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Convert media files between formats - video containers, audio formats, and codec transcoding
Codex または Claude でインストール この Prompt をコピーして Codex、Claude、または他のアシスタントに貼り付けると、Skill ページを確認してインストールできます。
SOC 職業分類に基づく
SkillsBench contribution workflow. Use when: (1) Creating benchmark tasks, (2) Understanding repo structure, (3) Preparing PRs for task submission.
SkillsBench task authoring — walk a contributor from idea to submission-ready task following CONTRIBUTING.md and the task-implementation rubric. Use when the user wants to create a new SkillsBench task, scaffold a task from an existing workflow (notebook, Excel workbook, document, dataset), convert a prompt or a benchmark item into a SkillsBench task, write skills for a task, or prepare a SkillsBench PR. Pairs with `task-review` (run that as a self-check before submitting).
SkillsBench task PR review — classifies the task track (standard / research / multimodal), runs static policy checks against the track-specific rubric, benchmarks the task across oracle plus Claude and Codex (with and without skills), audits trajectories for cheating and skill invocation, and produces a `pr-N-task-timestamp-run.txt` review report alongside a `prN.zip` bundle of trajectories. Use when reviewing a SkillsBench task PR (by number, branch, or local task path), when the user asks to review a task, run benchmarks on a PR, audit a submission, classify a task as research or multimodal track, or prepare a comment to post on a SkillsBench PR.
Methodology for clause-by-clause review of a contract against a structured deviation policy ("playbook"). Covers how to walk a playbook, locate the matching provision in the contract, apply rule types (max-value, must-be-present, must-be-absent, acceptable-set, must-have-feature), classify the result (ok / risk / reject), choose the prescribed action, and ground each finding in a verbatim excerpt. Use whenever reviewing any contract — NDA, MSA, vendor DD questionnaire, lease, DPA — against a structured rules-based playbook.
Reference for the standard clauses found in commercial non-disclosure agreements (mutual and one-way) — what each clause does, the surface forms it appears in, and how to recognise it in unfamiliar drafting. Use when reviewing, comparing, or extracting provisions from any confidentiality / NDA / mutual NDA / standstill-and-confidentiality agreement.
Read Microsoft Excel (.xlsx) files robustly with `openpyxl` (or `pandas`). Covers multi-sheet workbooks, header rows, empty cells, merged cells, comma-separated list cells, and converting a sheet to a list-of-dicts the rest of your code can consume. Use when a task input or reference document is an `.xlsx` file rather than JSON/CSV.
| name | ffmpeg-format-conversion |
| description | Convert media files between formats - video containers, audio formats, and codec transcoding |
Convert media files between different formats and containers.
# Convert container format (re-encode)
ffmpeg -i input.avi output.mp4
# Copy streams without re-encoding (fast, no quality loss)
ffmpeg -i input.mp4 -c copy output.mkv
# Convert with specific codec
ffmpeg -i input.mp4 -c:v libx264 -c:a aac output.mp4
# H.264
ffmpeg -i input.mp4 -c:v libx264 output.mp4
# H.265 (better compression)
ffmpeg -i input.mp4 -c:v libx265 output.mp4
# VP9 (web optimized)
ffmpeg -i input.mp4 -c:v libvpx-vp9 output.webm
# AV1 (modern codec)
ffmpeg -i input.mp4 -c:v libaom-av1 output.mp4
# MP3
ffmpeg -i input.wav -acodec libmp3lame -q:a 2 output.mp3
# AAC
ffmpeg -i input.wav -c:a aac -b:a 192k output.m4a
# Opus (best quality/bitrate)
ffmpeg -i input.wav -c:a libopus -b:a 128k output.opus
# FLAC (lossless)
ffmpeg -i input.wav -c:a flac output.flac
# CRF (Constant Rate Factor) - lower is better quality
ffmpeg -i input.mp4 -c:v libx264 -crf 23 output.mp4
# Bitrate
ffmpeg -i input.mp4 -b:v 2M -b:a 192k output.mp4
# Two-pass encoding (best quality)
ffmpeg -i input.mp4 -c:v libx264 -b:v 2M -pass 1 -f null /dev/null
ffmpeg -i input.mp4 -c:v libx264 -b:v 2M -pass 2 output.mp4
# Encoding speed presets (faster = larger file)
ffmpeg -i input.mp4 -c:v libx264 -preset fast output.mp4
# Options: ultrafast, superfast, veryfast, faster, fast, medium, slow, slower, veryslow
# Quality presets
ffmpeg -i input.mp4 -c:v libx264 -preset slow -crf 18 output.mp4
# Convert all MKV to MP4
for f in *.mkv; do
ffmpeg -i "$f" -c copy "${f%.mkv}.mp4"
done
# Convert with re-encoding
for f in *.avi; do
ffmpeg -i "$f" -c:v libx264 -c:a aac "${f%.avi}.mp4"
done
-c copy when possible for speed (no re-encoding)