Newest 'ffmpeg' Questions - Stack Overflow

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• Re-Stream a MPEG2 TS PAL Stream with crtmpserver

  2 octobre 2011, par mblaettermann

  I want to build up some kind of stream wrapper:

  I own an old Dreambox PAL Sat Reciever with Networking. This stream I want to transcode to a lower resultion an restream it.

  My Goal is, to have a simple website, where this stream is embedded via rtmp.

  I thougt crtmpserver should be the right software. For now I have a site running and can play local files through jwplayer/crtmpserver.

  I am looking for a solution for this:

  httpUrl -> ffmpeg -> crtmpserver

  Is that possible? May I redirect the output of ffmpeg to a filed pipe, and crtmpserver could grab that? Or go with UDP?

  Any hints appreciated!!! Thanks!!

• ffmpeg - Output file does not contain any stream [migrated]

  2 octobre 2011, par Sandeep Chandy

  When I try to take Screenshots from an AVI file I get the above message with an empty jpg/png file. But Screenshots from MP4 files works with any problems.

  My OS is Debian.

  MP4 Command:

  ffmpeg  -itsoffset -4  -i test.mp4 -vcodec mjpeg -vframes 1 -an -f rawvideo -s 320x240 test.jpg
  

  AVI Command:

  ffmpeg  -itsoffset -4  -i test.avi -vcodec mjpeg -vframes 1 -an -f rawvideo -s 320x240 test.jpg
  

• why is a sony .mts file so large ?

  1er octobre 2011, par Kejia

  I don't know much about multimedia knowledge. I know sony .mts file is a type of H.264 container. I use ffmpeg to dump my .mts file into a .mpeg file. Except the .mpeg file is shrunk around 5 times smaller in size than .mts, the ffmpeg dump information on both files is identical. I am confusing why .mts files have large size. What important features are lost by my conversion?

  Thanks!

  Kejia

  ---

  Thanks to all answers.

  I checked the output of both again and found that there is one different place: bitrate. Then I definitely lost quality. Now I adjust the bit rate in terms of the expectation to displaying equipment---yes, considering displaying equipments is necessary (an expert's advice): $ ffmpeg -b 9498k -i my.mts my.mpg. Another interesting option is -ab, audio bit rate.

• Can I create a virtual webcam and stream data to it ?

  1er octobre 2011, par Brad Bahls

  I am looking to stream a video from ffmpeg to OpenCV (a video manipulation library) and I am stumped. My idea is to create a virtual webcam device and then stream a video from ffmpeg to this device and the device will in turn stream like a regular webcam. My motivation is for OpenCV. OpenCV can read in a video stream from a webcam and go along its merry way.

  But is this possible? I know there is software to create a virtual webcam, but can it accept a video stream (like from ffmpeg) and can it stream this video like a normal webcam? (I am working in a cygwin environment , if that is important)

• error is coming lib-faac-dev not found

  30 septembre 2011, par Rahul Mehta

  i installed faac from here http://sourceforge.net/projects/faac/files/faac-src/faac-1.28/faac-1.28.tar.gz/ and then m running this command which is giving me this error basicall i want to install ffmpeg with audio conversion for libmp3lame , means with audio conversion.

  sudo apt-get install build-essential subversion git-core checkinstall yasm texi2html libfaac-dev libjack-jackd2-dev libmp3lame-dev libopencore-amrnb-dev libopencore-amrwb-dev libsdl1.2-dev libtheora-dev libvorbis-dev libvpx-dev libx11-dev libxfixes-dev libxvidcore-dev zlib1g-dev
  
  Reading package lists... Done
  Building dependency tree
  Reading state information... Done
  E: Unable to locate package libfaac-dev
  

  following this article http://pasindudps.blogspot.com/2010/12/compiling-ffmpeg-in-ubuntu-1010.html