Recherche avancée

Sur d’autres sites (12129)

• How to solve file path error while using ffprobe to find length of video file in python ?

  4 février 2018, par Mitchell Faas

  So, I’m trying to find the length of a video file by the methods discussed here : How to get the duration of a video in Python ?, Using ffmpeg to obtain video durations in python. But in doing so I run in to a problem which I haven’t been able to solve : I get

  FileNotFoundError:[WinError 2] The system cannot find the file specified

  after trying a bunch of troubleshooting steps I’ve started running in IPython and in cmd seperately to see where things might break down. Using a stripped down version of this code in IPython gives me

  In [11]: subprocess.Popen([ffmpeg_path+'ffprobe'], stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
  
  Out[11]: 

  which seems to be fine, as is CMD at this point. So to adding slight complexity :

  In [17]: subprocess.Popen([ffmpeg_path+'ffprobe -i "F:/tst.mp4"'], stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
  
  ---------------------------------------------------------------------------
  
  FileNotFoundError                         Traceback (most recent call last)
  
   in <module>()
  
  ----> 1 subprocess.Popen([ffmpeg_path+'ffprobe -i "F:/tst.mp4"'], stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
  
  
  
  C:\Python\Anaconda3\lib\subprocess.py in __init__(self, args, bufsize, executable, stdin, stdout, stderr, preexec_fn, close_fds, shell, cwd, env, universal_newlines, startupinfo, creationflags, restore_signals, start_new_session, pass_fds, encoding, errors)
  
      705                                 c2pread, c2pwrite,
  
      706                                 errread, errwrite,
  
  --> 707                                 restore_signals, start_new_session)
  
      708         except:
  
      709             # Cleanup if the child failed starting.
  
  
  
  C:\Python\Anaconda3\lib\subprocess.py in _execute_child(self, args, executable, preexec_fn, close_fds, pass_fds, cwd, env, startupinfo, creationflags, shell, p2cread, p2cwrite, c2pread, c2pwrite, errread, errwrite, unused_restore_signals, unused_start_new_session)
  
      988                                          env,
  
      989                                          cwd,
  
  --> 990                                          startupinfo)
  
      991             finally:
  
      992                 # Child is launched. Close the parent's copy of those pipe
  
  
  
  FileNotFoundError: [WinError 2] The system cannot find the file specified
  
  </module>

  This crashes IPython. Running the very same command ffprobe -i "F:/tst.mp4" in CMD works like a charm.

  Here’s what I tried : Changing / to \ and \ , adding and removing quotes around the file path, changing the path to C :\tst.mp4.

  Running the command os.system(ffmpeg_path+'ffprobe -i "F:/tst.mp4") does work.

  What could possibly be going wrong here ?

• There is a video stream option and player. But can't find where to manage video and stream

  26 janvier 2018, par Chanaka De Silva

  I’m working on this repository. in this application, we can upload a video taken by a action camera or drone, and it uses GPS coordinates (lat,lang) and draw the path of the video in the map. And also we can play the video via the system too after upload.

  Bt the size of the video is too much high. So it take a lot of time to process video and also download and play when we host in a server. I wanted to reduce size. So I write this code.

  try {
  
  new ffmpeg('demo.mp4', function (err, video) {
  
      if (!err) {
  
          video
  
              .setVideoSize('50%', true, false)
  
              .setVideoFrameRate(30)
  
              .save('output.mp4', function (error, file) {
  
                  if (error) {
  
                      console.log("error : ", error);
  
                  }
  
                  if (!error)
  
                      console.log('Video file: ' + file);
  
              });
  
          console.log('The video is ready to be processed');
  
      } else {
  
          console.log('Error: ' + err);
  
      }
  
  });

  }

  But the issue is I can’t find where is the video coming from in this application. We need to pass like "demo.mp4" to my code as you can see. This is the index file if this application : https://github.com/chanakaDe/replay-lite/blob/master/frontend/index.html

  And this is the player file : https://github.com/chanakaDe/replay-lite/blob/master/frontend/player.js

  This is the file called api.js : https://github.com/chanakaDe/replay-lite/blob/master/frontend/api.js

  This file also has some video functions : https://github.com/chanakaDe/replay-lite/blob/master/gopro/index.js

  Please guys, sometimes you will see this questions as a silly question. But you have the repo to check and can you guys please check and let me know where to get a video file or stream to add my size reduce code ?

• ffmpeg find 1st frame where the video starts

  1er janvier 2018, par Zoltan Hernyak

  My colleague had several video files, which were resized and re-encoded with libx264. Then the video files were split into segments with ffmpeg as well - without reencoding them. Unfortunately. Is far as I understand, the video files were split not at keyframes. Now the videos start with playing audio immediately, and a video frame, which act as a picture, are shown without any change for about 2-4 secs, then (and only then) the video starts to play as well.

  My goal is to modify the video segments to start playing the video immediately - the audio part before the 1st keyframe can be dropped out. The problem is - I don’t know where the 1st keyframe is, where the video start playing. It seems it differs for every video now.

  I have several videos, so I need to write a script to do this. Is there any tool or something which can detect the index of the 1st frame where the video really starts ? Any help or advice is appreciated !