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Opened 19 months ago
Closed 19 months ago
#10172 closed Bug Report - General (fixed)
Bad cc708 output from mythccextractor
| Reported by: | Jim Stichnoth <stichnot@…> | Owned by: | danielk |
|---|---|---|---|
| Priority: | minor | Milestone: | 0.25 |
| Component: | MythTV - General | Version: | Master Head |
| Severity: | medium | Keywords: | |
| Cc: | Ticket locked: | no |
Description
There are two problems with mythccextrator's cc708 output.
- Subtitle durations are all -1, which sounds like OneSubtitle::length isn't being set.
- It looks like each subtitle is a combination of the current and previous captions. The ordering of the captions alternates from one subtitle to the next, i.e. (1,2) ; (3,2) ; (3,4) ; (5,4) ; (5,6) ; etc.
I attached a sample output along with the corresponding correct-looking cc608 output.
Attachments (4)
Change History (11)
Changed 19 months ago by Jim Stichnoth <stichnot@…>
Changed 19 months ago by Jim Stichnoth <stichnot@…>
Changed 19 months ago by Jim Stichnoth <stichnot@…>
comment:1 Changed 19 months ago by danielk
- Milestone changed from unknown to 0.25
- Owner set to danielk
- Status changed from new to accepted
comment:2 Changed 19 months ago by Github
comment:3 Changed 19 months ago by danielk
Jim, can you verify whether this fixes the issue with your files?
It looks like the main problem was that windows weren't getting cleared, but there was also no code to try to ensure that on screen window was preserved respected & the on screen length wasn't initialized.
comment:4 follow-up: ↓ 6 Changed 19 months ago by Jim Stichnoth <stichnot@…>
Daniel: Thanks, the cc708 output now looks plausible. However, now all the cc608 durations are reported as 500ms. The reason for this is pretty clear, but I'm not sure what is the safest fix.
comment:5 Changed 19 months ago by danielk
I really need to revisit the durations.. I think they are really only plausible for DVB at the moment.
comment:6 in reply to: ↑ 4 Changed 19 months ago by Jim Stichnoth <stichnot@…>
Replying to Jim Stichnoth <stichnot@…>:
Daniel: Thanks, the cc708 output now looks plausible.
I take it back. The reported durations seem to have little to do with what is displayed on screen. This is probably related to the fact that every other end timestamp is equal to the following start timestamp. I uploaded the latest cc708 output for reference.
Changed 19 months ago by Jim Stichnoth <stichnot@…>
Updated version after Daniel's fixes.
comment:7 Changed 19 months ago by Github
- Resolution set to fixed
- Status changed from accepted to closed
Fixes #10172. Cleanup duration calculations.
We just set the 708 duration on clears as if we were getting a regular caption update + we introduce some sanity checking so if length is not initialized or initialized with a 0 ms duration we leave the caption on screen for 750 ms.
Jim, please open new tickets for any additonal problems you notice.
Branch: master
Changeset: 35750c4ebb024fdd29018ea88c5f5163e35f12ed

Refs #10172. Cleanup CEA 708 srt output.