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Autres articles (82)
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Les autorisations surchargées par les plugins
27 avril 2010, parMediaspip core
autoriser_auteur_modifier() afin que les visiteurs soient capables de modifier leurs informations sur la page d’auteurs -
Personnaliser les catégories
21 juin 2013, parFormulaire de création d’une catégorie
Pour ceux qui connaissent bien SPIP, une catégorie peut être assimilée à une rubrique.
Dans le cas d’un document de type catégorie, les champs proposés par défaut sont : Texte
On peut modifier ce formulaire dans la partie :
Administration > Configuration des masques de formulaire.
Dans le cas d’un document de type média, les champs non affichés par défaut sont : Descriptif rapide
Par ailleurs, c’est dans cette partie configuration qu’on peut indiquer le (...) -
Des sites réalisés avec MediaSPIP
2 mai 2011, parCette page présente quelques-uns des sites fonctionnant sous MediaSPIP.
Vous pouvez bien entendu ajouter le votre grâce au formulaire en bas de page.
Sur d’autres sites (9990)
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Can't fix timestamp of WebM video with dynamic resolution using FFmpeg
11 février 2019, par Yurii KitI’m developing the platform for 1-1 video calls with recording. For my purposes, I work with the following stack : WebRTC, Kurento Media Server, FFmpeg.
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It works perfectly in an ideal environment, but if my users have a poor connection, after the recording I see a lot of problems with the out of sync audio and video tracks.
As I understand, the problem appears due to the incorrect timestamp, so I’m doing a bit post-processing where I generate a new timestamp and it helps !
Here is the command example :
ffmpeg -fflags +genpts -acodec libopus -vcodec libvpx \
-i in.webm \
-filter_complex "fps=30, setpts=PTS-STARTPTS" \
-acodec libvorbis -vcodec libvpx \
-vsync 1 -async 1 -r 30 -threads 4 out.webm -
After that, I’ve faced one more problem. If the user has a poor connection, WebRTC can dynamically change the video resolution. After the post-processing for such type of videos (with the different resolutions during the video) I see the frozen image until the end of the video and it started from the moment, where the resolution was dynamically changed. There are no error in the FFmpeg logs, just information about changing the resolution :
[libvpx @ 0x559335713440] dimension change! 480x270 -> 320x180
-async is forwarded to lavfi similarly to -af aresample=async=1:min_hard_comp=0.100000.After analyzing the logs, I realized that the problem was due to the STARTPTS parameter, which, after automatically changing the extension, became very large (equal to the number of frames that were before it). I tried to remove STARTPTS and leave only PTS.
After that, the video started to work well, but only until the video resolution are dynamically changed, then again the audio and video tracks are out of sync.
I’ve tried to scale videos to a static resolution before fixing timestamp and it helps. But it’s a little bit extra work. Command example :
ffmpeg -acodec libopus -vcodec libvpx \
-i in.webm \
-vf scale=640:480 \
-acodec libvorbis -vcodec libvpx \
-threads 4 out.webmAlso I’ve tried to combine both commands using filter_complex, but it didn’t work.
I’ve worked with FFmpeg not so many time so far, so, maybe I’m doing something wrong ? Maybe there are some easier ways to do that ?
Since Kurento uses GStreamer for the video recording, so maybe it would be a better option to reconfigure Kurento to fix timestamp during the video recording ?
I can provide any videos and commands which I use.
I’m using :
Kurento Media Server 6.9.0,
FFmpeg 4.1 -
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avcodec/indeo2 : Check input size against resolution in ir2_decode_plane()
17 mars 2019, par Michael Niedermayeravcodec/indeo2 : Check input size against resolution in ir2_decode_plane()
Fixes : Timeout (56 sec -> 14 sec)
Fixes : 13708/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_INDEO2_fuzzer-5656342004498432Found-by : continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by : Michael Niedermayer <michael@niedermayer.cc> -
How can we merge two video in which one is horizontal resolution and other one is vertical resolution without stretching it using ffmpeg ?
26 février 2021, par Rohan PatilI want to make an application that merge two video, in which one video is of vertical resolution and other one is of horizontal resolution. I managed to merge but it leads to stretching of video which ideally shouldn't happen. Does anyone have any idea to do this ? Thank you !



command = new String[]{"-y", "-i", video1.mp4, "-i", video2.mp4,"-strict", "experimental", "-filter_complex",
 "[0:v]scale=1920x1080,setdar=4:3[v0];[1:v]scale=1920x1080,setdar=4:3[v1];[v0][0:a][v1][1:a] concat=n=2:v=1:a=1",
 "-ab", "48000", "-ac", "2", "-ar", "22050", "-s", "1920x1080", "-vcodec", "libx264", "-crf", "27", "-q", "4", "-preset", "ultrafast",output.mp4};