[FFmpeg-devel] [PATCH 1/4] avfilter/vf_drawtext: add option to draw timecode in S12M side data

[lance.lmwang at gmail.com]

From: Limin Wang <lance.lmwang at gmail.com>

Signed-off-by: Limin Wang <lance.lmwang at gmail.com>
---
 doc/filters.texi          |  4 ++++
 libavfilter/vf_drawtext.c | 19 +++++++++++++++++++
 2 files changed, 23 insertions(+)

diff --git a/doc/filters.texi b/doc/filters.texi
index 5f0eb28..8334f46 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -9825,6 +9825,10 @@ If both @var{text} and @var{textfile} are specified, an error is thrown.
 If set to 1, the @var{textfile} will be reloaded before each frame.
 Be sure to update it atomically, or it may be read partially, or even fail.
 
+ at item frame_tc
+If set to 1, the timecode in S12M side data will be used for each frame
+if have, 0 otherwise
+
 @item x
 @item y
 The expressions which specify the offsets where text will be drawn
diff --git a/libavfilter/vf_drawtext.c b/libavfilter/vf_drawtext.c
index abe1ca6..018997a 100644
--- a/libavfilter/vf_drawtext.c
+++ b/libavfilter/vf_drawtext.c
@@ -197,6 +197,7 @@ typedef struct DrawTextContext {
     AVRational  tc_rate;            ///< frame rate for timecode
     AVTimecode  tc;                 ///< timecode context
     int tc24hmax;                   ///< 1 if timecode is wrapped to 24 hours, 0 otherwise
+    int frame_tc;                   ///< 1 use timecode in S12M side data for each frame, 0 otherwise
     int reload;                     ///< reload text file for each frame
     int start_number;               ///< starting frame number for n/frame_num var
 #if CONFIG_LIBFRIBIDI
@@ -268,6 +269,7 @@ static const AVOption drawtext_options[]= {
         { "monochrome",                  NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_MONOCHROME },                  .flags = FLAGS, .unit = "ft_load_flags" },
         { "linear_design",               NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_LINEAR_DESIGN },               .flags = FLAGS, .unit = "ft_load_flags" },
         { "no_autohint",                 NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_NO_AUTOHINT },                 .flags = FLAGS, .unit = "ft_load_flags" },
+    {"frame_tc",   "use timecode in S21M side data for each frame if have", OFFSET(frame_tc),   AV_OPT_TYPE_BOOL, {.i64=0}, 0, 1, FLAGS},
     { NULL }
 };
 
@@ -1327,6 +1329,23 @@ static int draw_text(AVFilterContext *ctx, AVFrame *frame,
         break;
     }
 
+    if (s->frame_tc) {
+        AVFrameSideData *sd;
+
+        if (sd = av_frame_get_side_data(frame, AV_FRAME_DATA_S12M_TIMECODE)) {
+            uint32_t *tc = (uint32_t*)sd->data;
+            int m  = tc[0] & 3;
+
+            av_bprint_clear(bp);
+            av_bprintf(bp, "%s", s->text);
+            for (int j = 1; j <= m; j++) {
+                char tcbuf[AV_TIMECODE_STR_SIZE];
+                av_timecode_make_smpte_tc_string(tcbuf, tc[j], 0);
+                av_bprintf(bp, "%s%s", tcbuf, j != m ? ", " : "");
+            }
+        }
+    }
+
     if (s->tc_opt_string) {
         char tcbuf[AV_TIMECODE_STR_SIZE];
         av_timecode_make_string(&s->tc, tcbuf, inlink->frame_count_out);
-- 
1.8.3.1