Newest 'ffmpeg' Questions - Stack Overflow

Les articles publiés sur le site

• ffmpeg copy video in video with a specific time

  13 février 2017, par Alkl

  Im new in this topic (beginner) and Im german... So it's a bit difficult to find the correct words...

  I'll try to explain what I've done and what I want to do:

  1. Extract video area from the original video converted in PRORES codec:

     ffmpeg.exe -i test.mkv -ss 00:06:21.99 -t 00:00:01.94 -async 1 -strict -2 -c:v prores_ks -pix_fmt yuva444p10le -profile:v 4444 -bits_per_mb 8000 -s 1920x1080 cut_video.mov

  2. Edit the cut in After Effects

  3. Convert the PRORES in Matroska

     ffmpeg.exe -i "C:\Users\Alex\Desktop\ffmpeg-20170202-08b0981-win64-static\bin\cut_video\cut_video.mov" -vcodec ffv1 -acodec pcm_s16le temp.mkv

  4. Replace the video area in the originale video file at the time 00:06:21.99...

  I spend 4 hours for the two commands... So I despair at the fourth step. Is it possible? Can you help me?

  I made a picture, so you can understand better what Im doing...: http://i.imgur.com/HqlNxzW.jpg

  Best regards from germany,

  Alex

• MacOSx - port install package warning

  13 février 2017, par beetlej

  I maybe installed ffmpeg package by port before, but have manually deleted the binary.

  After that, when I install any other package by port, it alway show a warning message:

  Warning: Error parsing file /opt/local/bin/ffmpeg: Error opening or reading file
  

  How can I fix that? I don't want to install ffmpeg anyway since I have build it myself.

• Audio conversion of CAF file

  13 février 2017, par John

  I am recording audio on the iPhone to a CAF file with kAudioFormatiLBC, the recording works fine.

  I want to be able to take a sample and also get it to convert to other formats after I have uploaded it to by ruby on rails webservice.

  I am trying to use sox but get:

  sox in.caf out.mp3

sox FAIL formats: can't open input file `in.caf': Supported file format but unsupported encoding.

  Similar with ffmpeg I get:

  Unable to find a suitable output format for 'in.caf'

  Any ideas?

  Thanks

• How to add a silent audio frame using av_audio_fifo_write ?

  13 février 2017, par Michael

  How do you add a silent audio frame to the audio fifo using ffmpeg function:

  int av_audio_fifo_write (AVAudioFifo *af, void **data, int nb_samples)
  

  How do you initialize the 'data' parameter?

• Piping PCM data from FFMPEG to another process with Python subprocess

  13 février 2017, par Pete Bleackley

  I am trying to transcribe a podcast. To do so, I am decoding the mp3 stream with FFMPEG, and piping the resulting PCM output to the speech recognition component. My code looks like this.

  mp3=subprocess.Popen(['ffmpeg','-i',audio_url,
                                '-f','s16le','-ac','1','-ar','16000','pipe:0'],
                                stdout=subprocess.PIPE)
  sphinx=subprocess.Popen(['java','-jar','transcriber.jar'],
                                  stdin=mp3.stdout,
                                  stdout=subprocess.PIPE)
  

  Where audio_url is the url of the mp3 file.

  When I try to run this, it hangs. It appears that feeding the decoded PCM data through the pipe has deadlocked. What can I do to fix this? The size of the output data is likely to be too big for subprocess.Popen.communicate to be an option, and explicitly calling mp3.stdout.close() has had no effect.