[FFmpeg-devel] [PATCH] lavfi/drawtext: allow controling expression output

[Paul B Mahol]

Signed-off-by: Paul B Mahol <onemda at gmail.com>
---

Now fix it so it does not crash.

---
 libavfilter/vf_drawtext.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/libavfilter/vf_drawtext.c b/libavfilter/vf_drawtext.c
index 69124a9..4f4a7e5 100644
--- a/libavfilter/vf_drawtext.c
+++ b/libavfilter/vf_drawtext.c
@@ -669,6 +669,8 @@ static int func_eval_expr(AVFilterContext *ctx, AVBPrint *bp,
         av_log(ctx, AV_LOG_ERROR,
                "Expression '%s' for the expr text expansion function is not valid\n",
                argv[0]);
+    else if (argv[1])
+        av_bprintf(bp, argv[1], res);
     else
         av_bprintf(bp, "%f", res);
 
@@ -681,8 +683,8 @@ static const struct drawtext_function {
     int tag;                            /**< opaque argument to func */
     int (*func)(AVFilterContext *, AVBPrint *, char *, unsigned, char **, int);
 } functions[] = {
-    { "expr",      1, 1, 0,   func_eval_expr },
-    { "e",         1, 1, 0,   func_eval_expr },
+    { "expr",      1, 2, 0,   func_eval_expr },
+    { "e",         1, 2, 0,   func_eval_expr },
     { "pict_type", 0, 0, 0,   func_pict_type },
     { "pts",       0, 0, 0,   func_pts      },
     { "gmtime",    0, 1, 'G', func_strftime },
-- 
1.7.11.2