Newest 'ffmpeg' Questions - Stack Overflow

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• ffmpeg -itsoffset option has no effect

  30 avril 2014, par Dims

  I want to fix audio sync problems. I looked in MPC-HC that audio should be delayed by 2750 milleseconds.

  The following two commands

  ffmpeg -itsoffset +2.750 -i MyFile.avi -vcodec copy -ss 00:28:32 -to 00:29:30 MyFile2.avi
  ffmpeg -itsoffset -2.750 -i MyFile.avi -vcodec copy -ss 00:28:32 -to 00:29:30 MyFile2.avi
  

  give exactly the same result (video and audio non synchronized and shifted equally).

  I.e. -itsoffset option does not work.

  Why?

• What hardware can I use to convert MP4 files to MPEG2 transport streams ? All software solutions have failed

  30 avril 2014, par dsimms

  I have tried FFMPEG, as well as a number of other software encoders and converters. Nothing has worked so far.

  I have several MP4 files that I need to convert into MPEG2 transport streams to run on set top boxes. I'm hoping there is a hardware solution for this because all software solutions have failed. The output file doesn't run reliably without jitters and corruption on screen.

• How To Convert Bit Rate (VBR) Of MP3 File Using PHP ?

  29 avril 2014, par Dave

  Using php, I am trying to convert and overwrite an mp3 file using the following command....doesn't work.

  ffmpeg -i /Users/MacBookPro/Desktop/dragons.mp3 -ar 44100 -ab 128k -f mp3 /Users/MacBookPro/Desktop/dragons.mp3
  

  So even when I try the command from the terminal, the new mp3 file is only about 5 seconds (originally 3 minutes). What am I doing wrong & any ideas on how to get the command working?

  Thanks in advance!

• c# - best way stream images to a remote server ?

  29 avril 2014, par shikata

  I want to stream the user screen (of the computer using C# app) to a remote server (PHP) through an FLV player or any other way.

  I take a screenshot each 1 seconds, send it as base64 data to the remte server, then save it as X.jpg on the remote server, where X is an incrementing number.

  Once I reach 100 images, I use the command below in order to convert the images into a video :

  exec('ffmpeg -y -r 2 -f image2 -i img%d.jpg -r 20 temp.flv 2>&1 >/dev/null', $output, $exit_status);
  

  Once the video is created, I display it to the user and delete all files, then repeat the process again, and again in order to keep streaming.

  This way doesn't really work as expected and it has a lot of drawbacks.

  Is there any alternative way I can broadcast the taken screenshots to the remote client in his browser without having to convert the images to a video and play it and keep on repeating this process ??

• RTSP syntax for requesting video stream from IP Camera ?

  29 avril 2014, par TTGroup

  I'm using ffmpeg to request video stream from INGRASYS IP Camera, I'm using the follow syntax

  avformat_open_input(&pFormatCtx, "rtsp://192.168.1.100:554/stream1", NULL, NULL);
  

  The link syntax rtsp://192.168.1.100:554/stream1 is ok, but I want to do something bellow:

  1. How to insert username and password into above rtsp link?
  2. This rtsp link is ok to request the video stream, but with the codec, resolution and frame rate are corresponding with the current setting (configure on web) of camera. How do my application can get the stream with any codec (MJPEG/MPEG4/H264), resolution and frame rate without depending on the current setting of camera?

  Thank You!

  T&T