Evals / audio / Format conversion

Convert audio

Convert example.ogg to example.mp3.

easysinglesmokedeft audio convert

The task

The reference answer shows the job can be done with deft. It is not an agent run.

deft audio convert example.ogg -o example.mp3

Input

example.ogg 102.3 KB · vorbis, 6.1s

Reference output

example.mp3 113.2 KB · mp3, 6.1s
How a result is judged (1 check)
  • media: file = "example.mp3", audio_codec = "mp3", duration = 6.1, tolerance = 0.3

Runs

CodexWithout deftPassed2026-11-07

Time
9s
New tokens
3.9k
Total input
40.8k
Output tokens
0.2k
Commands
2
Failed
0

Trace

  1. I’ll check which audio converter is available, then convert the file in the current directory.

  2. pwd && ls -l example.ogg && (command -v ffmpeg || command -v avconv)
    output
    -rw-r--r--@ 1 user  staff  104793 Nov  5 21:11 example.ogg
    /opt/homebrew/bin/ffmpeg
  3. ffmpeg -y -i example.ogg example.mp3
    output
    ffmpeg version 7.1.1 Copyright (c) 2000-2025 the FFmpeg developers
      built with Apple clang version 15.0.0 (clang-1500.1.0.2.5)
      configuration: --prefix=/opt/homebrew/Cellar/ffmpeg/7.1.1_1 --enable-shared --enable-pthreads --enable-version3 --cc=clang --host-cflags= --host-ldflags='-Wl,-ld_classic' --enable-ffplay --enable-gnutls --enable-gpl --enable-libaom --enable-libaribb24 --enable-libbluray --enable-libdav1d --enable-libharfbuzz --enable-libjxl --enable-libmp3lame --enable-libopus --enable-librav1e --enable-librist --enable-librubberband --enable-libsnappy --enable-libsrt --enable-libssh --enable-libsvtav1 --enable-libtesseract --enable-libtheora --enable-libvidstab --enable-libvmaf --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libxvid --enable-lzma --enable-libfontconfig --enable-libfreetype --enable-frei0r --enable-libass --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libspeex --enable-libsoxr --enable-libzmq --enable-libzimg --disable-libjack --disable-indev=jack --enable-videotoolbox --enable-audiotoolbox --enable-neon
      libavutil      59. 39.100 / 59. 39.100
      libavcodec     61. 19.101 / 61. 19.101
      libavformat    61.  7.100 / 61.  7.100
      libavdevice    61.  3.100 / 61.  3.100
      libavfilter    10.  4.100 / 10.  4.100
      libswscale      8.  3.100 /  8.  3.100
      libswresample   5.  3.100 /  5.  3.100
      libpostproc    58.  3.100 / 58.  3.100
    Input #0, ogg, from 'ex
    … 693 more characters
  4. Converted `example.ogg` to [example.mp3](example.mp3).

Output

example.mp3 96.2 KB · mp3, 6.1s

CodexWith deft, skill installedPassedRead the skillUsed deft2026-11-07

Time
8s
New tokens
3.9k
Total input
41.6k
Output tokens
0.2k
Commands
2
Failed
0

Trace

  1. I’ll check the available local conversion tools and convert the file in place.

  2. cat .agents/skills/deft/SKILL.md
    output
    ---
    name: deft
    description: "Use deft first for any simple, direct operation on local files, whatever the type: convert, read, extract, edit, compress, merge, split, compare or inspect. Try it before writing a script or one-liner. If unsure, run deft find; if it says no command does this, use another tool. Not for programming work: to read, write or change source code, skip it."
    ---
    
    # deft
    
    One local command for file jobs. Prefer it over writing Python or shell scripts.
    
    Syntax: `deft <group> <command> [inputs] [-o output] [--options]`
    
    Groups:
    - `pdf`: Merge, split, compress, encrypt, forms, OCR, compare, convert
    - `image`: Resize, crop, convert, compress, adjust, montage, OCR
    - `video`: Trim, merge, convert, compress, subtitles, GIF, frames (ffmpeg)
    - `audio`: Convert, trim, normalize, denoise, cut silence (ffmpeg)
    - `doc`: Word/ODT/RTF: to text, Markdown, HTML, PDF; find and replace
    - `slides`: PowerPoint: extract text, Markdown outline
    - `sheet`: Excel/CSV/ODS tables: SQL query, pivot, merge, split, convert
    - `json`: JSON: convert, format, merge, diff, validate
    - `toml`: TOML: convert, format, merge, diff, validate
    - `xml`: XML: convert, format, merge, diff, validate
    - `yaml`: YAML: convert, format, merge, diff, validate
    - `md`: Markdown to PDF, HTML, Word, EPUB; table of contents
    - `html`: HTML to Markdown, text, Word and PDF
    - `epub`: E-books: info, to text, Markdown and PDF
    - `gps`: GPX and KML tracks: convert, distance and time
    - `qr`: Create QR codes and barcodes; r
    … 700 more characters
  3. deft audio convert example.ogg -o example.mp3
    output
    ok audio.convert example.ogg -> example.mp3  113KB  0.11s
  4. Converted `example.ogg` to `example.mp3` in the current directory.

Output

example.mp3 113.2 KB · mp3, 6.1s

CodexWith deft, skill as AGENTS.mdPassed2026-11-05

Time
9s
New tokens
9.2k
Total input
45.4k
Output tokens
0.2k
Commands
2
Failed
0

Trace

  1. I’ll use `deft` for the audio conversion and save the MP3 in the current directory.

  2. deft audio --help
    output
    deft audio - commands (input -> output)
      info        audio -> report  Duration, codec, sample rate, channels
      compress    audio -> mp3     Re-encode as MP3 at --bitrate (kbps)
      convert     audio -> audio   Change format: --to mp3|m4a|wav|flac|ogg|opus
      from-video  video -> audio   Save the soundtrack: --to mp3|m4a|wav|flac|ogg
      merge       audio... -> mp3  Join audio files in order
      normalize   audio -> audio   Even out loudness (EBU R128)
      split       audio -> audio   Cut out a part: --from 0:10 --to-time 0:25
    More: deft audio <command> --help
  3. deft audio convert example.ogg -o example.mp3 --to mp3
    output
    ok audio.convert example.ogg -> example.mp3  96KB  0.11s
  4. Converted `example.ogg` to [example.mp3](example.mp3).

Output

Its files were not kept in this run. The last line of the trace is its own report.

Claude Opus 5.5Without deftPassed2026-11-07

Time
11s
New tokens
8.6k
Total input
41.9k
Output tokens
0.4k
Commands
0
Failed
0

Trace

    Output

    example.mp3 113.2 KB · mp3, 6.1s

    Claude Opus 5.5With deft, skill installedPassedRead the skillUsed deft2026-11-07

    Time
    6s
    New tokens
    9.2k
    Total input
    43.5k
    Output tokens
    0.3k
    Commands
    0
    Failed
    0

    Trace

      Output

      ---
      name: deft
      description: "Use deft first for any simple, direct operation on local files, whatever the type: convert, read, extract, edit, compress, merge, split, compare or inspect. Try it before writing a script or one-liner. If unsure, run deft find; if it says no command does this, use another tool. Not for programming work: to read, write or change source code, skip it."
      ---
      
      # deft
      
      One local command for file jobs. Prefer it over writing Python or shell scripts.
      
      Syntax: `deft <group> <command> [inputs] [-o output] [--options]`
      
      Groups:
      - `pdf`: Merge, split, compress, encrypt, forms, OCR, compare, convert
      - `image`: Resize, crop, convert, compress, adjust, montage, OCR
      - `video`: Trim, merge, convert, compress, subtitles, GIF, frames (ffmpeg)
      - `audio`: Convert, trim, normalize, denoise, cut silence (ffmpeg)
      - `doc`: Word/ODT/RTF: to text, Markdown, HTML, PDF; find and replace
      - `slides`: PowerPoint: extract text, Markdown outline
      - `sheet`: Excel/CSV/ODS tables: SQL query, pivot, merge, split, convert
      - `json`: JSON: convert, format, merge, diff, validate
      - `toml`: TOML: convert, format, merge, diff, validate
      - `xml`: XML: convert, format, merge, diff, validate
      - `yaml`: YAML: convert, format, merge, diff, validate
      - `md`: Markdown to PDF, HTML, Word, EPUB; table of contents
      - `html`: HTML to Markdown, text, Word and PDF
      - `epub`: E-books: info, to text, Markdown and PDF
      - `gps`: GPX and KML tracks: convert, distance and time
      - `qr`: Create QR codes and barcodes; read QR codes
      
      How to use it:
      1. Run `deft <group>` to list commands, or `deft find "<what you want>"` to search. If it says `no command does this`, use another tool.
      2. Run `deft <group> <command> --help` for options and examples.
      3. `deft convert <in> -o <out.ext>` converts between formats by extension.
      4. Results are one line starting with `ok`, `partial` or `error`; add `--json` to parse them. Errors include a `hint:` with the fix.
      
      Inputs are never overwritten; pass `--force` or `--in-place` to allow it. Globs and directories work as inputs; several inputs run in parallel.
      
      If `deft` is not installed, ask the user, then follow https://github.com/firstprayer/deft/blob/main/docs/INSTALL.md
      
      example.mp3 113.2 KB · mp3, 6.1s

      Claude CodeWithout deftNot run yet

      Claude CodeWith deftNot run yet