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• How to combine audio and output with python

  27 octobre 2023, par Jojo Momo

  This question was asked a few times a couple of years ago, but none of the solutions seem to work.

  


  This code creates a video output.mp4 which is the same as video.mp4, but it doesn't have any sound from audio.mp3 even when video.mp4 has sound in the first place.

  


  import moviepy.editor as mp

audio = mp.AudioFileClip("audio_output/audio.mp3")
video1 = mp.VideoFileClip("video.mp4")
final = video1.set_audio(audio)

final.write_videofile("output.mp4")


  


  If anyone knows of alternative methods without using moviepy please let me know ! (Or if you know why this isn't working)

  


• WMA Lossless and ProRes Encoder

  4 mars 2012, par Multimedia Mike — General

  The projects (FFmpeg / Libav) just got a WMA lossless decoder. For those keeping score, this means that there are open source methods for decoding every single one of Microsoft’s proprietary audio codecs (Windows Media Audio, or WMA) : WMA v1, WMA v2, WMA9/Pro, WMA Voice, and now WMA lossless. Currently, it’s only advertised to decode 16-bit audio (no 24-bit). Also, when I first tried it a few days ago, it didn’t decode the very end of the single sample file I concocted many years ago (luckynight.wma). But that might be cleared up by now.

  Some other recent developments in the projects that I wanted to call out : An encoder for the Apple ProRes encoder from Kostya ; XWD (X window dump) image decoding and encoding from Paul B. Mahol ; a Sun rasterfile encoder from Aneesh Dogra.

  And then there’s the new playback system for CDXL files, also courtesy of Paul B. Mahol. I wasn’t familiar with this format until I wrote this post, which is surprising, given the format’s vintage. This was a CD-ROM FMV format favored for Amiga computers. Here it is in all its 160x120x10fps glory :

  
  
  

  That’s the amigaball.cdxl sample available in the repository. The sample is 3835910 bytes large and plays for about 24 seconds. This yields a data rate of about 159 kbytes/second. So, yeah, single-speed CD-ROM FMV.

• Theora puts incorrect PTS presentation time on video with held frames

  17 mars 2012, par hexatron

  I have a problem with the packet PTS/DTS on OGG Theora videos with held frames.
  Theora tries to be clever about held frames by omitting duplicate frames
  and using the packet PTS/DTS (they are equal) to skip the held frame time.

  For example, a 2-second-long 10 fps video with frames
  
    A A A A A A A A A A B C D E F G G G G G
  
  should encode with PTS (the frame start) as (note the encoder adds some dup frames)
  
      A 0.0
  
      A 0.1
  
      B 1.0
  
      C 1.1
  
      D 1.2
  
      E 1.3
  
      F 1.4
  
      G 1.5
  
      G 1.9
  
  But libtheora (and ffmpeg) put an incorrect time stamp on frame B
  
  (the first frame following a the dup frames)
  
      B 0.6
  
  This causes video to hiccup on the mislabeled frame.
  
  
  
  My crude fix for this is to use
  
      current frame PTS =  (next frame PTS time) - (one frame time)
  
  and
  
      last frame PTS = duration - (one frame time)

  (I tried submitting a bug report for theora at xiph.org, as the theora site recommends, but could not figure out how to register for a login. I also noticed the reports were several years old, so decided to document this behavior here)