问题
I need to resize input 3 (logo.gif) to 360x360, but using scale=360:360 just made my video quality really bad. Here's my code:
ffmpeg -y -hide_banner -safe 0 -f concat -i "concat.txt" -i "overlay.png" -i "audio.mp3" -ignore_loop 0 -i "logo.gif" -filter_complex "[0]scale=3840x2160,zoompan=z='if(lte(zoom,1.0),1.25,max(1.001,zoom-0.0012))':x='iw/2-(iw/zoom/2)':y='ih/2-(ih/zoom/2)':fps=20:d=200:s=1920x1080[p];[p][1]overlay, scale=1920:1080, drawtext=fontfile=Heathergreen.otf:text=TITLE':fontcolor=black:fontsize=62:x=135:y=940, drawtext=fontfile=voxbox.ttf:text='TEXT':fontcolor=white:fontsize=70:x=120:y=885[v];[2:a]showwaves=mode=cline:s=178x56:r=20:scale=sqrt:colors=0x222222,colorkey=0x000000:0.01:0.1,format=yuva420p[w];[v][3]overlay=20:500[z];[z][w]overlay=108:740[outv]" -map "[outv]" -map 2:a -pix_fmt yuv420p -c:v libx264 -c:a aac -preset veryfast -shortest -movflags faststart -fflags genpts -r 20 "output.mp4"
UPDATE: I've simply resized the image and used that as input rather than resizing during the encode. It works fine, but if anyone has an answer to this I'd be curious to know where I was going wrong.
回答1:
Instead of [v][3]overlay=20:500[z] you would use [3]scale=360:360[3v];[v][3v]overlay=20:500[z]. Your GIF should be square-shaped to begin with, to avoid distorting it.
来源：https://stackoverflow.com/questions/60481393/ffmpeg-how-to-resize-an-image-overlay