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• ffmpeg how to remove black borders when resizing an image

  3 juin 2021, par Mapg

  I am creating some thumbnails using FFmpeg and I see that some black borders are created when I resize them.

  


  I guess this is happening because the video source dimension doesn't match exactly the target dimension, so FFmpeg fills out the blank space with this black color.

  


  My question is ...

  


  Can I change this "black color" used by FFmpeg by default so I can match these extra borders added with the background of my application ?

  


  If this is not possible ...

  


  Can I convert these black borders to a transparent area so I can create a PNG to match my background which has a different color (a kind of light green)

  


  I have attached an example where you will see two black pixels height in the bottom zone of the picture.

  


  This is what I want to convert to transparent or being able to choose my own color.

  


  Any idea to solve this issue will be very helpful for me ?

  


  Thank you very much in advance !

  


  Mapg

  


  

  


• Batch process audio files and image files to create movie files by matching multiple wildcard values

  29 septembre 2022, par psychaudio

  I'm attempting to batch-process audio and image files to create video files using a Shell script with FFmpeg.

  


  

  1. The ffmpeg script works in Terminal :

  


  


  ffmpeg -loop 1 -i image.png -i audio.wav -c:v libx264 -tune stillimage -c:a aac -b:a 192k -pix_fmt yuv420p -shortest output.mp4


  


  

  2. A nested for loop with wildcards works as a batch script :

  


  


  #!/bin/sh
for img in *.png; do
    for wav in *.wav; do
        ffmpeg -loop 1 -i $img -i $wav -c:v libx264 -tune stillimage -c:a aac -b:a 192k -pix_fmt yuv420p -shortest ../mb/$img.mp4
    done
done


  


  The only problem here is that it creates more combinations than I need. I'd like to be able to match wildcard values and only mix those together. I'd like to be able to prepare the filenames to match in advance to make this easier : For example, only match 1.png with 1.wav to make 1.mp4, 2.png with 2.wav to make 2.mp4 and so on. I'm able to modify the script to match the wildcards in a Regex, but I'm not sure if there is a way to then execute the logic above. Here is what I am attempting :

  


  #!/bin/sh
img=*.png
wav=*.wav

if [[ ${img%.*} == ${wav%.*} ]];
    then
        ffmpeg -loop 1 -i $img -i $wav -c:v libx264 -tune stillimage -c:a aac -b:a 192k -pix_fmt yuv420p -shortest $img.mp4;
    else
        echo "Failure"
    fi


  


  This begins by overwriting the image files, so it does not appear to work as planned. Is there a simpler way to do this ? Perhaps looping through images 1..5 in one folder and audio files 1..5 in another ?

  


  Thanks for any insights, and happy to provide more context (very new to this, so still learning).

  


• stream_loop generate a big size video [FFMPEG]

  26 mars 2021, par Mouaad Abdelghafour AITALI

  I'm trying to loop a short video for e.g. 190 time to match the audio length, I use the following code :

  


  -y -stream_loop  190  -i input.mp4 -c copy output.mp4


  


  The command above works, but it generates video with huge size for video with 3min the size is 885 MB

  


  2021-03-25 23:52:30.445 5687-6253/maa.abc.music_maker D/XXX: LOOPING VIDEO SIZE ===> 885.845MB


  


  Or there's any way I can loop the video to match the audio length without using -stream_loop