app: migrate the viewer panel to the facade playback engine

app/widget/viewer/viewerplaybacktimer.cpp

@@ -1,69 +0,0 @@
-/***
-
-  Olive - Non-Linear Video Editor
-  Copyright (C) 2022 Olive Team
-  Modifications Copyright (C) 2025 mikesolar
-
-  This program is free software: you can redistribute it and/or modify
-  it under the terms of the GNU General Public License as published by
-  the Free Software Foundation, either version 3 of the License, or
-  (at your option) any later version.
-
-  This program is distributed in the hope that it will be useful,
-  but WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-  GNU General Public License for more details.
-
-  You should have received a copy of the GNU General Public License
-  along with this program.  If not, see <http://www.gnu.org/licenses/>.
-
-***/
-
-#include "viewerplaybacktimer.h"
-
-#include <QtMath>
-
-namespace olive
-{
-
-void ViewerPlaybackTimer::start(const int64_t &start_timestamp,
-								const int &playback_speed,
-								const double &timebase,
-								const PlaybackAudioClock *audio_clock)
-{
-	timer_.start();
-	start_timestamp_ = start_timestamp;
-	playback_speed_ = playback_speed;
-	timebase_ = timebase * 1000;
-	audio_clock_ = audio_clock;
-}
-
-int64_t ViewerPlaybackTimer::get_timestamp_now() const
-{
-	// The audio output clock is the master clock when available: sound card
-	// consumption is what the viewer must stay in sync with, and unlike the
-	// wall clock it cannot drift away from what is actually heard
-	if (audio_clock_) {
-		const double audio_seconds = audio_clock_->seconds();
-		if (audio_seconds >= 0.0) {
-			// At speeds other than 1x the audio tempo is scaled, so one
-			// output second corresponds to |speed| timeline seconds. The
-			// result is already in timeline frames, so it is applied
-			// signed rather than multiplied by the speed again.
-			const double timeline_ms =
-				audio_seconds * 1000.0 * qAbs(playback_speed_);
-			const int64_t frames_since_start = qFloor(timeline_ms / timebase_);
-			return start_timestamp_ +
-				frames_since_start * (playback_speed_ < 0 ? -1 : 1);
-		}
-	}
-
-	int64_t real_time = timer_.elapsed();
-
-	int64_t frames_since_start =
-		qFloor(static_cast<double>(real_time) / (timebase_));
-
-	return start_timestamp_ + frames_since_start * playback_speed_;
-}
-
-}