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• libavcodec/webp : treat out-of-bound palette index as translucent black

  16 septembre 2014, par Pascal Massimino

  libavcodec/webp : treat out-of-bound palette index as translucent black
  See https://code.google.com/p/webp/issues/detail?id=206
  
  for a description of the problem/fix.
  Signed-off-by : Michael Niedermayer <michaelni@gmx.at>
  This patch makes the decoder follow the recommendation of the spec.
  
  There is some disagreement (see "[FFmpeg-devel] [PATCH] : libavcodec/webp")
  
  about what would be best to be written in the spec, so in case the spec
  
  is changed again, this potentially would need to be amended or reverted
  

  • [DH] libavcodec/webp.c

• ffmpeg overlay picture is a black rectangle

  6 juin 2023, par robert

  I'm trying to overlay several images over an existing video, with the first image coming in with a fade-in effect. But instead I'm getting a black rectangle in place of the picture. But if I skip the fade-in and just put [img0] after decrease like so decrease[img0] then it works (but without fade in)

  


  please advise. TY

  


  -y
-i "G:\...\Videos\BLANK.mp4" 
-i "G:\...\Front\1.jpg" 
-i "G:\...\Front\2.jpg" 
-i "G:\...\Front\3.jpg" 
-i "G:\...\Front\4.jpg" 
-i "G:\...\Front\5.jpg" 
-i "G:\...\Front\6.jpg" 

-filter_complex [1:v]scale=880:545:force_original_aspect_ratio=decrease,fade=t=in:st=2.6:d=1[img0];
[0:v][img0]overlay=x='if(lte(2.6-t,0),450,NAN)':y='if(lte(2.6-t,0),5,NAN)':enable='between(t,2.6,4)'[v0];
[2:v]scale=880:545:force_original_aspect_ratio=decrease[img1];
[v0][img1]overlay=x='if(lte(4-t,0),450,NAN)':y='if(lte(4-t,0),5,NAN)':enable='between(t,4,5.6)'[v1];
[3:v]scale=880:545:force_original_aspect_ratio=decrease[img2];
[v1][img2]overlay=x='if(lte(5.6-t,0),450,NAN)':y='if(lte(5.6-t,0),5,NAN)':enable='between(t,5.6,6.3)'[v2];
[4:v]scale=880:545:force_original_aspect_ratio=decrease[img3];
[v2][img3]overlay=x='if(lte(6.3-t,0),450,NAN)':y='if(lte(6.3-t,0),5,NAN)':enable='between(t,6.3,6.9)'[v3];
[5:v]scale=880:545:force_original_aspect_ratio=decrease[img4];
[v3][img4]overlay=x='if(lte(6.9-t,0),450,NAN)':y='if(lte(6.9-t,0),5,NAN)':enable='between(t,6.9,7.4)'[v4];
[6:v]scale=880:545:force_original_aspect_ratio=decrease[img5];
[v4][img5]overlay=x='if(lte(7.4-t,0),450,NAN)':y='if(lte(7.4-t,0),5,NAN)':enable='between(t,7.4,7.9)'[v5];

 -map [v5] -map 0:a -c:v libx264 -c:a copy "G:\...\Videos\ffmpeg\output.mp4"


  


• add black&silence to beginning of a video

  21 août 2020, par Richard

  Hi I am struggling to add black&silence to the begining of a video with ffmpeg. I did search a lot but they look too complex for me.
Below command is what I find to add black&silence to the end of of video, now how can I tune it to the beginning of a video ?

  


  ffmpeg -i input.mp4 -f lavfi -i color=s=1920x1080:d=10 -filter_complex [0:v][1]concat -af [0]apad -shortest output.mp4


  


  Looks I need to use adelay instead of apad, below is the command that makes sense to me, but the audio is not delayed.

  


  ffmpeg -i input.mp4 -f lavfi -i color=s=1920x1080:d=10 -filter_complex [1][0:v]concat -af [0]adelay=10  output.mp4


  


  Here is the input info and ffmpeg version :

  


  ffmpeg -i input.mp4 
ffmpeg version 4.2.1-static https://johnvansickle.com/ffmpeg/  Copyright (c) 2000-2019 the FFmpeg developers
  built with gcc 6.3.0 (Debian 6.3.0-18+deb9u1) 20170516
  configuration: --enable-gpl --enable-version3 --enable-static --disable-debug --disable-ffplay --disable-indev=sndio --disable-outdev=sndio --cc=gcc-6 --enable-fontconfig --enable-frei0r --enable-gnutls     --enable-gmp --enable-libgme --enable-gray --enable-libaom --enable-libfribidi --enable-libass --enable-libvmaf --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb     --enable-libopencore-amrwb --enable-libopenjpeg --enable-librubberband --enable-libsoxr --enable-libspeex --enable-libsrt --enable-libvorbis --enable-libopus --enable-libtheora --enable-libvidstab     --enable-libvo-amrwbenc --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libdav1d --enable-libxvid --enable-libzvbi --enable-libzimg
  libavutil      56. 31.100 / 56. 31.100
  libavcodec     58. 54.100 / 58. 54.100
  libavformat    58. 29.100 / 58. 29.100
  libavdevice    58.  8.100 / 58.  8.100
  libavfilter     7. 57.100 /  7. 57.100
  libswscale      5.  5.100 /  5.  5.100
  libswresample   3.  5.100 /  3.  5.100
  libpostproc    55.  5.100 / 55.  5.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'input.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf58.29.100
  Duration: 00:01:00.00, start: 0.000998, bitrate: 2526 kb/s
    Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt709), 1920x1080, 2394 kb/s, 24 fps, 24 tbr, 16k tbn, 48 tbc (default)
    Metadata:
      handler_name    : VideoHandler
    Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 124 kb/s (default)
    Metadata:
      handler_name    : SoundHandler
At least one output file must be specified


  


  Thanks !