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| author | Carl Hetherington <cth@carlh.net> | 2023-01-21 23:41:23 +0100 |
|---|---|---|
| committer | Carl Hetherington <cth@carlh.net> | 2023-02-18 00:41:34 +0100 |
| commit | 9f646cd41ced9bf6f2e6fd735f92fae3aff1d6db (patch) | |
| tree | 3853b39447d0c88cec7194e317edab10476f1839 | |
| parent | 03cf7a7cbf1c2b38351eb0fbce5bb6e24dda04f0 (diff) | |
Align text subtitles from the bottom of the screen.
| -rw-r--r-- | src/lib/text_decoder.cc | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/src/lib/text_decoder.cc b/src/lib/text_decoder.cc index 2541bbc9b..58f631e59 100644 --- a/src/lib/text_decoder.cc +++ b/src/lib/text_decoder.cc @@ -153,13 +153,20 @@ TextDecoder::emit_plain_start (ContentTime from, sub::Subtitle const & sub_subti switch (line.vertical_position.reference.get_value_or(sub::BOTTOM_OF_SCREEN)) { case sub::BOTTOM_OF_SCREEN: case sub::TOP_OF_SUBTITLE: - /* This 0.9 is an arbitrary value to lift the bottom sub off the bottom + /* This 0.1 is an arbitrary value to lift the bottom sub off the bottom of the screen a bit to a pleasing degree. */ - v_position = 0.9 - + v_position = 0.1 + (1 + bottom_line.get() - line.vertical_position.line.get()) * multiplier; - v_align = dcp::VAlign::TOP; + /* Align our subtitles to the bottom of the screen, because if we are making a SMPTE + * DCP and the projection system uses the wrong standard to interpret vertical position, + * a bottom-aligned subtitle will be less wrong than a top-aligned one. This is because + * in the top-aligned case the difference will be the distance between bbox top an + * baseline, but in the bottom-aligned case the difference will be between bbox bottom + * and baseline (which is shorter). + */ + v_align = dcp::VAlign::BOTTOM; break; case sub::TOP_OF_SCREEN: /* This 0.1 is another fudge factor to bring the top line away from the top of the screen a little */ |