diff options
| author | Limin Wang | 2020-06-30 23:22:58 +0800 |
|---|---|---|
| committer | Limin Wang | 2020-07-15 05:47:14 +0800 |
| commit | c24c6a1bee10fc5526803dbeaf2a18453f50b9a8 (patch) | |
| tree | 1233fa1beae0602ebfa4e98802ef0a873e11a806 | |
| parent | 05f3d37dd58b1626c8e587cdf11af5a0ab65d377 (diff) | |
avutil/timecode: add description for SMPTE binary format
Signed-off-by: Limin Wang <lance.lmwang@gmail.com>
| -rw-r--r-- | libavutil/frame.h | 4 | ||||
| -rw-r--r-- | libavutil/timecode.h | 13 |
2 files changed, 15 insertions, 2 deletions
diff --git a/libavutil/frame.h b/libavutil/frame.h index 3fb8c56be8..3bd240fc97 100644 --- a/libavutil/frame.h +++ b/libavutil/frame.h @@ -162,8 +162,8 @@ enum AVFrameSideDataType { /** * Timecode which conforms to SMPTE ST 12-1. The data is an array of 4 uint32_t * where the first uint32_t describes how many (1-3) of the other timecodes are used. - * The timecode format is described in the av_timecode_get_smpte_from_framenum() - * function in libavutil/timecode.c. + * The timecode format is described in the documentation of av_timecode_get_smpte_from_framenum() + * function in libavutil/timecode.h. */ AV_FRAME_DATA_S12M_TIMECODE, diff --git a/libavutil/timecode.h b/libavutil/timecode.h index ab38e661f1..5801330921 100644 --- a/libavutil/timecode.h +++ b/libavutil/timecode.h @@ -62,6 +62,19 @@ int av_timecode_adjust_ntsc_framenum2(int framenum, int fps); * @param framenum frame number * @return the SMPTE binary representation * + * See SMPTE ST 314M-2005 Sec 4.4.2.2.1 "Time code pack (TC)" + * the format description as follows: + * bits 0-5: hours, in BCD(6bits) + * bits 6: BGF1 + * bits 7: BGF2 (NTSC) or PC (PAL) + * bits 8-14: minutes, in BCD(7bits) + * bits 15: BGF0 (NTSC) or BGF2 (PAL) + * bits 16-22: seconds, in BCD(7bits) + * bits 23: PC (NTSC) or BGF0 (PAL) + * bits 24-29: frames, in BCD(6bits) + * bits 30: drop frame flag (0: non drop, 1: drop) + * bits 31: color frame flag (0: unsync mode, 1: sync mode) + * @note BCD numbers (6 or 7 bits): 4 or 5 lower bits for units, 2 higher bits for tens. * @note Frame number adjustment is automatically done in case of drop timecode, * you do NOT have to call av_timecode_adjust_ntsc_framenum2(). * @note The frame number is relative to tc->start. |