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• How to speed up my video creating/encoding pipeline

  23 septembre 2015, par user606521

  I am creating a video from 120 JPEG images and concatening it with intro video.

  • video (and images) dimmensions : 960x540
  • video/audio output format that I need : mp4 H.264, AAC

  I am creating video from JPEG images using following command :

  ffmpeg -f lavfi -i anullsrc -r 60 -i pipe:0 -y -acodec aac -strict experimental \
  
  -shortest -movflags frag_keyframe+empty_moov -f mp4 video.mp4

  It creates 2 seconds (120 frames with 60FPS) mp4 video with "silence" (silent audio). video.mp4 size is 94KB. This process takes 1 second. (Note that I am passing images through pipe:0).

  Next I concatenate it with existing intro.mp4 video (H.264, AAC, 931KB, lasts 6 seconds) using following command :

  ffmpeg -i intro.mp4 -i video.mp4 -y \
  
  -filter_complex "[0:0] [0:1] [1:0] [1:1] concat=n=2:v=1:a=1 [v] [a]" \
  
  -map "[v]" -map "[a]" -acodec aac -strict experimental \
  
  -movflags frag_keyframe+empty_moov -f mp4 final.mp4

  It creates final mp4 H.254, AAC video which lasts 2 + 6 = 8 seconds and it’s size 990KB. This process takes 3.5 seconds.

  So the whole process takes 5.5 seconds on my Mac. I have to speed it up, especially concatening videos. I am not familiar with video encoding and video formats, but I thought that maybe creating first video in mp4 and then concatening it with another mp4 video is not efficient. Are there any other formats in which I could create video (and intro) that will be faster to create/concatenate so I could encode only final video as mp4 ?

  For example I could create video.<format></format>, concatenate it with intro.<format></format> and finally encode it as final.mp4.

  Use case : I have to create videos in almost real time. 5.5 secs is ok on my Mac, but I have to execute my app on a weaker machine on which this process currently takes 3 + 15 = 18 seconds.

  Also maybe there are some cool flags I could pass to ffmpeg to make it faster ?

• Can't write video using moviepy. output format error

  23 décembre 2022, par Ronnie Kisor

  I'm trying to concatenate videos in each folder so that I get one video in each folder instead of multiple short ones. This is an external USB drive if that matters.

  


  My code seems to iterate over the files as expected, but I keep getting this error after the audio is written, during the "writing video" action, I believe : b"[NULL @ 000002a8340ae640] Unable to find a suitable output format for 'D:\\taxes\\folder\\test'\r\nD:\\taxes\\folder\\test: Invalid argument\r\n"

  


  I haven't found a way to force an output format yet. Any thoughts ?

  


  import os
from moviepy.editor import *

startingDir = r'D:\taxes'

avoid = ['0incomplete', 'old', 'that', 'this']

for thing in os.listdir(startingDir):
    clips = []
    name = ''
    
    if thing in avoid:
        print('                              avoided {}'.format(thing))
        continue

    folder = os.path.join(startingDir, thing)

    if os.path.isdir(folder):
        for clip in os.listdir(folder):
            print (clip)
            clips.append(VideoFileClip(os.path.join(folder, clip)))
        print('\n')

        try:
            final = concatenate_videoclips(clips)
            final.write_videofile(os.path.join(folder, 'test'), audio=True, codec='libx264', threads=10)
            final.close() 
        except Exception as e:
            print (e)
            print('\n Continuing... \n\n')
            continue


  


• How to trim and merge using Fluent FFMpeg ?

  29 juillet 2016, par John D.

  Here’s what I want to do with fluent-ffmpeg :

  I have 3 input files. An intro, main, and outro video. I wish to merge the three, while trimming the main video. Here is my code :

  var ffmpegCommand = ffmpeg();
  
  ffmpegCommand.addInput(introVideo);
  
  ffmpegCommand.addInput(mainVideo).seekInput(20).duration(3);
  
  ffmpegCommand.addInput(outroVideo);
  
  ffmpegCommand.on('error', function(err, stdout, stderr){
  
    console.log("FAILED!\n\t"+err+"\n\t"+stdout+"\n\t"+stderr);
  
  });
  
  ffmpegCommand.on('end', function(){
  
    console.log('COMPLETE!');
  
  });
  
  ffmpegCommand.on('start', function(commandLine) {
  
    console.log('Spawned Ffmpeg with command: ' + commandLine);
  
  });
  
  ffmpegCommand.mergeToFile('final.mp4', './vid_files/tmp');

  The program executes fine, but when I ffplay final.mp4, the result is that introVideo plays then the video appears to freeze. According to the fluent-ffmpeg documentation, it states "Each of these [Input options] methods apply on the last input added". So I can’t figure out why that syntax doesn’t seem to work...

  How can I trim the main video to send to mergeToFile ?

  Note that this works fine if I don’t have .seekinput(20).duration(3) on the second addInput.

  Oh, here’s the outputted commandLine value :

  ffmpeg -i ./vid_files/intro.mp4 -ss 20 -i ./vid_files/main.mp4 -i ./vid_files/outro.mp4 -y -filter_complex concat=n=3:v=1:a=1 -t 3 final.mp4