Add video playback options for 500 ms before/after subtitle lines

po/zh_CN.po

@@ -2452,6 +2452,38 @@ msgstr "从该位置开始播放视频"
 msgid "Play line"
 msgstr "播放字幕行"
 
+#: ../src/command/video.cpp:621
+msgid "Play last 500ms"
+msgstr "播放最后500毫秒"
+
+#: ../src/command/video.cpp:622
+msgid "Play last 500 milliseconds of current line"
+msgstr "播放当前行的最后500毫秒"
+
+#: ../src/command/video.cpp:630
+msgid "Play first 500ms"
+msgstr "播放开始500毫秒"
+
+#: ../src/command/video.cpp:631
+msgid "Play first 500 milliseconds of current line"
+msgstr "播放当前行的开始500毫秒"
+
+#: ../src/command/video.cpp:639
+msgid "Play 500ms before"
+msgstr "播放前500毫秒"
+
+#: ../src/command/video.cpp:640
+msgid "Play 500 milliseconds before current line"
+msgstr "播放当前行之前500毫秒"
+
+#: ../src/command/video.cpp:648
+msgid "Play 500ms after"
+msgstr "播放后500毫秒"
+
+#: ../src/command/video.cpp:649
+msgid "Play 500 milliseconds after current line"
+msgstr "播放当前行之后500毫秒"
+
 #: ../src/command/video.cpp:656
 msgid "Show &Overscan Mask"
 msgstr "显示过扫描遮罩(&O)"

src/command/video.cpp

@@ -651,6 +651,54 @@ struct video_play_line final : public validator_video_loaded {
 	}
 };
 
+struct video_play_line_end final : public validator_video_loaded {
+    CMD_NAME("video/play/line/end")
+    CMD_ICON(button_playline)
+    STR_MENU("Play last 500ms")
+    STR_DISP("Play last 500ms")
+    STR_HELP("Play last 500 milliseconds of current line")
+
+    void operator()(agi::Context *c) override {
+        c->videoController->PlayLineEnd();
+    }
+};
+
+struct video_play_line_begin final : public validator_video_loaded {
+    CMD_NAME("video/play/line/begin")
+    CMD_ICON(button_playline)
+    STR_MENU("Play first 500ms")
+    STR_DISP("Play first 500ms")
+    STR_HELP("Play first 500 milliseconds of current line")
+
+    void operator()(agi::Context *c) override {
+        c->videoController->PlayLineBegin();
+    }
+};
+
+struct video_play_line_before final : public validator_video_loaded {
+    CMD_NAME("video/play/line/before")
+    CMD_ICON(button_playline)
+    STR_MENU("Play 500ms before")
+    STR_DISP("Play 500ms before")
+    STR_HELP("Play 500 milliseconds before current line")
+
+    void operator()(agi::Context *c) override {
+        c->videoController->PlayLineBefore();
+    }
+};
+
+struct video_play_line_after final : public validator_video_loaded {
+    CMD_NAME("video/play/line/after")
+    CMD_ICON(button_playline)
+    STR_MENU("Play 500ms after")
+    STR_DISP("Play 500ms after")
+    STR_HELP("Play 500 milliseconds after current line")
+
+    void operator()(agi::Context *c) override {
+        c->videoController->PlayLineAfter();
+    }
+};
+
 struct video_show_overscan final : public validator_video_loaded {
 	CMD_NAME("video/show_overscan")
 	STR_MENU("Show &Overscan Mask")
@@ -795,6 +843,10 @@ namespace cmd {
 		reg(std::make_unique<video_opt_autoscroll>());
 		reg(std::make_unique<video_play>());
 		reg(std::make_unique<video_play_line>());
+		reg(std::make_unique<video_play_line_end>());
+		reg(std::make_unique<video_play_line_begin>());
+		reg(std::make_unique<video_play_line_before>());
+		reg(std::make_unique<video_play_line_after>());
 		reg(std::make_unique<video_show_overscan>());
 		reg(std::make_unique<video_stop>());
 		reg(std::make_unique<video_zoom_100>());

src/video_controller.cpp

@@ -167,6 +167,90 @@ void VideoController::PlayLine() {
 	playback.Start(10);
 }
 
+void VideoController::PlayLineEnd() {
+    Stop();
+
+    AssDialogue *curline = context->selectionController->GetActiveLine();
+    if (!curline) return;
+
+    int end_time = curline->End;
+    int start_time = std::max(0, end_time - 500);
+
+    context->audioController->PlayRange(TimeRange(start_time, end_time));
+
+    int startFrame = FrameAtTime(start_time, agi::vfr::START);
+    start_ms = TimeAtFrame(startFrame);
+    end_frame = FrameAtTime(end_time, agi::vfr::END) + 1;
+
+    JumpToFrame(startFrame);
+
+    playback_start_time = std::chrono::steady_clock::now();
+    playback.Start(10);
+}
+
+void VideoController::PlayLineBegin() {
+    Stop();
+
+    AssDialogue *curline = context->selectionController->GetActiveLine();
+    if (!curline) return;
+
+    int start_time = curline->Start;
+    int end_time = std::min(static_cast<int>(curline->End), start_time + 500);
+
+    context->audioController->PlayRange(TimeRange(start_time, end_time));
+
+    int startFrame = FrameAtTime(start_time, agi::vfr::START);
+    start_ms = TimeAtFrame(startFrame);
+    end_frame = FrameAtTime(end_time, agi::vfr::END) + 1;
+
+    JumpToFrame(startFrame);
+
+    playback_start_time = std::chrono::steady_clock::now();
+    playback.Start(10);
+}
+
+void VideoController::PlayLineBefore() {
+    Stop();
+
+    AssDialogue *curline = context->selectionController->GetActiveLine();
+    if (!curline) return;
+
+    int end_time = curline->Start;
+    int start_time = std::max(0, end_time - 500);
+
+    context->audioController->PlayRange(TimeRange(start_time, end_time));
+
+    int startFrame = FrameAtTime(start_time, agi::vfr::START);
+    start_ms = TimeAtFrame(startFrame);
+    end_frame = FrameAtTime(end_time, agi::vfr::END) + 1;
+
+    JumpToFrame(startFrame);
+
+    playback_start_time = std::chrono::steady_clock::now();
+    playback.Start(10);
+}
+
+void VideoController::PlayLineAfter() {
+    Stop();
+
+    AssDialogue *curline = context->selectionController->GetActiveLine();
+    if (!curline) return;
+
+    int start_time = curline->End;
+    int end_time = start_time + 500;
+
+    context->audioController->PlayRange(TimeRange(start_time, end_time));
+
+    int startFrame = FrameAtTime(start_time, agi::vfr::START);
+    start_ms = TimeAtFrame(startFrame);
+    end_frame = FrameAtTime(end_time, agi::vfr::END) + 1;
+
+    JumpToFrame(startFrame);
+
+    playback_start_time = std::chrono::steady_clock::now();
+    playback.Start(10);
+}
+
 void VideoController::Stop() {
 	if (IsPlaying()) {
 		playback.Stop();
@@ -233,4 +317,4 @@ void VideoController::OnSubtitlesError(SubtitlesProviderErrorEvent const& err) {
 	wxLogError(
 		"Failed rendering subtitles. Error message reported: %s",
 		to_wx(err.GetMessage()));
-}
+}

src/video_controller.h

@@ -149,6 +149,14 @@ class VideoController final : public wxEvtHandler {
 	void NextFrame();
 	/// Play the previous frame then stop
 	void PrevFrame();
+	/// Play the last 500 milliseconds of the current line
+	void PlayLineEnd();
+	/// Play the first 500 milliseconds of the current line
+	void PlayLineBegin();
+	/// Play 500 milliseconds before the current line
+	void PlayLineBefore();
+	/// Play 500 milliseconds after the current line
+	void PlayLineAfter();
 	/// Seek to the beginning of the current line, then play to the end of it
 	void PlayLine();
 	/// Stop playing