Support changing overall playing speed at runtime, using a slider or a MIDI controller.

[nageru] / futatabi / player.cpp

diff --git a/futatabi/player.cpp b/futatabi/player.cpp
index 6a8612f86e43be0f0f2e1740edd31a0c53ec61d9..30dccc8e4e88132664d26cd4e8f7058586c6c430 100644 (file)
--- a/futatabi/player.cpp
+++ b/futatabi/player.cpp
@@ -114,6 +114,7 @@ void Player::play_playlist_once()
        bool clip_ready;
        steady_clock::time_point before_sleep = steady_clock::now();
        string pause_status;
+       float master_speed = 1.0f;
 
        // Wait until we're supposed to play something.
        {
@@ -184,9 +185,16 @@ void Player::play_playlist_once()
                        double out_pts = out_pts_origin + TIMEBASE * frameno / global_flags.output_framerate;
                        next_frame_start =
                                origin + microseconds(lrint((out_pts - out_pts_origin) * 1e6 / TIMEBASE));
-                       int64_t in_pts = lrint(in_pts_origin + TIMEBASE * frameno * clip->speed / global_flags.output_framerate);
+                       int64_t in_pts = lrint(in_pts_origin + TIMEBASE * frameno * clip->speed * master_speed / global_flags.output_framerate);
                        pts = lrint(out_pts);
 
+                       float new_master_speed = change_master_speed.exchange(0.0f / 0.0f);
+                       if (!std::isnan(new_master_speed)) {
+                               master_speed = new_master_speed;
+                               in_pts_origin = in_pts - TIMEBASE * frameno * clip->speed * master_speed / global_flags.output_framerate;
+                               out_pts_origin = out_pts - TIMEBASE * frameno / global_flags.output_framerate;
+                       }
+
                        if (in_pts >= clip->pts_out) {
                                break;
                        }