| name | transcode |
| description | Ad-hoc transcode of a video file or folder — pick codec, container, resolution, framerate, and rate-control on the spot. Uses the hardware encoder detected by profile-system when available, falls back to libx264/libx265. Use when the user says "transcode this", "convert these to h.265", "change the framerate to 30", "make these smaller", or "VBR to CBR". |
| disable-model-invocation | false |
| allowed-tools | Bash(ffmpeg *), Bash(ffprobe *), Bash(test *), Bash(mkdir *), Bash(ls *), Bash(find *), Bash(jq *), Bash(stat *), Bash(basename *), Bash(dirname *), Bash(realpath *), Read, Write |
Transcode
Generic, on-demand transcoding. Unlike render-with-profile (which uses a saved preset), this skill takes parameters per invocation. Use it for one-offs, format conversions, framerate changes, or fixes (VBR → CBR).
Procedure
1. Resolve system profile
DATA_DIR="${CLAUDE_USER_DATA:-${XDG_DATA_HOME:-$HOME/.local/share}/claude-plugins}/video-editing"
SYS_FILE="$DATA_DIR/system-profile.json"
test -f "$SYS_FILE" && HAVE_SYS=1 || HAVE_SYS=0
If missing, warn the user that the skill will fall back to libx264/libx265 (slower, CPU-only) and offer to run profile-system.
2. Inputs
Ask if not provided:
| Field | Example |
|---|
| Source | file or folder |
| Codec | h264 / hevc / av1 / copy (stream-copy) |
| Container | mp4 / mkv / mov |
| Resolution | source / 1920x1080 / 1280x720 |
| Framerate | source / 24 / 30 / 60 |
| Rate control | crf / qp / cbr / vbr — with value |
| Output dir | default: sibling transcoded/ folder |
3. Pick encoder
If HAVE_SYS=1, read .encoders.<codec>.preferred from system-profile.json. Otherwise:
| Codec | Software fallback |
|---|
| h264 | libx264 |
| hevc | libx265 |
| av1 | libsvtav1 |
For codec=copy, skip encoder selection — just -c:v copy -c:a copy (useful for container changes).
4. Build the ffmpeg command
VAAPI hardware path:
ffmpeg -hide_banner -i "$IN" \
-vaapi_device "$RENDER_NODE" \
-vf 'format=nv12,hwupload[,scale_vaapi=...]' \
-c:v "$ENCODER" -qp "$QP" \
-r "$FPS" \
-c:a aac -b:a 192k \
-movflags +faststart \
"$OUT"
Software path:
ffmpeg -hide_banner -i "$IN" \
[-vf scale=...] -r "$FPS" \
-c:v "$ENCODER" -crf "$CRF" -preset medium \
-c:a aac -b:a 192k \
-movflags +faststart \
"$OUT"
For CBR: -c:v libx264 -b:v <rate> -minrate <rate> -maxrate <rate> -bufsize <2*rate>.
Show the resolved command before running. Ask for confirmation when transcoding more than 1 file.
5. Loop and report
mkdir -p "$OUT_DIR"
for in in <inputs>; do
out="$OUT_DIR/$(basename "${in%.*}").$CONTAINER"
ffmpeg -hide_banner -y -i "$in" <args> "$out"
echo "$in -> $out ($(stat -c%s "$out") bytes)"
done
Originals are never modified. Summarize input vs. output total bytes at the end.
