ass: move text_event_to_ass from textdec.c to ass.c and export it

Signed-off-by: Marton Balint <cus@passwd.hu>

1 files changed, 39 insertions, 0 deletions

diff --git a/libavcodec/ass.c b/libavcodec/ass.c
index ef64b1ecd6..ccc9570650 100644
--- a/libavcodec/ass.c
+++ b/libavcodec/ass.c
@@ -148,3 +148,42 @@ err:
     av_bprint_finalize(&buf, NULL);
     return ret;
 }
+
+void ff_ass_bprint_text_event(AVBPrint *buf, const char *p, int size,
+                             const char *linebreaks, int keep_ass_markup)
+{
+    const char *p_end = p + size;
+
+    for (; p < p_end && *p; p++) {
+
+        /* forced custom line breaks, not accounted as "normal" EOL */
+        if (linebreaks && strchr(linebreaks, *p)) {
+            av_bprintf(buf, "\\N");
+
+        /* standard ASS escaping so random characters don't get mis-interpreted
+         * as ASS */
+        } else if (!keep_ass_markup && strchr("{}\\", *p)) {
+            av_bprintf(buf, "\\%c", *p);
+
+        /* some packets might end abruptly (no \0 at the end, like for example
+         * in some cases of demuxing from a classic video container), some
+         * might be terminated with \n or \r\n which we have to remove (for
+         * consistency with those who haven't), and we also have to deal with
+         * evil cases such as \r at the end of the buffer (and no \0 terminated
+         * character) */
+        } else if (p[0] == '\n') {
+            /* some stuff left so we can insert a line break */
+            if (p < p_end - 1)
+                av_bprintf(buf, "\\N");
+        } else if (p[0] == '\r' && p < p_end - 1 && p[1] == '\n') {
+            /* \r followed by a \n, we can skip it. We don't insert the \N yet
+             * because we don't know if it is followed by more text */
+            continue;
+
+        /* finally, a sane character */
+        } else {
+            av_bprint_chars(buf, *p, 1);
+        }
+    }
+    av_bprintf(buf, "\r\n");
+}