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Video d’abeille en portrait
14 mai 2011, par
Mis à jour : Février 2012
Langue : français
Type : Video
Autres articles (78)
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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 -
XMP PHP
13 mai 2011, parDixit Wikipedia, XMP signifie :
Extensible Metadata Platform ou XMP est un format de métadonnées basé sur XML utilisé dans les applications PDF, de photographie et de graphisme. Il a été lancé par Adobe Systems en avril 2001 en étant intégré à la version 5.0 d’Adobe Acrobat.
Étant basé sur XML, il gère un ensemble de tags dynamiques pour l’utilisation dans le cadre du Web sémantique.
XMP permet d’enregistrer sous forme d’un document XML des informations relatives à un fichier : titre, auteur, historique (...) -
Encoding and processing into web-friendly formats
13 avril 2011, parMediaSPIP automatically converts uploaded files to internet-compatible formats.
Video files are encoded in MP4, Ogv and WebM (supported by HTML5) and MP4 (supported by Flash).
Audio files are encoded in MP3 and Ogg (supported by HTML5) and MP3 (supported by Flash).
Where possible, text is analyzed in order to retrieve the data needed for search engine detection, and then exported as a series of image files.
All uploaded files are stored online in their original format, so you can (...)
Sur d’autres sites (7677)
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ffmpeg : Preventing Unecessary Duplication of Frames In Overlay
10 avril 2018, par SuperUser_NoviceI’m using ffmpeg to overlay two videos. The overlay which sits in the top left corner is a collection of png images that act as a frame-counter and time-stamp for the video that the frames have been created around.
The problem I’m having is that the frames have been generated to exactly match the number of frames the video it is overlaid to has, that way the counter is accurate and frames can be analyzed later. Right now :
"ffmpeg", "-i", fmt.Sprintf("%s%s", CCME.PathsToUse[0], CCME.UnderlayVideo),
"-i", fmt.Sprintf("%s%s", CCME.PathsToUse[1], CCME.VideoName),
"-filter_complex", fmt.Sprintf("overlay=%s", CCME.OverlayPosition),
"-vsync", "0", "-y", "-strict", "-2",
fmt.Sprintf("%s%s.%s", CCME.PathsToUse[2], CCME.FinalVideoName, CCME.VidFormat(This is a go program running ffmpeg through exec thus the weird format) produces exactly the number of frames expected, but upon analyzing it, every third frame in the overlay video is dropped and the frame before it is duplicated, taking the correct frames place.
I’ve analyzed the overlay video on its own and it does not have any duplicated frames and the underlay videos frames do not duplicate either.
This behavior is confusing the rest of the program which is expecting an ordered set of frames and is instead getting repeats of one frame then a jump ahead to the frame it’s supposed to be at (It is also confusing me). Can anyone explain this behavior and perhaps let me know if there is a way to prevent this from happening ? Is there a problem with the arguments I’m passing to ffmpeg in the snippet that may contribute to this behavior ?
Command :
ffprobe -f lavfi -i "movie=inputvid.format,fps=fps=24[out0]" -show_frames -show_entries frame=pkt_pts_time -of csv=p=0
Please note the 1000fps reported by the videos window is wrong. Running ffprobe shows the video is actually 24 fps or 24/1.
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Convert H.264 Annex B to MPEG-TS
4 juin 2014, par LaneSO...
I have RAW H.264 video data captured via RTSP in a local file and I am attempting to playback the video in a Java FX application. In order to do this, I need to use Http Live Streaming.
I have successfully prototyped a Java FX architecture that can play a video via HLS with a local server using a local folder containing a .m3u8 (HLS index) file and collection of .ts (MPEG-TS) files. The last piece for me is to replace the .ts files with .264 / .h264 files and in the local server, perform the conversion / wrapping of the H.264 Annex B data into MPEG-TS.
I am having trouble figuring out what is required to get H.264 Annex B into MPEG-TS. I have found the following information...
"Annex B is commonly used in live and streaming formats such as
transport streams..."szatmary.org/blog/25
"Annex B of of the document specifies one such format, which wraps NAL
units in a format resembling a traditional MPEG video elementary
stream, thus making it suitable for use with containers like MPEG
PS/TS unable to provide the required framing..."wiki.multimedia.cx/ ?title=H.264
"Java FX supports a number of different media types. A media type is
considered to be the combination of a container format and one or more
encodings. In some cases the container format might simply be an
elementary stream containing the encoded data."docs.oracle.com/javafx/2/api/javafx/scene/media/package-summary.html
"Use the CODECS attribute of the EXT-X-STREAM-INF tag. When this
attribute is present, it must include all codecs and profiles required
to play back the stream..."developer.apple.com/library/ios/documentation/networkinginternet/conceptual/streamingmediaguide/FrequentlyAskedQuestions/FrequentlyAskedQuestions.html
It seems like I am missing something simple around Elementary and Transport Streams. I have used ffmpeg to convert my H.264 file into a TS file and try to understand the differences. I have an idea of the approximate format differences, but I am still lacking on the details to do it. Does anyone have a link showcasing this or know something simple about how to serve H.264 Annex B data over MPEG-TS ?
I am not looking to use a tool, I need to have a custom file format locally where I parse out the H.264 Annex B data and perform the format change in memory, on the fly. I know of a way to use ffmpeg with pipes to accomplish this, but I do not want to have any dependencies and performance is important.
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Convert H.264 Annex B to MPEG-TS
24 octobre 2019, par LaneSO...
I have RAW H.264 video data captured via RTSP in a local file and I am attempting to playback the video in a Java FX application. In order to do this, I need to use Http Live Streaming.
I have successfully prototyped a Java FX architecture that can play a video via HLS with a local server using a local folder containing a .m3u8 (HLS index) file and collection of .ts (MPEG-TS) files. The last piece for me is to replace the .ts files with .264 / .h264 files and in the local server, perform the conversion / wrapping of the H.264 Annex B data into MPEG-TS.
I am having trouble figuring out what is required to get H.264 Annex B into MPEG-TS. I have found the following information...
"Annex B is commonly used in live and streaming formats such as
transport streams..."szatmary.org/blog/25
"Annex B of of the document specifies one such format, which wraps NAL
units in a format resembling a traditional MPEG video elementary
stream, thus making it suitable for use with containers like MPEG
PS/TS unable to provide the required framing..."wiki.multimedia.cx/ ?title=H.264
"Java FX supports a number of different media types. A media type is
considered to be the combination of a container format and one or more
encodings. In some cases the container format might simply be an
elementary stream containing the encoded data."docs.oracle.com/javafx/2/api/javafx/scene/media/package-summary.html
"Use the CODECS attribute of the EXT-X-STREAM-INF tag. When this
attribute is present, it must include all codecs and profiles required
to play back the stream..."developer.apple.com/library/ios/documentation/networkinginternet/conceptual/streamingmediaguide/FrequentlyAskedQuestions/FrequentlyAskedQuestions.html
It seems like I am missing something simple around Elementary and Transport Streams. I have used ffmpeg to convert my H.264 file into a TS file and try to understand the differences. I have an idea of the approximate format differences, but I am still lacking on the details to do it. Does anyone have a link showcasing this or know something simple about how to serve H.264 Annex B data over MPEG-TS ?
I am not looking to use a tool, I need to have a custom file format locally where I parse out the H.264 Annex B data and perform the format change in memory, on the fly. I know of a way to use ffmpeg with pipes to accomplish this, but I do not want to have any dependencies and performance is important.