- MPEG-4 Part 17
:
MPEG-4 is a suite of standards which has many "parts", where each part standardizes various entities related to multimedia, such as audio, video, and file formats. To know more about various parts and what they mean, please see the entry forMPEG-4 .MPEG-4 Part 17, or MPEG-4 Timed Text is the text based subtitle format for
MPEG-4 . It is also streamable, which was one of the main aspects when creating the format. It is mainly aimed for use in the .mp4 container, but can also be used in the .3gp container (as 3GPP Timed Text), which is technically almost identical with .mp4 but more used incell phone s. 3GPP Timed Text is exactly the same as MPEG-4 Timed Text when used in the .mp4 container. QuickTime Pro andMP4Box can create or produce these kind of subtitle streams out of various subtitle input formats. MP4Box uses thefourcc tx3g for MPEG-4 Timed Text because of its inherently higher compatibility. MPEG-4 Timed Text is heavily based onXML semantics.The ISO document defining the Timed Text format is ISO 14496-17.
upporting implementations
On
October 7 ,2005 ,VideoLAN added decoding support for MPEG-4 Timed Text subtitles in VLC. [http://forum.videolan.org/viewtopic.php?t=9507]On
October 30 ,2005 ,Gabest added decoding support for MPEG-4 Timed Text subtitles in MPC. [http://forum.doom9.org/showthread.php?t=101835]ee also
*
Ogg Writ External links
* [http://gpac.sourceforge.net/doc_ttxt.php GPAC MP4Box explanation of 3GPP Timed Text]
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