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• Recording with python librtmp RTMP shrinks. Please help because i´m asking for solution for 2 months and i cant solve this

  21 décembre 2022, par Yojuan

  The code for capturing a video stream using python librtmp is this :

  


  import librtmp

conn = librtmp.RTMP('rtmp://some_program', live=True)
conn.connect()
stream = conn.create_stream(update_buffer=True)
        
f = open("my_program.flv", 'wb')
while True:
    try:
        data=stream.read(1024)
        if data:
            f.write(data)
            f.flush()
    except:
        print("Error during stream")


  


  The duration of the program is of 1 hour, but when i play the video, the duration becomes in 59 min and 52 secs or 59 min and 56 secs.... but in the most cases the duration is 1 hour exactly.

  


  I noticed that the first record always is perfect but in some cases the second shrinks. (when i use the function for second time or more)

  


  First i thought the problem was on ffmpeg because i use it to encode the video but it isnt because the video without encoding (the raw capture) shrinks anyway and i have other program that capture the same video with duration of 1 hour every time.

  


  I want to know if somebody knows what happends. I suppose that there is a buffer that is not being emptied correctly or something like that. Please help !

  


• fluent ffmpeg => how to trim and concate parts of video into one output file without writing many output files. Make a most efficient solution

  30 avril 2024, par Shreyansh Gupta

  I'm currently working on a online video website and i need to make a quick preview of videos using random timestamps and duration of the video.

  


  Suppose the video is of 15 min then i want to cut out some parts like ->

  


  1. from 00:00:40 take out next 2s 
2. from 00:01:20 take out next 2s 
3. ... and so on until the new video becomes 15s


  


  How can i do this with fluent-ffmpeg in the nodejs project

  


  Can i get the most efficient way of doing this without writing many output files and then concating them separately and removing then later

  


  Only concating the trimmed videos in one output file and save when it is done.

  


  I also came through a solution that uses complex filters but i don't know how to use it

  


     ffmpeg("video.mp4")
  .complexFilter([
    ....// some filters here

  ])
  .on('end',  function () {
    console.log('files have been merged and saved.')
  })
  .on('error',function (err){
    console.log(err)
  }
  .saveToFile("output.mp4")```


  


• How do you get exactly equal segments when splitting an audio file using ffmpeg ? [duplicate]

  13 septembre 2022, par dev404

  I'm trying to split a WAV audio file into several 3 second segments.

  


  I tried the following, but I get files with irregular sizes that are slightly above or under 3 seconds :

  


  ffmpeg -i input.wav -c:a libvorbis -segment_time 3 -f segment output%d.ogg


  


  My files look like this :

  


  Duration: 00:00:03.01, start: 0.000000, bitrate: 125 kb/s
Duration: 00:00:03.01, start: 3.008435, bitrate: 132 kb/s
Duration: 00:00:02.99, start: 6.021224, bitrate: 129 kb/s
Duration: 00:00:02.99, start: 9.010794, bitrate: 130 kb/s
Duration: 00:00:03.01, start: 12.000363, bitrate: 128 kb/s
Duration: 00:00:03.00, start: 15.005896, bitrate: 134 kb/s
Duration: 00:00:03.02, start: 18.005624, bitrate: 135 kb/s
Duration: 00:00:02.98, start: 21.031474, bitrate: 131 kb/s


  


  Unfortunately the difference is significant enough that when I later try to chain them together, the gaps between some of them are clearly perceivable.

  


  I found these other two questions that mention similar problems, but they're converting video files not audio.

  


  ffmpeg not splitting into EXACT same length chunks

  


  How to get equal segment times using ffmpeg ?

  


  Is there something that could be used for audio files instead ?