Abstract

This is about technical properties of audiovisual files, how to identify and check/validate them.

Trinity

Structure

Tools

We'll show these here:

• VLC
• MediaInfo
• ffprobe

VLC

• Great videoplayer
• 99% chance you have it on the computer
• Allows quick-check of tech-MD
  (Ctrl + J)
• For all formats it can play!

Website: videolan.org/vlc

VLC

Very handy, but not the best for this job.

MediaInfo

"MediaInfo is a convenient unified display of the most relevant technical and tag data for video and audio files."

Website: mediaarea.net/MediaInfo

MediaInfo

MediaInfo GUI

View 'Easy'

• General = container level
• Video / Audio
• Other

A/B comparison

(Only in view 'Easy')

• Load more than 1 file:
  • Select multiple files
  • or drag/drop a whole folder
• Scroll dropdown = switch between files

Excellent for a quick spotting of common/different values in a given set.

View 'HTML'

• Nicer to read than view 'Text'.
  
• Identical content.

Machine Readable

(aka "parsable output formats")

• More suited for automated workflows.
• Can be saved from GUI.
• But: Usually commandline.

Machine Readable Output Formats

• XML
• JSON
• CSV
• EBUCore
• PBCore
• MPEG-7
• FIMS
• ...

Machine readable

Text

• Tradeoff between human- and machine-readable
• Spaced "Name:value" pairs
• No hierarchy!

Machine readable

XML

• Schema definition:
  mediaarea.net/mediainfo/mediainfo_2_0.xsd
  (is referenced inside XML)
• Hierarchy: Yes!

--output=XML

Machine readable

CSV

• Comma Separated Values. Literally.
• Nice option to use in e.g. spreadsheet tables.

--output=CSV

Machine readable

JSON

• XML vs JSON:
  • JSON is quicker to read and write
  • JSON was designed for web

--output=JSON

MediaInfo CLI

CLI = Command Line Interface

CAUTION:
Mediainfo's arguments are often case sensitive!

Example: --output=XML is not --output=xml

View only

$ mediainfo input.mov
$ mediainfo --full input.mov
$ mediainfo --full --output=XML input.mov

Save to file

# Redirect output:
$ mediainfo --full input.mov > info.txt

# Nicer:
$ mediainfo --full --output=XML --logfile=info.xml input.mov

Advanced

Extract individual values:

$ mediainfo
 --inform="Video;%Format%,%Width%,%Height%,%FrameRate%"
 input.mov

$ mediainfo
 --inform="Audio;%Format%,%Channels%,%SamplingRate%,%BitDepth%"
 input.mov

ffprobe

• Comes with ffmpeg
• CLI only
• Extremely powerful
• Allows analysis of media streams
• Output different parsable formats

Website: ffmpeg.org/ffprobe.html

ffprobe

Basic infos (streams, resolution, fps, duration, etc):

$ ffprobe -hide_banner MEDIAFILE

ffprobe - Example 1

ffprobe - Example 2

Questions?

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