MP4 Analyzer

Tool for analyzing MP4 files, providing both command-line box parsing and GUI-based frame-level analysis.

CLI	GUI

Features

CLI Tool

• Parse and display MP4 box structure
• Extract metadata and technical information (e.g. duration, bitrate, codec info, track details)
• Supports output to JSON. No external dependencies needed

GUI Application

• Frame-by-frame video analysis with timeline visualization
• Per-frame details: type (I/P/B), byte size, timestamp, and decode vs presentation order
• Requires FFmpeg for video decoding

Installation and Usage

CLI Tool

pip install mp4analyzer

CLI Help

usage: mp4analyzer [-h] [-o {stdout,json}] [-d] [-s] [-e] [-c | --no-color] [-j JSON_PATH] file

Analyze MP4 files and display metadata information

positional arguments:
  file                  MP4 file to analyze

options:
  -h, --help            show this help message and exit
  -o {stdout,json}, --output {stdout,json}
                        Output format (default: stdout)
  -d, --detailed        Show detailed box properties and internal fields
  -s, --summary         Show concise summary instead of full analysis
  -e, --expand          Expand all arrays and large data structures
  -c, --color           Enable colored output (default: True)
      --no-color        Disable colored output
  -j JSON_PATH, --json-path JSON_PATH
                        Path to save JSON output. If specified, JSON will be saved even if
                        output format is not json.

Examples:
  mp4analyzer video.mp4                    # Basic analysis with color
  mp4analyzer -d video.mp4                 # Detailed view with box properties
  mp4analyzer -s video.mp4                 # Quick summary
  mp4analyzer -e -d video.mp4              # Expand arrays/matrices in details
  mp4analyzer --no-color video.mp4         # Disable ANSI colors
  mp4analyzer -o json video.mp4            # JSON to stdout
  mp4analyzer -j output.json video.mp4     # Save JSON to file (in addition to stdout)

GUI Application

Download and run the executable from GitHub Releases. The application will not run without FFmpeg. Works best with files < 100 MB.

Supported Box Types

ISO Base Media (MP4)

ac4, av01, av1C, avc1, avcC, btrt, colr, ctts, dac4, dinf, dref, edts, elst, esds, free, ftyp, hdlr, hev1, hvcC, iods, mdat, mdhd, mdia, mehd, meta, mfhd, mfra, mfro, minf, moof, moov, mp4a, mvex, mvhd, pasp, sbgp, sdtp, sgpd, smhd, stbl, stco, stsc, stsd, stss, stsz, stts, tfdt, tfhd, tfra, tkhd, traf, trak, tref, trex, trun, udta, url , vmhd

QuickTime Extensions

chpl, gmhd, gmin, text (gmhd), ilst, data, text (sample entry), fiel

TODO

Add more boxes (e.g., VP9 codec, fragmented MP4, etc.)

Development

# Setup
uv sync --extra dev

# Run tests
uv run pytest

# Build CLI package
uv build

# Build GUI app
uv run python build_exe.py

# Create large .mp4 test file
ffmpeg -f lavfi -i "testsrc2=duration=1800:size=1920x1080:rate=30" -c:v libx264 -fs 1000M test_1000mb.mp4

Built With