Opened 7 years ago

Closed 7 years ago

#10688 closed Patch - Bug Fix (fixed)

“Bitmap” subtitles can appear in the wrong position

Reported by: almvtb@… Owned by: Jim Stichnoth
Priority: minor Milestone: 0.26
Component: MythTV - Captions Version: Master Head
Severity: medium Keywords:
Cc: Ticket locked: no

Description

“Bitmap” subtitles appear in the wrong position for 24 fps film that has been slowed to 23.976 for NTSC television and transcoded to a lower resolution.

I do not have any examples of this that I am willing to post, but it should not be hard to find or create an example of the issues. You can play the video with the Internal Player, and then enable the subtitles. Finally, you can compare the position of the subtitles to the original source.

The list of standard frame rates on Wikipedia leads me to believe this patch will not break anything else. http://en.wikipedia.org/wiki/Frame_rate#Film_and_television

Attachments (2)

subtitle.patch (819 bytes) - added by almvtb@… 7 years ago.
sample.tar.gz (7.0 KB) - added by almvtb@… 7 years ago.
small sample video clip

Download all attachments as: .zip

Change History (5)

Changed 7 years ago by almvtb@…

Attachment: subtitle.patch added

comment:1 Changed 7 years ago by Jim Stichnoth

Status: newaccepted

I will look at this as part of #10402 ("Implement DVD subtitle zoom"). It would be very helpful if you had a sample to upload.

Changed 7 years ago by almvtb@…

Attachment: sample.tar.gz added

small sample video clip

comment:2 Changed 7 years ago by Jim Stichnoth

Milestone: unknown0.26

Thanks for providing the sample.

comment:3 Changed 7 years ago by almtvb <almvtb@…>

Resolution: fixed
Status: acceptedclosed

In 53f7a1d2aa38a0343f33e91760ac88ffc6d596e9/mythtv:

Subtitles: Adjust AVSub scaling in some cases.

Tweaks the heuristic for determining when the video was resized
without correspondingly rescaling the AV subtitles. Fixes #10688.

Signed-off-by: Jim Stichnoth <jstichnoth@…>

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