I try to extract specific frame and crop frame by one command using ffmpeg.

I use those answers:

https://video.stackexchange.com/questions/4563/how-can-i-crop-a-video-with-ffmpeg

https://superuser.com/questions/1009969/how-to-extract-a-frame-out-of-a-video-using-ffmpeg

The problem is that I can't use both commands. That is, only the first command is executed:

when I use this command the crop doesn't work:

from moviepy.config import get_setting

cmd = [get_setting("FFMPEG_BINARY"), "-i", url, "-filter:v", f"crop={x2-x1}:{y2-y1}:{x1}:{y1}", "-vf", "select=gte(n\,10)", "-vframes", "1",frame_dir_out]

When I use this command it crop only the first frame and not the frame number 10:

cmd = [get_setting("FFMPEG_BINARY"), "-i", url, "-vf", "select=gte(n\,10)", "-vframes", "1", "-filter:v", f"crop={x2-x1}:{y2-y1}:{x1}:{y1}" ,frame_dir_out]

How can I combine 2 filter:v/vf options into a single filter chain?

CodePudding user response：

-filter and -vf are equivalent options. In both examples, simple Filtergraphs (one input -> one output) in ffmpeg are used. They can be combined by concatenating the filter expressions separated by a comma:

cmd = [get_setting("FFMPEG_BINARY"), "-i", url, "-filter:v", f"crop={x2-x1}:{y2-y1}:{x1}:{y1},select=gte(n\,10)", "-vframes", "1",frame_dir_out]

Best regards, Marc