Add frame step buttons to internal video player

src/main/assets/changelog-alpha.txt

@@ -1,3 +1,6 @@
+/Alpha 360 (2025-04-21)
+Added video frame step controls (thanks to ecawthorne and japanesephundroid)
+
 /Alpha 359 (2025-04-20)
 Added support for emotes in comment flairs (thanks to bharatknv)
 Added "Mark as Read/Unread" fling action, and optional context menu item (thanks to JoshAusHessen and codeofdusk)

src/main/assets/changelog.txt

@@ -1,5 +1,6 @@
 114/1.25
 Added video playback speed control (thanks to folkemat)
+Added video frame step controls (thanks to ecawthorne and japanesephundroid)
 Added support for emotes in comment flairs (thanks to bharatknv)
 Show label on crossposts, and add "Go to Crosspost Origin" to post menu (thanks to folkemat)
 Added "Mark as Read/Unread" fling action, and optional post menu item (thanks to JoshAusHessen and codeofdusk)

src/main/java/org/quantumbadger/redreader/common/PrefsUtility.java

@@ -802,6 +802,11 @@ public static boolean pref_behaviour_video_playback_controls() {
 				true);
 	}
 
+	public static boolean pref_behaviour_video_frame_step() {
+		return getBoolean(R.string.pref_behaviour_video_frame_step_key,
+				false);
+	}
+
 	public static boolean pref_behaviour_video_mute_default() {
 		return getBoolean(
 				R.string.pref_behaviour_video_mute_default_key,

src/main/java/org/quantumbadger/redreader/views/video/ExoPlayerWrapperView.java

@@ -146,7 +146,7 @@ public ExoPlayerWrapperView(
 			addButton(createButton(
 					context,
 					mControlView,
-					R.drawable.icon_previous,
+					R.drawable.icon_restart,
 					R.string.video_restart,
 					view -> {
 						mVideoPlayer.seekTo(0);
@@ -178,7 +178,68 @@ public ExoPlayerWrapperView(
 						updateProgress();
 					});
 
-			addButton(mPlayButton, buttons);
+			if (PrefsUtility.pref_behaviour_video_frame_step()) {
+				final long frameDuration = (long)(1000f / (mVideoPlayer.getVideoFormat() != null
+						? mVideoPlayer.getVideoFormat().frameRate
+						: 30));
+
+				final ImageButton stepBackButton = createButton(
+						context,
+						mControlView,
+						R.drawable.icon_step_back,
+						R.string.video_step_back,
+						view -> {
+							mVideoPlayer.seekTo(mVideoPlayer.getCurrentPosition() - frameDuration);
+							updateProgress();
+						}
+				);
+
+				final ImageButton stepForwardButton = createButton(
+						context,
+						mControlView,
+						R.drawable.icon_step_forward,
+						R.string.video_step_forward,
+						view -> {
+							mVideoPlayer.seekTo(mVideoPlayer.getCurrentPosition() + frameDuration);
+							updateProgress();
+						}
+				);
+
+				mVideoPlayer.addListener(new Player.Listener() {
+					@Override
+					public void onIsPlayingChanged(final boolean isPlaying) {
+						if (isPlaying) {
+							stepBackButton.setImageAlpha(0x3F);
+							stepBackButton.setContentDescription(
+									context.getString(R.string.video_step_back_disabled));
+							stepBackButton.setEnabled(false);
+
+							stepForwardButton.setImageAlpha(0x3F);
+							stepForwardButton.setContentDescription(
+									context.getString(R.string.video_step_forward_disabled));
+							stepForwardButton.setEnabled(false);
+
+						} else {
+							stepBackButton.setImageAlpha(0xFF);
+							stepBackButton.setContentDescription(
+									context.getString(R.string.video_step_back));
+							stepBackButton.setEnabled(true);
+
+							stepForwardButton.setImageAlpha(0xFF);
+							stepForwardButton.setContentDescription(
+									context.getString(R.string.video_step_forward));
+							stepForwardButton.setEnabled(true);
+						}
+					}
+				});
+
+				addButton(stepBackButton, buttons);
+				addButton(mPlayButton, buttons);
+				addButton(stepForwardButton, buttons);
+
+			} else {
+				addButton(mPlayButton, buttons);
+			}
 
 			addButton(createButton(
 					context,

src/main/res/drawable/icon_restart.xml

@@ -0,0 +1,26 @@
+<!-- Copyright (C) 2024 The Android Open Source Project
+
+     Licensed under the Apache License, Version 2.0 (the "License");
+     you may not use this file except in compliance with the License.
+     You may obtain a copy of the License at
+
+          http://www.apache.org/licenses/LICENSE-2.0
+
+     Unless required by applicable law or agreed to in writing, software
+     distributed under the License is distributed on an "AS IS" BASIS,
+     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+     See the License for the specific language governing permissions and
+     limitations under the License.
+-->
+
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+	android:width="32dp"
+	android:height="32dp"
+	android:viewportHeight="24.0"
+	android:viewportWidth="24.0">
+
+	<path
+		android:fillColor="#FFFFFFFF"
+		android:pathData="M12,4C14.1,4 16.1,4.8 17.6,6.3C20.7,9.4 20.7,14.5 17.6,17.6C15.8,19.5 13.3,20.2 10.9,19.9L11.4,17.9C13.1,18.1 14.9,17.5 16.2,16.2C18.5,13.9 18.5,10.1 16.2,7.7C15.1,6.6 13.5,6 12,6V10.6L7,5.6L12,0.6V4M6.3,17.6C3.7,15 3.3,11 5.1,7.9L6.6,9.4C5.5,11.6 5.9,14.4 7.8,16.2C8.3,16.7 8.9,17.1 9.6,17.4L9,19.4C8,19 7.1,18.4 6.3,17.6Z"/>
+
+</vector>

src/main/res/drawable/icon_previous.xml → src/main/res/drawable/icon_step_back.xml

@@ -1,4 +1,4 @@
-<!-- Copyright (C) 2017 The Android Open Source Project
+<!-- Copyright (C) 2024 The Android Open Source Project
 
      Licensed under the Apache License, Version 2.0 (the "License");
      you may not use this file except in compliance with the License.
@@ -12,14 +12,17 @@
      See the License for the specific language governing permissions and
      limitations under the License.
 -->
+
 <vector xmlns:android="http://schemas.android.com/apk/res/android"
     android:width="32dp"
-    android:height="32dp"
-    android:viewportHeight="24.0"
-    android:viewportWidth="24.0">
+	android:height="32dp"
+	android:viewportHeight="24.0"
+	android:viewportWidth="24.0">
 
-  <path
-      android:fillColor="#FFFFFFFF"
-      android:pathData="M6,6h2v12L6,18zM9.5,12l8.5,6L18,6z"/>
+	<path
+	    android:fillColor="#FFFFFFFF"
+		android:pathData="M6,18V6H8V18H6M9.5,12L18,6V18L9.5,12Z"/>
 
 </vector>
+
+

src/main/res/drawable/icon_step_forward.xml

@@ -0,0 +1,26 @@
+<!-- Copyright (C) 2024 The Android Open Source Project
+
+     Licensed under the Apache License, Version 2.0 (the "License");
+     you may not use this file except in compliance with the License.
+     You may obtain a copy of the License at
+
+          http://www.apache.org/licenses/LICENSE-2.0
+
+     Unless required by applicable law or agreed to in writing, software
+     distributed under the License is distributed on an "AS IS" BASIS,
+     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+     See the License for the specific language governing permissions and
+     limitations under the License.
+-->
+
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+		android:width="32dp"
+		android:height="32dp"
+		android:viewportHeight="24.0"
+		android:viewportWidth="24.0">
+
+	<path
+			android:fillColor="#FFFFFFFF"
+			android:pathData="M16,18H18V6H16M6,18L14.5,12L6,6V18Z"/>
+
+</vector>

src/main/res/values/strings.xml

@@ -1482,9 +1482,13 @@
 	<string name="video_unmute">Unmute</string>
 	<string name="video_restart">Restart video</string>
 	<string name="video_rewind">Rewind</string>
+	<string name="video_step_back">Step back</string>
+	<string name="video_step_back_disabled">Step back disabled</string>
 	<string name="video_play">Play</string>
 	<string name="video_pause">Pause</string>
 	<string name="video_fast_forward">Fast forward</string>
+	<string name="video_step_forward">Step forward</string>
+	<string name="video_step_forward_disabled">Step forward disabled</string>
 	<string name="video_zoom_in">Zoom in</string>
 	<string name="video_zoom_out">Zoom out</string>
 
@@ -1910,4 +1914,8 @@
 	<string name="pref_appearance_post_subtitle_items_crosspost">Crosspost tag</string>
 	<string name="accessibility_subtitle_crosspost">Crosspost.</string>
 	<string name="action_crosspost_origin">Go to Crosspost Origin</string>
+
+	<string name="pref_behaviour_video_frame_step_title">Enable stepping frame by frame</string>
+	<string name="pref_behaviour_video_frame_step_key" translatable="false">pref_behaviour_video_frame_step</string>
+
 </resources>

src/main/res/xml/prefs_images_video.xml

@@ -43,6 +43,10 @@
 							android:key="@string/pref_behaviour_video_playback_controls_key"
 							android:defaultValue="true"/>
 
+		<CheckBoxPreference android:title="@string/pref_behaviour_video_frame_step_title"
+							android:key="@string/pref_behaviour_video_frame_step_key"
+							android:defaultValue="false"/>
+
 		<CheckBoxPreference android:title="@string/pref_behaviour_video_mute_default_title"
 							android:key="@string/pref_behaviour_video_mute_default_key"
 							android:defaultValue="true"/>