In Closed Captions (US), the non-breaking space (0xA0) can be used to align
text horizontally from the left by using it 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 over 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 <mart...@proxyid.net>
---
libavcodec/ccaption_dec.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/libavcodec/ccaption_dec.c b/libavcodec/ccaption_dec.c
index faf058ce97..591013d202 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);
--
2.34.1
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