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• FFMPEG FDKAAC and Python

  3 avril 2024, par Eric Barker

  Been banging my head against the wall for days on this. I'm writing a python program to take a 48kHz WAV file, convert it to 44.1kHz and encode it to HE-AAC via FDKAAC. FDK cannot convert to sample rates, so I'm using FFMPEG as the wrapper and piping it through FDKAAC. In a perfect world, I'd make a custom build of FFMPEG with FKD, but I've run into loads of issues on our Windows Server 2019 machine trying to build out FFMPEG, so I'm using vanilla FFMPEG with FDK piped in.

  


  I can get the command to work perfectly from a command prompt :

  


  ffmpeg -progress pipe:2 -i  -f wav -ar 44100 - | fdkaac -p 5 -b 64000 -o 


  


  But when I try to split it in Python for a Popen, it tries to evaluate the arguments and fails because ffmpeg doesn't have a "-p" argument :

  


  cmd = ['ffmpeg', '-progress', 'pipe:2', '-i', inFile, \
    '-f', 'wav', '-ar', '44100', '-', '|', \
    'fdkaac', '-p', '5', '-b', '64000', '-o', outFile]
fdkProcess = subprocess.Popen(cmd,
            stdout=subprocess.PIPE,
            universal_newlines=True)
for line in fdkProcess.stdout:
    print(line)


  


  RESULT :

  


  Unrecognized option 'p'.
Error splitting the argument list: Option not found


  


  I'll admit, I don't fully understand the pipeline process, and how to split commands via the "|" flag, and have them properly feed into stdout for the subprocess function to work correctly. I'm fairly new to python, and very new to programmatically capturing the output of a process like ffmpeg.

  


• How to convert audio/music to video with static image (commandline) [closed]

  8 mai 2013, par lefterav

  I have an audio file which I would like to convert to a video. If possible, I would like to use a static image for appearing at the video. I have investigated a couple possible solutions, but non of them is fully functional.

  This solution in previous thread

  ffmpeg -loop_input -shortest -y -i image8.jpg -i sound11.mp3 -acodec copy -vcodec mjpeg result.avi

  does not work any more, as it does not extend the video to the duration of the audio file. Additionally, ffmpeg complains that it is deprecated and suggests to use avconv instead.

  avconv -i sound11.mp3 -strict experimental -i 341410.jpg -map 0:a  out.mp4

  but the image does not appear

  Finally I have tried with gstreamer

  gst-launch filesrc location=deltio.mp3 ! mp3parse ! mp4mux name=mux filesink location=output.mp4  filesrc location=341410.jpg ! jpegdec ! x264enc ! mux.

  but I get an error

  ERROR: from element /GstPipeline:pipeline0/GstX264Enc:x264enc0: Can not initialize x264 encoder. 
  
  Additional debug info: gstx264enc.c(1269): gst_x264_enc_init_encoder (): /GstPipeline:pipeline0/GstX264Enc:x264enc0 
  
  ERROR: pipeline doesn't want to preroll.

  Since I want to include this conversion into a Python script, the latter solution seems the best, as there is a Python wrapper for GStreamer

• How to insert lots of small looped videos or GIFs in HTML (thousand or more), but keep decent quality and page size ?

  10 novembre 2020, par Armen Avakian

  I need to place a thousand of small GIFs (20x20 pixels or slightly bigger) in the HTML. Almost all of them are visible at once, when page is loaded. There are several ways I tried, but each one has a problem.

  


  Way 1. Placing GIF images. GIFs are inefficient and heavy, so a lot of traffic will be needed to load the page. WEBP is better, but it is not supported fully in recent versions of Safari. So I made GIFs smaller, with low quality. In Safari I am loading this low quality GIFs, in other browsers I load WEBP. And it works nice, but the problem is that with a thousand of small GIFs, a user will need to load more than 600 MB for this page... So this way is... not as good. I can make them even lower in quality, but I don't want to make experience worse. Even now the quality is average.

  


  Way 2. Making MP4 and embedding them into looped video tags with autostart, so they look like a GIF. This way would be AWESOME, because MP4 is much smaller in size, but it keeps good quality. The problem here is when I add even 10-15 small videos in tags, the browser can't manage with it and starts working veeeery slowly. Each video is becoming very slow. So the experience is even worse than with low quality GIFs.

  


  My question is – how to achieve best way in this case, keeping decent quality and low sizes for each video ? Maybe I can use somehow MP4 videos in another way ? Does anyone know how to solve this issue ?

  


  For scaling videos and converting to GIF/WEBP I use ffmpeg.