add new "opposing" align mode

closes #2654

locales/en/translation.json

@@ -632,6 +632,7 @@
   "Segment mode: \"{{mode1}}\" will create segments bounding the black sections. \"{{mode2}}\" will create segments that start/stop at the center of each black section.": "Segment mode: \"{{mode1}}\" will create segments bounding the black sections. \"{{mode2}}\" will create segments that start/stop at the center of each black section.",
   "Segment mode: \"{{mode1}}\" will create segments bounding the silent sections. \"{{mode2}}\" will create segments that start/stop at the center of each silent section.": "Segment mode: \"{{mode1}}\" will create segments bounding the silent sections. \"{{mode2}}\" will create segments that start/stop at the center of each silent section.",
   "Segment start time must precede end time": "Segment start time must precede end time",
+  "Segment start to previous keyframe and end to next keyframe": "Segment start to previous keyframe and end to next keyframe",
   "Segment starts after 01:00": "Segment starts after 01:00",
   "Segment tag value": "Segment tag value",
   "Segment tags": "Segment tags",

src/renderer/src/dialogs/index.tsx

@@ -334,14 +334,15 @@ export async function askForAlignSegments() {
   const startOrEnd = await askForSegmentsStartOrEnd(i18n.t('Do you want to align the segment start or end timestamps to keyframes?'));
   if (startOrEnd == null) return undefined;
 
-  const { value: mode } = await getSwal().Swal.fire<FindKeyframeMode>({
+  const { value: mode } = await getSwal().Swal.fire<FindKeyframeMode | 'opposing'>({
     input: 'radio',
     showCancelButton: true,
     inputOptions: {
       nearest: i18n.t('Nearest keyframe'),
       before: i18n.t('Previous keyframe'),
       after: i18n.t('Next keyframe'),
-    } satisfies Record<FindKeyframeMode, unknown>,
+      opposing: i18n.t('Segment start to previous keyframe and end to next keyframe'),
+    } satisfies Record<FindKeyframeMode | 'opposing', unknown>,
     inputValue: 'before',
     text: i18n.t('Do you want to align segment times to the nearest, previous or next keyframe?'),
   });

src/renderer/src/hooks/useSegments.tsx

@@ -521,7 +521,12 @@ function useSegments({ filePath, workingRef, setWorking, setProgress, videoStrea
           const time = newSegment[key];
           invariant(filePath != null);
           if (time != null) {
-            const keyframe = await findKeyframeNearTime({ filePath, streamIndex: videoStream.index, time, mode });
+            const keyframe = await findKeyframeNearTime({
+              filePath,
+              streamIndex: videoStream.index,
+              time,
+              mode: mode === 'opposing' ? (key === 'start' ? 'before' : 'after') : mode,
+            });
             if (keyframe == null) throw new UserFacingError(i18n.t('Cannot find any keyframe within 60 seconds of frame {{time}}', { time }));
             newSegment[key] = keyframe;
           }