Changes between Version 26 and Version 27 of SponsoringPrograms/GSoC/2015


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Timestamp:
Feb 24, 2015, 3:08:19 AM (5 years ago)
Author:
philipl
Comment:

Finishing movtext project description

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  • SponsoringPrograms/GSoC/2015

    v26 v27  
    296296== Implement full support for 3GPP Timed Text (movtext, QuickTime) subtitles ==
    297297
    298 The standard subtitle format used in MP4 containers is 3GPP timed text, as defined in 3GPP TS 26.245. It is the only subtitle format supported in Apple's media players on OS X and iOS, and the only format that's part of the mpeg4 standard. As such it is important for FFmpeg to support the format as fully as possible. Currently, it supports a limited subset of the format without any rich text formatting or the ability to position text on the screen. For this project, the goal would be to implement complete support for these features and have the implementation fully reviewed and merged into FFmpeg.
     298The standard subtitle format used in MP4 containers is 3GPP timed text, as defined in [http://www.3gpp.org/DynaReport/26245.htm 3GPP TS 26.245]. It is the only subtitle format supported in Apple's media players on OS X and iOS, and the only format that's part of the mpeg4 standard. As such it is important for FFmpeg to support the format as fully as possible. Currently, it supports a limited subset of the format without any rich text formatting or the ability to position text on the screen. For this project, the goal would be to implement complete support for these features and have the implementation fully reviewed and merged into FFmpeg.
    299299
    300300'''Expected Results:'''
    301301- A display window for subtitles can be specified by the user when encoding or transcoding subtitles
    302  - ideally a default window size based on the primary video stream will be implemented,
    303 - As much text formatting as can be expressed in ASS will be supported for both transcoding to and from timed text, including positional metadata
    304  - The OSX QuickTime player should be used to evaluate the behaviour of formatting metadata.
    305 - Subtitle merging for overlapping subtitles will be supported
    306 
    307 '''Prerequisites:''' C coding skills, basic familiarity with git, access to a video player with full support for these subtitles (eg: OS X QuickTime player)
    308 
    309 '''Qualification Task:''' Implement support for transcoding bold and italic formatting to and from ffmpeg's internal ASS format.
     302 - A default window size based on the primary video stream will be implemented
     303- As much text formatting metadata as can be expressed in ASS will be supported for both transcoding to and from timed text, including positional metadata
     304 - The OSX QuickTime player should be used to evaluate the behaviour of formatting metadata. (This appears to be the most feature complete player with respect to the formatting features of 3GPP Timed Text)
     305- Subtitle merging for overlapping subtitles will be implemented
     306
     307'''Prerequisites:''' C coding skills, basic familiarity with git, access to the OS X QuickTime player for playback verification.
     308
     309'''Qualification Task:''' Implement support for transcoding bold and italic formatting to and from ffmpeg's internal ASS format. (Will require temporary patches (which already exist) for display window sizing/positioning)
    310310
    311311'''Mentor:''' Philip Langdale (''philipl'' in #ffmpeg-devel on Freenode IRC, philipl AT overt DOT org)