encodingffmpegx264

Better way to use ffmpeg with vidstab and encoding 2 pass


I scan old 8mm films so I have folder with set of jpeg

I transform them to films using ffmpeg ( I choose x264 2 pass encoding)

//On all folder that start by 1 I launch the pass1 for x264

for f in 1*/ ; do cd "$f"; ffmpeg -y -r 18 -i img%05d.jpg -c:v libx264 -s 1200x898 -b:v 3000k -pass 1 -an -f mp4 /dev/null; cd ..; done

//On all folder that start by 1 I launch the pass2 x264

for f in 1*/ ; do cd "$f"; ffmpeg -y -r 18 -i img%05d.jpg -c:v libx264 -s 1200x898 -b:v 3000k -pass 2 ../"`echo ${PWD##*/}`.mp4"; cd ..; done

--> Before I have set of folder with jpeg

1965-FamilyStuff01\img1111.jpg,..,img9999.jpg

1965-FamilyStuff02\img1111.jpg,..,img9999.jpg

and I get

1965-FamilyStuff01.mp4

1965-FamilyStuff02.mp4

then I discover vidstab that also need 2 pass

// Stabilize every Video of a folder

mkdir stab;for f in ./*.mp4 ; do echo "Stabilize $f" ; 
ffmpeg -i "$f" -vf vidstabdetect=shakiness=5:accuracy=15:stepsize=6:mincontrast=0.3:show=2 -y -f mp4 /dev/null; 
ffmpeg -i "$f" -vf vidstabtransform=smoothing=30:input="transforms.trf":interpol=linear:crop=black:zoom=0:optzoom=1,unsharp=5:5:0.8:3:3:0.4 -y "stab/$f" 
; done; rm transforms.trf;

But I ask myself, that perhaps the order is not correct or perhaps there is a way to do the encoding with vidstab in less than 4 pass (2 pass for x264 encoding then 2 pass for vidstab) or perhaps the order should be change to optimize quality of film output)


Solution

  • You will need to run two commands to use vidstab. But x264 does not need two-passes for best quality. Two-pass encoding is used to target a specific output file size. Just use a single pass with the -crf option.

    So you only need to use two commands:

    ffmpeg -i input.mp4 -vf "scale=1200:-2,vidstabdetect=shakiness=5:accuracy=15:stepsize=6:mincontrast=0.3:show=2" -f null -
    ffmpeg -i input.mp4 -vf "scale=1200:-2,vidstabtransform=smoothing=30:interpol=linear:crop=black:zoom=0:optzoom=1,unsharp=5:5:0.8:3:3:0.4,format=yuv420p" -crf 23 -preset medium output.mp4
    

    See FFmpeg Wiki: H.264 for more info on -crf and -preset.