Recherche avancée

Sur d’autres sites (10262)

• How to trim a video recorded from mobile or picked from gallery.

  20 juillet 2020, par Amna Mirza

  Java android video ffmpeg trim
I want to trim a video just like trimmed in whatsapp, instagram or vine, where user can select the duration from below showing trim bar.

  



  I am also using FFMPEG, so once user selects the duration. But FFMPEG 
integartions are not going smooth. If any idea than leme know.

  


• pass ffmpeg options through mlt xml

  17 avril 2021, par carsten

  I'm looking at an MLT XML file that I created with kdenlive and would like to tweak the command line options passed to ffmpeg.

  


  If I understand correclty, this is the part that I need to edit :

  


   <consumer f="mp4" g="15" channels="2" crf="15" progressive="1" target="thetargetfile.mp3" threads="0" vcodec="libx264" ab="256k" movflags="&#x2B;faststart" bf="2" preset="faster" acodec="aac" in="0" out="18263"></consumer>&#xA;

  


  Now, I would like to pass an additional flag to ffmpeg, in my case -stillimage for still image optimization of the output (my file is a recorded slideshow presentation, so there's really no excuse for it being hundreds of MB large).

  


  Is there an option in that allows to just pass arbitrary flags to ffmpeg, or how else would I go about performing such an optimization ?

  


• How to use ffmpeg / x264 2-Pass encoding for multiple bitrate output files

  10 septembre 2019, par Jonesy

  While performing a 2-Pass encode to multiple output files I was receiving the error

  



  ratecontrol_init: can't open stats file 1 ffmpeg2pass-2.log


  



  My setup is to do a single first pass and then multiple second pass encodes to output files with different target bitrates using the same first pass results.

  



  ffmpeg -y -i $INPUT_FILE -an -vcodec libx264 -pass 1 -b:v 700k -f rawvideo /dev/null

ffmpeg -y -i $INPUT_FILE -i out-aud.mp4 \
$AUDIO_OPTIONS_P2 -vcodec libx264 -pass 2 -b:v 250k -f mp4 out-250.mp4 \
$AUDIO_OPTIONS_P2 -vcodec libx264 -pass 2 -b:v 500k -f mp4 out-500.mp4 \
$AUDIO_OPTIONS_P2 -vcodec libx264 -pass 2 -b:v 700k -f mp4 out-700.mp4


  



  This sequence resulted in the error listed above. What I discovered thru code-inspection is that ffmpeg/x264 looks for a different set of first-pass files for each second-pass encoding path. The first encoding path uses the set of files originally created

  



  ffmpeg2pass-0.log
ffmpeg2pass-0.log.mbtree


  



  The second encoding path requires first-pass files with the names

  



  ffmpeg2pass-2.log
ffmpeg2pass-2.log.mbtree


  



  The third encoding path requires first-pass files with the names starting with ffmpeg2pass-4*, etc.

  



  My solution was to create soft-links to the originally created set of files with the new names that were required for each pass before running the second-pass command.

  



  ln -s ffmpeg2pass-0.log ffmpeg2pass-2.log
ln -s ffmpeg2pass-0.log.mbtree ffmpeg2pass-2.log.mbtree
ln -s ffmpeg2pass-0.log ffmpeg2pass-4.log
ln -s ffmpeg2pass-0.log.mbtree ffmpeg2pass-4.log.mbtree


  



  This seems to work as it results in the output encodes that I needed. However, I don't know if this method is legitimate. Am I getting sub-optimal encoding results by using a first-pass output for one bitrate (700k) as the input to second-pass encodings for other bitrates ?