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• How to use FFMpeg -timestamp syntax

  6 janvier 2015, par reinhard.lee

  

  Hi, All !

       ffMpeg -timstamp 

  option works likes upper image ?
  07:21:54 07/07/05 white text in black box container.

  in ubuntu 12.04
  typed the excute like this.

       ffmpeg -y -f video4linux2 -s vga -r 30 -fs 1M -i /dev/video0 -timestamp now -copyts ./USB1_Test_vga.mp4

  but it doesn’t work.

  is there any other option for display video recorded time ?

• FFmpeg screencast recording : which codecs to use ?

  24 avril 2013, par mkaito

  I've been experimenting with recording screencasts using FFmpeg's X11grab module, which has worked more or less fine so far. I understand that a/v encoding is a complex process with many fine details, but I'm doing my best to learn.

  I'd like to do "lightweight" recording of a video stream, that puts as little strain as possible on the system while the stream is being recorded. I record two audio streams separately with pacat and sox. Later, the whole thing is filtered, normalized, encoded, and combined into a Matroska container.

  Right now, I'm having ffmpeg record a rawvideo stream to be fed to x264's yuv4 demuxer. I experimented with ffv1 and straight x264 recording before. My system can't handle real time encoding with x264 on the settings I want for the final stream, so I have to recompress separately once the recording is done. I've found that ffv1 gives me terrible frame dropping, and yuv4 too, but less so. I suspect this is due to hard drive speed, even if I'm sitting in a SATA3 Caviar Black that's being used exclusively to hold the recorded data.

  The question is, which combination of video codecs should I look at ? Record straight in x264 and recompress to "better" x264 later ? Raw video, then compress ? How would I go about pinpointing issues such as the frame drops I've been experiencing ?

  EDIT : This is the ffmpeg line I currently use.

  ffmpeg -v warning -f x11grab -s 1920x1080 -r 30000/1001 -i :0.0\
  
  -vcodec rawvideo -pix_fmt yuv420p -s 1280x720\
  
  -threads 0\
  
  recvideo.y4m

• Simple example of using ffmpeg to convert a movie into a format that can be viewed on Apple products

  16 janvier 2014, par ensnare

  I have a directory of AVI and MOV movies taken from my digital camera. I'd like to write a Python script to go through them, and for every AVI or MOV it finds, generate a file in place that can be viewed on Apple products (iPad, Apple TV, etc ...). My videos are 1080p, and I'm interested in preserving as much of the original quality as possible.

  Any examples of how to do this with ffmpeg ? Specifically, flags to pass to the executable ? Would I want to do a one or two-pass encoding (what's the difference ?)

  I'm hoping to do the scripting part in Python.