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• Adobe connect video : FLV to MP4 (export, convert)

  4 mai 2022, par Guillaume Chevalier

  I would like to convert an adobe connect video from .flv in the downloaded zip to .mp4. I have already done the steps explained in this question and answer, however I get .flv files organised like this inside the .zip :

  



  

  



  Moreover, I know that ffmpeg can merge video and sound files together as well as concatenating resulting clips directly from the command-line which could be quite useful : https://www.labnol.org/internet/useful-ffmpeg-commands/28490/

  



  I can't ask the owner of the video to make it available as an .mp4 from within the adobe connect admin interface. Briefly, I would like to listen to those videos in x2 speed in VLC (just like what I do when listening to random math classes on YouTube - I put ON the x2 speed). The amount of time I would gain to watch adobe connect videos in x2 speed is MASSIVE.

  



  I think I am not the only one that would like to do this. There are a lot of questions on forums about downloading adobe connect videos, but the .flv format mixed with some .xml is generally a killer when the host does not make the videos properly available in .mp4.

  



  Dealing with the order of the .flv files is a puzzle. At least, I would not care to flush the chat away and leave some details like that behind, that would help to reconstruct the videos. Any scripts to automate the process would be useful.

  


• m4a/mp3 files to wav for Bing Speech API

  17 décembre 2018, par Waqas

  Bing Speech API only accepts wav files so I have been trying to convert m4a (Skype) and mp3 (Facebook) audio files I am getting in my chatbot to wav format. I am using fluent-ffmpeg in node.js.

  For now, I am downloading the audio file, converting it to wav and returning the piped output for use ahead.

  if (attachment.contentType === 'audio/x-m4a') {
  
    request.get(attachment.contentUrl).pipe(fs.createWriteStream('file.m4a'));
  
    var command = ffmpeg('file.m4a')
  
          .toFormat('wav')
  
          .on('error', function (err) {
  
              console.log('An error occurred: ' + err.message);
  
          })
  
          .on('progress', function (progress) {
  
              // console.log(JSON.stringify(progress));
  
              console.log('Processing: ' + progress.targetSize + ' KB converted');
  
          })
  
          .on('end', function () {
  
              console.log('Processing finished !');
  
          });
  
  
  
    return command.pipe();
  
  }

  Right now, the conversion works when I send the m4a file through the botframework-emulator on my pc. But when I specify my pc as the endpoint (through ngrok) and try to send the m4a file from the chat test at the bot framework developer end, ffmpeg returns an error :

  An error occurred: ffmpeg exited with code 1: file.m4a: Invalid data found when processing input

  But when I play the downloaded m4a file, it plays alright.

  The content URL is https in the second case if that matters.

  Kindly help me with two things :

  1. Downloading, Converting and Returning without storing anything on my end
  2. Downloading/Accessing m4a/mp3 files properly

  I am new to streams, pipes and ffmpeg and all the above code is after googling.

• Input seeking for frame at specified timestamp with Py-AV

  9 décembre 2019, par neonScarecrow

  I have a project already using Py-AV and am trying to replicate a specific ffmpeg command. The goal is to get a frame roughly around the specified timestamp.

  Here’s the ffmpeg commmand :
  https://trac.ffmpeg.org/wiki/Seeking

  ffmpeg -ss 14 -i https://some_url.mp4 -frames:v 1 frame_at_14_seconds.jpg

  Here’s my code :

      #return one frame around 14 seconds into the movie
  
      target_sec = 14 
  
      container = av.open('https://some_url.mp4', 'r')
  
      container.streams.video[0].thread_type = 'AUTO'
  
      video_stream = next(s for s in container.streams if s.type == 'video')
  
      time_base = float(video_stream.time_base)
  
      target_timestamp = int(target_sec / time_base) + video_stream.start_time
  
      video_stream.seek(target_timestamp)
  
      for frame in container.decode(video_stream):
  
          frame.to_image().save('frame_at_14_seconds.jpg')
  
          break

  Additionally, I have found any documentation about this, but does anyone know if either command (ffmpeg/av.open) is downloading the entire file to a tmp file behind the scenes. I’m looking for a less memory-intensive way to read a frame for every second in an up to 60 second video.