old_list->insert(old_list->end(), new_list.begin() + splice_start_new_list, new_list.end());
}
+// Keeps track of the various timelines (wall clock time, output pts,
+// position in the clip we are playing). Generally we keep an origin
+// and assume we increase linearly from there; the intention is to
+// avoid getting compounded accuracy errors, although with double,
+// that is perhaps overkill. (Whenever we break the linear assumption,
+// we need to reset said origin.)
+class TimelineTracker
+{
+public:
+ struct Instant {
+ steady_clock::time_point wallclock_time;
+ int64_t in_pts;
+ int64_t out_pts;
+ int64_t frameno;
+ };
+
+ TimelineTracker(double master_speed, int64_t out_pts_origin)
+ : master_speed(master_speed), last_out_pts(out_pts_origin) {
+ origin.out_pts = out_pts_origin;
+ }
+
+ void new_clip(steady_clock::time_point wallclock_origin, const Clip *clip, int64_t start_pts_offset)
+ {
+ this->clip = clip;
+ origin.wallclock_time = wallclock_origin;
+ origin.in_pts = clip->pts_in + start_pts_offset;
+ origin.out_pts = last_out_pts;
+ origin.frameno = 0;
+ }
+
+ // Returns the current time for said frame.
+ Instant advance_to_frame(int64_t frameno);
+
+ int64_t get_in_pts_origin() const { return origin.in_pts; }
+ bool playing_at_normal_speed() const {
+ const double effective_speed = clip->speed * master_speed;
+ return effective_speed >= 0.999 && effective_speed <= 1.001;
+ }
+
+ void snap_by(int64_t offset) {
+ origin.in_pts += offset;
+ }
+
+ void change_master_speed(double new_master_speed, Instant now);
+
+private:
+ double master_speed;
+ const Clip *clip = nullptr;
+ Instant origin;
+ int64_t last_out_pts;
+};
+
+TimelineTracker::Instant TimelineTracker::advance_to_frame(int64_t frameno)
+{
+ Instant ret;
+ double in_pts_double = origin.in_pts + TIMEBASE * clip->speed * (frameno - origin.frameno) * master_speed / global_flags.output_framerate;
+ ret.in_pts = lrint(in_pts_double);
+ double out_pts_double = origin.out_pts + TIMEBASE * (frameno - origin.frameno) / global_flags.output_framerate;
+ ret.out_pts = lrint(out_pts_double);
+ ret.wallclock_time = origin.wallclock_time + microseconds(lrint((out_pts_double - origin.out_pts) * 1e6 / TIMEBASE));
+ ret.frameno = frameno;
+
+ last_out_pts = ret.out_pts;
+
+ return ret;
+}
+
+void TimelineTracker::change_master_speed(double new_master_speed, Instant now)
+{
+ master_speed = new_master_speed;
+
+ // Reset the origins, since the calculations depend on linear interpolation
+ // based on the master speed.
+ origin = now;
+}
+
} // namespace
void Player::play_playlist_once()
bool clip_ready;
steady_clock::time_point before_sleep = steady_clock::now();
string pause_status;
- float master_speed = start_master_speed;
// Wait until we're supposed to play something.
{
should_skip_to_next = false; // To make sure we don't have a lingering click from before play.
steady_clock::time_point origin = steady_clock::now(); // TODO: Add a 100 ms buffer for ramp-up?
- int64_t in_pts_origin = clip_list[0].clip.pts_in;
+ TimelineTracker timeline(start_master_speed, pts);
+ timeline.new_clip(origin, &clip_list[0].clip, /*pts_offset=*/0);
for (size_t clip_idx = 0; clip_idx < clip_list.size(); ++clip_idx) {
const Clip *clip = &clip_list[clip_idx].clip;
const Clip *next_clip = (clip_idx + 1 < clip_list.size()) ? &clip_list[clip_idx + 1].clip : nullptr;
- int64_t out_pts_origin = pts;
double next_clip_fade_time = -1.0;
if (next_clip != nullptr) {
- double duration_this_clip = double(clip->pts_out - in_pts_origin) / TIMEBASE / clip->speed;
+ double duration_this_clip = double(clip->pts_out - timeline.get_in_pts_origin()) / TIMEBASE / clip->speed;
double duration_next_clip = double(next_clip->pts_out - next_clip->pts_in) / TIMEBASE / clip->speed;
next_clip_fade_time = min(min(duration_this_clip, duration_next_clip), clip->fade_time_seconds);
}
lock_guard<mutex> lock(frame_mu);
// Find the first frame such that frame.pts <= in_pts.
- auto it = find_last_frame_before(frames[stream_idx], in_pts_origin);
+ auto it = find_last_frame_before(frames[stream_idx], timeline.get_in_pts_origin());
if (it != frames[stream_idx].end()) {
- in_pts_origin = it->pts;
+ timeline.snap_by(it->pts - timeline.get_in_pts_origin());
}
}
steady_clock::time_point next_frame_start;
for (int64_t frameno = 0; !should_quit; ++frameno) { // Ends when the clip ends.
- 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 * master_speed / global_flags.output_framerate);
- pts = lrint(out_pts);
+ TimelineTracker::Instant instant = timeline.advance_to_frame(frameno);
+ int64_t in_pts = instant.in_pts;
+ pts = instant.out_pts;
+ next_frame_start = instant.wallclock_time;
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;
+ timeline.change_master_speed(new_master_speed, instant);
}
if (should_skip_to_next.exchange(false)) { // Test and clear.
// Only play audio if we're within 0.1% of normal speed. We could do
// stretching or pitch shift later if it becomes needed.
- bool play_audio = clip->speed * master_speed >= 0.999 && clip->speed * master_speed <= 1.001;
+ const bool play_audio = timeline.playing_at_normal_speed();
{
lock_guard<mutex> lock(queue_state_mu);
// (or we may have gone from no new clip to having one, or the other way).
next_clip = (clip_idx + 1 < clip_list.size()) ? &clip_list[clip_idx + 1].clip : nullptr;
if (next_clip != nullptr) {
- double duration_this_clip = double(clip->pts_out - in_pts) / TIMEBASE / clip->speed;
+ double duration_this_clip = double(clip->pts_out - timeline.get_in_pts_origin()) / TIMEBASE / clip->speed;
double duration_next_clip = double(next_clip->pts_out - next_clip->pts_in) / TIMEBASE / clip->speed;
next_clip_fade_time = min(min(duration_this_clip, duration_next_clip), clip->fade_time_seconds);
}
display_single_frame(primary_stream_idx, snap_frame, secondary_stream_idx,
secondary_frame, fade_alpha, next_frame_start, /*snapped=*/true,
subtitle, play_audio);
- in_pts_origin += snap_frame.pts - in_pts;
+ timeline.snap_by(snap_frame.pts - in_pts);
snapped = true;
break;
}
1.0 / 5.0, 2.0 / 5.0, 3.0 / 5.0, 4.0 / 5.0 }) {
double subsnap_pts = frame_lower.pts + fraction * (frame_upper.pts - frame_lower.pts);
if (fabs(subsnap_pts - in_pts) < pts_snap_tolerance) {
- in_pts_origin += lrint(subsnap_pts) - in_pts;
+ timeline.snap_by(lrint(subsnap_pts) - in_pts);
in_pts = lrint(subsnap_pts);
break;
}
// Start the next clip from the point where the fade went out.
if (next_clip != nullptr) {
- origin = next_frame_start;
- in_pts_origin = next_clip->pts_in + lrint(next_clip_fade_time * TIMEBASE * clip->speed);
+ timeline.new_clip(next_frame_start, next_clip, /*pts_start_offset=*/lrint(next_clip_fade_time * TIMEBASE * clip->speed));
}
}