aboutsummaryrefslogtreecommitdiffstats
path: root/libavcodec
diff options
context:
space:
mode:
authorPhilip Langdale <philipl@overt.org>2018-03-27 19:55:24 -0700
committerPhilip Langdale <philipl@overt.org>2018-03-29 20:46:47 -0700
commitaf043b839c38e850af1184fd6be691f8475c048e (patch)
tree97fd6f00572408fcb1dd2c7c9837389958b83fda /libavcodec
parentc42c99c3e5ac4f5fe55e06d5cbdfe8a83beed0e8 (diff)
downloadffmpeg-af043b839c38e850af1184fd6be691f8475c048e.tar.gz
movtextenc: fix handling of utf-8 subtitles
See the earlier fix for movtextdec for details. The equivalent bug is present on the encoder side as well. We need to track the text length in 'characters' (which seems to really mean codepoints) to ensure that styles are applied across the correct ranges.
Diffstat (limited to 'libavcodec')
-rw-r--r--libavcodec/movtextenc.c30
1 files changed, 28 insertions, 2 deletions
diff --git a/libavcodec/movtextenc.c b/libavcodec/movtextenc.c
index d795e317c3..c19ef384bc 100644
--- a/libavcodec/movtextenc.c
+++ b/libavcodec/movtextenc.c
@@ -72,6 +72,7 @@ typedef struct {
uint8_t style_fontsize;
uint32_t style_color;
uint16_t text_pos;
+ uint16_t byte_count;
} MovTextContext;
typedef struct {
@@ -304,11 +305,34 @@ static void mov_text_color_cb(void *priv, unsigned int color, unsigned int color
*/
}
+static uint16_t utf8_strlen(const char *text, int len)
+{
+ uint16_t i = 0, ret = 0;
+ while (i < len) {
+ char c = text[i];
+ if ((c & 0x80) == 0)
+ i += 1;
+ else if ((c & 0xE0) == 0xC0)
+ i += 2;
+ else if ((c & 0xF0) == 0xE0)
+ i += 3;
+ else if ((c & 0xF8) == 0xF0)
+ i += 4;
+ else
+ return 0;
+ ret++;
+ }
+ return ret;
+}
+
static void mov_text_text_cb(void *priv, const char *text, int len)
{
+ uint16_t utf8_len = utf8_strlen(text, len);
MovTextContext *s = priv;
av_bprint_append_data(&s->buffer, text, len);
- s->text_pos += len;
+ // If it's not utf-8, just use the byte length
+ s->text_pos += utf8_len ? utf8_len : len;
+ s->byte_count += len;
}
static void mov_text_new_line_cb(void *priv, int forced)
@@ -316,6 +340,7 @@ static void mov_text_new_line_cb(void *priv, int forced)
MovTextContext *s = priv;
av_bprint_append_data(&s->buffer, "\n", 1);
s->text_pos += 1;
+ s->byte_count += 1;
}
static const ASSCodesCallbacks mov_text_callbacks = {
@@ -333,6 +358,7 @@ static int mov_text_encode_frame(AVCodecContext *avctx, unsigned char *buf,
int i, length;
size_t j;
+ s->byte_count = 0;
s->text_pos = 0;
s->count = 0;
s->box_flags = 0;
@@ -368,7 +394,7 @@ static int mov_text_encode_frame(AVCodecContext *avctx, unsigned char *buf,
}
}
- AV_WB16(buf, s->text_pos);
+ AV_WB16(buf, s->byte_count);
buf += 2;
if (!av_bprint_is_complete(&s->buffer)) {