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• How To Use FFMPEG -filter_complex_script When Merging Multiple Videos With Different Resolution

  12 janvier 2021, par Matte

  Here's the command I'm using when merging two videos with different resolution, It works well

  


  $command = 'ffmpeg -i first.mp4 -i second.mp4 -filter_complex "[0:v]scale='.$originalDimensions.':force_original_aspect_ratio=decrease,pad='.$originalDimensions.':-1:-1,setsar=1,fps=30,format=yuv420p[v0]; [1:v]scale='.$originalDimensions.':force_original_aspect_ratio=decrease,pad='.$originalDimensions.':-1:-1,setsar=1,fps=30,format=yuv420p[v1]; 
  [v0][0:a][v1][1:a]concat=n=2:v=1:a=1[v][a]" -map "[v]" -map "[a]" -c:v libx264 -c:a aac -movflags +faststart '.$dupSavePath.' 2>&1';


  


  It works nice and the output has no issues.

  


  But now I want to merge multiple videos using a list of files.

  


  We can use concat command and provide the list.txt file having a path to all the other video files.

  


  I was going through the documentation and found that it's possible by using -filter_complex_script but have no idea how to make it work

  


  Here's the command I used so far but the output having audio sync errors

  


  ffmpeg -f concat -i downloads/list.txt -acodec ac3_fixed -vcodec libx264 -s 720x480 -r 60 -strict experimental output.mp4 2>&1


  


  I can use the filter-graph here but I want to do it using concat command because the number of input files may vary.

  


• avutils/vulkan : hwmap, respect src frame resolution

  21 janvier 2021, par Xu Guangxin

  avutils/vulkan : hwmap, respect src frame resolution
  fixes http://trac.ffmpeg.org/ticket/9055
  The hw decoder may allocate a large frame from AVHWFramesContext, and adjust width and height based on bitstream.
  
  We need to use resolution from src frame instead of AVHWFramesContext.
  test command :
  
  ffmpeg -loglevel debug -hide_banner -hwaccel vaapi -init_hw_device vaapi=va :/dev/dri/renderD128 -hwaccel_device va -hwaccel_output_format vaapi -init_hw_device vulkan=vulk -filter_hw_device vulk -i 1920x1080.264 -c:v libx264 -r:v 30 -profile:v high -preset veryfast -vf "hwmap,chromaber_vulkan=0:0,hwdownload,format=nv12" -map 0 -y vaapiouts.mkv
  expected :
  
  No green bar at bottom.
  

  • [DH] libavutil/hwcontext_vulkan.c

• FFmpeg : Batch convert all audio (mp3) in folder to video (mp4) with album artwork (but it down scales my resolution)

  9 février 2021, par unknownman

  I followed this source (FFmpeg : Batch convert all audio (mp3) in folder to video (mp4) with album artwork) and it works, but it down scales my album cover from 1425 x 1406 dimension to 400 x 396.

  


  My Batch code is

  


  echo off
for %%a in ("*.mp3") do (
  ffmpeg -i "%%a" -an -vcodec copy "C:\mp4\%%~na.jpg"
  "C:\ffmpeg\bin\ffmpeg" -loop 1 -i  "C:\mp4\%%~na.jpg" -i "%%a" -c:v libx264 -vf pad="width=ceil(iw/2)*2:height=ceil(ih/2)*2" -preset veryslow -tune stillimage -crf 18 -pix_fmt yuv420p -c:a aac -shortest -strict experimental -b:a 192k -shortest "C:\mp4\%%~na.mp4" )
pause


  


  Problem is I don't know how to fix "down scaling" thing, and I am sorry for stupid questions but I need to know it. I watched other errors or tried to understand codes from others but I am not doing it well.