[FFmpeg-devel] [PATCH 2/3] lavf/timecode: document SMPTE struct

[joshdk at ob-encoder.com]

From: Devin Heitmueller <dheitmueller at ltnglobal.com>

There are a number of different binary representations in which
SMPTE timecodes can use.  Make clear that the specific representation
that ffmpeg refers to corresponds to the DV video spec, which is
SMPTE S314M:2005 for standard definition video and ST 370-2013 for
high definition video.
---
 libavutil/timecode.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/libavutil/timecode.c b/libavutil/timecode.c
index 60077ba0c0..5b2bf85caa 100644
--- a/libavutil/timecode.c
+++ b/libavutil/timecode.c
@@ -117,6 +117,7 @@ static unsigned bcd2uint(uint8_t bcd)
 
 char *av_timecode_make_smpte_tc_string(char *buf, uint32_t tcsmpte, int prevent_df)
 {
+    /* See SMPTE ST 314M-2005 Sec 4.4.2.2.1 "Time code pack (TC)" */
     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
-- 
2.17.1