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• Revision 1480ba6f0a : Revert "Fix a bug in VP9Worker which leads to unit test hang." The caller shoul

  1er juillet 2014, par hkuang

  Changed Paths :
   Modify /vp9/decoder/vp9_thread.c

  
  
  Revert "Fix a bug in VP9Worker which leads to unit test hang."

  The caller should reset the state instead of letting worker
  to reset.

  This reverts commit 34b2ce15f95ee0944ebe6d569e7a9179a7e4cc5b.

  Change-Id : Idb546ea6386cffc44e98dee772900d21ab79710f

• ffmpeg, add static image to beginning and end with transitions

  14 mars 2021, par CreateChange

  ffmpeg noob here, trying to help my mother with some videos for real estate walkthroughs. I'd like to set up a simple pipeline that I can run videos through and have outputted as such :

  


  

  • 5 second (silent) title card ->

  


  • xfade transition ->

  


  • property walk through ->

  


  • xfade transition ->

  


  • 5 second (silent) title card

  


  


  Considerations :

  


  

  • The intro / outro card will be the same content.

  


  • The input walkthrough videos will be of variable length so, if possible, a dynamic solution accounting for this would be ideal. If this requires me to script something using ffprobe, I can do that - just need to gain an understanding of the syntax and order of operations.

  


  • The video clip will come in with some audio already overlaid. I would like for the title cards to be silent, and have the video/audio clip fade in/out together.

  


  


  I have gotten a sample working without the transitions :

  


  ffmpeg -loop 1 -t 5 -i title_card.jpg \
    -i walkthrough.MOV \
    -f lavfi -t 0.1 -i anullsrc \
    -filter_complex "[0][2][1:v][1:a][0][2]concat=n=3:v=1:a=1[v][a]" \
    -map "[v]" -map "[a]" \
    -vcodec libx265 \
    -crf 18 \
    -vsync 2 \
    output_without_transitions.mp4


  


  I have been unable to get it to work with transitions. See below for the latest iteration :

  


  ffmpeg -loop 1 -t 5 -r 60 -i title_card.jpg \
    -r 60 -i walkthrough.MOV \
    -f lavfi -t 0.1 -i anullsrc \
    -filter_complex \
    "[0][1:v]xfade=transition=fade:duration=0.5:offset=4.5[v01]; \
    [v01][0]xfade=transition=fade:duration=0.5:offset=12.8[v]" \
    -map "[v]" \
    -vcodec libx265 \
    -crf 18 \
    -vsync 2 \
    output_with_transitions.mp4


  


  This half-works, resulting in the initial title card, fading into the video, but the second title card never occurs. Note, I also removed any references to audio, in an effort to get the transitions alone to work.

  


  I have been beating my head against the wall on this, so help would be appreciated :)

  


• FFmpeg : replacing audio in live video stream

  28 janvier 2020, par Mathijs

  I’m using FFmpeg to encode and live-stream video captured through a DeckLink capture card. The video from the card comes with an audio stream, but I want to replace the audio stream with another. This other audio stream originates from the same source but is ran through an audio processor that adds a fixed delay. The audio is fed back in the pc that runs FFmpeg through a virtual soundcard (audio over IP, but to Windows it looks like a sound card).

  I know how to compensate for this fixed delay, but the issue is that audio and video drift slowly out of sync as the stream runs. I’m assuming this is due to the small difference in clock speeds between the virtual soundcard and the DeckLink card.

  I’ve tried the vsync option and the aresample filter in FFmpeg in an attempt to get audio and video to stay synced. However I haven’t succeeded in this yet. Is there a way to make FFmpeg resample the audio and/or drop/dup frames in order to get both streams to stay in sync ?

  Currently I’m running this command, which fails to stay in sync.

  ffmpeg.exe -f dshow -i audio="WNIP Input  1 (Wheatstone Network Audio (WDM))" -itsoffset 2.3 -f decklink -thread_queue_size 128 -i "DeckLink SDI (3)" -filter_complex "[1:v:0]bwdif,format=yuv420p,setdar=16/9,scale=-1:576:flags=bicubic[vidout];[0:a:0]aresample=min_comp=0.02:comp_duration=15:max_soft_comp=0.005[audioout]" -c:v libx264 -preset slow -crf 25 -maxrate 1200k -bufsize 2400k -map "[vidout]:0" -map "[audioout]:0" -vsync 1 -r 50 -g 90 -keyint_min 90 -sc_threshold 0 -c:a libfdk_aac -b:a 192k -ac 2 -f flv "rtmp://somewhere"