[FFmpeg-devel] [PATCH] drawtext: unescape fontconfig patterns

[bn]

Hi,

This fixes drawtext's handling of fontconfig patterns with ':' attached properties, e.g. 'Times-12:italic' which when escaped to get past the options parser ('Times-12\:italic') will naturally fail in fontconfig itself unless unescaped again.

Please note that I took the expedient approach of altering the string in-place, which may or may not be ideal.

cheers,
Bahman

-----------------------------------------------------------
diff --git a/libavfilter/vf_drawtext.c b/libavfilter/vf_drawtext.c
index 2358e35..6a54d46 100644
--- a/libavfilter/vf_drawtext.c
+++ b/libavfilter/vf_drawtext.c
@@ -322,6 +322,25 @@ static int load_font_file(AVFilterContext *ctx, const char *path, int index,
     return 0;
 }
 
+static char* unescape(char *text)
+{
+    char *p = text;
+    int shift = 0;
+
+    while (*p) {
+        if (*p == '\\' && p[1])) {
+            shift++;
+            p++;
+        }
+        if (shift) {
+            *(p - shift) = *p;
+        }
+        p++;
+    }
+    *(p - shift) = '\0';
+    return text;
+}
+
 #if CONFIG_FONTCONFIG
 static int load_font_fontconfig(AVFilterContext *ctx, const char **error)
 {
@@ -338,7 +357,7 @@ static int load_font_fontconfig(AVFilterContext *ctx, const char **error)
         *error = "impossible to init fontconfig\n";
         return AVERROR(EINVAL);
     }
-    pattern = FcNameParse(dtext->fontfile ? dtext->fontfile :
+    pattern = FcNameParse(dtext->fontfile ? (uint8_t *)unescape(dtext->fontfile) :
                           (uint8_t *)(intptr_t)"default");
     if (!pattern) {
         *error = "could not parse fontconfig pattern";