Recherche avancée

Sur d’autres sites (21130)

• ffmpeg break up videos with frame persecond

  25 mai 2018, par jameshwart lopez

  Theres a command to extract images of a video providing frame per seconds

  ffmpeg -i "vide.mp4" -vf fps=1 frames/frame_%04d.png -hide_banner

  Is there a command in ffmpeg to cut video providing fps and save it as video(.mp4 / avi) file like the command above ?

  What i currently have is i created a method to cut the videos with start and endtime but i firstly created a method to get the length of a video so that i could cut the video base on how many frames that was generated by the above command.

   def get_length(self):
  
          """
  
          Gets the length of a video in seconds
  
  
  
          Returns:
  
              float : Length of the video
  
          """
  
  
  
          print("Getting video length: " + self.video_string_path)
  
          command = 'ffprobe -i "'+self.video_string_path+'" -show_entries format=duration -v quiet -of csv="p=0"'
  
          self.command = command
  
          length = str(cmd.execute(command)).strip()
  
          print("lenght: "+length+" second(s)")
  
          return float(length)
  
  
  
  def cut(self, start_time, duration, output_file_name = 'output_file_name.mp4', save_to =''):
  
          """
  
          Cut a video on a specific start time of the video and duration.
  
          Check ffmpeg documentation https://ffmpeg.org/ffmpeg.html for more information about the parameters
  
  
  
          Parameters:
  
              start_time : string
  
                  is the value of ffmpeg -ss with the format: 00:00:00.000
  
  
  
              duration : string | int | float
  
                  is the end point where the video will be cut. Can be the same with start_time format but it could also handle integer as in seconds
  
  
  
              output_file_name : string
  
                  is the file name once the file is save in the hardisk
  
  
  
              save_to : string | optional
  
                  is the directory where the file will be saved
  
  
  
          Returns:
  
              string: file location of the cutted video
  
  
  
          """
  
  
  
          self.make_sure_save_dir_exits(save_to)
  
          print('Cutting ' + self.video_string_path + ' from ' + start_time + ' to ' + str(duration))
  
          print('Please wait...')
  
          file = '"' + self.save_to + output_file_name + '"'
  
          command = 'ffmpeg -i "' + self.video_string_path + '" -ss ' + str(start_time) + ' -t ' + str(duration) + ' -c copy -y ' + file
  
          self.command = command
  
          cmd.execute(command)
  
  
  
          file_loc = self.get_save_to_dir() + output_file_name
  
          print('Done: Output file was saved to "' + file_loc + '"')
  
  
  
          return file_loc + output_file_name

• How to detetc hardware acceleration in ffmpeg

  19 décembre 2020, par Ali Razmkhah

  I am writing c++ program to screen record by ffmpeg 4.3 ! I need to detect hardware acceleration support such as h264_qsv or h264_nvenc without running ffmpeg.exe !

  


  I explored ffmpeg.exe source code and found no results ! some solutions are deprecated or dose not work on 4.3 !
As instance,

  


  avcodec_find_encoder_by_name("h264_qsv")


  


  returns null even it is exist and works properly !

  


• Problems using Cuda for video transcoding [closed]

  19 août 2022, par Jay Adlard

  I just bought a new pc as my faithful old windows 7 i7 laptop died. Now the laptop had both intel and nvidea gtx660m chips. When I transcoded video with handbrake the intel graphics managed 8fps when I changed over to the nvidia it managed 80fps and the graphics card got nice and hot so was obviously working.

  


  The new machine i bought is a i9 with an nvidea gtx780 running windows 10. When I tried to transcode some video hoping for it to use the cpu and Gpu but no joy,the card stays cool power usage is only a handful of watts higher than it running something simple.I had been using handbrake but I read it doesn’t support Cuda so why the laptop speeded up I don’t know. A friend of mine that is into ffmpeg came round found that ffmpeg reports no Cuda yet the card works fine in every other respect. Unlike the rest of the machine the graphics card wasn’t new but it looked like new…

  


  One thing to note I am not talking about nvenc as the quality is rather poor, no point in capturing uncompressed files cleaning them up and not using an encoder that will do 2 pass and an exhaustive search.
Can anyone recommend a reasonably priced encoder that will use the Cuda cores ?

  


  Has anyone got any idea what the problem is ?