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Autres articles (29)
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Publier sur MédiaSpip
13 juin 2013Puis-je poster des contenus à partir d’une tablette Ipad ?
Oui, si votre Médiaspip installé est à la version 0.2 ou supérieure. Contacter au besoin l’administrateur de votre MédiaSpip pour le savoir -
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 (...) -
Support de tous types de médias
10 avril 2011Contrairement à beaucoup de logiciels et autres plate-formes modernes de partage de documents, MediaSPIP a l’ambition de gérer un maximum de formats de documents différents qu’ils soient de type : images (png, gif, jpg, bmp et autres...) ; audio (MP3, Ogg, Wav et autres...) ; vidéo (Avi, MP4, Ogv, mpg, mov, wmv et autres...) ; contenu textuel, code ou autres (open office, microsoft office (tableur, présentation), web (html, css), LaTeX, Google Earth) (...)
Sur d’autres sites (6405)
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Parsing avconv/ffmpeg rawvideo output ?
23 avril 2013, par DigitalManI'm about to begin a project that will involve working with the output of avconv/ffmpeg, pixel-by-pixel, in rgb32 format. I intend to work with a raw byte stream, such as from the
pipe
protocol. Basic pointer arithmetic (C/C++) will be used to iterate over these pixels, and modify them in arbitrary manners in real-time.I've created a very small file using rawvideo format and codec, and opened it up in a hex editor. As expected, it's just a series of pixels, read right to left, top to bottom. No distinguishing between lines - no problem, if you know how wide the video is beforehand. No distinguishing between frames - no problem, if you also know how tall the video is. No file header for frame rate, or even what the encoding (rgb32, rgb24, yuv, etc.) is - again, as long as you already know, it can be worked with.
The problem occurs when - for one reason or another - some bytes are missing. Maybe the stream isn't being examined from the beginning, which is likely be the case in my project, or maybe something just got lost. All the pre-existing knowledge in the world (besides maybe a byte count of what's been missed, not gonna happen) won't prevent it from happily chugging along, with an incorrect offset of line and frame.
So, what I'm looking for is an option for rawvideo, or possibly some other format/codec, that will allow me to work with the resulting stream at the pixel level, in RGB, yet still have a clear definition of where a new frame begins, even if it happens to start "looking" in the middle of a frame. (Width, height, and framerate will indeed be known.)
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ffmpeg is overlying images when making movie from png files of an evolving chart
15 octobre 2020, par James CarrollI am trying to make a movie of a series of charts as they change through time. I have 30 or so still versions of the chart in .png format.


But when I combine them into a movie, the charts are progressively overlaid on top of each other, rather than progressing through time.


I have tried several variations including :


ffmpeg -r 1 -f image2 -start_number 0 -i name%2d.png -q:v 5 movie.wmv



and


ffmpeg -r 1/5 -start_number 1 -i name%2d.png -c:v libx264 -r 30 -pix_fmt yuv420p out.mp4



All do the same thing.


Any idea why this is happening ?


Update 1 :


git repo of sample images and failed movie here : https://github.com/jlc42/MovieTest.git


Update 2 :


Just in case, I tried removing the alpha channel with the following command which I found in another thread Remove alpha channel in an image :


for i in `ls *.png`; do convert $i -background black -alpha remove -alpha off $i; done



because my background is white, I also tried :


for i in `ls *.png`; do convert $i -background white -alpha remove -alpha off $i; done



I THINK I have now successfully removed the alpha channel in the images, but this did not seem to make a difference for what ffmpeg is doing.


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How to create video by stitching together images (.png) where the serial on each image file increases by 6
10 avril 2024, par DataStatsExplorerI am trying to create a video (preferably mp4) from a series of png images. However, the name of each image file increases by 6 every frame. For example, I would have depthframe_0000 as the first frame, and depthframe_0001 for the next frame.


There are a few answers that have answered a similar question but I am unable to process the video when the image files are not increasing by 1.


I would like to keep the fps at 5. I am using ffmpeg as the suggested in the answers above but am open to any other suggestion.


The collab code that I have put together is as follows :


import subprocess

# Define the frame rate and the input/output paths
output_fps = 5
input_path = "/content/drive/MyDrive/depth/depthframe_%04d.png"
output_path = "/content/drive/MyDrive/depth.mp4"

# Create a list of the frames
frames = [input_path % i for i in range(0, 2671, 6)] # Update range as needed

# Write the list of frames to a temporary text file
with open('frames.txt', 'w') as f:
 for frame in frames:
 f.write(f"file '{frame}'\n")

# Create the command
command = [
 "ffmpeg",
 "-f", "concat",
 "-safe", "0",
 "-i", "frames.txt",
 "-c:v", "libx264",
 "-pix_fmt", "yuv420p",
 output_path
]

# Run the command
subprocess.run(command, check=True)