00:52
I use this code to slide previous and next pages up, the problem is the [v]tpad=stop_mode=clone:stop_duration=10[s1]; is clone the first frame not last frame of [s0], how can I use last frame of [s0] to countdown?
color=white:864x504[c];
[0:v]scale=864:504:force_original_aspect_ratio=decrease,pad=864:504:-1:-1,setsar=1[s0];
[1:v]scale=864:504:force_original_aspect_ratio=decrease,pad=864:504:-1:-1,setsar=1[s1];
[c][s0]overlay=y=0-h*t[c];
[c][s1]overlay=y='if(between(t,0,18),max(H-h*t,0),max(0-h*(t-18),0-H))'[v],
[v]tpad=stop_mode=clone:stop_duration=10[s2];

00:16
I have tried to make a bitstream filter for FFmpeg that drops the nth keyframe for positive numbers and allows the first n keyframes and drops the rest for nonpositive numbers, called "datamosh":
ffmpeg -i input.webm -bsf:v datamosh=target=20 -c copy output.webm
outputs the error:
Option 'target' not found
[vost#0:0/copy ⓐ 0x54edc40] Error parsing bitstream filter sequence 'datamosh=target=20': Option not found
Here is the code for the "datamosh" bitstream filter:
#include "bsf.h"
#include "bsf_internal.h"
#include (...)