More and more media players make good use of meta information embedded inside video files. Only such meta information allows for organizing potentially large video collections. Also, you may get a description or synopsis of what to except before watching.
Of particular note surely is Apple's iTunes software. It more or less is the reference for what meta data can be used at best.
Ffmpeg Supported Meta Information
It's unfortunate that the current official ffmpeg documentation on supported meta data tags for MP4 containers is neither comprehensive nor completely correct. After a lot of fruitless attempts at getting my meta data correctly attached to my video files, I finally found this place in the source (that is, mov_write_ilst_tag() in movenc.c) where ffmpegs actually lists the meta data keys it writes to MP4 audio/video container files (file ending .mp4, .m4v, as well as some others).
Note: a video file name ending in .mov is considered to be of type MODE_MOV: this mode supports only a subset of the elements listed above. Most other file endings, such as .mp4, will make ffmpeg default to type MODE_MP4. In this mode, ffmpeg supports most iTunes meta data elements. Also, such iTunes meta data ends up in a different meta data branch than meta data for MODE_MOV. Oh, well...
|Element||ffmpeg Metadata Key||Description||Internal Tag Name|
|Title||title||Title of video. (String)||©nam|
|Year||date||The data of production. (String)|
Please note that the ffmpeg documentation unfortunately is completely wrong here; the correct key for this meta data is in fact date but definitely not year. This can also been in the source code: ffmpeg/movenc.c.
|Copyright||copyright||The copyright of the video. (String)||©cpy|
|Artist||artist||The name of the (video) artist. Please don't use this element for the composer, as there is a dedicated element for it (see below). (String)||©ART|
|Album Artist||album_artist||The name of the album artist: this may be a guest artist or a featured artist. This can also be left out or the same name as the artist. |
|Composer||composer||The name of the composer. |
|Album||album||The title or name of the album. |
|Description||description||A (content) description of this video. For a synopsis, see below instead. (String)||desc|
|Comment||comment||A comment on this video. This will be probably a comment set by an end user but not at time of production. (String)||©cmt|
|Synopsis||synopsis||A synopsis (or longer description) of this video. (String)||ldes|
|Genre||genre||The genre this video belongs to. (String)||©gen|
|Grouping||grouping||The name of a group of videos that somehow belong together. In contrast to the album element, grouping is inside the album level. |
|Show||show||The name of the TV show. |
|Episode||episode_id||Either a episode name or episode number for display. Different from display is an optional episode number for sorting, see below.|
|Episode for Sorting||episode_sort||The episode number as used for sorting. This field is for sorting only, never for display. It allows numerical sort for episode names that are originally a string. The valid range is 0 to 255, so don't let your mega busta run for too many seasons. (int8)||tves|
|Season||season_number||The season number, which can be in the range of 0 to 255. |
|Lyrics||lyrics||Optional lyrics for this video. |
|Compilation||compilation||Is this file part of a compilation? Allowed values are: 0 or 1. (int8)||cpil|