| Message ID | 20240312060005.2111135-4-marth64@proxyid.net |
|---|---|
| State | New |
| Headers | show |
| Series | Closed Captions improvements (phase 1) | expand |
| Context | Check | Description |
|---|---|---|
| yinshiyou/make_loongarch64 | success | Make finished |
| yinshiyou/make_fate_loongarch64 | success | Make fate finished |
| andriy/make_x86 | success | Make finished |
| andriy/make_fate_x86 | success | Make fate finished |
On date Tuesday 2024-03-12 01:00:02 -0500, Marth64 wrote: > In Closed Captions (US), the non-breaking space (0xA0) can be used to > align text horizontally from the left when used as a leading character. > However, CC decoder does not ignore it as a leading character > like it does an ordinary space, so a blank padding is rendered > on the black CC box. This is not the intended viewing experience. > > Ignore the leading non-breaking spaces, thus creating the intended > transparency which aligns the text. Since all characters are > fixed-width in CC, it can be handled the same way as we currently > treat leading ordinary spaces. > > Also, as a nit, lowercase the NBSP's hex code in the entry table to match > casing of the other hex codes. > > Signed-off-by: Marth64 <marth64@proxyid.net> > --- > libavcodec/ccaption_dec.c | 9 ++++++--- > 1 file changed, 6 insertions(+), 3 deletions(-) Still LGTM.
Hi Stefano, I would like to withdraw this patch for now. I have found content where this breaks center justified text further (which is already not supported). I will instead try to implement center justification and incorporate this through that route. Please ignore it. Thank you for understanding,
diff --git a/libavcodec/ccaption_dec.c b/libavcodec/ccaption_dec.c index 9d4a93647c..25b0f2e064 100644 --- a/libavcodec/ccaption_dec.c +++ b/libavcodec/ccaption_dec.c @@ -91,7 +91,7 @@ enum cc_charset { ENTRY(0x36, "\u00a3") \ ENTRY(0x37, "\u266a") \ ENTRY(0x38, "\u00e0") \ - ENTRY(0x39, "\u00A0") \ + ENTRY(0x39, "\u00a0") \ ENTRY(0x3a, "\u00e8") \ ENTRY(0x3b, "\u00e2") \ ENTRY(0x3c, "\u00ea") \ @@ -471,7 +471,8 @@ static int capture_screen(CCaptionSubContext *ctx) const char *row = screen->characters[i]; const char *charset = screen->charsets[i]; j = 0; - while (row[j] == ' ' && charset[j] == CCSET_BASIC_AMERICAN) + while ((row[j] == ' ' && charset[j] == CCSET_BASIC_AMERICAN) || + (row[j] == 0x39 && charset[j] == CCSET_SPECIAL_AMERICAN)) j++; if (!tab || j < tab) tab = j; @@ -491,7 +492,9 @@ static int capture_screen(CCaptionSubContext *ctx) j = 0; /* skip leading space */ - while (row[j] == ' ' && charset[j] == CCSET_BASIC_AMERICAN && j < tab) + while (j < tab && + (row[j] == ' ' && charset[j] == CCSET_BASIC_AMERICAN) || + (row[j] == 0x39 && charset[j] == CCSET_SPECIAL_AMERICAN)) j++; x = ASS_DEFAULT_PLAYRESX * (0.1 + 0.0250 * j);
In Closed Captions (US), the non-breaking space (0xA0) can be used to align text horizontally from the left when used as a leading character. However, CC decoder does not ignore it as a leading character like it does an ordinary space, so a blank padding is rendered on the black CC box. This is not the intended viewing experience. Ignore the leading non-breaking spaces, thus creating the intended transparency which aligns the text. Since all characters are fixed-width in CC, it can be handled the same way as we currently treat leading ordinary spaces. Also, as a nit, lowercase the NBSP's hex code in the entry table to match casing of the other hex codes. Signed-off-by: Marth64 <marth64@proxyid.net> --- libavcodec/ccaption_dec.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)