问题
Here, New in FFmpeg . I am using and testing in console in FFmpeg .
I already done with 2 video join with cross fading with this question : I am doing for 5 videos merging with cross fade I just done 90% in merging i just need to manage setpts=PTS-STARTPTS Just look into this pls.
ffmpeg -i big_buck.mp4 -i big_buck.mp4 -i big_buck.mp4 -i big_buck.mp4 -i
big_buck.mp4 -filter_complex "[0:v]trim=0:4,setpts=PTS-
STARTPTS,fade=out:st=4:d=1:alpha=1[1]; [1:v]trim=1:4,setpts=PTS-
STARTPTS,format=yuva420p,fade=in:st=0:d=1:alpha=1,fade=out:st=4:d=1:alpha=1[2];
[2:v]trim=1:4,setpts=PTS-
STARTPTS,format=yuva420p,fade=in:st=0:d=1:alpha=1,fade=out:st=4:d=1:alpha=1[3];
[3:v]trim=1:4,setpts=PTS-
STARTPTS,format=yuva420p,fade=in:st=0:d=1:alpha=1,fade=out:st=4:d=1:alpha=1[4];
[4:v]trim=1:4,setpts=PTS-STARTPTS,format=yuva420p,fade=in:st=0:d=1:alpha=1[5];
[1][2]overlay,format=yuv420p[12]; [12][3]overlay,format=yuv420p[123]; [4]
[5]overlay,format=yuv420p[45]; [123][45]concat=n=2 [v]" -map [v] result.mp4
****Note that every input video big_buck.mp4 length is 5 sec ****. now see setpts=PTS-STARTPTS in code How to Manage that in every video Input????
I also see in variuos forums about that but i didnt find!!! Thank you
回答1:
Use
ffmpeg -i big_buck.mp4 -i big_buck.mp4 -i big_buck.mp4 -i big_buck.mp4 -i
big_buck.mp4 -filter_complex \
"[0:v]setpts=PTS-STARTPTS[v1]; \
[1:v]format=yuva420p,fade=in:st=0:d=1:alpha=1,setpts=PTS-STARTPTS+(4/TB)[v2];
[2:v]format=yuva420p,fade=in:st=0:d=1:alpha=1,setpts=PTS-STARTPTS+(8/TB)[v3];
[3:v]format=yuva420p,fade=in:st=0:d=1:alpha=1,setpts=PTS-STARTPTS+(12/TB)[v4];
[4:v]format=yuva420p,fade=in:st=0:d=1:alpha=1,setpts=PTS-STARTPTS+(16/TB)[v5];
[v1][v2]overlay[v12]; [v12][v3]overlay[v123]; [v123][v4]overlay[v1234]; [v1234][v5]overlay,format=yuv420p[v]" \
-map [v] result.mp4
The PTS has to be modified so that each new clip starts 1 second before the current combination of clips ends i.e. the 3rd clip should start fading in at 8 seconds, since the combination of the first two clips is 9 seconds (4 seconds of first clip + 1 second transition + 4 seconds of 2nd clip).
You don't need the fade out as the next clip is fading in on top. The concat is only required if you want a cut.
With audio crossfades:
ffmpeg -i big_buck.mp4 -i big_buck.mp4 -i big_buck.mp4 -i big_buck.mp4 -i
big_buck.mp4 -filter_complex \
"[0:v]setpts=PTS-STARTPTS[v1]; \
[1:v]format=yuva420p,fade=in:st=0:d=1:alpha=1,setpts=PTS-STARTPTS+(4/TB)[v2];
[2:v]format=yuva420p,fade=in:st=0:d=1:alpha=1,setpts=PTS-STARTPTS+(8/TB)[v3];
[3:v]format=yuva420p,fade=in:st=0:d=1:alpha=1,setpts=PTS-STARTPTS+(12/TB)[v4];
[4:v]format=yuva420p,fade=in:st=0:d=1:alpha=1,setpts=PTS-STARTPTS+(16/TB)[v5];
[v1][v2]overlay[12]; [12][v3]overlay[123]; [123][v4]overlay[1234]; [1234][v5]overlay,format=yuv420p[v]; \
[1][2]acrossfade=d=1[a12]; [a12][3]acrossfade=d=1[a123]; [a123][4]acrossfade=d=1[a];" \
-map [v] -map [a] result.mp4
来源：https://stackoverflow.com/questions/37783044/ffmpeg-command-for-crossfading-between-5-videos-how-to-manage-setpts-pts-startp