我的目标是使用 ffmpeg complex_filters 来做到这一点：
我有一个 1080 视频背景，喜欢插入一些叠加图形和文本。所以我的输入是 vid 和 2 个 jpg 文件。文件应滑入背景视频上方的位置，同时淡入，停留几秒钟，然后淡出。此外，还应显示文本。
我的主要问题是，它只适用于一个输入 jpg，但是当我添加第二个块时，我在这里遇到了一个错误：
[fc#0 @ 000001bf9d0d0c00] Stream specifier 'merge1C:v' in filtergraph description [1:v]format=pix_fmts=yuva420p,scale=765:1083,fade=in:st=0:d=1:alpha=1 [overlay1A], [0:v][overlay1A] overlay=x='if(lte(-w+(t)*1065,300),-w+(t)*1065,300)':y=300:enable='between(t,0,1):shortest=1'[merge1A]; [1:v]format=pix_fmts=yuva420p,scale=765:1083,fade=out:st=3:d=1:alpha=1 [overlay1B], [merge1A][overlay1B] overlay=300:300:enable='between(t,1,4)':shortest=1[merge1B]; [merge1B] drawtext=alpha=if(lt(t\,0.3)\,0\,if(lt(t\,1.3)\,(t-0.3)/1\,if(lt(t\,3)\,1\,if(lt(t\,4)\,(1-(t-3))/1\,0)))):fontcolor=ffffff:fontsize=64:text=test:x=200:y=200 [merge1C]; [2:v]format=pix_fmts=yuva420p,scale=765:1083,fade=in:st=4:d=1:alpha=1 [overlay2A], [merge1C:v][overlay2A] overlay=x='if(lte(-w+(t)*1065,300),-w+(t)*1065,300)':y=300:enable='between(t,4,5):shortest=1'[merge2A]; [2:v]format=pix_fmts=yuva420p,scale=765:1083,fade=out:st=7:d=1:alpha=1 [overlay2B], [merge2A][overlay2B] overlay=300:300:enable='between(t,5,8)':shortest=1[merge2B]; [merge2B] drawtext=alpha=if(lt(t\,4.3)\,0\,if(lt(t\,5.3)\,(t-4.3)/1\,if(lt(t\,7)\,1\,if(lt(t\,8)\,(1-(t-7))/1\,0)))):fontcolor=ffffff:fontsize=64:text=test:x=200:y=200 [merge2C]; matches no streams.
Error initializing complex filters: Invalid argument
我的 ffmpeg 命令如下所示：
ffmpeg -i concat-video.mp4 -loop 1 -i card1.jpg -loop 1 -i card2.jpg -filter_complex "[1:v]format=pix_fmts=yuva420p,scale=765:1083,fade=in:st=0:d=1:alpha=1 [overlay1A], [0:v][overlay1A] overlay=x='if(lte(-w+(t)*1065,300),-w+(t)*1065,300)':y=300:enable='between(t,0,1):shortest=1'[merge1A]; [1:v]format=pix_fmts=yuva420p,scale=765:1083,fade=out:st=3:d=1:alpha=1 [overlay1B], [merge1A][overlay1B] overlay=300:300:enable='between(t,1,4)':shortest=1[merge1B]; [merge1B] drawtext=alpha=if(lt(t\,0.3)\,0\,if(lt(t\,1.3)\,(t-0.3)/1\,if(lt(t\,3)\,1\,if(lt(t\,4)\,(1-(t-3))/1\,0)))):fontcolor=ffffff:fontsize=64:text=test:x=200:y=200 [merge1C]; [2:v]format=pix_fmts=yuva420p,scale=765:1083,fade=in:st=4:d=1:alpha=1 [overlay2A], [merge1C:v][overlay2A] overlay=x='if(lte(-w+(t)*1065,300),-w+(t)*1065,300)':y=300:enable='between(t,4,5):shortest=1'[merge2A]; [2:v]format=pix_fmts=yuva420p,scale=765:1083,fade=out:st=7:d=1:alpha=1 [overlay2B], [merge2A][overlay2B] overlay=300:300:enable='between(t,5,8)':shortest=1[merge2B]; [merge2B] drawtext=alpha=if(lt(t\,4.3)\,0\,if(lt(t\,5.3)\,(t-4.3)/1\,if(lt(t\,7)\,1\,if(lt(t\,8)\,(1-(t-7))/1\,0)))):fontcolor=ffffff:fontsize=64:text=test:x=200:y=200 [merge2C];" -pix_fmt yuva420p -map "[merge2C]" output.mp4
或者这里稍微格式化一下以提高可读性：
ffmpeg -i concat-video.mp4 -loop 1 -i card1.jpg -loop 1 -i card2.jpg -filter_complex "
# start of block for first input jpg
[1:v]format=pix_fmts=yuva420p,scale=765:1083,fade=in:st=0:d=1:alpha=1 [overlay1A],
[0:v][overlay1A] overlay=x='if(lte(-w+(t)*1065,300),-w+(t)*1065,300)':y=300:enable='between(t,0,1):shortest=1'[merge1A];
[1:v]format=pix_fmts=yuva420p,scale=765:1083,fade=out:st=3:d=1:alpha=1 [overlay1B],
[merge1A][overlay1B] overlay=300:300:enable='between(t,1,4)':shortest=1[merge1B];
[merge1B] drawtext=alpha=if(lt(t\,0.3)\,0\,if(lt(t\,1.3)\,(t-0.3)/1\,if(lt(t\,3)\,1\,if(lt(t\,4)\,(1-(t-3))/1\,0)))):fontcolor=ffffff:fontsize=64:text=test:x=200:y=200 [merge1C];
# start of block for second input jpg
[2:v]format=pix_fmts=yuva420p,scale=765:1083,fade=in:st=4:d=1:alpha=1 [overlay2A],
[merge1C:v][overlay2A] overlay=x='if(lte(-w+(t)*1065,300),-w+(t)*1065,300)':y=300:enable='between(t,4,5):shortest=1'[merge2A];
[2:v]format=pix_fmts=yuva420p,scale=765:1083,fade=out:st=7:d=1:alpha=1 [overlay2B],
[merge2A][overlay2B] overlay=300:300:enable='between(t,5,8)':shortest=1[merge2B];
[merge2B] drawtext=alpha=if(lt(t\,4.3)\,0\,if(lt(t\,5.3)\,(t-4.3)/1\,if(lt(t\,7)\,1\,if(lt(t\,8)\,(1-(t-7))/1\,0)))):fontcolor=ffffff:fontsize=64:text=test:x=200:y=200 [merge2C];
"
-pix_fmt yuva420p -map "[merge2C]" output.mp4
希望有人能给我提示，这让我发疯：D
我尝试了几次语法更改，但总是出错。
问题似乎是输出“merge1C”（包括第一个 jpg 叠加层的淡入淡出、幻灯片、文本和淡出）与另一个 jpg 的第二个块之间的链。
@Gyan 的评论解决了这个问题