Recherche avancée

Sur d’autres sites (5058)

• Why do the results of my "ffmpeg -ss -to" split have audio but no video ?

  10 avril 2018, par BenKnght

  I am trying to split clips into short intervals (that I am reading in from a csv) using ffmpeg. The commands that I’m using look like this :

  ffmpeg -i filename.mp4 -ss 00:00:00.030000 -to 00:00:02.030000   
  
  -pix_fmt yuv420p -c copy new_filename.mp4

  This successfully splits the parent mp4 into many smaller mp4s, but the smaller files lose some or all of their video. Most of them end up being just audio. Some have video - but only for about half of the clip (the rest is black). The audio is always there. Any ideas why this might be happening ?

  A couple notes : I’m using ffmpeg 3.0.2. Also, I am creating this command as a Python list and running it with the following call

  subprocess.run(cmd, stderr=subprocess.STDOUT)

• creating simple DVD structure ?

  24 mars 2016, par Rambo Actionha

  I’m trying to make a DVD builder using C# , and I know that DVD’s have a specific structure which I tried to find and I couldn’t see any thing helpful , however , I found some half-completed posts about this structure , which indicate the following :

  • all DVD videos must be in ’.VOB’ format
  • all DVD Videos must be in a folder named "VIDEO_TS" and DVD audios in a folder named "AUDIO_TS" (specifically)
  • "VIDEO_T" and "AUDIO_TS" must be burned to a DVD disk that follows a special filesystem called [UDF][1]

  My question is If I managed to convert my video to suitable ".VOB" format , then I burn it to a disk after adding it to those folders , would it be playable in any DVD player ? I mean is this enough to have a simple DVD disk , and if it wouldn’t .. what would be the simplest DVD structure I can make ( without menus and chapters and other extra stuff ) ? any links related to DVD would be great

• How to extract video clip from larger video based on specific time and duration

  26 juillet 2022, par user19019404

  I have video clips that get created. Each video is recorded for 5 minutes and starts at a time e.g. 10:01:20 to 10:06:19 then the next video from 10:06:20 etc. These videos are recorded at a specific frame rate, be it 5 frames or 30 frames (its dependent on the platform making the recording). The net result is NOT a 5 minute video clip but might be a 2 minute video clip (where everyone moves very quickly in the view as a result of the frame rates). I cannot restrict a 1 to 1 recording as these are generated by external systems.

  


  I need to extract specific portions out of the video. For example I need to extract from 10:03:10 to 10:03:35 (25 seconds). This would equate to 10 seconds into the video up to 14 seconds into the video, in those 4 seconds of video, 25 real world seconds are displayed.

  


  My question is do you have any guidance as to how I can calculate that each second of recording actually means 10 or 12 seconds in real life, therefore go to this frame and record to this frame for example.

  


  I have been looking at cv2.CAP_PROP_FPS to get the video frame rates, CAP_PROP_POS_MSEC and CAP_PROP_FRAME_COUNT and believe the answer might lie there, but not sure.

  


  The thinking being if I work out the frame rate of the video, the total frames then I can divide the one by the other to get to how many frames make up real world seconds (this is where I fail). This way I can run from frame to frame as a result.

  


  Thank you