Recherche avancée

Sur d’autres sites (11211)

• Convert one PNG image to webm video with transparency and fade in and out effect

  11 août 2021, par Xiang Chen

  I have an image named c.png 
First I convert it to webm with transparency, use command :

  


  ffmpeg -framerate 1/9 -i c.png  -i c.mp3 -c:v libvpx-vp9 -pix_fmt yuva420p -lossless 1 out.webm


  


  Then I want add fade in and fade out to out.webm, but I used many command like this still not working :

  


  ffmpeg  -i out.webm -vf "fade=t=in:st=0:d=3:alpha=1" -c:v libvpx-vp9 -pix_fmt yuv420p -c:a copy out_ok.webm
ffmpeg -i out.webm -vf "fade=in:0:3:alpha=1" out3.webm

ffmpeg -c:v libvpx-vp9 -i out.webm -vf "fade=t=in:st=0:d=3:alpha=1" out_ok.webm

ffmpeg -c:v libvpx-vp9 -i out.webm -filter_complex "fade=t=in:st=0:d=3:alpha=1" -map "[v]" -lossless 1  -b 10M -r 30 all.web


  


  How do I fix that ?

  


  Thank you.

  


• FFmpeg create boomerang GIF effect from video trimmed Flutter

  3 septembre 2022, par nicover

  I have a 45seconds video file which I want to create a boomerang GIF from a trimmed part of the video, let's say from 20s to 23s.

  


  I tried to run in flutter a basic GIF command :

  


  " -i $videoInput -filter_complex ${"[0]reverse[r];[0][r]concat=n=2:v=1:a=0"} $gifOutput";


  


  But it was crashing every time without a short video file (OOM) :

  


  INFO: frame=  362 fps= 15 q=-0.0 size=  162048kB time=00:00:12.06 bitrate=110074.4kbits/s speed=0.514x
INFO: Skipping NAL unit 62
INFO: Skipping NAL unit 62
INFO: Skipping NAL unit 62
INFO: Skipping NAL unit 62
 * thread #50, queue = 'com.apple.root.default-qos', stop reason = EXC_RESOURCE RESOURCE_TYPE_MEMORY (limit=3072 MB, unused=0x0)
    frame #0: 0x0000000250474d60 libsystem_platform.dylib`__bzero + 64
libsystem_platform.dylib`__bzero:
->  0x250474d60 <+64>: dc     zva, x3
    0x250474d64 <+68>: add    x3, x3, #0x40
    0x250474d68 <+72>: subs   x2, x2, #0x40
    0x250474d6c <+76>: b.hi   0x250474d60               ; <+64>
Target 0: (Runner) stopped.


  


  Questions :

  


  


  • Can the video be trimmed and the boomerang GIF created in the same command ?

    


  


  • Can the GIF in the same command be scaled down (as compression for low res files) ?

    


  


  • Can preset like veryfast or medium be used for GIF creation or only for video ?

    


  


  


  Thanks in advance for any help

  


• Does FFmpeg Support Multiple Image File Inputs Using -i [closed]

  30 août 2023, par Lemons

  I've been working with simple video generation in ffmpeg using a set of .jpg files with irregular indexing. For example, my files might be named input8.jpg, input16.jpg, input24.jpg

  


  I'm aware that using glob format is the recommended way to generate an output .mp4 file from a set of input images with non-sequential indexing. Since I'm using Windows and glob isn't supported on Windows, I've produced my desired output using :

  


  cat *.jpg | ffmpeg -framerate 1/2 -i - -c:v libx264 -r 30 -pix_fmt yuv420p -y output.mp4


  


  I've been looking around for another solution that will effectively do the same thing as above and I tried the following :

  


  ffmpeg -framerate 1/2 -i input8.jpg -i input16.jpg -c:v libx264 -r 30 -pix_fmt yuv420p -y output.mp4


  


  Basically, just manually feeding in my input files using more than one -i. The command will run, but for some reason, it's producing a 2 second output video that only uses the first frame I passed in.

  


  I looked at FFmpeg's documentation and found that some options like -filter_complex support the use of multiple -i inputs, but I can't find any documentation or reason as to why normal video output from images doesn't let me use more than one -i. Is there something in the documentation I'm missing that can help me understand why that usage of the command is invalid ?