Recherche avancée

Sur d’autres sites (5808)

• How to extract time-accurate video segments with ffmpeg ?

  30 octobre 2023, par Jim Miller

  This is not a particularly new question area around here, but I've tried what's been suggested there without much luck. So, my story :

  


  I've got a hunk of 15 seconds of straight-from-the-camera.mov video out of which I want to extract a specific chunk, which I can identify by start time and stop time, in seconds. I started by trying to do what I'll call a "copy extraction" : to get seconds 9 to 12,

  


  ffmpeg -i test.mov -vcodec copy -acodec copy -ss 9 -to 12 test-copy.mov


  


  This was a not-bad start, but there are some black frames at the beginning and end of the clip, which I can't have — it has to be a clean edit from the original. So, I tried recoding the original into a new, trimmed clip :

  


  ffmpeg -i test.mov -ss 00:00:09 -t 00:00:03 test-out.mov


  


  This is better, but not quite : There are no longer any black frames at the beginning of the clip, but they're still there at the end.

  


  After some more browsing and reading, I then suspected that the problem is that ffmpeg is having trouble finding the proper points because of a lack of keyframes in the original video. So I recoded the original video to (presumably) add keyframes, in a couple of different ways. Since I want to be able to pick video at boundaries of a second ("from 9 seconds to 12 seconds"), I tried, copying various suggestions around the web,

  


  ffmpeg -i test.mov -force_key_frames "expr:gte(t, n_forced)" test-forced.mp4


  


  and

  


  ffmpeg -i test.mov -g 1 test-g-inserted.mp4


  


  (I built these as mp4's based on some comments about an mp4 container being needed to support the keyframe search, but I'm honestly just hacking here.) I then tried the extraction as before, but on these new videos that presumably now have keyframes in them. No luck — both seem to be about the same ; the start is OK but there are still black frames at the end. (FWIW, both test-forced.mp4 and test-g-inserted.mp4 also have trailing black frames.)

  


  So : I'm still stuck, and would like to not be. Any insights out there as to what I'm doing wrong ? I feel like I'm close, but I really need to get rid of those trailing black frames....

  


• Audio problems when resizing video - moviepy

  17 août 2020, par Jordan

  I am resizing an mp4 video with this code (moviepy) :

  


  video_clip = VideoFileClip(url)
resized = video_clip.resize(width=720)
d = tempfile.mkdtemp()
video_path = os.path.join(d, 'output.mp4')
resized.write_videofile(video_path)


  


  The resized clip's audio works when I play it on my pc, but not on an iPhone. (The original clip's audio does work on my iPhone.)

  


  How can I fix this ?

  


  First image : Codec of resized video
  
Second image : Codec of original video

  


  


  


• How would I delete a file after a remux has been completed using a batch automation file ? [closed]

  10 août 2024, par Voidmaster01

  Ive already automated the process of remuxing to a new file even with new names and all, but how would i go about deleting the original file after the process is completed. currently if i were to run the batch file it would supposedly delete the original file as it was starting the remux, also the remux can take anywhere from a couple of seconds to a couple of hours due to file sizes.

  


  @Echo off
set /p newname=Enter new file name:
ffmpeg -i "V:\Before Remux\01.mkv" -c copy -map 0 "M:\1 REMUX HUB\%newname%.mp4"
Del "V:\Before Remux\01.mkv"
pause


  


  Ive tried using the Del function to delete the file automatically but it deleted the file prematurely causing the file to not be completely processed.