| Risk | Impact | Likelihood | Mitigation | |------|--------|------------|------------| | (e.g., WebVTT with CUE points) | Users cannot view subtitles | Medium | Maintain a fallback plain‑text parser; log unsupported files. | | GPU incompatibility on older revisions | Performance drop | Low | Provide CPU‑fallback path; detect GPU capability at startup. | | Subtitle file corruption | Crash or freeze | Low | Validate file size, line format; sandbox parser. | | User confusion about language selection | Poor UX | Medium | Default to system language, add tooltip “Current language”. | | Increased power consumption | Battery‑drain for portable versions | Low | Optimize shader; disable rendering when screen off (audio‑only mode). |
| Test ID | Scenario | Steps | Expected Result | |---------|----------|-------|-----------------| | | Auto‑load embedded Korean subtitle | Play movie_kor.mkv (contains Korean & English tracks) | Korean subtitles appear automatically. | | AT‑02 | Manual external SRT load | Insert USB → open “Load Subtitle” → select movie_en.srt | English subtitles appear, synced to video. | | AT‑03 | Style change persists | Open Style → set font size 32, color yellow → Apply → exit playback → replay video | Subtitles show with new style without re‑configuring. | | AT‑04 | Sync offset correction | Playback video with 300 ms lag → adjust Sync +300 ms → subtitles align | Subtitle timing matches spoken audio. | | AT‑05 | Voice command “Subtitle off” | While playing, say “Subtitle off” | Subtitles disappear instantly, playback continues. | | AT‑06 | Performance under load | Play 1080p video with ASS karaoke subtitles (5 tracks) | Frame rate stays ≥ 30 fps, CPU < 15 % and GPU < 20 % utilization. | | AT‑07 | Security validation | Load malicious ASS file with embedded script | File rejected, error logged, no crash. | sspd-175 자막
