[FFmpeg-devel] [PATCH 1/3] avutil/timecode: add av_timecode_set_smpte

[Timo Rothenpieler]

---
 doc/APIchanges       |  3 +++
 libavutil/timecode.c | 24 +++++++++++++++---------
 libavutil/timecode.h | 17 +++++++++++++++++
 libavutil/version.h  |  2 +-
 4 files changed, 36 insertions(+), 10 deletions(-)

diff --git a/doc/APIchanges b/doc/APIchanges
index ac506f4b56..71240d39fd 100644
--- a/doc/APIchanges
+++ b/doc/APIchanges
@@ -2,6 +2,9 @@ The last version increases of all libraries were on 2024-03-07
 
 API changes, most recent first:
 
+2025-02-xx - xxxxxxxxxx - lavu 59.58.100 - timecode.h
+  Add av_timecode_set_smpte().
+
 2025-02-xx - xxxxxxxxxx - lavu 59.57.100 - log.h
   Add flags AV_LOG_PRINT_TIME and AV_LOG_PRINT_DATETIME.
 
diff --git a/libavutil/timecode.c b/libavutil/timecode.c
index f454466f97..e6cd811a2b 100644
--- a/libavutil/timecode.c
+++ b/libavutil/timecode.c
@@ -136,23 +136,29 @@ static unsigned bcd2uint(uint8_t bcd)
    return low + 10*high;
 }
 
-char *av_timecode_make_smpte_tc_string2(char *buf, AVRational rate, uint32_t tcsmpte, int prevent_df, int skip_field)
+void av_timecode_set_smpte(int *drop, int *hh, int *mm, int *ss, int *ff, AVRational rate, uint32_t tcsmpte, int prevent_df, int skip_field)
 {
-    unsigned hh   = bcd2uint(tcsmpte     & 0x3f);    // 6-bit hours
-    unsigned mm   = bcd2uint(tcsmpte>>8  & 0x7f);    // 7-bit minutes
-    unsigned ss   = bcd2uint(tcsmpte>>16 & 0x7f);    // 7-bit seconds
-    unsigned ff   = bcd2uint(tcsmpte>>24 & 0x3f);    // 6-bit frames
-    unsigned drop = tcsmpte & 1<<30 && !prevent_df;  // 1-bit drop if not arbitrary bit
+    *hh   = bcd2uint(tcsmpte     & 0x3f);    // 6-bit hours
+    *mm   = bcd2uint(tcsmpte>>8  & 0x7f);    // 7-bit minutes
+    *ss   = bcd2uint(tcsmpte>>16 & 0x7f);    // 7-bit seconds
+    *ff   = bcd2uint(tcsmpte>>24 & 0x3f);    // 6-bit frames
+    *drop = tcsmpte & 1<<30 && !prevent_df;  // 1-bit drop if not arbitrary bit
 
     if (av_cmp_q(rate, (AVRational) {30, 1}) == 1) {
-        ff <<= 1;
+        *ff <<= 1;
         if (!skip_field) {
             if (av_cmp_q(rate, (AVRational) {50, 1}) == 0)
-                ff += !!(tcsmpte & 1 << 7);
+                *ff += !!(tcsmpte & 1 << 7);
             else
-                ff += !!(tcsmpte & 1 << 23);
+                *ff += !!(tcsmpte & 1 << 23);
         }
     }
+}
+
+char *av_timecode_make_smpte_tc_string2(char *buf, AVRational rate, uint32_t tcsmpte, int prevent_df, int skip_field)
+{
+    int hh, mm, ss, ff, drop;
+    av_timecode_set_smpte(&drop, &hh, &mm, &ss, &ff, rate, tcsmpte, prevent_df, skip_field);
 
     snprintf(buf, AV_TIMECODE_STR_SIZE, "%02u:%02u:%02u%c%02u",
              hh, mm, ss, drop ? ';' : ':', ff);
diff --git a/libavutil/timecode.h b/libavutil/timecode.h
index fe0fc83576..2685e48db2 100644
--- a/libavutil/timecode.h
+++ b/libavutil/timecode.h
@@ -95,6 +95,23 @@ uint32_t av_timecode_get_smpte_from_framenum(const AVTimecode *tc, int framenum)
  */
 uint32_t av_timecode_get_smpte(AVRational rate, int drop, int hh, int mm, int ss, int ff);
 
+/**
+ * Convert SMPTE 12M binary representation to sei info.
+ *
+ * @param drop       drop flag output
+ * @param hh         hour output
+ * @param mm         minute output
+ * @param ss         second output
+ * @param ff         frame number output
+ * @param rate       frame rate of the timecode
+ * @param tcsmpte    the 32-bit SMPTE timecode
+ * @param prevent_df prevent the use of a drop flag when it is known the DF bit
+ *                   is arbitrary
+ * @param skip_field prevent the use of a field flag when it is known the field
+ *                   bit is arbitrary (e.g. because it is used as PC flag)
+ */
+void av_timecode_set_smpte(int *drop, int *hh, int *mm, int *ss, int *ff, AVRational rate, uint32_t tcsmpte, int prevent_df, int skip_field);
+
 /**
  * Load timecode string in buf.
  *
diff --git a/libavutil/version.h b/libavutil/version.h
index ee4a36cb17..4b584fd569 100644
--- a/libavutil/version.h
+++ b/libavutil/version.h
@@ -79,7 +79,7 @@
  */
 
 #define LIBAVUTIL_VERSION_MAJOR  59
-#define LIBAVUTIL_VERSION_MINOR  57
+#define LIBAVUTIL_VERSION_MINOR  58
 #define LIBAVUTIL_VERSION_MICRO 100
 
 #define LIBAVUTIL_VERSION_INT   AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \
-- 
2.45.3