double snap_pts_as_frameno = (snap_frame.pts - in_pts_origin) * output_framerate / TIMEBASE / speed;
if (fabs(snap_pts_as_frameno - frameno) < 0.01) {
auto display_func = [this, primary_stream_idx, snap_frame, secondary_frame, fade_alpha]{
double snap_pts_as_frameno = (snap_frame.pts - in_pts_origin) * output_framerate / TIMEBASE / speed;
if (fabs(snap_pts_as_frameno - frameno) < 0.01) {
auto display_func = [this, primary_stream_idx, snap_frame, secondary_frame, fade_alpha]{