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What Is The Codec Long Name?

codec-long-name

What does it mean when a file contains a Codec Long Name? Find out where this metadata value comes from and what it tells you about your audio or video file.

The Codec Long Name is the full, spelled-out name of the codec used for one stream in a file. A codec is the scheme that packs sound or picture into a compact form for storage and unpacks it again for playback, and most codecs are better known by an abbreviation than by their real name.

Where the value comes from

Audio and video files, as well as other data streams, are encoded and decoded using a codec, so any file that holds sound or moving pictures has one. You find the field on MP4, MOV, MKV, AVI and WebM videos and on MP3, AAC, WAV and FLAC audio, and it is reported once per stream. A video file normally shows one entry for the picture and another for the sound, and a subtitle track gets its own.

Encoding here means compressing and packaging the data so that it takes less room and travels more easily. It is not encryption and it does not protect the file in any way. What it does mean is that the same codec, or a compatible decoder, is needed at the other end to view or play the file.

One detail explains a lot about this field. The file itself usually stores only a short identifier for its codec, such as the four-character code avc1. The long name is supplied by the software reading the file, from its own list of known codecs. That is why the wording can differ slightly from one program to another while describing exactly the same stream.

What the values look like

Long names are descriptive, and often list the several names a codec is known by:

  • H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10 - the most widely used video codec, under all of its names at once
  • AAC (Advanced Audio Coding)
  • MP3 (MPEG audio layer 3)
  • PCM signed 16-bit little-endian - plain uncompressed audio, as found inside a WAV file
  • Motion JPEG

Next to the long name you will usually find the short codec name for the same stream, such as h264 or aac.

Why it matters for your file

Playback compatibility is decided by the codec, not by the file extension. A file ending in .mp4 tells you only which container it uses, the box that holds the streams, and two MP4 files can contain entirely different codecs. That is why one plays on every phone, browser and television in the house while the other opens to a black screen or a silent picture. When something will not play, this field is the first place to look.

The name also tells you what the stream costs you in quality. H.264, AAC and MP3 are lossy, meaning detail was discarded to save space and re-saving the file discards a little more, while PCM and FLAC keep the audio intact. And for anything you intend to keep for years, knowing the codec is how you judge whether the file will still be easy to open later, and what to convert it to if not. The field describes the file's construction and contains no personal information.

Meta Keys

Channels Wondering what the number of Audio Channels says about your file? Find out what a channel is and what the count tells you about your music, recording or video file. Character Count With Spaces The Character Count is important information about your document or even e-book file, and you can easily find it out by checking the metadata of a file. But what does Character Count With Spaces mean? Characters Characters is a rather generic piece of metadata. Find out what it means precisely and in which kinds of files you are likely to find this kind of meta information. Codec Type Certain files can be encoded using a so-called codec. Next to other information, the Codec Type can be interesting when looking at audio or video encoding. Read more about Codec Type. Coded Height What is the Coded Height of a file? This meta information can be found in many different files; image and video, document and e-book, and even audio. Find out what it says about your file. Coded Width A file can only have so many values about it’s width. One of them is the so-called Coded Width. Find out what this means about your file and how it differs with respect to other width values.
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