Recherche avancée

Sur d’autres sites (6235)

• fixing (with ffmpeg) the chrominance position on a video after capturing

  23 mai 2016, par APLU

  I’m trying to convert some video from VHS to digital using an (old) video capture card (and obviously an old VHS player). Due to the input from my video capture card and the output available from the VHS, I have no other choice than capture with an S-Video cable to a computer.

  Almost everything works except a little mis-synchronization between chroma and luma which do not happen on TV.

  For example, in the original video, I have something like that :
  

  After capturing the video looks like this :
  

  As you may see, there is a little desynchronization of the chroma with the luma channel (I will say about 10 lines errors).

  I’m capturing with ffmpeg on a Linux system with the following commands :

  $ v4lctl setnorm PAL-BG

  $ v4lctl setinput S-video

  $ ffmpeg -y -f alsa -ac 2 -i pulse -f video4linux2 -i /dev/video0 -c:a pcm_s16le -vcodec rawvideo -t $duration -r 25 -loglevel error -stats /tmp/tmp.mkv

  I tried other input norm in v4l, tried an other VHS player, tried an other conversion cable from SCART to S-Video but it didn’t change anything,

  My question is simple : is there a way to fix this with a post-processing video filter in ffmpeg ?

  I already looked at the long list of video filter available in ffmpeg but I didn’t find anything.

  Also, please note I can’t apply filter during the capture commands (old capture cards, old cpu, ..), this is why I capture in rawvideo and native audio. When the capture is done I convert the video/audio into h264/vorbis, at this step I can apply as much as audio/video filtering needed (even if it include extracting chroma & luma to new files, fixing and merging again).

  Thanks !

• Resize videos in android

  18 février 2014, par Christopher Johnson

  I'm looking to resize videos captured using the MediaStore Intent after they have been saved to the SD card. I've done similar things with c# and ffmpeg and thought about using that with android but I've yet to be able to find a way to incorporate that into my eclipse running on my windows 7 machine.

  I'm a total *nix noob so all of the solutions that I've found for building ffmpeg into an android app are completely greek to me.

  Is there an alternative solution to ffmpeg that perhaps is already built into the android sdk for resizing videos ?

  I'm just looking for the path of least resistance here...

• raw h264 converts without audio but ip cam software plays with audio

  12 août 2017, par aesteve218

  Why when I convert .h264 raw files from the sd card on my ip cam they convert without audio stream. When I open the video through the proprietary software it will play the stream with audio so I know it’s there. Also on a ffprobe it only shows a single stream and lists no audio. I know that the cam uses adpmc for audio and most linux-distros don’t support it but I get the same when trying to use Windows. Any ideas ?