Somewhat hacky but seemingly functional frame back/forward (rest of #68).

6 files changed, 88 insertions, 12 deletions

diff --git a/src/lib/decoder.h b/src/lib/decoder.h
index f2f523516..2bc462c33 100644
--- a/src/lib/decoder.h
+++ b/src/lib/decoder.h
@@ -59,6 +59,8 @@ public:
 	virtual bool pass () = 0;
 	virtual bool seek (double);
 	virtual bool seek_to_last ();
+	virtual void seek_back () {}
+	virtual void seek_forward () {}
 
 	boost::signals2::signal<void()> OutputChanged;
 
diff --git a/src/lib/ffmpeg_decoder.cc b/src/lib/ffmpeg_decoder.cc
index 2d7092789..7c88c3c35 100644
--- a/src/lib/ffmpeg_decoder.cc
+++ b/src/lib/ffmpeg_decoder.cc
@@ -530,7 +530,7 @@ FFmpegDecoder::filter_and_emit_video ()
 bool
 FFmpegDecoder::seek (double p)
 {
-	return do_seek (p, false);
+	return do_seek (p, false, false);
 }
 
 bool
@@ -540,21 +540,57 @@ FFmpegDecoder::seek_to_last ()
 	   (used when we change decoder parameters and want to re-fetch the frame) we end up going forwards rather than
 	   staying in the same place.
 	*/
-	return do_seek (last_source_time(), true);
+	return do_seek (last_source_time(), true, false);
+}
+
+void
+FFmpegDecoder::seek_back ()
+{
+	do_seek (last_source_time() - 2.5 / frames_per_second (), true, true);
+}
+
+void
+FFmpegDecoder::seek_forward ()
+{
+	do_seek (last_source_time() - 0.5 / frames_per_second(), true, true);
 }
 
 bool
-FFmpegDecoder::do_seek (double p, bool backwards)
+FFmpegDecoder::do_seek (double p, bool backwards, bool accurate)
 {
 	int64_t const vt = p / av_q2d (_format_context->streams[_video_stream]->time_base);
 
 	int const r = av_seek_frame (_format_context, _video_stream, vt, backwards ? AVSEEK_FLAG_BACKWARD : 0);
-	
+
 	avcodec_flush_buffers (_video_codec_context);
 	if (_subtitle_codec_context) {
 		avcodec_flush_buffers (_subtitle_codec_context);
 	}
-	
+
+	if (accurate) {
+		while (1) {
+			int r = av_read_frame (_format_context, &_packet);
+			if (r < 0) {
+				return true;
+			}
+			
+			avcodec_get_frame_defaults (_frame);
+			
+			if (_packet.stream_index == _video_stream) {
+				int finished = 0;
+				int const r = avcodec_decode_video2 (_video_codec_context, _frame, &finished, &_packet);
+				if (r >= 0 && finished) {
+					int64_t const bet = av_frame_get_best_effort_timestamp (_frame);
+					if (bet > vt) {
+						break;
+					}
+				}
+			}
+			
+			av_free_packet (&_packet);
+		}
+	}
+		
 	return r < 0;
 }
 
diff --git a/src/lib/ffmpeg_decoder.h b/src/lib/ffmpeg_decoder.h
index 2a4d40b1d..0c89b973d 100644
--- a/src/lib/ffmpeg_decoder.h
+++ b/src/lib/ffmpeg_decoder.h
@@ -102,11 +102,13 @@ public:
 
 	bool seek (double);
 	bool seek_to_last ();
+	void seek_forward ();
+	void seek_back ();
 
 private:
 
 	bool pass ();
-	bool do_seek (double p, bool);
+	bool do_seek (double p, bool, bool);
 	PixelFormat pixel_format () const;
 	AVSampleFormat audio_sample_format () const;
 	int bytes_per_audio_sample () const;
diff --git a/src/lib/format.cc b/src/lib/format.cc
index 640eee167..8c3d0d8ad 100644
--- a/src/lib/format.cc
+++ b/src/lib/format.cc
@@ -50,7 +50,7 @@ FixedFormat::name () const
 		s << _nickname << N_(" (");
 	}
 
-	s << setprecision(3) << (_ratio / 100.0) << N_(":1");
+	s << setprecision(3) << _ratio << N_(":1");
 
 	if (!_nickname.empty ()) {
 		s << N_(")");
diff --git a/src/wx/film_viewer.cc b/src/wx/film_viewer.cc
index 00f895285..5770c5b70 100644
--- a/src/wx/film_viewer.cc
+++ b/src/wx/film_viewer.cc
@@ -51,6 +51,8 @@ FilmViewer::FilmViewer (shared_ptr<Film> f, wxWindow* p)
 	: wxPanel (p)
 	, _panel (new wxPanel (this))
 	, _slider (new wxSlider (this, wxID_ANY, 0, 0, 4096))
+	, _back_button (new wxButton (this, wxID_ANY, wxT("<")))
+	, _forward_button (new wxButton (this, wxID_ANY, wxT(">")))
 	, _frame (new wxStaticText (this, wxID_ANY, wxT("")))
 	, _timecode (new wxStaticText (this, wxID_ANY, wxT("")))
 	, _play_button (new wxToggleButton (this, wxID_ANY, _("Play")))
@@ -72,14 +74,18 @@ FilmViewer::FilmViewer (shared_ptr<Film> f, wxWindow* p)
 	wxBoxSizer* time_sizer = new wxBoxSizer (wxVERTICAL);
 	time_sizer->Add (_frame, 0, wxEXPAND);
 	time_sizer->Add (_timecode, 0, wxEXPAND);
-	
+
+	h_sizer->Add (_back_button, 0, wxALL, 2);
 	h_sizer->Add (time_sizer, 0, wxEXPAND);
+	h_sizer->Add (_forward_button, 0, wxALL, 2);
 	h_sizer->Add (_play_button, 0, wxEXPAND);
 	h_sizer->Add (_slider, 1, wxEXPAND);
 
 	_v_sizer->Add (h_sizer, 0, wxEXPAND | wxALL, 6);
 
 	_frame->SetMinSize (wxSize (84, -1));
+	_back_button->SetMinSize (wxSize (32, -1));
+	_forward_button->SetMinSize (wxSize (32, -1));
 
 	_panel->Connect (wxID_ANY, wxEVT_PAINT, wxPaintEventHandler (FilmViewer::paint_panel), 0, this);
 	_panel->Connect (wxID_ANY, wxEVT_SIZE, wxSizeEventHandler (FilmViewer::panel_sized), 0, this);
@@ -88,6 +94,8 @@ FilmViewer::FilmViewer (shared_ptr<Film> f, wxWindow* p)
 	_slider->Connect (wxID_ANY, wxEVT_SCROLL_PAGEDOWN, wxScrollEventHandler (FilmViewer::slider_moved), 0, this);
 	_play_button->Connect (wxID_ANY, wxEVT_COMMAND_TOGGLEBUTTON_CLICKED, wxCommandEventHandler (FilmViewer::play_clicked), 0, this);
 	_timer.Connect (wxID_ANY, wxEVT_TIMER, wxTimerEventHandler (FilmViewer::timer), 0, this);
+	_back_button->Connect (wxID_ANY, wxEVT_COMMAND_BUTTON_CLICKED, wxCommandEventHandler (FilmViewer::back_clicked), 0, this);
+	_forward_button->Connect (wxID_ANY, wxEVT_COMMAND_BUTTON_CLICKED, wxCommandEventHandler (FilmViewer::forward_clicked), 0, this);
 
 	set_film (f);
 
@@ -121,7 +129,7 @@ FilmViewer::film_changed (Film::Property p)
 		if (_decoders.video == 0) {
 			break;
 		}
-		_decoders.video->Video.connect (bind (&FilmViewer::process_video, this, _1, _2, _3));
+		_decoders.video->Video.connect (bind (&FilmViewer::process_video, this, _1, _2, _3, _4));
 		_decoders.video->OutputChanged.connect (boost::bind (&FilmViewer::decoder_changed, this));
 		_decoders.video->set_subtitle_stream (_film->subtitle_stream());
 		calculate_sizes ();
@@ -392,7 +400,7 @@ FilmViewer::check_play_state ()
 }
 
 void
-FilmViewer::process_video (shared_ptr<Image> image, bool, shared_ptr<Subtitle> sub)
+FilmViewer::process_video (shared_ptr<Image> image, bool, shared_ptr<Subtitle> sub, double t)
 {
 	_raw_frame = image;
 	_raw_sub = sub;
@@ -401,7 +409,6 @@ FilmViewer::process_video (shared_ptr<Image> image, bool, shared_ptr<Subtitle> s
 
 	_got_frame = true;
 
-	double const t = _decoders.video->last_source_time ();
 	double const fps = _decoders.video->frames_per_second ();
 	_frame->SetLabel (wxString::Format ("%d", int (rint (t * fps))));
 
@@ -465,3 +472,28 @@ FilmViewer::active_jobs_changed (bool a)
 	_play_button->Enable (!a);
 }
 
+void
+FilmViewer::back_clicked (wxCommandEvent &)
+{
+	if (!_decoders.video) {
+		return;
+	}
+	
+	_decoders.video->seek_back ();
+	get_frame ();
+	_panel->Refresh ();
+	_panel->Update ();
+}
+
+void
+FilmViewer::forward_clicked (wxCommandEvent &)
+{
+	if (!_decoders.video) {
+		return;
+	}
+
+	_decoders.video->seek_forward ();
+	get_frame ();
+	_panel->Refresh ();
+	_panel->Update ();
+}
diff --git a/src/wx/film_viewer.h b/src/wx/film_viewer.h
index 859bf7ede..a78c772a4 100644
--- a/src/wx/film_viewer.h
+++ b/src/wx/film_viewer.h
@@ -48,7 +48,7 @@ private:
 	void slider_moved (wxScrollEvent &);
 	void play_clicked (wxCommandEvent &);
 	void timer (wxTimerEvent &);
-	void process_video (boost::shared_ptr<Image>, bool, boost::shared_ptr<Subtitle>);
+	void process_video (boost::shared_ptr<Image>, bool, boost::shared_ptr<Subtitle>, double);
 	void calculate_sizes ();
 	void check_play_state ();
 	void update_from_raw ();
@@ -56,12 +56,16 @@ private:
 	void raw_to_display ();
 	void get_frame ();
 	void active_jobs_changed (bool);
+	void back_clicked (wxCommandEvent &);
+	void forward_clicked (wxCommandEvent &);
 
 	boost::shared_ptr<Film> _film;
 
 	wxSizer* _v_sizer;
 	wxPanel* _panel;
 	wxSlider* _slider;
+	wxButton* _back_button;
+	wxButton* _forward_button;
 	wxStaticText* _frame;
 	wxStaticText* _timecode;
 	wxToggleButton* _play_button;