Recherche avancée

Sur d’autres sites (7118)

• How to write frames to a video file ?

  20 juillet 2019, par Mike Chen

  I am currently writing an application that read frames from camera, modify them, and save them into a video file. I’m planing to do it with ffmpeg. There’s rarely a documentation about ffmpeg. I can’t find a way. Does any know how to do it ?

  I need it to be done on unix, and in C or C++. Does any can provide some instructions ?

  Thanks.

  EDIT :

  Sorry, I haven’t write clearly. I want some developer APIs to write frames to a video file. I open up camera stream, I get every single frame, then I save them into a video file with those APIs available in ffmpeg’s public apis. So using command line tool actually doesn’t help me. And I’ve seen output_example.c under the ffmpeg src folder. It’s pretty great that I may copy some parts of the code directly without change. And I am still looking for a easier way.

  Also, I’m thinking of porting my app to iPhone, as far as I know, only ffmpeg has been ported on iPhone. GStreamer is based on glib, and it’s all GNU stuff. I’m not sure if I can get it work on iPhone. So ffmpeg is still the best choice for now.

  Any comments is appreciated.

• Download youtube videos with youtube-dl/ffmpeg in php

  24 juillet 2019, par Baraque Obahamas

  I have been using youtube-dl for a long time, and I now want to install it on my dedicated server to make it easier for me to download content.

  I created a php script that allows me to download the video of my choice to the server, then I download it to my computer, pretty cool !

  I am now trying to improve this script in order to redirect only the feed to avoid uploading the video to the server.

  Example with this site : https://mpgun.com
  It seems to redirect the stream without downloading the video to the server. If you try to download a video that lasts 3 hours, the site will offer you the download immediately !

  I think ffmpeg allows you to do that, only I don’t know where to start in the code.

  Do you have any idea how to set this up in php ?

  Thank you

• How to detect a common scene in a set of videos with ffmpeg

  6 août 2019, par Hans J

  I have a set of videos that are assumed to contain a common (or very similar) scene. I want to be able to detect (with FFmpeg) what that common scene is, how long the scene is, and where the scene is in each individual video.

  The scene would be assumed to be longer than 10 seconds (This is an arbitrary choice, it can be changed).

  The final output of the command would include the various time-codes of the instance of the scene in each video. Assuming a timebase 1/1, with a common scene that is 60 seconds long, an output would along the lines of :

  Video1.mp4 0 60
  
  Video2.mp4 120 180
  
  Video3.mp4 50 110
  
  Video4.mp4 null

  where video4 does not contain any common scene.

  For example, I could have three episodes of a TV show. They all contain the same commercial. Without knowing what that commercial is, I want to be able to find where that commercial shows up in each of the episodes.

  Note : For the purpose of a good solution, the common scenes do not have to exactly match. Because there could be artifacts or embedded subtitles in one episode and not the other.