Universal Subtitle Format

{{Notability|date=February 2023}}

{{Infobox file format

| name = USF

| icon =

| screenshot =

| extension = .usf

| mime = text/xml

| released = {{start date and age|2002|11|10}}{{cite web |url=http://www.titlevision.dk/usf.htm|title=USF FORMAT|accessdate={{TODAY}} }}

| latest_release_version = 1.1

| latest_release_date = {{start date and age|2010|11|28}}

| genre = Timed text

| url = http://www.titlevision.dk/usf.htm

| open = Yes

| free = Proprietary

}}

Universal Subtitle Format (USF) was a CoreCodec project that attempted to create a clean, documented, powerful and easy to use subtitle file format. It is based on XML for flexibility, unicode support, hierarchical system, and ease of administration.

USF subtitles are usually used in Matroska containers.

The format has come under criticism, especially from the fansub community,{{cite web

| url = http://blog.aegisub.org/2008/07/universal-subtitle-format-post-mortem.html

| title = Universal Subtitle Format: a post-mortem?

| author = amz

| date = 23 July 2008

| publisher = Aegisub blog

}} because compared to the format it aimed to replace, Advanced Substation Alpha (which is based on comma-separated values), it is more verbose and far harder for software to read, write and manipulate. Also, it is not easily human readable and much harder to edit "by hand" in text editors such as Notepad. For these reasons, as well as the lack of a generic cross-platform parsing/rasterizing library and mature editing programs that natively support it, the format has not gained wide acceptance.

No known media player software implements more than basic support for this format. VSFilter, and VLC media player (starting with the 0.9.0 release) can extract the subtitle text, timing information and very restricted formatting.

Documentation for the format is now hosted by the Danish subtitling software company Titlevision [http://www.titlevision.dk/usf.htm here].