Juq-968-engsub Convert02-23-49 Min -

# 2️⃣ Concatenate the original + padding ffmpeg -i "concat:JUQ-968‑engsub.mkv|pad_extra.mp4" \ -c copy \ "JUQ-968‑padded.mkv"

| Issue | Reason | Fix | |-------|--------|-----| | | MP4 only supports mov_text . Using -c:s copy on an ass / srt track will drop it. | Use -c:s mov_text (or -c:s srt for MKV). | | Audio sync drift | Different framerates or variable‑frame‑rate (VFR) video. | Add -vsync 2 or -fflags +genpts . | | File size too large | Low CRF (high quality) or high audio bitrate. | Increase CRF (e.g., 24) or lower audio bitrate ( -b:a 128k ). | | Hard‑coded subtitles look blurry | Source subtitle is a bitmap (PGS) at low resolution. | Upscale with -vf "scale=1920:1080" before burning, or extract and OCR to text before re‑encoding. | | Container mismatch (e.g., trying to put mov_text subtitles into MKV) | MKV expects text subtitles in SRT/ASS, not mov_text . | For MKV, use -c:s srt or -c:s ass . | JUQ-968-engsub Convert02-23-49 Min

ffmpeg -i "JUQ-968‑engsub.mkv" \ -c copy \ -metadata:s:s:0 language=eng \ "JUQ-968‑final.mkv" # 2️⃣ Concatenate the original + padding ffmpeg

Converting video files while preserving subtitles can be a bit tricky, but it's definitely doable with the right tools. Here are some steps and recommendations: | | Audio sync drift | Different framerates

You’ll need the (e.g., 0:0 for video, 0:1 for audio, 0:2 for subtitles) when you build ffmpeg commands.