Given the questions regarding the format used for the timecodes, this
patch from my personal repo might help:
commit e4c9ae661fb55e59eff1461140a8cd039b7c3f04
Author: Devin Heitmueller <dheitmuel...@ltnglobal.com>
Date: Thu Jul 5 17:18:36 2018 -0400
Clarify where the binary representation comes from for ffmpeg's SMPTE struct
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.
diff --git a/libavutil/timecode.c b/libavutil/timecode.c
index e9d8504ee7..93bba2af31 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
On Wed, Jul 1, 2020 at 9:40 AM <lance.lmw...@gmail.com> wrote:
>
> From: Limin Wang <lance.lmw...@gmail.com>
>
> Signed-off-by: Limin Wang <lance.lmw...@gmail.com>
> ---
> doc/APIchanges | 3 +++
> libavcodec/avpacket.c | 1 +
> libavcodec/decode.c | 1 +
> libavcodec/packet.h | 8 ++++++++
> libavcodec/version.h | 2 +-
> libavformat/dump.c | 21 +++++++++++++++++++++
> 6 files changed, 35 insertions(+), 1 deletion(-)
>
> diff --git a/doc/APIchanges b/doc/APIchanges
> index 1d6cc36..7aa8d9e 100644
> --- a/doc/APIchanges
> +++ b/doc/APIchanges
> @@ -15,6 +15,9 @@ libavutil: 2017-10-21
>
> API changes, most recent first:
>
> +2020-06-xx - xxxxxxxxxx - lavc 58.94.101 - packet.h
> + Add AV_PKT_DATA_S12M_TIMECODE.
> +
> 2020-06-12 - b09fb030c1 - lavu 56.55.100 - pixdesc.h
> Add AV_PIX_FMT_X2RGB10.
>
> diff --git a/libavcodec/avpacket.c b/libavcodec/avpacket.c
> index dce26cb..4801163 100644
> --- a/libavcodec/avpacket.c
> +++ b/libavcodec/avpacket.c
> @@ -400,6 +400,7 @@ const char *av_packet_side_data_name(enum
> AVPacketSideDataType type)
> case AV_PKT_DATA_PRFT: return "Producer Reference
> Time";
> case AV_PKT_DATA_ICC_PROFILE: return "ICC Profile";
> case AV_PKT_DATA_DOVI_CONF: return "DOVI configuration
> record";
> + case AV_PKT_DATA_S12M_TIMECODE: return "SMPTE ST 12-1:2014
> timecode";
> }
> return NULL;
> }
> diff --git a/libavcodec/decode.c b/libavcodec/decode.c
> index de9c079..f2244fc 100644
> --- a/libavcodec/decode.c
> +++ b/libavcodec/decode.c
> @@ -1699,6 +1699,7 @@ int ff_decode_frame_props(AVCodecContext *avctx,
> AVFrame *frame)
> { AV_PKT_DATA_CONTENT_LIGHT_LEVEL,
> AV_FRAME_DATA_CONTENT_LIGHT_LEVEL },
> { AV_PKT_DATA_A53_CC, AV_FRAME_DATA_A53_CC },
> { AV_PKT_DATA_ICC_PROFILE, AV_FRAME_DATA_ICC_PROFILE
> },
> + { AV_PKT_DATA_S12M_TIMECODE,
> AV_FRAME_DATA_S12M_TIMECODE },
> };
>
> if (pkt) {
> diff --git a/libavcodec/packet.h b/libavcodec/packet.h
> index 96f237f..0a19a0e 100644
> --- a/libavcodec/packet.h
> +++ b/libavcodec/packet.h
> @@ -283,6 +283,14 @@ enum AVPacketSideDataType {
> AV_PKT_DATA_DOVI_CONF,
>
> /**
> + * Timecode which conforms to SMPTE ST 12-1:2014. 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 documentation of
> av_timecode_get_smpte_from_framenum()
> + * function in libavutil/timecode.h.
> + */
> + AV_PKT_DATA_S12M_TIMECODE,
> +
> + /**
> * The number of side data types.
> * This is not part of the public API/ABI in the sense that it may
> * change when new side data types are added.
> diff --git a/libavcodec/version.h b/libavcodec/version.h
> index 05f5990..51fba22 100644
> --- a/libavcodec/version.h
> +++ b/libavcodec/version.h
> @@ -28,7 +28,7 @@
> #include "libavutil/version.h"
>
> #define LIBAVCODEC_VERSION_MAJOR 58
> -#define LIBAVCODEC_VERSION_MINOR 93
> +#define LIBAVCODEC_VERSION_MINOR 94
> #define LIBAVCODEC_VERSION_MICRO 101
>
> #define LIBAVCODEC_VERSION_INT AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \
> diff --git a/libavformat/dump.c b/libavformat/dump.c
> index 1083d7d..46db039 100644
> --- a/libavformat/dump.c
> +++ b/libavformat/dump.c
> @@ -34,6 +34,7 @@
> #include "libavutil/replaygain.h"
> #include "libavutil/spherical.h"
> #include "libavutil/stereo3d.h"
> +#include "libavutil/timecode.h"
>
> #include "avformat.h"
>
> @@ -407,6 +408,22 @@ static void dump_dovi_conf(void *ctx, const
> AVPacketSideData *sd)
> dovi->dv_bl_signal_compatibility_id);
> }
>
> +static void dump_s12m_timecode(void *ctx, const AVPacketSideData *sd)
> +{
> + const uint32_t *tc = (const uint32_t *)sd->data;
> +
> + if ((sd->size != sizeof(uint32_t) * 4) || (tc[0] > 3)) {
> + av_log(ctx, AV_LOG_ERROR, "invalid data\n");
> + return;
> + }
> +
> + for (int j = 1; j <= tc[0]; j++) {
> + char tcbuf[AV_TIMECODE_STR_SIZE];
> + av_timecode_make_smpte_tc_string(tcbuf, tc[j], 0);
> + av_log(ctx, AV_LOG_INFO, "timecode - %s%s", tcbuf, j != tc[0] ? ", "
> : "");
> + }
> +}
> +
> static void dump_sidedata(void *ctx, const AVStream *st, const char *indent)
> {
> int i;
> @@ -473,6 +490,10 @@ static void dump_sidedata(void *ctx, const AVStream *st,
> const char *indent)
> av_log(ctx, AV_LOG_INFO, "DOVI configuration record: ");
> dump_dovi_conf(ctx, sd);
> break;
> + case AV_PKT_DATA_S12M_TIMECODE:
> + av_log(ctx, AV_LOG_INFO, "SMPTE ST 12-1:2014: ");
> + dump_s12m_timecode(ctx, sd);
> + break;
> default:
> av_log(ctx, AV_LOG_INFO,
> "unknown side data type %d (%d bytes)", sd->type,
> sd->size);
> --
> 1.8.3.1
>
> _______________________________________________
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> ffmpeg-devel@ffmpeg.org
> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>
> To unsubscribe, visit link above, or email
> ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
--
Devin Heitmueller, Senior Software Engineer
LTN Global Communications
o: +1 (301) 363-1001
w: https://ltnglobal.com e: devin.heitmuel...@ltnglobal.com
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