Skip to content

GitLab

  • Menu
Projects Groups Snippets
  • Help
    • Help
    • Support
    • Community forum
    • Submit feedback
    • Contribute to GitLab
  • Sign in / Register
  • gst-plugins-bad gst-plugins-bad
  • Project information
    • Project information
    • Activity
    • Labels
    • Members
  • Repository
    • Repository
    • Files
    • Commits
    • Branches
    • Tags
    • Contributors
    • Graph
    • Compare
  • Issues 985
    • Issues 985
    • List
    • Boards
    • Service Desk
    • Milestones
  • Merge requests 132
    • Merge requests 132
  • CI/CD
    • CI/CD
    • Pipelines
    • Jobs
    • Schedules
  • Deployments
    • Deployments
    • Environments
    • Releases
  • Monitor
    • Monitor
    • Incidents
  • Packages & Registries
    • Packages & Registries
    • Container Registry
  • Analytics
    • Analytics
    • Value stream
    • CI/CD
    • Repository
  • Snippets
    • Snippets
  • Activity
  • Graph
  • Create a new issue
  • Jobs
  • Commits
  • Issue Boards
Collapse sidebar
  • GStreamer
  • gst-plugins-badgst-plugins-bad
  • Issues
  • #72

Closed
Open
Created Jun 15, 2012 by Bugzilla Migration User@bugzilla-migration

Closed Caption support

Submitted by Edward Hervey @bilboed

Link to original bug (#678146)

Description

Right now we don't suport any kind of Closed Caption (not to be confused with subtitles).

https://en.wikipedia.org/wiki/Closed_captioning

There are a few problems that need to be solved:

  1. CC format support

There are a few standards out there for CC, the main ones are:

  • CEA 608 and 708
  • teletext

teletext is supported by teletextdec (needs to be checked). An alternative would be the vbidec element (which wasn't ported to 0.10).

the zvbi library seems to have support for CEA 608 and maybe 708, this would need to be investigated. Proper caps need to be determined also.

CEA 608/708 require a new element

  1. Extracting CC stream

For teletext it is always contained as a separate stream in the container format (mostly mpeg-ts).

This is where it gets really painful.
For CEA 608/708 it is almost always contained in either the mpeg video stream (as user data) or in the h264 RBSP stream (as SEI data).

So the question is:

  • where to parse it. The logical place would be in the mpegvideo/h264 parsers.
  • How to expose it. Do we create a new pad ? Do we emit them as messages ?

There is also CEA 608/708 in quicktime/iso file formats, see bug 606643

Depends on

  • Bug 704881
  • Bug 794901

Blocking

  • Bug 606643
Assignee
Assign to
Time tracking