20images) but I’m wondering if I can loop it AND apply an overlay with the countdown to a given date.Any ideas ?
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Is it possible to change volume with no reencode with ffmpeg ?
30 juin 2023, par John SmithI just had this question because I used the following command with ffmpeg :



ffmpeg -i input.wav -filter:a "volume=0.2" output.wav




Following the documentation here : https://trac.ffmpeg.org/wiki/AudioVolume



However, when I created the new file, the output was half the size of the input and the bitrate of the audio track was reduced as well.



So my questions are :



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- Is the bitrate supposed to decrease with decreasing and increasing volume like so ?
- Is it possible to change volume without reencoding with ffmpeg ?