Recherche avancée

Sur d’autres sites (7885)

• fftools/sync_queue : make sure audio duration matches sample count

  22 mars 2023, par Anton Khirnov

  fftools/sync_queue : make sure audio duration matches sample count
  For audio AVFrames, nb_samples is typically more trustworthy than
  
  duration. Since sync queues look at durations, make sure they match the
  
  sample count.
  The last audio frame in the fate-shortest test is now gone. This is more
  
  correct, since it outlasts the last video frame.
  

  • [DH] fftools/sync_queue.c
  • [DH] tests/ref/fate/shortest

• Per second frame count using ffmpeg

  11 janvier 2023, par mab

  I need to count the number of frames in a video captured by a camera on a per-second basis. I haven't found a solution using ffmpeg or ffprobe (or something else) to output the number of frames per second (maintaining a constant frame rate is not guaranteed because of the capture mechanism and needs to be verified).

  


  So far, I've needed to run ffmpeg and ffprobe separately. First, I run ffmpeg to trim the video :

  


  ffmpeg -ss 00:00:00 -to <desired time="time" in="in" seconds="seconds"> -i  -c copy &#xA;</desired>

  


  Then, I run ffprobe to count the number of frames in the snippet :

  


  ffprobe -v error -select_streams v:0 -count_frames -show_entries stream=nb_read_frames -print_format csv 


  


  Is there one command to output the number of frames for each second in the video ?

  


• Unable To Get Frame Count Using ffmpeg To Stich To Beginning

  23 décembre 2022, par SopMe

  I am using Python to make a script with ffmpeg where the script exports the middle frame into a jpg file and then stitches it back into beginning of the video. This is my script

  


  video_filename = "test_video.webm"
import ffmpeg

# Open the input video file
input_video = ffmpeg.input(video_filename)

# Get the video stream from the input video
video_stream = next(s for s in input_video.streams if s.type == 'video')

# Get the total number of frames in the stream
num_frames = video_stream.frame_count

# Calculate the middle frame number
middle_frame = num_frames // 2

# Extract the middle frame from the input video
middle_frame_extract = input_video.trim(start_frame=middle_frame, end_frame=middle_frame+1).setpts('PTS-STARTPTS')

# Save the extracted frame to an image file
ffmpeg.output(middle_frame_extract, 'middle_frame.jpg').run()

# Open the image file
middle_frame_image = ffmpeg.input('middle_frame.jpg')

# Concatenate the image file with the rest of the video
output_video = ffmpeg.concat(middle_frame_image, input_video, v=1, a=0).setpts('PTS+STARTPTS')

# Save the output video to a file
ffmpeg.output(output_video, 'output.mp4').run()


  


  I get this error though

  


  AttributeError                            Traceback (most recent call last)&#xA;&#xA; in <module>&#xA;      6 &#xA;      7 # Get the video stream from the input video&#xA;----> 8 video_stream = next(s for s in input_video.streams if s.type == &#x27;video&#x27;)&#xA;      9 &#xA;     10 # Get the total number of frames in the stream&#xA;&#xA;AttributeError: &#x27;FilterableStream&#x27; object has no attribute &#x27;streams&#x27;&#xA;&#xA;</module>

  


  The issue is that there is little documentation to do this and I only found this snippet of code online. How do I modify it to make it work for my use case ?