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Médias (21)
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1,000,000
27 septembre 2011, par
Mis à jour : Septembre 2011
Langue : English
Type : Audio
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Demon Seed
26 septembre 2011, par
Mis à jour : Septembre 2011
Langue : English
Type : Audio
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The Four of Us are Dying
26 septembre 2011, par
Mis à jour : Septembre 2011
Langue : English
Type : Audio
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Corona Radiata
26 septembre 2011, par
Mis à jour : Septembre 2011
Langue : English
Type : Audio
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Lights in the Sky
26 septembre 2011, par
Mis à jour : Septembre 2011
Langue : English
Type : Audio
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Head Down
26 septembre 2011, par
Mis à jour : Septembre 2011
Langue : English
Type : Audio
Autres articles (104)
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Soumettre améliorations et plugins supplémentaires
10 avril 2011Si vous avez développé une nouvelle extension permettant d’ajouter une ou plusieurs fonctionnalités utiles à MediaSPIP, faites le nous savoir et son intégration dans la distribution officielle sera envisagée.
Vous pouvez utiliser la liste de discussion de développement afin de le faire savoir ou demander de l’aide quant à la réalisation de ce plugin. MediaSPIP étant basé sur SPIP, il est également possible d’utiliser le liste de discussion SPIP-zone de SPIP pour (...) -
Emballe médias : à quoi cela sert ?
4 février 2011, parCe plugin vise à gérer des sites de mise en ligne de documents de tous types.
Il crée des "médias", à savoir : un "média" est un article au sens SPIP créé automatiquement lors du téléversement d’un document qu’il soit audio, vidéo, image ou textuel ; un seul document ne peut être lié à un article dit "média" ; -
ANNEXE : Les plugins utilisés spécifiquement pour la ferme
5 mars 2010, parLe site central/maître de la ferme a besoin d’utiliser plusieurs plugins supplémentaires vis à vis des canaux pour son bon fonctionnement. le plugin Gestion de la mutualisation ; le plugin inscription3 pour gérer les inscriptions et les demandes de création d’instance de mutualisation dès l’inscription des utilisateurs ; le plugin verifier qui fournit une API de vérification des champs (utilisé par inscription3) ; le plugin champs extras v2 nécessité par inscription3 (...)
Sur d’autres sites (10187)
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A Comprehensive Guide to Robust Digital Marketing Analytics
15 novembre 2023, par Erin — Analytics Tips -
Encode Frames to Video with C Library
31 juillet 2018, par NetherGraniteFor the sake of continuity, let us assume "RGB values" are the following :
typedef struct RGB {
uint8_t r, g, b;
} rgb;However, if you feel that a different color space is more appropriate for this question, please use that instead.
How might I go about writing 2D arrays of RGB values to a video in C given an output format and framerate ?
Before I continue, I should specify that I wish to be able to do this all within one program. I am trying to add functionality to an application that would allow it to compile videos frame by frame without having to leave it.
Additionally, my needs for this functionality are extremely basic ; I simply need to be able to set individual pixels to certain colors.
The closest I have come to a solution so far is the C library FFmpeg. Allow me to describe what I was able to learn on my own :
After looking through its documentation, I came across the function
avcodec_send_frame(avctx, frame)
, whose parameters are of the typesAVCodexContext*
andconst AVFrame*
respectively. If these are not the right tools for what I am trying to do, please ignore the rest of the question and instead point me towards what I should be using.However, I do not know which fields of
avctx
andframe
must be set manually and which do not. The reason I assume some do not is because both are extremely large structures, but correct me if I am wrong.Question 1 : What values of an
AVCodecContext
andAVFrame
must be set ? Of these, what is/are the recommended value(s) for each of them ?Additionally, I was only able to find instructions on how to initialize an
AVFrame
(usingav_frame_alloc()
andav_frame_get_buffer()
) but not for anAVCodexConstant
.Question 2 : Is there a proper way to initialize an
AVCodexConstant
? And just in case, is the method of initializing anAVFrame
described above correct ? Do any of the fields of either have a proper method of initialization ?Also, I was not able to find official documentation on how to take this
AVCodexConstant
(which I assume contains the video information) and turn it into a video. I apologize if the documentation for this is easy to find and I just missed it.Question 3 : How do I turn an
AVCodexConstant
into a file of a given format ?And, given my limited knowledge :
Question 4 : Are there any other parts to this process that I am missing, and do I have any of the above parts wrong ?
Please keep in mind that I found out about FFmpeg for the first time very recently, and as a result, I am a complete beginner to this. Additionally, my experience with C is very limited, so I would greatly appreciate it if you could note which files need to be included with
#include
.Feel free to even go as far as recommending something other than FFmpeg, just as long as it is written in C. I do not need power-user options, but I would greatly prefer flexibility in what audio and video file types the library can handle.
Addressing Potential Duplicates
I appologize for how long this section is ; I just want to have my bases covered. I heavily apologize, however, if this is in fact a duplicate of a question that I was just unable to find.
- ffmpeg C API documentation/tutorial [closed] — This question was too open-ended and received answers pointing the asker towards a tutorial at dranger.com, a tutorial that confusingly muddied the waters by focusing heavily on a graphics library of choice. Please do not take this as me saying it is bad ; I am just enough of a beginner that I could not wade through it all.
- Encoding frames to video with ffmpeg — Although this question seems to have been asking the same thing, it is geared towards Unreal Engine 4, and the asker provided sample code, making it difficult for me to understand which of parts of the accepted answer were necessary for me and which were not.
- How to write frames to a video file ? — While this also asked the same thing, the accepted answer simply provides a command instead of an explanation of code.
- YUV Raw frames to video stream — While the accepted answer for this question is a command, the question states that it is looking for a way to encode frames generated by C++ code. Is there some way to run commands in code that I haven’t been able to find ?
- Converting sequenced frames to video — Not only is the asker’s code written in Python, but it also seems to use already-existing image files as frames.
- How to write bitmaps as frames to H.264 with x264 in C\C++ ? — The accepted answer seems to describe a process that would take multiple applications, but I could be wrong as I am enough of a beginner that I am not sure exactly what it means other than Step 3.
- How to write bitmaps as frames to Ogg Theora in C\C++ ? — Although it isn’t a problem that the question specifies the ogg format, it is a problem that the accepted answer suggests libtheora, which appears to only work with ogg files.
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libavutil : add version component accessor macros
4 décembre 2015, par Reynaldo H. Verdejo Pinochetlibavutil : add version component accessor macros
Pretty standard macros, these should help libav*
users avoid repeating ver.si.on parsing code,
which aids in compatibility-checking tasks like
identifying FFmpeg from Libav (_MICRO >= 100 check).
Something many are doing since we are not
intercompatible anymore.Signed-off-by : Reynaldo H. Verdejo Pinochet <reynaldo@osg.samsung.com>