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Autres articles (38)
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Support audio et vidéo HTML5
10 avril 2011MediaSPIP utilise les balises HTML5 video et audio pour la lecture de documents multimedia en profitant des dernières innovations du W3C supportées par les navigateurs modernes.
Pour les navigateurs plus anciens, le lecteur flash Flowplayer est utilisé.
Le lecteur HTML5 utilisé a été spécifiquement créé pour MediaSPIP : il est complètement modifiable graphiquement pour correspondre à un thème choisi.
Ces technologies permettent de distribuer vidéo et son à la fois sur des ordinateurs conventionnels (...) -
HTML5 audio and video support
13 avril 2011, parMediaSPIP uses HTML5 video and audio tags to play multimedia files, taking advantage of the latest W3C innovations supported by modern browsers.
The MediaSPIP player used has been created specifically for MediaSPIP and can be easily adapted to fit in with a specific theme.
For older browsers the Flowplayer flash fallback is used.
MediaSPIP allows for media playback on major mobile platforms with the above (...) -
De l’upload à la vidéo finale [version standalone]
31 janvier 2010, parLe chemin d’un document audio ou vidéo dans SPIPMotion est divisé en trois étapes distinctes.
Upload et récupération d’informations de la vidéo source
Dans un premier temps, il est nécessaire de créer un article SPIP et de lui joindre le document vidéo "source".
Au moment où ce document est joint à l’article, deux actions supplémentaires au comportement normal sont exécutées : La récupération des informations techniques des flux audio et video du fichier ; La génération d’une vignette : extraction d’une (...)
Sur d’autres sites (4374)
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(FFMPEG) Make areas transparent before overlaying a vid with perspective
7 octobre 2020, par aaeimI'm trying to add perspective to a small video then overlay it on top of an other.



So far I can make the video small, add perspective to it and overlay it to an other video. but after applying the perspective filter, the excess areas don't turn transparent, they just stretch out the pixels.



the perspective filter doesn't have much documentation but as far as i could find out there was no way of setting the extra pixels to transparent.



So I'm guessing ill need to apply some kind of alpha mask, to the desired area ?



this is the command I'm using for perspective :



ffmpeg -i /synced_folder/testvid.mp4 -vf perspective=0:0:W:H/4:0:H:W:3*H/4:0:1:0 /synced_folder/output5.mp4




Don't think it matters but I'm running ffmpeg on a VM with centOS.



This is a SS of how the result looks like :


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(FFMPEG) Make areas transparent before overlaying a vid with perspective
3 août 2016, par aaeimI’m trying to add perspective to a small video then overlay it on top of an other.
So far I can make the video small, add perspective to it and overlay it to an other video. but after applying the perspective filter, the excess areas don’t turn transparent, they just stretch out the pixels.
the perspective filter doesn’t have much documentation but as far as i could find out there was no way of setting the extra pixels to transparent.
So I’m guessing ill need to apply some kind of alpha mask, to the desired area ?
this is the command I’m using for perspective :
ffmpeg -i /synced_folder/testvid.mp4 -vf perspective=0:0:W:H/4:0:H:W:3*H/4:0:1:0 /synced_folder/output5.mp4
Don’t think it matters but I’m running ffmpeg on a VM with centOS.
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Converting alpha channel of PNG sequence to Y channel of H265
31 mai 2018, par KrumelurI have a video renderer that expects two H265 streams (YUV420) and I need to bake them to have one of them form an alpha mask to the other one. This is all solved and works well, however if I follow the instructions here :
ffmpeg splitting RGB and Alpha channels using filter
the alpha channel is slighly off. My hypothesis is that this is due to the alpha channel being scaled through the RGB->YUV matrix.The input is a sequence of PNG files, the output is two MKV files.
The question is then : How can I tell FFmpeg to “reinterpret” the alpha channel as the Y channel without touching the pixel data ? Ideally by producing both MKV:s in one command line as shown in the other question, but at least without rewriting the source files.