Opened 14 years ago
Closed 14 years ago
#9772 closed Patch - Feature (fixed)
EIA-608 closed caption colors
| Reported by: | Owned by: | danielk | |
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| Priority: | minor | Milestone: | 0.25 |
| Component: | MythTV - General | Version: | Master Head |
| Severity: | medium | Keywords: | |
| Cc: | Ticket locked: | no |
Description
This patch adds support for colors, italics, and underlining to EIA-608 closed captions. (Sorry to say that I didn't add flashing support...)
Currently only intra-line formatting is supported, and not formatting associated with preamble address codes, as I haven't seen any examples of the latter in my testing.
In an ideal implementation, each character would be decorated with color/italic/underline attributes which would be extracted by the caption renderer. However, this approach looked like it would involve fairly major changes, so I took a different approach. Formatting commands are embedded into the caption string as two-character control sequences like "%a", "%b", etc. for the renderer to decode. This works well in practice, but might cause anomalies with backspacing and direct addressing via preamble address codes.
See also [85a5266e1].
Attachments (5)
Change History (8)
Changed 14 years ago by
| Attachment: | cc608_colors_v1.patch added |
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Changed 14 years ago by
| Attachment: | cc608_colors_v2.patch added |
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Changed 14 years ago by
| Attachment: | cc608_colors_v3.patch added |
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Add support for preamble address codes.
comment:1 Changed 14 years ago by
Revised patch adds support for formatting via preamble address codes.
Also, changes the internal buffer representation of a format control character to a single QChar in the arbitrarily chosen 0x70nn range, instead of a "%n" pair of characters.
At this point, the caption colors and italics look nice. The mpeg2-ts test file http://ncamftp.wgbh.org/DTV/CEA%20test%20material/Iteration_1/CEAv1.2zero.trp located by faginbagin seems to display captions correctly as intended, except for two strings "biu" (blue/italic/underline) and "giu" (green/italic/underline), but I believe the test file is wrong and the implementation correctly follows the spec.
BTW, when creating the ticket, I forgot to set the component (my best guess is video/osd rendering), in case someone wants to update it.
comment:2 Changed 14 years ago by
| Owner: | set to danielk |
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| Status: | new → assigned |
comment:3 Changed 14 years ago by
| Milestone: | unknown → 0.25 |
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| Resolution: | → fixed |
| Status: | assigned → closed |
Fixes #9772. Applies patch by Jim Stichnoth to for CEA-608 to add color, italic and underline support.
Branch: master Changeset: 11adb5bf74bbf0326691f40b8c588e01d73febe2
Fix a bug exposed by roll-up captions.