SwiftMediaInfo v2.0 — Field Reference

Plain-language explanations for the MediaInfo fields SwiftMediaInfo describes. These are the same texts shown as tooltips in the app: hover any field label marked with an ⓘ to see them in place.

This list is deliberately incomplete. MediaInfo emits several hundred fields depending on container and codec; these are the ones people actually read. Fields not listed here show no tooltip in the app rather than a generated guess — a wrong explanation of a technical field is worse than none.

70 fields across 9 categories.

Identity

FileName
The file’s name, without its folder path.

FileExtension
The part after the last dot. It suggests the container but doesn’t guarantee it — MediaInfo reads the actual contents.

Format
The container or codec. A container (MKV, MP4) holds streams; a codec (HEVC, AAC) is how a stream is encoded.

Format_Profile
A named subset of the format's features. Decoders support specific profiles, so this often decides whether a device can play the file.

Format_Level
How demanding the stream is within its profile — roughly resolution and bitrate combined. Higher levels need more capable hardware.

Format_Version
Which revision of the format specification the file follows.

Format_Commercial_IfAny
The marketing name for this format, such as Dolby Vision or DTS-HD Master Audio.

CodecID
The container's own four-character identifier for the stream's codec.

InternetMediaType
The MIME type, as used by web servers and browsers.

UniqueID
A random identifier written when the file was created. Useful for telling apart two files with identical contents.

Size and duration

FileSize
Total size on disk, including every stream and all metadata.

StreamSize
How much of the file this particular stream accounts for.

Duration
How long the file plays.

Delay
How far this stream is offset from the start. A non-zero audio delay is how lip sync is corrected.

Delay_Source
Where the delay value came from — the container or the stream itself.

Bitrate

BitRate
Data used per second. Higher generally means better quality for the same codec, but the codec matters more than the number.

OverallBitRate
Data per second for the whole file — every stream added together.

BitRate_Mode
Constant spends the same data every second. Variable spends more on complex scenes and less on simple ones, which is usually the better trade.

BitRate_Maximum
The highest rate the stream reaches. Playback devices must sustain at least this much.

BitRate_Nominal
The rate the encoder targeted, which may differ from what it achieved.

Picture

Width
Picture width in pixels.

Height
Picture height in pixels.

DisplayAspectRatio
The shape the picture should be shown at. It can differ from width ÷ height when the pixels themselves aren't square.

PixelAspectRatio
Whether the pixels are square. Anything other than 1.000 means the picture is stretched on display.

FrameRate
Frames shown per second. 23.976 is film, 25 is PAL broadcast, 29.97 is NTSC.

FrameRate_Mode
Constant keeps a fixed interval between frames. Variable doesn't, which some editors handle poorly.

FrameCount
Total number of frames in the stream.

ScanType
Progressive draws whole frames. Interlaced draws alternating half-frames, a legacy of broadcast television, and usually needs deinterlacing.

ScanOrder
For interlaced video, which half-frame comes first.

Rotation
How far the picture should be turned on playback. Phone video often carries a rotation instead of being re-encoded.

Colour

ColorSpace
How colour is represented. YUV separates brightness from colour, which is why chroma can be stored at lower resolution.

ChromaSubsampling
How much colour detail is kept relative to brightness. 4:2:0 keeps a quarter, which the eye barely notices; 4:4:4 keeps all of it.

BitDepth
Bits per colour sample. 8-bit gives 256 levels per channel, 10-bit gives 1024 — the difference shows most in gradients like skies.

colour_primaries
Which set of physical colours the values refer to. BT.709 is standard HD; BT.2020 is the wider range used for HDR.

transfer_characteristics
The curve mapping stored values to brightness. PQ and HLG are the HDR curves.

matrix_coefficients
The formula converting between RGB and YUV. A mismatch here is a classic cause of washed-out or oversaturated playback.

colour_range
Limited uses 16–235 for historical broadcast reasons; Full uses 0–255. Getting this wrong crushes blacks or blows out whites.

HDR_Format
Which HDR system the video uses — HDR10, HDR10+, or Dolby Vision.

HDR_Format_Compatibility
What a display without full HDR support will fall back to.

MasteringDisplay_Luminance
The brightness range of the reference monitor the content was graded on.

MaxCLL
The brightest single pixel anywhere in the content.

MaxFALL
The brightest frame average. Displays use it to manage sustained brightness.

Audio

Channels
How many audio channels. 2 is stereo, 6 is 5.1 surround, 8 is 7.1.

ChannelPositions
Where each channel is meant to sit in the room.

ChannelLayout
The channels in their standard order, by short name.

SamplingRate
Audio samples per second. 48 kHz is standard for video; 44.1 kHz comes from CD.

Compression_Mode
Lossy discards detail permanently to save space. Lossless can be restored exactly.

Format_Settings_Endianness
Byte order for uncompressed audio. Rarely matters unless something plays back as noise.

SamplesPerFrame
How many audio samples each compressed frame carries.

Text and menus

Language
The language of this stream, as declared in the file. It's a label, not a guarantee.

Title
A human-readable name for this stream, shown by players in track menus.

Default
Whether players should select this stream automatically.

Forced
Marks subtitles meant to appear even with subtitles off — usually for foreign dialogue in an otherwise untranslated film.

ElementCount
How many entries this stream contains, such as chapter markers.

Provenance

Encoded_Date
When the file was encoded, as recorded inside it. Independent of the filesystem's date, which changes when a file is copied.

Tagged_Date
When the metadata was last written.

File_Modified_Date
When the filesystem last saw the file change. Resets on copy, so it says little about the content.

Encoded_Application
The program that produced the file.

Encoded_Library
The encoder library and version. Often the most telling field about how a file was made.

Encoded_Library_Settings
The exact parameters the encoder was given. Verbose, and the closest thing to a recipe for the encode.

Writing_Application
The program that assembled the container, which is frequently not the program that did the encoding.

Writing_Library
The library used to write the container.

Streaming and structure

IsStreamable
Whether playback can begin before the whole file has downloaded. This depends on where the index sits in the file.

Interleaved
Whether audio and video are woven together through the file rather than stored in separate blocks.

MuxingMode
How the streams were combined into the container.

ID
The stream's identifier within the container. Players and tools use it to select tracks.

StreamOrder
The stream's position in the file, which can differ from its ID.

Alternate_Group
Streams in the same group are alternatives to one another — typically the same audio in different languages.

Attachments
Extra files carried inside the container, such as subtitle fonts or cover art.

Cover
Whether embedded artwork is present.

Some fields appear in MediaInfo output with suffixes such as Duration_String3 or BitRate_String. These describe the same quantity as the base field and share its explanation.