Contribution to Shotcut community: AfterEffects-like animated alpha transitions

Suggestion
1

Hi!
Thank you for the Shotcut!
I made a 1-line script that allows applying cool animated alpha transitions, here is the result example:
YouTube Video

frame
frame.jpg1920×1080 325 KB

Here is the script (bash):
#!/bin/bash
length_sec=3
transition_length_sec=1
a_file="./a.mp4"
b_file="./b.mp4"
alpha_transition_file="./t.mp4"
result_file="./out.mp4"
offset_sec=$((length_sec-transition_length_sec))

ffmpeg -y -i "${a_file}" -i "${b_file}" -i "${alpha_transition_file}" -filter_complex "[1:v][2:v]alphamerge,setpts=PTS-STARTPTS+${offset_sec}/TB[tb];[0:v]setpts=PTS-STARTPTS[a];[a][tb]overlay[v]" -map "[v]" -pix_fmt yuv420p -c:v libx264 -an "${result_file}"

The sample data and working script: test_data.zip (2.4 MB)

Footage and transition sources (thanks, guys!):
https://videos.pexels.com/videos/bubble-turning-into-ice-855627
https://videos.pexels.com/videos/bokeh-video-of-leaves-854717
https://www.premiumbeat.com/blog/category/free-for-video/

I suggest adding this method to Shotcut transitions because current ones are boring. :slight_smile:

1 Like
2

This (calls out to ffmpeg) is not how transitions work in MLT and Shotcut. Shotcut is not a simple ffmpeg command line frontend. More transitions are pending a rewrite to that part of the Shotcut GUI to make it extensible similar to Filters in Shotcut. Something like this may be possible using HTML5 when that time comes.