| Symptom | Likely Cause | Fix | |---------|--------------|-----| | | Source SRT timestamps don’t match trimmed segment. | Open the SRT in a text editor, subtract the start offset (e.g., 00:00:00 ). Or re‑extract subtitles after trimming. | | Black screen at beginning | Cutting on a non‑keyframe while using -c copy . | Re‑encode the first few seconds ( -c:v libx264 with -ss after -i ) or use -accurate_seek . | | File too large | Using lossless codecs or very high bitrate. | Increase -crf (e.g., -crf 26 ) or add -b:v 1500k . | | No subtitle track in final MP4 | Forgetting -c:s mov_text for soft‑subs. | Add -c:s mov_text (or -c:s srt for MKV). | | Audio pitch change | Using -ss before -i with some codecs. | Place -ss after -i if you need accurate audio (slower but safe). | | Playback fails on older devices | Using HEVC ( hevc ) or unsupported subtitle codec. | Encode to H.264 ( -c:v libx264 ) and use mov_text subtitles for MP4. |

Codes like JUQ-968 are primarily used within the Japanese adult video (JAV) industry. You can often find detailed information about the cast, director, and studio by searching the code on specialized databases like R18 or DMM.

Look for:

setup) to be a bit long, though fans of the genre appreciate the buildup.

: Detailed metadata, including actor profiles and scene screenshots, are listed on databases like JAVLibrary .